JP4179030B2 - Recording apparatus and method, and reproducing apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording apparatus and method capable of recording audio and video data of a plurality of different formats in a mixed manner on a single disk-shaped recording medium so that continuous reproduction is possible.
[0002]
[Prior art]
In recent years, a disk-shaped recording medium has emerged that uses a laser beam having a shorter wavelength as a light source and enables recording and reproduction with a larger capacity. For example, a recording capacity of 23 GB (gigabyte) is realized by using a blue-violet laser emitting laser light having a wavelength of 405 nm as a light source and using an optical disk having a single-sided single layer structure.
[0003]
On the other hand, the data format of video data has been diversified in recent years with the increase in the definition of images in television broadcasting, and the encoding / decoding method, data bit rate, frame rate, number of pixels, screen aspect ratio, etc. A plurality of types such as ratios are generally used. Similarly, a plurality of types of audio data such as bit resolution and encoding / decoding method are generally used.
[0004]
Furthermore, in video cameras and the like, it has been proposed to output a high-resolution main video signal and generate a low-resolution auxiliary video signal based on an imaging signal. The auxiliary video signal is suitable for use when, for example, it is desired to send a video signal as soon as possible via a network, or when a shuttle operation is performed when cueing a video image by fast-forwarding or rewinding.
[0005]
Non-Patent Document 1 describes a video camera that uses the above-described large-capacity disk-shaped recording medium, outputs a high-resolution main video signal, and generates a low-resolution auxiliary video signal. .
[0006]
[Non-Patent Document 1]
AV Watch editorial department, “Sony, camcorder using blue-violet laser disc, etc.”, “Sony, camcorder using blue-violet laser disc, etc. Exhibited at NAB 2003 held in April. Studio recorder etc. also exhibited” [online] , March 5, 2003, Impression Corporation, AV Watch website, [Search on March 25, 2003], Internet <URL: http://www.watch.impress.co.jp/av/docs/20030305/ sony.htm>
[0007]
[Problems to be solved by the invention]
In such a situation, audio / video data (hereinafter referred to as AV data) having a plurality of different data formats can be mixed with the above-described large-capacity disc-shaped recording medium, and can be continuously recorded and reproduced. Is required.
[0008]
Conventionally, a plurality of AV data of different data formats are mixed and continuously recorded on a recording medium, and a plurality of AV data of different data formats are recorded from the recording medium. There has been no technique for continuously reproducing and editing AV data of a plurality of different data formats.
[0009]
In particular, regarding audio data, it is common to handle data of a plurality of channels at the same time, and it is required to be able to flexibly cope with changes in the channel configuration used.
[0010]
Accordingly, an object of the present invention is to provide a recording apparatus and method capable of recording audio and video data of a plurality of different formats mixedly on a single disk-shaped recording medium so that continuous reproduction is possible. There is to do.
[0011]
Another object of the present invention is to provide a recording apparatus and method that can flexibly cope with changes in the channel configuration of audio data.
[0012]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention provides a recording apparatus for recording audio data input by multiplexing audio data of a plurality of channels on a disk-shaped recording medium. Preamble added for each sample The data type of the audio data Based on information indicating whether or not the audio data contained in the preamble is separable The detection means to detect, and a plurality of channels of audio data are sampled based on the detection result by the detection means Every Separation means for separating audio data into each of a plurality of channels when it is determined that the audio data is multiplexed so as to be separable; Separation The separated audio data separated into a plurality of channels by means is recorded on a disc-shaped recording medium as individual files of the plurality of channels. If it is determined that the audio data is multiplexed in such a manner that a plurality of channels cannot be separated for each sample based on the detection result by the detection means, the audio data is stored in a disc-shaped recording medium as a single file. Record And a recording device.
[0013]
Also, the present invention provides a recording method for recording audio data input by multiplexing audio data of a plurality of channels on a disk-shaped recording medium. Preamble added for each sample The data type of the audio data Based on information indicating whether or not the audio data contained in the preamble is separable Multiple channels of audio data are sampled based on the detection step to detect and the detection results from the detection step Every A separation step of separating the audio data into a plurality of channels when it is determined that the audio data is multiplexed so as to be separated; Separation The audio data separated into each of the plurality of channels in the above step is recorded on a disc-shaped recording medium as individual files of the plurality of channels. When it is determined that the audio data is multiplexed audio data in which a plurality of channels cannot be separated for each sample based on the detection result of the detection step, the audio data is recorded as a single file on a disc-shaped recording medium. To record And a recording step.
[0014]
The present invention also relates to a separated audio in which audio data in which a plurality of channels are multiplexed is separated for each of a plurality of channels in a reproducing apparatus for reproducing audio data from a disc-shaped recording medium on which audio data of a plurality of channels is recorded. Reproducing means for reproducing separated audio data from a disc-shaped recording medium in which data is recorded as individual files, and a plurality of separated audio data reproduced by the reproducing means For each sample, a preamble including information indicating whether the audio data can be separated is added to each sample. And a multiplexing means for multiplexing.
[0015]
The present invention also relates to a reproduction method for reproducing audio data from a disc-shaped recording medium on which audio data of a plurality of channels are recorded, and separated audio in which audio data in which a plurality of channels are multiplexed is separated for each of the plurality of channels. A reproduction step of reproducing separated audio data from a disk-shaped recording medium in which data is recorded as individual files, and a plurality of separated audio data reproduced by the reproduction step For each sample, a preamble including information indicating whether the audio data can be separated is added to each sample. And a multiplexing step for multiplexing.
[0016]
As described above, the present invention is based on the detection result of detecting the data type of the audio data, and when it is determined that the audio data is the multiplexed audio data that can be separated based on the samples of a plurality of channels. Audio data is separated into a plurality of channels and recorded on a disc-shaped recording medium as individual files for each of the plurality of channels. Therefore, when audio data types are mixed and input, multiple channels are recorded. Audio data that can be separated can be determined and recorded as a file divided for each channel.
[0017]
Further, the present invention reproduces and reproduces separated audio data from a disc-shaped recording medium in which separated audio data obtained by separating audio data in which a plurality of channels are multiplexed for each of the plurality of channels is recorded as individual files. Since the plurality of separated audio data is multiplexed, the plurality of audio data recorded on the disk-shaped recording medium can be reproduced to create the original multiplexed audio data.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described. In the present invention, audio data and video data (hereinafter abbreviated as AV data as appropriate) of a plurality of signal types (formats) are recorded on one disc-shaped recording medium (hereinafter abbreviated as a disc). AV data of a plurality of signal types can be mixed and continuously recorded so that they can be reproduced continuously.
[0019]
In the following description, “a single disc-shaped recording medium is mixed with AV data of a plurality of signal types so that the AV data of the plurality of signal types can be continuously reproduced. “Continuous recording” is referred to as “can be mixed on one disk” as appropriate in order to avoid complication.
[0020]
First, an example of signal types (formats) of data that can be mixed in one disk in the present invention will be described.
[0021]
As an encoding method, for example, in the MPEG2 (Moving Pictures Experts Group 2) method, an encoding method in which video data is configured only by an I picture by intraframe encoding, an I picture, and a P picture and a B picture by predictive encoding, Thus, the encoding system constituting the video data can be mixed on one disk. Of course, it is possible to mix encoding methods other than the MPEG2 method.
[0022]
Note that, in the above-described encoding method in which video data is configured by only I pictures, a GOP (Group Of Picture) which is a unit of random access is configured by one I picture. Hereinafter, this method is referred to as a “single GOP method” for convenience. In the embodiment of the present invention, the MPEG2 4: 2: 2 profile is applied to the single GOP method. In addition, in an encoding method in which video data is configured using I, P, and B pictures, a GOP is completed with an I picture and includes one or more P and B pictures. Hereinafter, for convenience, this method in which a GOP is composed of a plurality of frames is referred to as a “long GOP method”.
[0023]
For video data, as an example, the bit rate mode of 30 Mbps (Mega bit per second), 40 Mbps, and 50 Mbps in the single GOP method described above can be mixed in one disk, and the bit rate mode in the long GOP is 25 Mbps. Video data can be further mixed in one disc. Other bit rate modes may be mixed in a single GOP or a long GOP.
[0024]
The bit rate mode is a mode for compressing and encoding video data so that the bit rate value indicated in the bit rate mode is the maximum value. For example, video data in a bit rate mode of 50 Mbps actually includes data with a bit rate of 50 Mbps or less in the transmission data depending on the complexity of the image. For frames with a data amount less than the bit rate indicated in the bit rate mode, the apparent bit rate is changed to the bit rate by filling the difference in the data amount with the bit rate indicated in the bit rate mode with the specified padding data. The bit rate indicated by the mode can be used.
[0025]
As for video data, interlaced and progressive data can be mixed in one disk as a scanning method, and data of a plurality of frame rates can be mixed in one disk in each method. With respect to the screen size, data with aspect ratios of 4: 3 and 16: 9 can be recorded on a single disc. For example, when the aspect ratio is 4: 3, the standard (SD: Standard Definision 640 pixels × 480 lines and higher definition (HD) data of 1440 pixels × 1088 lines can be mixed in one disc. Even when the aspect ratio is 16: 9, data of a plurality of types of image sizes can be similarly mixed on one disk.
[0026]
Further, the color profile is not limited to 4: 2: 2 described above, and other formats such as 4: 2: 0 can be mixed.
[0027]
As for audio data, audio data encoded with linear PCM (Pulse Code Modulation) (hereinafter abbreviated as linear PCM audio data) and audio data encoded with an encoding method other than linear PCM (for example, linear PCM) Audio data obtained by further compressing and encoding audio data) can be mixed in one disc. The audio data corresponds to a plurality of types of bit resolutions such as 16 bits and 24 bits, and a combination of a plurality of channels such as 4 channels and 8 channels can be mixed in one disc.
[0028]
In the embodiment of the present invention, the number of recording channels is selected from 0 channel (no audio), 4 channels, and 8 channels. If the number of input audio data channels is less than the selected number of recording channels, audio data indicating silence is recorded for the remaining channels, and the number of recording channels is maintained. For example, when 8 channels are selected as the number of recording channels and audio data of 2 channels is input, silent audio data is recorded in the remaining 6 channels, and 8 channels of audio data are recorded as recording data. It is said.
[0029]
In addition, audio data input by multiplexing a plurality of channels is recorded as individual audio data for each channel. At the time of reproduction, for example, individual audio data is multiplexed and output by the original multiplexing method.
[0030]
In one embodiment of the present invention, in addition to the above-mentioned main line system, that is, AV data to be actually broadcasted and edited, auxiliary AV data and metadata corresponding to the main line AV data are further included. Recorded on the same disc.
[0031]
The auxiliary AV data is audio / video data having a lower bit rate based on main line AV data. The auxiliary AV data is generated by compressing and encoding main-line AV data so as to reduce the bit rate to, for example, several Mbps. There are a plurality of types of encoding methods for generating auxiliary AV data, including MPEG4. In one embodiment of the present invention, one piece of auxiliary AV data encoded by a plurality of different encoding methods is used. Can be mixed on different disks. Also, auxiliary AV data that is the same encoding method and is encoded using different encoding parameters can be mixed in one disc.
[0032]
In the embodiment of the present invention, the number of channels of audio data handled by the auxiliary AV data is fixed to 8 channels. That is, for example, the number of channels of audio data of auxiliary AV data is set to 8 channels, and in the main line audio data described above, when any one of channels 0 and 4 is selected as the recording channel, or the selected recording channel On the other hand, even when the number of input channels is smaller, the number of audio data channels in the auxiliary AV data is eight. When the number of recording channels of main audio data is less than eight, audio data indicating silence is recorded in the remaining audio data channels in the auxiliary AV data (that is, channels not corresponding to main audio data channels). Is done.
[0033]
Metadata is high-order data related to certain data, and functions as an index for representing the contents of various data. The metadata includes time series metadata generated along the time series of the main AV data and non-time series metadata generated for a predetermined section such as for each scene in the main AV data. There are two types of data.
[0034]
The time series metadata includes, for example, a time code, a UMID (Unique Material Identifier), and an essence mark as essential data. Furthermore, camera metadata such as iris and zoom information of the video camera at the time of shooting can be included in the time-series metadata. Furthermore, information defined in ARIB (Association of Radio Industries and Businesses) can be included in the time-series metadata. Note that the data based on ARIB and the camera meta information have a relatively large data size and are therefore preferably mixed exclusively. The camera metadata and ARIB can be included in the time series metadata by time division multiplexing with a reduced time resolution.
[0035]
The non-time series metadata includes time code and UMID change point information, information on essence marks, user bits, and the like.
[0036]
The UMID will be schematically described. The UMID is an identifier standardized by SMPTE-330M that is uniquely determined to identify video data, audio data, and other material data.
[0037]
FIG. 1 shows the data structure of UMID. The UMID includes basic UMID as ID information for identifying material data, and signature metadata for identifying each content in the material data. The basic UMID and signature metadata each have a data area having a data length of 32 bytes. An area having a data length of 64 bytes in which the signature metadata is added to the basic UMID is referred to as an extended UMID.
[0038]
The basic UMID includes an area Universal Label having a data length of 12 bytes, an area Length Value having a data length of 1 byte, an area Instance Number having a data length of 3 bytes, and an area Material Number having a data length of 16 bytes. It consists of.
[0039]
The area Universal Label stores a code for identifying that the data string that immediately follows is a UMID. The area Length Value indicates the length of the UMID. Since the code length differs between the basic UMID and the extended UMID, the basic UMID is indicated by the value [13h] and the extended UMID is indicated by the value [33h] in the area Length. In the notation in parentheses [], “h” after the number indicates that the number is in hexadecimal notation. The area Instance Number indicates whether or not the material data has been overwritten or edited.
[0040]
The region Material Number is composed of three regions: a region Time Snap having a data length of 4 bytes, a region Rnd having a data length of 8 bytes, and a region Machine node having a data length of 4 bytes. The area Time Snap indicates the number of snap clock samples per day. As a result, the creation time of the material data is shown in units of clocks. The area Rnd is a random number to prevent duplicate numbers from being assigned when an incorrect time is set, or when the network address of a device defined by IEEE (Institute Electrical and Erectronic Engineers) changes, for example. It is.
[0041]
The signature metadata includes an area Time.Date having a data length of 8 bytes, an area Spatial Co-ordinated having a data length of 12 bytes, and an area Country, an area organization, and an area User each having a data length of 4 bytes. Composed.
[0042]
The area Time / Date indicates the time and date when the material was generated. In the area Spatial Co-ordinated, correction information (time difference information) relating to the time when the material is generated and position information represented by latitude, longitude, and altitude are indicated. The position information can be acquired, for example, by providing a function corresponding to GPS (Global Positioning System) in the video camera. In the area Country, the area Organization, and the area User, a country name, an organization name, and a user name are indicated by using omitted alphabetic characters and symbols, respectively.
[0043]
As described above, when the extended UMID is used, the UMID has a data length of 64 bytes and has a relatively large capacity for sequential recording in time series. Therefore, when embedding the UMID in the time series metadata, it is preferable to compress the UMID by a predetermined method.
[0044]
As long as the UMID is used for the application of the embodiment of the present invention, the first 10 bytes to 13 bytes are fixed values. Therefore, in one embodiment of the present invention, the first 10 bytes to the first 13 bytes of the UMID can be omitted. Further, when storing the UMID in the time-series metadata, it can be encoded by a predetermined method. In this case, it is preferable to use Base64 as the encoding method because the encoding result is an ASCII code, which can be easily embedded in, for example, an XML document. Furthermore, it is possible to use only the difference. For example, UMID that is partially shared is assigned to data generated at the same time in the same directory. By using only the UMID difference using this, the amount of data can be reduced.
[0045]
The essence mark will be schematically described. The essence mark represents an index related to video scene data which is a video scene (or cut) configured in video data, for example, at the time of shooting. By using the essence mark, it is possible to grasp what kind of scene it is after shooting without performing reproduction processing of video scene data.
[0046]
In one embodiment of the present invention, the essence mark is defined as a reserved word in advance. Therefore, for example, common control can be performed between the interfaces of the imaging device, the playback device, and the editing device without converting the essence mark according to the counterpart device.
[0047]
FIG. 2 shows an example of reserved words used to define essence marks. Note that the example of FIG. 2 is an example, and further essence marks can be additionally defined. “_RecStart” is a shooting start mark indicating a recording start position. “_RecEnd” is a shooting end mark indicating the recording end position. “_ShotMark1” and “_ShotMark2” are shot marks indicating arbitrary positions such as time points to be noted. “_Cut” is a cut mark indicating a cut position. “_Flash” is a flash mark indicating a flash detection position where the position where the flash is emitted is detected. “_FilterChange” is a filter change mark indicating a position where the lens filter is changed in the imaging apparatus. “_ShutterSpeedChange” is a shutter speed change mark indicating a position where the shutter speed is changed in the imaging apparatus. “_GainChange” is a gain change mark indicating a position where a gain of a filter or the like is changed. “_WhiteBalanceChange” is a white balance change mark indicating a position where the white balance is changed. “_OverBrightness” is a mark indicating a position where the output level of the video signal exceeds the limit value. “_OverAudioLimiter” is a large volume mark indicating a position where the output level of the audio signal exceeds the limit value. Each mark described above is recorded, for example, in units of video data frames.
[0048]
“_In-XXX” is an edit start mark indicating a cut start position of a cut or material. “_Out-XXX” is an edit end mark indicating the cut end position of the cut or material. The edit start mark and the edit end mark are numbered sequentially in the “XXX” portion every time an edit start point (IN point) or an edit end point (OUT point) is added. For example, “_In-001”, “_In-002”, and so on.
[0049]
By using the essence marks defined as described above as index information during the rough editing process, it is possible to efficiently select a target video scene.
[0050]
FIG. 3 shows an example of the data structure of the essence mark. As described with reference to FIG. 2, the essence mark is metadata in which the characteristics of the video scene and the like are represented by text data and associated with video content data (main-line AV data). The essence mark is KLV (Key Length Value) encoded and recorded or transmitted. FIG. 3 shows a format of the KLV encoded essence mark. This format is based on the metadata dictionary of SMPTE 335M / RP210A.
[0051]
The KLV encoded essence mark includes a “Key” portion having a data length of 16 bytes, an “L (length)” portion having a data length of 1 byte, and a “Value” portion having a data length of 32 bytes at the maximum. It consists of. The “Key” portion is an identifier indicating a KLV-encoded data item based on SMPTE 335M / RP210A, and in this example, is a value indicating an essence mark. The “L” part represents the data length following the “L” part in bytes. A maximum data length of 32 bytes is expressed. The “Value” portion is an area composed of text data in which essence marks are stored.
[0052]
Next, data arrangement on a disk according to an embodiment of the present invention will be described. In one embodiment of the present invention, data is recorded so as to form an annual ring on a disk. The annual ring data is data recorded on the disc in units of the data amount indicated by the data reproduction time. For example, when limited to main line audio data and video data, audio data and video data corresponding to a reproduction time zone are alternately arranged for each predetermined reproduction time unit having a data size of one track or more of a track. And record. By recording in this way, a set of audio data and video data corresponding to the reproduction time zone is layered in time series to form an annual ring.
[0053]
In this embodiment, in fact, in addition to the audio data and video data corresponding to the playback time zone, auxiliary AV data and time-series metadata corresponding to the playback time zone are recorded as a set to these data. An annual ring is formed and data is recorded on the optical disc 1.
[0054]
The data forming the annual ring is referred to as annual ring data. The annual ring data has a data amount that is an integral multiple of the sector, which is the smallest recording unit on the disc. The annual rings are recorded so that their boundaries coincide with the boundaries of the disk sectors.
[0055]
FIG. 4 shows an example of annual ring data formed on the optical disc 1. In the example of FIG. 4, in order from the inner circumference side of the optical disc 1, audio annual ring data # 1, video annual ring data # 1, audio annual ring data # 2, video annual ring data # 2, auxiliary AV annual ring data # 1, and time series meta data. Annual ring data # 1 is recorded, and annual ring data is handled in this cycle. On the outer peripheral side of the time series meta annual ring data # 1, a part of the annual ring data of the next cycle is further shown as audio annual ring data # 3 and video annual ring data # 3.
[0056]
In the example of FIG. 4, the playback time zone for the 1-year ring data of the time-series meta annual ring data and the playback time zone for the 1-year ring data of the auxiliary AV annual ring data correspond to each other. It is shown that the playback time zone of 2 corresponds to the playback time zone for two periods of the audio annual ring data. Similarly, it is shown that the playback time zone for one annual ring data of the time series meta annual ring data corresponds to the playback time zone for two cycles of video annual ring data. Such association between the reproduction time zone and the cycle of each annual ring data is set based on, for example, each data rate. It should be noted that the playback time for one year ring data of video annual ring data and audio annual ring data is preferably about 1.5 to 2 seconds in terms of experience.
[0057]
FIG. 5 shows an example of reading / writing data from / to the optical disc 1 on which annual rings are formed as shown in FIG. If there is a continuous free area of sufficient size on the optical disc 1 and there is no defect in the free area, each data series of audio data, video data, and auxiliary AV data time series metadata is used based on the playback time zone. The generated audio annulus data, video annulus data, auxiliary AV annulus data, and time-series meta annulus data are written so that a single stroke is written in an empty area of the optical disc 1 as shown in FIG. 5A. It is. At this time, any data boundary is written so as to coincide with the sector boundary of the optical disc 1. Reading of data from the optical disc 1 is performed in the same manner as in writing.
[0058]
On the other hand, when reading a specific data series from the optical disc 1, the operation of seeking to the recording position of the read data series and reading the data is repeated. FIG. 5B shows how the auxiliary AV data series is selectively read in this way. For example, referring also to FIG. 4, when auxiliary AV annual ring data # 1 is read out, time series meta annual ring data # 1, audio annual ring data # 3 and video annual ring data # 3, and audio annual ring data are recorded. # 4 and video annual ring data # 4 (not shown) are skipped by seeking, and auxiliary AV annual ring data # 2 of the next cycle is read out.
[0059]
As described above, the recording of data on the optical disc 1 is periodically performed as the annual ring data corresponding to the playback time zone in units of the playback time, so that the audio annual ring data and the video annual ring data in the same playback time zone can be obtained. Are arranged at close positions on the optical disc 1, it is possible to quickly read out and reproduce the audio data and video data corresponding to the reproduction time from the optical disc 1. Further, since the annual ring boundary and the sector boundary are recorded so as to coincide with each other, it is possible to read out only the audio data or the video data from the optical disc 1, and it is possible to quickly edit only the audio data or the video data. It becomes possible. Further, as described above, the audio annulus data, video annulus data, auxiliary AV annulus data, and time-series meta annulus data have a data amount that is an integral multiple of the sector of the optical disc 1, and further, the boundaries of the annulus data and the sector Recorded to coincide with the boundary. Therefore, when only one series of data is required among audio annual ring data, video annual ring data, auxiliary AV annual ring data and time series meta annual ring data, only necessary data is read without reading other data. Can be read.
[0060]
In order to take advantage of the convenience of data arrangement by annual rings as described above, it is necessary to record data on the optical disc 1 so as to ensure the continuity of annual rings. This will be described with reference to FIG. For example, consider reading only auxiliary AV annual ring data (indicated as “LR” in FIG. 6).
[0061]
For example, if a sufficiently large continuous space is secured at the time of recording, a plurality of cycles of annual rings can be continuously recorded. In this case, as shown in FIG. 6A, temporally continuous auxiliary AV annual ring data can be read with the minimum track jump. That is, when the auxiliary AV annual ring data is read, it is possible to repeat the operation of reading the auxiliary AV annual ring data in the annual ring of the next cycle, and the distance that the pickup jumps becomes the shortest.
[0062]
On the other hand, for example, when a continuous free area cannot be secured at the time of recording and auxiliary AV data that is temporally continuous is recorded in a skipped area on the optical disc 1, as shown in FIG. When the auxiliary AV annual ring data is read, for example, the pickup jumps a distance corresponding to a plurality of cycles of the annual ring, and the next auxiliary AV annual ring data must be read. Since this operation is repeated, the reading speed of the auxiliary AV annual ring data is reduced as compared with the case shown in FIG. 6A. Further, in the main line AV data, as shown in FIG. 6C, the reproduction of unedited AV data (AV clip) may be delayed.
[0063]
Therefore, in one embodiment of the present invention, in order to guarantee the continuity of the annual ring, an allocation unit having a length corresponding to a plurality of cycles of the annual ring is defined, and when the data is recorded with the annual ring, Allocate a contiguous free space whose length exceeds the defined allocation unit length.
[0064]
This will be described more specifically with reference to FIG. The allocation unit length is set in advance. The allocation unit length is set to a multiple of the total playback time of each data recorded in one cycle with annual rings. For example, if the playback time corresponding to one cycle of the annual ring is 2 seconds, the allocation unit length is set to 10 seconds. This allocation unit length is used as a ruler for measuring the length of the empty area of the optical disc 1 (see the upper right in FIG. 7). As an example, FIG. 7A shows an initial state in which three used areas are arranged so as to be separated from the optical disc 1, and a portion sandwiched between the used areas is an empty area.
[0065]
When recording AV data having a certain length on the optical disc 1 and auxiliary AV data corresponding to the AV data, first, the allocation unit length is compared with the length of the free area. An empty area having the above length is secured as a reserved area (FIG. 7B). In the example of FIG. 7, it is assumed that the right empty area of the two empty areas is longer than the allocation unit length, and is reserved as a reserved area. Next, annual ring data is sequentially recorded in this reserved area from the beginning of the reserved area (FIG. 7C). In this way, when the annual ring data is recorded, and the length of the free space in the reserved area is less than the length of one cycle of the annual ring data to be recorded next (FIG. 7D), the reserved area is released, As in 7A, a free area that can be made a reserved area is searched for while applying the allocation unit length to another free area on the optical disc 1.
[0066]
In this way, by searching for an empty area that can be recorded by an annual ring for a plurality of cycles and recording the annual ring in the empty area, a certain degree of continuity of the annual ring is guaranteed, and the annual ring data can be reproduced smoothly. It is possible. Although the allocation unit length is set to 10 seconds in the above description, this is not limited to this example, and a length corresponding to a longer reproduction time can be set as the allocation unit length. Actually, it is preferable to set the allocation unit length between 10 seconds and 30 seconds.
[0067]
Next, a data management structure according to an embodiment of the present invention will be described with reference to FIGS. In one embodiment of the present invention, data is managed in a directory structure. For example, UDF (Universal Disk Format) is used as the file system, and a directory PAV is provided immediately below the root directory (root) as shown in FIG. In this embodiment, the directory PAV and below are defined.
[0068]
That is, the above-described mixed recording of a plurality of signal types of audio data and video data on one disc is defined under the directory PAV. The recording of data in the directory PAV that cannot be managed in the embodiment of the present invention is optional.
[0069]
Four files (INDEX.XML, INDEX.RSV, DISCINFO.XML, and DISCINFO.RSV) are placed directly under the directory PAV, and two directories (CLPR and EDTR) are provided.
[0070]
The directory CLPR manages clip data. A clip here is a set of data from when shooting is started to when it is stopped, for example. For example, in the operation of the video camera, one clip is a period from when the operation start button is pressed until the operation stop button is pressed (the operation start button is released).
[0071]
This group of data includes the main line audio data and video data described above, auxiliary AV data generated from the audio data and video data, time-series metadata corresponding to the audio data and video data, and non-data. It consists of time series metadata. In the directories “C0001”, “C0002”,... Provided immediately below the directory CLPR, a set of data constituting the clip is stored for each clip.
[0072]
That is, as an example is shown in FIG. 9, the clip is a video data having a common time axis from the start to the end of recording, audio data (1), (2),..., Auxiliary AV data of each channel. And time-series metadata, and non-time-series metadata. In FIG. 9, the non-time series metadata is omitted.
[0073]
FIG. 10 shows an example of the structure of a directory “C0001” corresponding to one clip “C0001” provided immediately below the directory CLPR. Hereinafter, a directory corresponding to one clip immediately below the directory CLPR is appropriately referred to as a clip directory. The structure of the clip directory substantially corresponds to the structure of FIG. 9 described above. That is, in the clip directory “C0001”, each of the above-described pieces of data is stored by being distinguished by the file name. In the example of FIG. 10, the file name is composed of 12 digits, and among the 8 digits before the delimiter “.”, The front 5 digits are used to identify the clip, and the 3 digits immediately before the delimiter are the audio digits. Used to indicate the type of data, such as data, video data, auxiliary AV data. Further, the three digits after the delimiter are an extension and indicate the data format.
[0074]
More specifically, in the example of FIG. 10, the file “C0001C01.SMI” indicating the clip information, the main line video data file “C0001V01.MXF”, the main line system are included as a group of files constituting the clip “C0001”. Audio data files “C0001A01.MXF” to “C0001A08.MXF”, auxiliary AV data file “C0001S01.MXF”, non-time series metadata file “C0001M01.XML”, time series metadata file “C0001R01.BIM” And the pointer information file “C0001I01.PPF” are stored in the clip directory “C0001”.
[0075]
As described above, in one embodiment of the present invention, main-line audio data is stored and recorded in the files (“C0001A01.MXF” to “C0001A08.MXF”) for each channel. At this time, it is more preferable to record the audio data of the channel pair as a unit because an effect such as shortening of the access time during reproduction can be expected. For example, files that are in a channel pair relationship with each other are placed on physically close positions on the disk.
[0076]
In the embodiment of the present invention, mixing of the above-described data signal types between the clip directories in the directory CLPR is permitted. For example, for main line video data signal types, single GOP and bit rate 50 Mbps video data are stored in the clip directory “C0001”, and long GOP and bit rate 25 Mbps video data are stored in the clip directory “C0002”. Is possible. On the other hand, mixing of data signal types in each data in the clip directory is not permitted. For example, in video data, a video data file recorded at a bit rate mode of 50 Mbps from the beginning to a certain point and a video data file recorded at a bit rate mode of 25 Mbps from that point to the end cannot be stored. .
[0077]
Returning to FIG. 8, the directory EDTR manages editing information. In one embodiment of the present invention, the editing result is recorded as an edit list or a play list. In the directories “E0001”, “E0002”,... Provided immediately below the directory EDTR, a set of data constituting the editing result is stored for each editing result.
[0078]
The edit list is a list in which edit points (IN point, OUT point, etc.) and playback order for clips are described. The edit list includes nondestructive edit results for clips and a play list described later. When the edit result of non-destructive editing of the edit list is played back, the files stored in the clip directory are referred to according to the description of the list. Playback video is obtained. However, as a result of nondestructive editing, the file in the list is referred regardless of the position of the file on the optical disc 1, so that continuity during reproduction is not guaranteed.
[0079]
When it is determined that it is difficult to continuously reproduce a file or a part of a file that is referred to by the playlist based on the editing result, the playlist is stored on the optical disc 1 as a predetermined part of the file or the file. By re-arranging in this area, the continuity at the time of playback of the edit list is guaranteed.
[0080]
Based on the result of creating the above edit list by editing work, the management information of the file used for editing (for example, an index file “INDEX.XML” described later) is referred to, and non-destructive based on the editing work, that is, the editing result It is estimated whether or not continuous reproduction is possible with the file referred to based on the file being placed in each clip directory. As a result, if it is determined that continuous reproduction is difficult, the corresponding file is copied to a predetermined area of the optical disc 1. The file rearranged in the predetermined area is referred to as a bridge essence file. A list in which the bridge essence file is reflected in the edited result is referred to as a play list.
[0081]
For example, if the editing result is a reference to a complicated clip, there is a possibility that the pickup seek may not be in time for the transition from clip to clip during playback based on the editing result. is there. In such a case, a playlist is created and a bridge essence file is recorded in a predetermined area of the optical disc 1.
[0082]
FIG. 11 shows an example of the structure of the directory “E0002” corresponding to one editing result “E0002” provided immediately below the directory EDTR. Hereinafter, a directory corresponding to one editing result directly under the directory EDTR is appropriately referred to as an edit directory. In the edit directory “E0002”, data generated by the above-described editing result is stored with being distinguished by file names. The file name is composed of 12 digits. Of the 8 digits before the delimiter “.”, The first 5 digits are used to identify the editing operation, and the 3 digits immediately before the delimiter are used to indicate the type of data. Used. Further, the three digits after the delimiter are an extension and indicate the data format.
[0083]
More specifically, in the example of FIG. 11, as a file constituting the editing result “E0002”, an edit list file “E0002E01.SMI” file “E0002M01.S” in which information of time series and non-time series metadata is described. `` XML '', playlist file `` E0002P01.SMI '', bridge essence files `` E0002V01.BMX '' and `` E0002A01.BMX '' to `` E0002A04.BMX '' with main line data, bridge essence file `` E0002S01.BMX '' with auxiliary AV data and A bridge essence file “E0002R01.BMX” based on time-series and non-time-series metadata is stored in the edit directory “E0002”.
[0084]
Of these files stored in the edit directory “E0002”, the shaded files, that is, the bridge essence files “E0002V01.BMX” and “E0002A01.BMX” to “E0002A04.BMX” by the main line data, auxiliary The bridge essence file “E0002S01.BMX” based on AV data and the bridge essence file “E0002R01.BMX” based on time-series and non-time-series metadata are files belonging to a playlist.
[0085]
As described above, for example, video data stored in the clip directory is referred to by the edit list. Since different data signal types can be mixed between clip directories, as a result, different data signal types can be mixed on the edit list.
[0086]
Returning to FIG. 8, the file “INDEX.XML” is an index file for managing material information stored under the directory PAV. In this example, the file “INDEX.XML” is described in an XML (Extensible Markup Language) format. Each file and edit list described above are managed by this file “INDEX.XML”. For example, the conversion table of file name and UMID, length information (Duration), the playback order of each material when playing back the entire optical disc 1, and the like are managed. In addition, video data, audio data, auxiliary AV data, and the like belonging to each clip are managed, and clip information managed by files is managed in the clip directory.
[0087]
The file “DISCINFO.XML” manages information about this disc. Playback position information and the like are also stored in this file “DISCINFO.XML”.
[0088]
In one embodiment of the present invention, when a predetermined change is detected in a set of data constituting a clip from when shooting is started to when it is stopped, it corresponds to the change detection position. The clip is divided at the position, and the clip after the division position is set as a new clip. A new directory corresponding to the new clip is automatically created for the directory CLPR, and a set of data constituting the new clip is stored in the created directory.
[0089]
Clip division is performed when a change in signal type (format) is detected in at least one of video data and audio data constituting the clip. More specifically, the following example can be considered as a condition for division. First, regarding video data,
(1) Bit rate change
(2) Change in frame rate
(3) Change in image size
(4) Change in image aspect ratio
(5) Changes in encoding method
For audio data,
(1) Bit resolution change
(2) Change in sampling frequency
(3) Change in the number of input channels
(4) Changes in encoding method
[0090]
When a change is detected in any one of these, the clip is automatically divided at a position corresponding to the timing when the change is detected. At this time, when a change is detected in certain data, other data belonging to the same clip as that data is also divided at the same timing.
[0091]
Of course, clip division is not limited to this, and may be performed in accordance with changes in other attributes of video data and audio data. Further, not only video data and audio data, but also clip division may be performed by detecting a predetermined change in auxiliary AV data or time-series metadata.
[0092]
For example, the auxiliary AV data can be clip-divided when the bit rate mode or the encoding method is changed, for example. As for the time series metadata, for example, when the metadata by ARIB and the camera data are exclusively recorded, the clip can be divided when the data type is changed between the ARIB and the camera data. Furthermore, it is possible to perform clip division when the data rate initially set for transmitting time-series metadata is changed.
[0093]
Furthermore, it is possible not to divide the main line audio data and the time-series metadata when the clip is divided along with the change of the main line video data. By doing in this way, the increase of the file by clip division can be suppressed. Even in this case, the auxiliary AV data is divided along with the change of the main line video data.
[0094]
When dividing a clip, it is preferable to make the division boundary coincide with the GOP boundary of the auxiliary AV data because the relationship between the time axis and the byte offset in the clip becomes simple, and the processing becomes easy. For example, when the above-described change is detected in video data or audio data, as shown in an example in FIG. 12A, whether clip division is waited until the next GOP boundary of auxiliary AV data (division position B), or This is done by dividing the clip back to the previous GOP boundary (division position A). Actually, it is preferable to perform clip division at the division position B.
[0095]
Not limited to this, when the division boundary at the time of clip division does not coincide with the GOP boundary of the auxiliary AV data, the surplus portion of the GOP of the auxiliary AV data is filled with stuffing bytes, and the auxiliary AV data and the main video data are recorded. It is also possible to arrange the data amount for other data. That is, as shown in FIG. 12B, in the auxiliary AV data, for example, the GOP immediately before the position where the change is detected in the video data is set as the last GOP of the clip, and from the boundary at the rear end of the last GOP. The change detection position (indicated by hatching in FIG. 12B) is filled with stuffing bytes.
[0096]
If the main line video data is a single GOP, clip division can be performed at an arbitrary frame position. On the other hand, when the main line video data is a long GOP, the frame at the clip division position may be a frame of P picture or B picture by predictive coding. Therefore, when clip division is performed on video data of a long GOP, the GOP is once completed at the clip division position. For example, if the frame immediately before the division position is a B picture, the frame can be converted into a P picture or an I picture.
[0097]
At the time of clip division, an overlapping portion may be provided between the original clip of the division and the clip newly generated by the division. For example, in the original clip and / or the new clip, the clip division is performed with a time allowance with respect to the change timing so that the change point of the signal type is included in time.
[0098]
As an example, a case where the original bit rate of 50 Mbps is switched to 30 Mbps in main line video data will be described with reference to FIG. As shown in FIG. 12, in the case of video data with a bit rate of 50 Mbps, the bit rate remains at 50 Mbps after a predetermined time (shaded area in the figure) further from the position where the bit rate switching is instructed. Is recorded. On the other hand, video data with a bit rate of 30 Mbps is recorded at a bit rate of 30 Mbps from a predetermined time before the position instructed to switch the bit rate (the hatched portion in the figure).
[0099]
Since the bit rate switching point becomes the clip division position, it is necessary to adjust the start position of the clip with respect to the actual start position of the file using, for example, “clip Begin” which is a command for specifying the start position of the clip. .
[0100]
As an example, such recording is performed by buffering the hatched portions in FIG. 13 in the baseband video data before compression encoding, and compressing them at the corresponding bit rate. For example, in the case of video data of 50 Mbps, it is possible to add a hatched file to a file of video data before the bit rate switching point. This may be described in the edit list described above or the file “C0001C01.SMI” indicating the clip information in the clip directory without actually adding files.
[0101]
Note that the naming rules for the clip directory name and the file name of each file in the clip directory are not limited to the above example. For example, the above-described UMID may be used as a file name or clip directory name. As described above, the UMID has a data length of 64 bytes when considering the extended UMID and is long to be used for a file name or the like, so it is preferable to use only a part. For example, a part in UMID where a different value is obtained for each clip is used for a file name or the like.
[0102]
In addition, when the clip is divided, it is preferable in terms of clip management that the clip directory name and the file name are named so as to reflect the reason for dividing the clip. In this case, it is named so that at least it can be discriminated whether the clip has been explicitly divided by the user or by automatic processing on the apparatus side.
[0103]
FIG. 14 shows an example of the configuration of a disc recording / reproducing apparatus 10 applicable to one embodiment of the present invention. Here, it is assumed that the disk recording / reproducing apparatus 10 is a recording / reproducing unit built in a video camera (not shown), and a video signal based on an imaging signal imaged by the video camera and an audio signal input along with imaging. Are input to the signal processing unit 31 and supplied to the disk recording / reproducing apparatus 10. The video signal and audio signal output from the signal input / output unit 31 are supplied to, for example, a monitor device.
[0104]
Of course, this is merely an example, and the disk recording / reproducing apparatus 10 may be an apparatus used independently. For example, it can be used in combination with a video camera that does not have a recording unit. Video signals and audio signals output from the video camera, predetermined control signals, and data are input to the disc recording / reproducing apparatus 10 via the signal input / output unit 31. Further, for example, video signals and audio signals reproduced by other recording / reproducing apparatuses can be input to the signal input / output unit 31. In addition, the audio signal input to the signal input / output unit 31 is not limited to that input along with the imaging of the video signal. For example, after the imaging, the audio signal is recorded in a desired section of the video signal. It may be an after-recording audio signal for recording.
[0105]
The spindle motor 12 rotationally drives the optical disc 1 with CLV (Constant Linear Velocity) or CAV (Constant Angler Velocity) based on the spindle motor drive signal from the servo control unit 15.
[0106]
The pickup unit 13 controls the output of the laser light based on the recording signal supplied from the signal processing unit 16 and records the recording signal on the optical disc 1. The pickup unit 13 also condenses and irradiates the optical disc 1 with laser light, photoelectrically converts the reflected light from the optical disc 1 to generate a current signal, and supplies it to an RF (Radio Frequency) amplifier 14. The irradiation position of the laser beam is controlled to a predetermined position by a servo signal supplied from the servo control unit 15 to the pickup unit 13.
[0107]
The RF amplifier 14 generates a focus error signal, a tracking error signal, and a reproduction signal based on the current signal from the pickup unit 13, supplies the tracking error signal and the focus error signal to the servo control unit 15, and reproduces the reproduction signal. Is supplied to the signal processing unit 16.
[0108]
The servo control unit 15 controls the focus servo operation and the tracking servo operation. Specifically, the servo control unit 15 generates a focus servo signal and a tracking servo signal based on the focus error signal and the tracking error signal from the RF amplifier 14 and supplies them to an actuator (not shown) of the pickup unit 13. . The servo control unit 15 generates a spindle motor drive signal for driving the spindle motor 12 and controls a spindle servo operation for rotating the optical disc 1 at a predetermined rotation speed.
[0109]
Further, the servo control unit 15 performs thread control for moving the pickup unit 13 in the radial direction of the optical disc 1 to change the irradiation position of the laser beam. The signal reading position of the optical disc 1 is set by the control unit 20, and the position of the pickup unit 13 is controlled so that a signal can be read from the set reading position.
[0110]
The signal processing unit 16 modulates the recording data input from the memory controller 17 to generate a recording signal, and supplies the recording signal to the pickup unit 13. The signal processing unit 16 also demodulates the reproduction signal from the RF amplifier 14 to generate reproduction data, and supplies the reproduction data to the memory controller 17.
[0111]
The memory controller 17 controls the write address for the memory 18 and stores the recording data supplied from the data converter 19 in the memory 18 as appropriate. The memory controller 17 controls the read address for the memory 18 and supplies the data stored in the memory 18 to the read signal processor 16 as appropriate. Similarly, the memory controller 17 also appropriately stores the reproduction data from the signal processing unit 16 in the memory 18, reads out the data stored in the memory 18, and supplies the data to the data conversion unit 19.
[0112]
A video signal and an audio signal based on a photographed image photographed by the video camera are supplied to the data conversion unit 19 via the signal input / output unit 31. As will be described in detail later, the data conversion unit 19 compresses and encodes the supplied video signal in a mode instructed by the control unit 20 using a compression encoding method such as MPEG2, for example, and generates main-line video data. To do. At this time, compression encoding processing with a lower bit rate is also performed, and auxiliary AV data is generated.
[0113]
Further, the data conversion unit 19 compresses and encodes the supplied audio signal by a method instructed by the control unit 20 and outputs it as main-line audio data. In the case of an audio signal, linear PCM audio data may be output without being compressed and encoded.
[0114]
The main-line audio data and video data and auxiliary AV data processed as described above by the data converter 19 are supplied to the memory controller 17.
[0115]
The data converter 19 also decodes the reproduction data supplied from the memory controller 17 as necessary, converts it into an output signal of a predetermined format, and supplies it to the signal input / output unit 31.
[0116]
The control unit 20 includes a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a bus for connecting them, and the like, and controls the entire disk recording / reproducing apparatus 10. To do. The ROM stores in advance an initial program that is read when the CPU is started, a program for controlling the disk recording / reproducing apparatus 10, and the like. The RAM is used as a work memory for the CPU. The video camera unit is also controlled by the control unit 20.
[0117]
Further, the control unit 20 provides a file system for recording data on the optical disc 1 and reproducing the recorded data in accordance with a program stored in advance in the ROM. That is, in the disc recording / reproducing apparatus 10, recording of data on the optical disc 1 and reproduction of data from the optical disc 1 are performed under the control of the control unit 20.
[0118]
The operation unit 21 is operated by a user, for example, and supplies an operation signal corresponding to the operation to the control unit 20. The control unit 20 controls the servo control unit 15, the signal processing unit 16, the memory controller 17, and the data conversion unit 19 based on an operation signal from the operation unit 21, and executes recording / reproduction processing.
[0119]
Further, for example, a bit rate, a frame rate, an image size, and an image aspect ratio for recording video data are set based on an operation signal from the operation unit 21. Further, ON / OFF of compression encoding processing for recorded audio data and setting of bit resolution may be performed from the operation unit 21. Control signals based on these settings are supplied to the memory controller 17 and the data converter 19.
[0120]
Furthermore, the number of recording channels for main line audio data can be set by the operation unit 21. An operation signal based on this setting is supplied from the operation unit 21 to the control unit 20. In the control unit 20, based on this operation signal, a control signal instructing to record audio data with the set number of recording channels is supplied from the control unit 20 to the signal processing unit 16, the memory controller 17, the data conversion unit 19, and the like. Is done.
[0121]
The disk recording / reproducing apparatus 10 includes an antenna 22 for receiving a GPS signal, and a GPS unit 23 that analyzes the GPS signal received by the antenna 22 and outputs position information including latitude, longitude, and altitude. And have. The position information output from the GPS unit 23 is supplied to the control unit 20. The antenna 22 and the GPS unit 23 may be provided in the video camera unit or may be externally attached to the disk recording / reproducing apparatus 10.
[0122]
FIG. 15 shows an exemplary configuration of the data converter 19. When recording data on the optical disc 1, a signal to be recorded input from the signal input / output unit 31 is supplied to the demultiplexer 41. The signal input / output unit 31 receives a video signal of a moving image and an audio signal accompanying the video signal from the video camera unit, and inputs camera shooting information, for example, information related to iris and zoom, as camera data in real time. Is done.
[0123]
The demultiplexer 41 separates a plurality of related data series from the signal supplied from the signal input / output unit 31, that is, for example, a video signal of a moving image and an audio signal accompanying the video signal, and detects a data amount To the unit 42. Further, the demultiplexer 41 separates and outputs camera data from the signal supplied from the signal input / output unit 31. This camera data is supplied to the control unit 20.
[0124]
The data amount detection unit 42 supplies the video signal and audio signal supplied from the demultiplexer 41 to the image signal conversion unit 43, the audio signal conversion unit 44, and the auxiliary AV data conversion unit 48 as they are, The data amount of the signal and the audio signal is detected and supplied to the memory controller 17. That is, the data amount detection unit 42 detects, for example, a data amount for a predetermined reproduction time for each of the video signal and the audio signal supplied from the demultiplexer 41 and supplies the detected data amount to the memory controller 17.
[0125]
The image signal conversion unit 43 compresses and encodes the video signal supplied from the data amount detection unit 42 in accordance with, for example, the MPEG2 system in accordance with an instruction from the control unit 20, and the data sequence of the video data obtained as a result is converted to the memory controller 17 To supply. For the image signal converter 43, the control unit 20 sets the maximum bit rate of the generated code amount by, for example, compression coding. The image signal conversion unit 43 estimates the data amount of one frame after compression coding, controls the compression coding processing based on the result, and applies the video data to the video data so that the generated code amount is within the set maximum bit rate. An actual compression encoding process is performed. The difference between the set maximum bit rate and the amount of data by actual compression encoding is filled with, for example, predetermined padding data, and the maximum bit rate is maintained. The data sequence of the compressed and encoded video data is supplied to the memory controller 17.
[0126]
When the audio signal supplied from the data amount detection unit 42 is not linear PCM audio data, the audio signal conversion unit 44 converts the audio signal into linear PCM audio data according to an instruction from the control unit 20. The audio signal conversion unit 44 is not limited to this, and the audio signal may be compression-encoded by, for example, MP3 (Moving Pictures Experts Group 1 Audio Layer 3) or AAC (Advanced Audio Coding) method according to the MPEG method. it can. The compression encoding method of audio data is not limited to these, and other methods may be used. A data series of audio data output from the audio signal conversion unit 44 is supplied to the memory controller 17.
[0127]
The main-line audio data (that is, the audio signal supplied from the data amount detection unit 42) is input in a channel pair in which, for example, two channels are paired. As such an audio data transmission format, for example, there is AES3-1992 (r1997) established by AES (Audio Engineering Society). According to AES3-1992 (r1997), audio data is serially transmitted through a channel pair in which samples are interleaved for each channel.
[0128]
According to AES3-1992 (r1997), audio data is stored in a subframe for each sample. As shown in an example in FIG. 16A, in the subframe, a preamble including a predetermined bit pattern is arranged from the 0th bit to the 3rd bit, and in this example in which the bit resolution is 24 bits, the 4th bit to the 27th bit. One sample of audio data is stored in. Following the audio data, bits V, U, C and P are arranged. These bits V, U, C and P are a validity bit, a user data bit, a channel status bit and a parity bit, respectively. As an example is shown in FIG. 16B, one frame of audio data is composed of two subframes, and one block is composed of 192 frames.
[0129]
The preamble arranged at the head of each subframe is composed of a specific bit pattern. For the preamble of the first channel, a different value (referred to as “Z”) is used only for the start frame frame (0) of the block, and thereafter, the same value (“X”) is assumed for frames (1) to (191). ) Is used. For the second channel preamble, the same value ("Y") different from the first channel preamble is used. According to this format, it is possible to identify the block start position and the samples of the first and second channels by detecting the preamble.
[0130]
In addition, channel status data (C) for transmitting 1 bit for each subframe is collected for one block, that is, 192 bits (24 bytes) to form channel status data. The 24 bytes are used to store various attribute information of audio data to be transmitted. FIG. 16C shows the first byte (0th byte) of this channel status data. The 0th bit indicates that this data is channel status data, and the 1st bit 1 (shaded portion in FIG. 16C) indicates whether or not the data to be transmitted is linear PCM audio data. The second to fourth bits store emphasis information of audio data. The fifth bit indicates whether or not the sampling frequency of transmitted audio data is locked. The sixth and seventh bits indicate the sampling frequency of the audio data to be transmitted.
[0131]
In an embodiment of the present invention, when linear PCM audio data is input, the audio data input in the channel pair is separated into respective channels, and the audio data for each channel is stored in individual files. Record. The audio data channel separation processing can be performed by the audio signal conversion unit 44, for example. For example, the preamble is detected based on the bit pattern of the input audio data, the samples of the audio data of the first and second channels are extracted based on the detected preamble, are rearranged for each channel, and are output.
[0132]
The audio data separated into each channel is supplied to the pickup unit 13 via the memory controller 17 and the signal processing unit 16, and is recorded on the optical disc 1 as an individual audio data file for each channel. As described above, the audio data input in pairs of two channels is recorded separately as audio data for each channel, thereby facilitating processing in units of channels.
[0133]
The channel separation of audio data is not limited to this, and can be performed using the memory 18 and the memory controller 17, for example. The audio data stored in the memory 18 for the two channel pairs is read while being input, while the memory controller 17 controls the read address to a predetermined value. For example, the readout is controlled so that samples of the same channel are output side by side. Further, channel separation of audio data may be performed in the signal input / output device 31.
[0134]
In the embodiment of the present invention, as described above, when audio data is input with a number of channels smaller than the set number of recording channels, the unused channels output audio data indicating silence. . As audio data indicating silence, for example, one sample of audio data indicating silence is generated and stored in a memory or a register. By repeatedly reading it according to the clock, audio data indicating silence can be continuously output. Such processing can be performed by the audio signal converter 44. Of course, it may be performed using the memory 18 and the memory controller 17 or may be performed in the signal input / output device 31.
[0135]
Furthermore, according to an embodiment of the present invention, when non-audio audio data is input as main-line audio data and recorded without decoding into linear PCM audio data, channel separation is not performed. . For example, according to AES3-1992 (r1997) described above, data other than linear PCM audio data can be transmitted. Whether or not the data to be transmitted is linear PCM audio data can be known by referring to the first bit in the first byte of the channel status data as described above with reference to FIG. 16C. If the first bit indicates that the input data is not linear PCM audio data, the channel separation process described above is not performed on the data. For example, data is extracted one word at a time from the subframe, arranged in order, and output.
[0136]
On the other hand, the auxiliary AV data conversion unit 48 compresses and encodes the video signal supplied from the data amount detection unit 42 according to an instruction from the control unit 20, for example, according to the MPEG4 system, and generates auxiliary AV data. In this embodiment, at this time, the bit rate is fixed to several Mbps, and a GOP is formed by 10 frames of one I picture and nine P pictures.
[0137]
Further, as described above, in the embodiment of the present invention, in the auxiliary AV data, the audio data is always handled as 8-channel audio data regardless of the number of main-line audio data channels. When the number of channels of the audio data supplied from the data amount detection unit 42 is less than 8 channels, the auxiliary AV data conversion unit 48 generates audio data indicating silence for the remaining channels and encodes it with the video signal. Turn into. For example, as described above, audio data indicating silence can be generated by storing one sample of audio data indicating silence in, for example, a memory or the like, and repeatedly reading the sample.
[0138]
In addition, the above-mentioned structure is an example, Comprising: It is not limited to this. For example, when main line AV data, camera data, and the like are independently input to the signal input / output unit 31, the demultiplexer 41 can be omitted. Further, when the main line audio data is linear PCM audio data, the processing in the audio signal conversion unit 44 can be omitted.
[0139]
The video data and audio data supplied to the memory controller 17 are supplied to the optical disc 1 and recorded as described above.
[0140]
Recording is performed while annual rings are formed on the optical disc 1 as described above. The data amount detection unit 42 of the data conversion unit 19 notifies the memory controller 17 of the fact that, for example, in the audio data, the audio data necessary for reproduction of the time corresponding to the annual ring data is detected. In response to this notification, the memory controller 17 determines whether or not the audio data necessary for reproduction of the annual ring data is stored in the memory 18 and notifies the control unit 20 of the determination result. Based on the determination result, the control unit 20 controls the memory controller 17 so as to read out audio data corresponding to the reproduction time for one year ring data from the memory 18. Based on this control, the memory controller 17 reads audio data from the memory 18, supplies the audio data to the signal control unit 16, and records the audio data on the optical disc 1.
[0141]
When the audio data corresponding to the playback time for one annual ring data is recorded, next, for example, the same processing is performed on the video data, and the video annual ring data for one annual ring data is recorded after the audio annual ring data. The Similarly, the auxiliary AV data is sequentially recorded with data corresponding to the reproduction time for the annual ring data.
[0142]
As for the time series metadata, for example, camera data is supplied from the demultiplexer 41 to the control unit 20, and some data such as UMID among the time series metadata is generated by the control unit 20. The camera data and the data generated by the control unit 20 are combined into time series metadata and stored in the memory 18 via the memory controller 17. In the same manner as described above, the memory controller 17 reads time-series metadata corresponding to the reproduction time for one annual ring data from the memory 18 and supplies it to the signal processing unit 16.
[0143]
Note that the control unit 20 also generates non-time series metadata. Non-time series metadata is recorded in the clip directory of the clip to which the data belongs.
[0144]
The data recorded on the optical disc 1 as described above is stored in a file as described above with reference to FIGS. 8 to 11, and the audio data is stored in a file for each channel and managed by a directory structure. Is done. For example, when data is recorded on the optical disk 1, management information such as address information of each file, pointer information in the directory structure, file name, and directory name information is recorded in a predetermined management area of the optical disk 1 by the control unit 20. Is done. Also, the recorded file information is reflected in the index file “INDEX.XML”.
[0145]
On the other hand, when data is reproduced from the optical disc 1, video data, audio data of each channel, auxiliary AV data, and time-series metadata are read from the optical disc 1 as described above. At this time, low bit rate data such as main line audio data, auxiliary AV data, and time series metadata is also reproduced at the high bit rate main line video data reproduction rate, and the data reproduction rate from the optical disc 1 is reproduced. Is not changed depending on the data to be read. Video data and auxiliary AV data read from the optical disc 1 are supplied from the memory controller 17 to the image data conversion unit 45 and the auxiliary AV data conversion unit 49, respectively. The audio data is supplied from the memory controller 17 to the audio data conversion unit 46.
[0146]
The image data conversion unit 45 decodes the data series of the main line video data supplied from the memory controller 17 and supplies the resulting video signal to the multiplexer 47. Further, the auxiliary AV data conversion unit 49 decodes the data series of the auxiliary AV data supplied from the memory controller 17, and supplies the resulting video signal and audio signals for 8 channels to the multiplexer 47.
[0147]
Further, the audio data conversion unit 46, for example, if the audio data supplied from the memory controller 17 is linear PCM audio data, for example, the data series is paired for every two channels, and a preamble and a bit V for each sample. U, C and P are added to form a subframe, and subframes are interleaved for each channel to form a frame, and 192 frames constitute one block, which is defined by AES3-1992 (r1997). Output as serial audio data. The audio data is supplied to the multiplexer 47. On the other hand, when the audio data supplied from the memory controller 17 is non-audio audio data, for example, it is stored in a subframe for each word, and serial data is formed and output as described above. This data is supplied to the multiplexer 47.
[0148]
In the image data conversion unit 45, the audio data conversion unit 46, and the auxiliary AV data conversion unit 49, the supplied reproduction data can be supplied as it is to the multiplexer 47 without being decoded, and multiplexed and output. is there. Further, it is possible to omit the multiplexer 47 and output each data independently.
[0149]
In the disc recording / reproducing apparatus 10 configured as described above, when the user commands the data recording by operating the operation unit 21, the data supplied from the signal input / output unit 31 is converted to the data conversion unit 19, the memory controller. 17, supplied to the optical disc 1 through the signal processing unit 16 and the pickup unit 13 and recorded.
[0150]
At the time of recording, the user can change the bit rate of the main line video data by operating the operation unit 21. For example, initially, recording is performed with the bit rate set to 50 Mbps, and when the recordable area of the optical disk 1 is reduced, the bit rate is changed to a low bit rate such as 30 Mbps so that no recording is missed. Can be used.
[0151]
At this time, the clip is divided in accordance with the timing of changing the bit rate, and the changed data is recorded on the optical disc 1 as a new clip. The change of the bit rate may be detected by detecting an operation performed on the operation unit 21 or based on the result of monitoring the bit rate of the video data by the control unit 20. For example, the memory controller 17 extracts data at a predetermined bit position in which the bit rate information is described in the header of the main line video data supplied from the data conversion unit 19 to confirm that the bit rate has been changed. It is possible to detect.
[0152]
When the change in the bit rate is detected, for example, the memory controller 17 is controlled by the control unit 20, the data before the bit rate change is swept from the memory 18 and recorded on the optical disc 1, and a new data is created by the data after the change. Annual rings are formed.
[0153]
When a change in main line video data is detected, other data, that is, main line audio data, auxiliary AV data, and time-series metadata are similarly controlled by the memory controller 17 to divide the clip. Is called. At this time, as described above, the main AV data can be divided in accordance with the GOP boundary of the auxiliary AV data.
[0154]
Further, when the bit rate of the main line video data is changed, it is preferable to gradually change the bit rate of the actual video data so that an unnatural change does not appear in the reproduced image.
[0155]
First, the case of changing from a high bit rate to a low bit rate will be described with reference to FIG. Assume that the bit rate mode is initially set to 50 Mbps. By operating the operation unit 21 during recording, the time t ₀ Is instructed to change the bit rate mode to 30 Mbps. In response to the instruction, the control unit 20 instructs the image signal conversion unit 43B of the data conversion unit 19 to change the bit rate. At this time, time t ₀ Time t after a predetermined time from ₁ A time constant process is performed on the change rate of the bit rate so that the bit rate gradually decreases. And time t ₁ Is the actual bit rate change point, and clip division is performed at this point.
[0156]
Also in this case, time t ₀ Even if the change of the bit rate is instructed at ₁ Until it is reached, it is treated as video data in the bit rate mode before the change. For example, the difference between the data amount at the bit rate specified in the bit rate mode and the generated code amount by the actual compression encoding is filled with predetermined padding data.
[0157]
When changing from a low bit rate to a high bit rate, the above processing is reversed. That is, for example, when the bit rate initially set to 30 Mbps is changed to 50 Mbps, first, the bit rate mode is changed from 30 Mbps to 50 Mbps at the timing of the change instruction. Then, the time constant processing is performed on the change rate of the bit rate so that the bit rate is gradually increased over a predetermined time from the control unit 20 to the image signal conversion unit 43B of the data conversion unit 19. . Further, for example, the difference between the data amount at the bit rate specified in the bit rate mode and the generated code amount by the actual compression encoding is filled with predetermined padding data. Clip division is performed, for example, at a change point of the bit rate mode.
[0158]
As described above, the bit rate can be gradually changed by instructing the image signal conversion unit 43B from the control unit 20 to a bit rate with a small value at predetermined time intervals. In the image signal conversion unit 43B, the total code amount of the encoded frame is estimated according to the value of the bit rate that is instructed little by little, and the encoding process is performed according to the estimated value.
[0159]
On the other hand, with respect to audio data, for example, it is possible to cope with a change in bit resolution of main-line audio data input as linear PCM audio data. When a change is detected, the clip is divided at the change point as in the case of the video data described above. Again, clip division can be performed in accordance with the GOP boundary of the auxiliary AV data.
[0160]
In the case of audio data, the bit resolution before the change can be maintained after the bit resolution is changed, and clip division by changing the bit resolution can be prevented. For example, when audio data input from the outside to the disk recording / reproducing apparatus 10 according to the embodiment of the present invention is recorded on the optical disk 1, the bit resolution of the input audio data was initially 24 bits. If the bit resolution is changed to 16 bits at a certain time, the bit resolution can be kept at 24 bits even after the bit resolution is changed.
[0161]
Hereinafter, regarding audio data, “24-bit bit resolution” and “16-bit bit resolution” are abbreviated as “24-bit” and “16-bit”, respectively, as appropriate.
[0162]
This will be described with reference to FIG. The audio data that was initially input in 24 bits is changed to 16 bits in the bit resolution change point (FIG. 18A). At this time, data indicating silence (for example, a value “0”) in the audio data is added to the lower 8 bits (LSB side) of the audio data changed to 16 bits, as shown in FIG. 18B. The total is 24 bits. At this time, 8-bit data to be added is not limited to silence, and dither may be added.
[0163]
For example, when the audio data that was originally 16 bits is changed to 24 bits, the bit resolution can be kept at 16 bits even after the bit resolution is changed.
[0164]
This will be described with reference to FIG. The audio data that was initially input at 16 bits is changed to a bit resolution of 24 bits at the bit resolution change point (FIG. 19A). At this time, as shown in an example in FIG. 19B, 8 bits on the lower side (LSB side) of the audio data input in 24 bits are discarded to be 16 bits as a whole.
[0165]
Furthermore, when the audio data input as linear PCM audio data is changed to audio data encoded by an encoding method other than linear PCM (hereinafter referred to as non-audio audio data), non-audio Audio data can be muted and recording can continue without splitting the clip. The mute is performed, for example, by recording audio data representing silence, and non-audio audio data is recorded as silence audio data. That is, non-audio audio data is replaced with audio data representing silence.
[0166]
If the non-audio audio data is changed to linear PCM audio data, the linear PCM audio data can be recorded with the divided clips.
[0167]
The audio data bit resolution conversion process and the silence process when inputting non-audio audio data as described above can be performed by the audio signal conversion unit 45 based on an instruction from the control unit 20, for example. However, the present invention is not limited to this, and the processing can be performed by reading audio data from the memory 18 under the control of the memory controller 17 based on an instruction from the control unit 20. For example, data representing non-audio audio data, for example, for one sample is stored in the memory 18 and the data is repeatedly read out.
[0168]
The resolution of the audio data is a format (for example, the above-mentioned AES3-1992 (r1997)) compliant with the standard by AES / EBU (Audio Engineering Society / European Broadcasting Union), in which the audio data is generally used in broadcasting stations, for example. In the case of transmission, since information of bit resolution is stored at a predetermined position of the header, it can be determined by extracting this data. Also, identification of linear PCM audio data and non-audio audio data can be similarly determined from header information and the like.
[0169]
In the above description, the bit rate change during recording is described for main line video data. However, this is not limited to this example, and the disc recording / reproducing apparatus 10 according to the embodiment of the present invention is recording It is possible to cope with changes in the frame rate, image size, aspect ratio, etc. In this case, during playback, interpolation / decimation processing in the time axis direction is performed when the frame rate is changed, and interpolation / decimation processing within the frame is performed when the image size or aspect ratio is changed. Video data can be output at a constant frame rate, image size, and image aspect ratio. Such interpolation / decimation processing is performed on the video data stored in the memory 18 by the memory controller 17, for example. You may perform in the image signal conversion part 43B.
[0170]
In the above description, the encoding method of main line video data has been described as MPEG2, but this is not limited to this example, and video data encoded by another method can be recorded in a mixed manner. Similarly, the bit rate and other parameters of the video data can be dealt with other than those described above.
[0171]
Similarly, when encoding audio data to be non-audio, another encoding method can be used. For audio data, the bit resolution is not limited to 16 bits and 24 bits, and audio data of other bit resolutions such as 32 bits, 8 bits, and 12 bits can be recorded together. The sampling frequency of audio data is typically 48 kHz, but is not limited to this example, and audio data of other sampling frequencies such as 96 kHz and 192 kHz can be recorded in a mixed manner.
[0172]
Further, the auxiliary AV data is not limited to the MPEG4 system, and video data encoded by another system can be recorded together.
[0173]
Furthermore, it is preferable to display a list of clips recorded on the optical disc 1 on a monitor device (not shown). For example, the index file “INDEX.XML” is read according to the user's operation on the operation unit 21 to obtain information on all clips recorded on the optical disc 1. Then, referring to each clip directory, a thumbnail image is automatically created based on the auxiliary AV data. A thumbnail image is created each time, for example, by reading a frame at a predetermined position of auxiliary AV data and reducing it to a predetermined image size.
[0174]
Thumbnail image data of each clip is supplied to the memory controller 17 and stored in the memory 18. Then, the thumbnail image data stored in the memory 18 is read out by the memory controller 17 and supplied to a monitor device (not shown) via the data conversion unit 19 and the signal input / output unit 31, and a list of thumbnail images is displayed on the monitor device. The Display control of thumbnail images on the monitor device can be performed by an operation from the operation unit 21. Further, a predetermined operation on the operation unit 21 can be used to select a desired image from the thumbnail images and reproduce a clip corresponding to the selected thumbnail image.
[0175]
When displaying the above-described thumbnail image on the monitor device, various information of the clip corresponding to the displayed thumbnail image, for example, the bit rate of the main video data, the encoding method, etc. can be displayed together with the thumbnail image. . This is possible by reading time-series metadata and non-time-series metadata from each clip directory.
[0176]
In the above description, channel pair audio data defined in AES3-1992 (r1997) is channel-separated and recorded on the optical disc 1 as an audio data file for each channel, and the audio data recorded on the optical disc 1 for each channel. Is described as being output as serial audio data by interleaving between channels for each sample, but this is not limited to this example. That is, even in the case of audio data supplied with multiple channels multiplexed by other methods, the channels can be separated and recorded on the optical disc 1 as audio data files for each channel. The same applies to the output. In the case of output, multi-channel audio data can be multiplexed and output by a method different from the method input when recording on the optical disc 1.
[0177]
【The invention's effect】
As described above, according to the present invention, linear PCM audio data input by multiplexing a plurality of channels is separated into channels, stored in a file for each channel, and recorded on a recording medium. Therefore, data processing for each channel is facilitated, and there is an effect that a change in channel configuration can be flexibly handled.
[0178]
In the embodiment of the present invention, audio data indicating silence is output to an unused channel when the number of input audio data channels is less than the set recording channel. Even if the number of channels of audio data is changed, the number of channels is maintained, and there is an effect that processing at the time of reproduction becomes easy.
[0179]
Furthermore, in the embodiment of the present invention, the channel processing method is selected according to the data type of the input audio data. Therefore, if the input audio data is linear PCM audio data, The channel pair is separated and recorded as an audio data file for each channel. If the input audio data is non-audio audio data, the channel pair can be recorded without being separated.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a data structure of a UMID.
FIG. 2 is a schematic diagram illustrating an example of a reserved word used for defining an essence mark.
FIG. 3 is a schematic diagram illustrating a data structure of an example of an essence mark.
FIG. 4 is a schematic diagram illustrating an example in which annual ring data is formed on an optical disc.
FIG. 5 is a schematic diagram showing an example in which data is read from and written to an optical disk on which annual rings are formed.
FIG. 6 is a diagram for explaining that data recording is performed so as to ensure continuity of annual rings.
FIG. 7 is a diagram for explaining an allocation unit;
FIG. 8 is a diagram for illustrating a data management structure according to an embodiment of the present invention.
FIG. 9 is a schematic diagram schematically showing the structure of a clip.
FIG. 10 is a diagram for illustrating a data management structure according to an embodiment of the present invention.
FIG. 11 is a diagram for illustrating a data management structure according to an embodiment of the present invention.
FIG. 12 is a diagram for explaining that the boundary of clip division is matched with the boundary of GOP of auxiliary AV data.
FIG. 13 is a diagram for explaining that an overlap portion is provided between an original clip and a clip newly generated by division at the time of clip division.
FIG. 14 is a block diagram showing a configuration of an example of a disc recording / reproducing apparatus applicable to an embodiment of the present invention.
FIG. 15 is a block diagram illustrating an exemplary configuration of a data conversion unit.
FIG. 16 is a schematic diagram illustrating a data format of an example of audio data.
FIG. 17 is a diagram for explaining that the bit rate of actual video data is gradually changed when the bit rate is changed;
FIG. 18 is a diagram for explaining processing when the bit resolution of audio data is changed;
FIG. 19 is a diagram for explaining processing when the bit resolution of audio data is changed;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical disk, 10 ... Disc recording / reproducing apparatus, 16 ... Signal processing part, 17 ... Memory controller, 18 ... Memory, 19 ... Data conversion part, 20 ... Control part , 21, operation unit, 31, signal input / output unit, 42, data amount detection unit, 43, image signal conversion unit, 44, audio signal conversion unit, 45, image data. Conversion unit, 46... Audio data conversion unit, 48... Auxiliary AV data conversion unit, 49... Auxiliary AV data conversion unit

Claims (10)

In a recording apparatus for recording audio data input by multiplexing audio data of a plurality of channels on a disk-shaped recording medium,
Detection means for detecting the data type of audio data to which a preamble is added for each sample based on information indicating whether or not the audio data included in the preamble is separable ;
Separation that separates the audio data into each of the plurality of channels when it is determined that the audio data is multiplexed in such a manner that a plurality of channels can be separated for each sample based on the detection result by the detection means Means,
The separated audio data separated into each of the plurality of channels by the separating means is recorded on a disc-shaped recording medium as an individual file for each of the plurality of channels, and the plurality of audio data is recorded based on the detection result by the detecting means. And a recording means for recording the audio data as a single file on the disk-shaped recording medium when the channel is determined to be multiplexed audio data that cannot be separated for each sample. Recording device. The recording apparatus according to claim 1,
When the plurality of channels of the audio data are less than the number of recording channels set for the recording means, the recording means generates silence as data of channels not used for recording the audio data among the recording channels. A recording apparatus for recording audio data to be recorded on the disk-shaped recording medium. The recording apparatus according to claim 1,
The audio data is data in which audio data of channel pairs is multiplexed, and the recording means records the individual files of the plurality of channels on the disk-shaped recording medium in units of the channel pairs. A recording apparatus characterized by that. The recording apparatus according to claim 1,
2. The recording apparatus according to claim 1, wherein the audio data is multiplexed by interleaving 2-channel audio data for each sample. In a recording method of recording audio data input by multiplexing audio data of a plurality of channels on a disk-shaped recording medium,
A detection step of detecting the data type of audio data to which a preamble is added for each sample based on information indicating whether or not the audio data included in the preamble is separable ;
When it is determined that the audio data is multiplexed audio data so that a plurality of channels can be separated for each sample based on the detection result in the detection step, the audio data is separated into each of the plurality of channels. The separation step,
A plurality of audio data separated into each of the plurality of channels in steps of the separation, and recorded on the disc-shaped recording medium as separate files for each of the plurality of channels, the audio data based on the detection result of the step of the detection A recording step of recording the audio data as a single file on the disk-shaped recording medium when it is determined that the audio data is multiplexed audio data that cannot be separated for each sample. Recording method. In a playback device for playing back audio data from a disc-shaped recording medium on which audio data of a plurality of channels is recorded,
Reproduction means for reproducing the separated audio data from a disc-shaped recording medium in which separated audio data obtained by separating the audio data in which a plurality of channels are multiplexed for each of the plurality of channels is recorded as individual files;
For a plurality of the separating audio data reproduced by the reproducing means, and a multiplexing means for multiplexing and pressurized with each preamble for each sample containing information indicating whether the audio data is separable A playback device comprising: The playback device according to claim 6 , wherein
The reproducing apparatus according to claim 1, wherein the multiplexing means multiplexes the plurality of separated audio data so as to allow separation for each sample. The playback device according to claim 6 , wherein
The reproducing apparatus according to claim 1, wherein the multiplexing means multiplexes the plurality of separated audio data constituting a channel pair with each other. The playback device according to claim 6 , wherein
The reproducing apparatus according to claim 1, wherein the multiplexing means interleaves 2-channel audio data for each sample and performs the multiplexing. In a reproduction method for reproducing audio data from a disk-shaped recording medium on which audio data of a plurality of channels is recorded,
A reproduction step of reproducing the separated audio data from a disc-shaped recording medium in which separated audio data obtained by separating audio data in which a plurality of channels are multiplexed for each of the plurality of channels is recorded as individual files;
A multiplexing step in which a preamble including information indicating whether or not the audio data can be separated is added to each of the plurality of separated audio data reproduced in the reproduction step and multiplexed for each sample ; A reproduction method characterized by comprising:

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