JP4013800B2 - Data creation method and data recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize quick recording onto an external recording medium by encoding a digital signal in an encoding system other than the encoding system of the digital signal to record it simultaneously with inputting of the digital signal. <P>SOLUTION: Input data are decoded to extract encoding information and synchronizing information when a digitally encoded AV signal is inputted, and audio decoded data are encoded again simultaneously with decoding in accordance with extracted encoding information, and extracted synchronizing information is given, and thus reencoded data are generated. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data creation method for executing re-encoding recording by once decoding digitally encoded audio / video data and then converting the digitally encoded audio / video data into a digital encoding method that can be handled by an external device other than the present device. The present invention also relates to a data recording apparatus for recording the created data.
[0002]
[Prior art]
In recent years, AV playback apparatuses that read AV signals that have been digitally compressed and recorded on various recording media such as CDs, DVDs, and hard disks, and play the expanded signals through video monitors, audio speakers, and the like connected to the apparatus are widely used. It has become widespread.
[0003]
MPEG (Motion Picture Experts Group) is known as a known standard for digital compression in an AV reproduction apparatus that reproduces an audio component signal and a video component signal by respectively decompressing digital compression encoded AV signal data. It has been. In MPEG, after decoding multiplexed and compression-encoded AV signal data, playback is performed synchronously, so that playback and display are performed on each of the audio component signal and video component signal in the AV signal at the time of encoding. Time information to be executed is added and compressed. Thus, at the time of decompression, reproduction is executed while synchronizing the audio component signal and the video component signal with reference to the time information with respect to the system time base reference value possessed by the apparatus.
[0004]
Furthermore, not only a reproducing apparatus but also a recording apparatus that performs an digital encoding of an input AV signal and has an encoding function has become widespread. A conventional data creation method for creating encoded data will be described below. The applicant is aware of the data creation method disclosed in Patent Document 1, and in order to clarify the problem of the present invention, the contents of the prior art will be briefly described as a conventional example.
[0005]
The prior art describes a method and system for replacing an already encoded digital bitstream with another section or encoded video. The number of bits consumed in each picture in the modified interval, the number of bits in the sequence header of each picture, the number of bits in each picture group (GOP) header, and the total stuff for the inserted encoding instead of the video to be removed Calculated by adding bits. Then, the process of replacing with the encoded data is performed.
[0006]
[Patent Document 1]
Japanese National Patent Publication No. 11-500592
[0007]
[Problems to be solved by the invention]
However, although the method disclosed in Patent Document 1 described above describes a method for exchanging video data of a specified portion by the same encoding method, a method for exchanging audio data is not described. In particular, in audio data, the encoding method differs between the AAC method in digital broadcasting and the Dolby method in DVD players, etc., so that the audio data received and recorded in the digital broadcasting is reproduced in an audio method that can be reproduced by a DVD player or the like. It was necessary to convert and record the audio encoding method. However, even if the conventional method is adopted as it is on the audio side, there is a problem that it cannot be applied as it is due to a difference in encoding processing.
[0008]
The present invention has been made in order to solve the above-described problems. A digital code that can be handled by an external device other than the present device after once decoding externally input digitally encoded audio data. It is possible to provide a data creation method or a data recording apparatus for performing re-encoding recording by converting to a conversion method.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention (corresponding to claim 1), when a digitally encoded AV signal is input, the input data is decoded to extract synchronization information, and at the same time as the decoding, the audio decoded data is re-encoded. And re-encoding data is created by adding the extracted synchronization information, and the video data and re-encoded audio data are later re-encoded in the same manner as the AV synchronous playback based on the original input data. Even in such a group, synchronized playback is possible.
[0010]
According to a second aspect of the present invention (corresponding to claim 2), when digitally encoded AV signals are input, the input data is decoded to extract encoded information and synchronization information, and the extracted information is extracted simultaneously with decoding. The audio decoding data is re-encoded with the same or less bit amount as the encoded information, and the re-encoded data is created by adding the extracted synchronization information. Since the amount of re-encoded audio data for performing synchronous reproduction with the set of encoded audio data is less than or equal to the original audio data amount, the re-encoded audio data recording capacity can be suppressed.
[0011]
According to a third aspect of the present invention (corresponding to claim 3), when a digitally encoded AV signal is input, the input data is decoded to extract encoded information and synchronization information, and at the same time, a decoding buffer model Obtains information, re-encodes audio decode data with the same or less bit amount as the extracted encoded information in the extracted buffer model, and creates re-encoded data by adding the extracted synchronization information When performing synchronous playback with a pair of video data and re-encoded audio data later, encoding is performed with reference to the original buffer model information, so that the buffer model can be encoded without failing. Has an effect.
[0012]
According to a fourth aspect of the present invention (corresponding to claim 4), input data is decoded to extract encoded information and synchronization information, and at the same or lower bit rate than the extracted encoded information simultaneously with audio decoding. In order to encode and re-encode the original audio data at the same or lower bit rate, the recording capacity of the recording medium can be reduced, or the transmission bandwidth can be reduced. It is possible to correspond to the output at.
[0013]
According to a fifth aspect of the present invention (corresponding to claim 5), the input data is decoded to extract the encoded information and the synchronization information, and the audio channel is the same as or less than the extracted encoded information simultaneously with the audio decoding. The number of audio channels is limited due to the re-encoding method and the limitation of the playback equipment, so that re-encoding is performed. For example, even if the total number of channels is reduced This has the effect that recording can be performed by increasing the bit rate per channel.
[0014]
According to a sixth aspect of the present invention (corresponding to claim 6), the input data is decoded to extract the encoded information and the synchronization information, and the audio channel is the same as or less than the extracted encoded information simultaneously with the audio decoding. It is characterized by re-encoding by adding a new sound effect by synthesizing each audio channel signal with a number, and a special sound effect can be put at the time of re-encoding, so that the low range is increased. It has the function of recording with increased processing and surround effect.
[0015]
According to a seventh aspect of the present invention (corresponding to claim 7), when a digitally encoded AV signal is inputted, original data in which the input signal is recorded as it is, and claim 1, claim 2 or claim 3 The digital encoding data is generated by referring to both the re-encoded data on which the data recording is performed and performing system encoding using a part of the original data, the re-encoded data and the respective synchronization information. Thus, even if the original audio data and the re-encoded audio data are exchanged, the video data and the re-encoded audio data can be used for synchronized reproduction.
[0016]
According to an eighth aspect of the present invention (corresponding to claim 8), when a digitally encoded AV signal is inputted, the original data in which the input signal is recorded as it is and the data recording according to claim 2 or claim 3 are recorded. Digitally encoded data is generated by referring to both of the re-encoded data and performing system encoding using a part of the original data, the re-encoded data, each synchronization information, and encoded information. Since the amount of re-encoded audio data is equal to or less than the original audio data amount, the recording capacity to the recording medium does not increase even after replacing the original audio data. Have
[0017]
According to a ninth aspect of the present invention (corresponding to claim 9), when digitally encoded AV signals are inputted, original data in which the input signals are recorded as they are, and re-encoded data in which the data recording according to claim 3 is performed The digital encoded data is generated by performing system encoding using a part of the original data and the re-encoded data and the respective synchronization information, encoding information, and buffer model information. Generates the system encoded data so that overflow and underflow do not occur even when re-encoded audio data and video data are decoded together.
Has the effect of being able to.
[0018]
A data creation method according to a tenth aspect of the present invention (corresponding to claim 10) is a primary record A file in which a digitally encoded AV input signal is recorded without decoding, and claim 1, claim 2, or claim The primary recording B file in which the digitally encoded data generated according to the item 3 is recorded is stored as a single file, and the AV stream data having the same synchronization information can be collectively managed. Have.
[0019]
A data creation method according to an eleventh aspect of the present invention (corresponding to claim 11) is a primary record A file in which a digitally encoded AV input signal is recorded without decoding, and claim 1, claim 2, or claim A file of the primary record B in which the digitally encoded data generated in the item 3 is recorded, and a separate file according to related information that associates each file, and the original information file of the primary record A A file created after input can be played back in association with it even if it is stored in a separate recording medium.
[0020]
A data recording method according to a twelfth aspect of the present invention (corresponding to claim 12) is the digitally encoded data generated by claim 7, 8, or 9 by setting output information by input from a user or the like. Is converted to a format for recording directly on a secondary recording medium, and recording can be performed in a shorter time than reproduction if high-speed recording on the secondary recording medium is possible. Has the effect of
[0021]
The data output method according to the thirteenth aspect of the present invention (corresponding to claim 13) is the digitally encoded data generated according to claim 7, 8, or 9 by setting output information by input from a user or the like. Is converted to the specifications of the connected external device interface, and output according to the transmission band and quality is possible, and playback or recording on the partner device side can be guaranteed. Have.
[0022]
A data recording apparatus according to a fourteenth aspect of the present invention (corresponding to claim 14) is an input unit for inputting a digitally encoded AV signal, a primary recording A unit for recording the input data without decoding, and an input data A decoding unit that performs decoding; a decoding information storage unit that extracts and stores encoded information and synchronization information by the decoding unit; an encoding unit that re-encodes decoded data decoded by the decoding unit; and the encoding unit A primary recording B section that records the encoded data created in step 1, an encoding information storage section that stores encoded information and synchronization information created during encoding by the encoding section, and the primary recording A section and at least one primary recording B section And a system encoder that performs system encoding based on the information in the encoding information storage unit. And a secondary recording unit that records the digitally encoded AV signal generated by the system encoding unit, and the system encoding unit stores the encoded information and synchronization stored in the encoding information storage unit. It is characterized in that a part of the content of the primary recording A part is replaced with the content of the primary recording B part by using information and system encoding is performed. The video data remains as the original data without being re-encoded, and the audio is recorded. By replacing the re-encoded data with only the data, the system encoding can be converted at high speed using each synchronization information, and high-speed recording can be performed on the secondary recording unit.
[0023]
According to a fifteenth aspect of the present invention (corresponding to claim 15), an input unit for inputting a digitally encoded AV signal, a primary recording A unit for recording the input data without decoding, and an input data A decoding unit that performs decoding; a decoding information storage unit that extracts and stores encoded information and synchronization information by the decoding unit; an encoding unit that re-encodes decoded data decoded by the decoding unit; and the encoding unit A primary recording B section that records the encoded data created in step 1, an encoding information storage section that stores encoded information and synchronization information created during encoding by the encoding section, and the primary recording A section and at least one primary recording B section And a system encoder that performs system encoding based on the information in the encoding information storage unit. And a separate device output unit that outputs the digitally encoded AV signal created by the system encode unit to an external device, and the system encode unit stores the code stored in the encode information storage unit. The system encoding is performed by replacing part of the contents of the primary recording A section with the contents of the primary recording B section using the conversion information and the synchronization information. The system encoding can be converted at high speed using each synchronization information by replacing the re-encoded data with only the audio data, and the high-speed transfer to the external output device can be performed.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the drawings.
[0025]
(Embodiment 1)
First, a data creation method according to the present embodiment will be described with reference mainly to FIGS. 1 and 2 which are block diagrams showing the configuration of the data recording apparatus according to the first embodiment of the present invention.
[0026]
First, the process of creating primary recording data from input data will be described with reference to the block diagrams of FIGS. 1, 3, and 5 and the flowcharts of FIGS.
[0027]
Data recording device such as DVHS recorder and optical disc for storing digital compression encoded audio / video data, input unit 1 for reading data from a receiver such as BS digital broadcast, and data input from input unit 1 are recorded A primary recording A section 7 for decoding, and a decoding section 2 for separating audio / video data recorded in a multiplexed manner, extracting video playback time information, audio playback time information, and the like, and performing expansion processing according to the playback time information A decoding information storage unit 3 for storing decoding information such as reproduction time information extracted by the decoding unit 2, audio data decoded by the decoding unit 2, and synchronization information stored in the decoding information storage unit 3 An encoding unit 4 for performing audio encoding, and an encoding audio created by the encoding unit 4 A primary recording portion B 5 for storing data, and a encoding information storage unit 6 for storing the synchronization information of the coded audio data created by the encoding unit 4.
[0028]
FIG. 3 is a block diagram showing details of the decoding unit 2, which separates the audio / video data recorded by multiplexing and extracts the video reproduction time information and the audio reproduction time information, The video decoding unit 22 performs decompression processing on the compressed video data separated by the system decoding unit 21 according to the video playback time information, and the audio performs decompression processing on the compressed audio data separated by the system decoding unit 21 according to the audio playback time information. The decoding unit 23 is configured.
[0029]
The video processing includes a compressed video buffer unit 212 that stores video data separated by the parser unit 211 in the system decoder unit 21, and a table that associates video signals stored in the compressed video buffer unit 212 with video playback time information. A video playback time information management unit 213, a video decoder unit 22 that performs analysis and decompression of attribute information (video header information) of compressed video data, a frame buffer unit 221 that stores decompressed video data, and a frame buffer unit The video output unit 222 is configured to output a video signal from 221 to the outside.
[0030]
The audio processing includes a compressed audio buffer unit 214 that stores audio data separated by the parser unit 211 in the system decoding unit 21, and a table that associates audio signals stored in the compressed audio buffer unit 214 with audio reproduction time information. Audio playback time information management unit 215, audio decoder unit 23 that performs analysis and decompression of attribute information (audio header information) of compressed audio data, PCM buffer unit 231 that stores the decompressed audio data, and PCM buffer unit The audio output unit 232 outputs the audio data in the H.231 to the outside.
[0031]
The audio reproduction time information management unit 215 stores time information until the corresponding audio data is reproduced by the audio decoding unit 23. If the audio data corresponding to the corresponding time is reproduced, the table value becomes unnecessary, and the table is updated in such a manner that the next input data is registered from the parser unit 211.
[0032]
In order to realize the synchronization in MPEG, time stamp information indicating when to decode and reproduce is added to each unit of decoding and reproduction called video and audio access units (one frame for video and one audio frame for audio). ing. This time stamp value is called PTS (Presentation Time Stamp), and represents the time management information of the reproduction output of Video PTS (abbreviated as VPTS) for video and AudioPTS (abbreviated as APTS) for audio.
[0033]
A standard system standard reference unit 24 in the playback apparatus generates an STC (System Time Clock) inside the MPEG system standard decoder. In order to create an STC on the device side, an SCR (System Clock Reference) used in a program stream (PS) used in a DVD disc or the like, or a transport stream (used in BS digital broadcasting) The value of PCR (Program Clock Reference) used in TS) is used. The reference time can be set by setting the value indicated by the SCR or PCR in the STC when the last byte arrives (when reading). Furthermore, by combining this STC value setting with a PLL (phase lock loop) circuit, it is possible to have an STC whose frequency completely matches the reference time system clock on the decoder side. The STC system clock is composed of 27 MHz. Each PTS (90 kHz cycle) is referred to by dividing the STC by a counter or the like. Each decoder reproduces and outputs the access unit when the STC matches the VPTS for video and the APTS for audio. The accuracy of PTS is 90 kilohertz. Therefore, if each decoding is performed so that STC, VPTS, and APTS can be synchronized within the accuracy range of 90 kilohertz, an AV-synchronized output can be obtained.
[0034]
FIG. 4 is a flowchart of AV synchronization processing according to the present invention. In steps A301 and A302, the system decoding unit 21 separates the encoded data input from the data recording device or the like into compressed video data and compressed audio data. The compressed video data is stored in the compressed video buffer unit 212, and the compressed audio data is stored in the compressed audio buffer unit 214. Also, the video playback time information VPTS attached to the video frame is extracted and stored in the video playback time management unit 213 together with the reference address to the compressed video buffer unit 212.
[0035]
On the other hand, the audio playback time information APTS attached to the audio frame is extracted from the compressed audio data, and divided into slots, for example, for each APTS, as shown in FIG. 5, and the audio playback together with the reference address to the compressed audio buffer unit 214 is performed. Stored in the time management unit 215. The number of APTS entries indicates the number of times of time information managed in this table.
[0036]
In step A303, video decoding is performed and stored in the frame buffer unit 221 before the VPTS reaches the system time reference (STC). Similarly, in step A304, audio decoding is performed and stored in the PCM buffer unit 231 before the APTS reaches STC. Each decoding is performed, but it is not output immediately after decoding. In step A305, the STC is referenced, and when the VPTS matches or exceeds, the video decode data related to the VPTS is output from the frame buffer unit 221 via the video output unit 222.
[0037]
Next, in step A306, the STC is referred to, and when the APTS matches or exceeds, audio decode data related to the APTS is output from the PCM buffer unit 231 via the audio output unit 232.
[0038]
Depending on the device, there may be a case where the optical output terminal is output as a Dolby Digital stream. In such a case, the data is temporarily stored in a stream buffer (not shown), is referred to the STC, and is output from the audio output unit 232 when the APTS matches or exceeds.
[0039]
If the input data is finished or the user instructs to stop the reproduction, the decoding is finished in step A307.
[0040]
Video decoding and audio decoding are performed so that VPTS and APTS are synchronized with the STC. In particular, if the VPTS is set to the APTS between the time of 50 milliseconds preceding and the time of 30 milliseconds delay, the lip sync will not be noticed.
[0041]
The operation for decoding the input data has been described. The block diagram of FIG. 1 and the flowchart of FIG. 6 are shown for the process of re-encoding the data with the decoded data as input (hereinafter referred to as re-encoding). The description will be given with reference.
[0042]
Input for recording the digitally encoded AV signal is started (step A101). Here, if it is not necessary to change the encoding method of the input AV signal, it is not necessary to activate the re-encoding system. If conversion to a detachable recording medium or an encoding method suitable for reproduction of an external output is necessary, the encoding method is converted (hereinafter abbreviated as codec conversion). In step A102, it is determined whether codec conversion is necessary. If not, input data is recorded in the primary recording A section 7 without being decoded. If codec conversion is necessary, the decoding operation described above is started.
[0043]
At the time of decoding, encoded information and synchronization information are extracted by the decoding unit (step A104, step A105) and recorded in the decoding information storage unit 3. Even at the time of codec conversion, the input data is recorded in the primary recording A section 7. At the end of recording, if part or all of each information recorded in the decode information storage unit 3 is recorded in the primary recording A unit 7 together with the input data, re-encoding and editing are added after the recording is completed. Sometimes it is convenient because there is synchronization information and time information. The decode information storage unit 3 is configured as shown in FIG. 8, for example. Reference numeral 31 denotes a codec information unit that stores encoded information. Reference numeral 32 denotes a synchronization time information section. Reference numeral 33 denotes a buffer model information storage unit which will be described later.
[0044]
In step A106, in order to perform codec conversion, audio encoding is performed by the encoding unit 5 that re-encodes, for example, audio decoded data decoded by the decoding unit 2. In order to perform the encoding, the encoding information stored in the decoding information storage unit 3 is referred to.
[0045]
The codec information unit 31 of the decode information storage unit 3 includes, for example, MPEG-2 AAC (Advanced Audio Coding) method (hereinafter abbreviated as AAC method) and encoding conversion such as Dolby Digital method. The scheme information, the number of channels, the bit rate, the sampling frequency information, the number of quantization bits, etc. are applicable.
[0046]
In the re-encoding of audio, the encoding information to be encoded is determined while referring to the encoding information of the input audio. Conversion from AAC system to Dolby Digital system, conversion from 5.1 channel to stereo 2-channel format, conversion from 384 kilobits / second to 256 kilobits / second, and the like. In some cases, the sampling frequency suitable for the recording / reproducing apparatus is changed from the sampling frequency of the input signal. In addition, when the encoding method is linear PCM, the number of quantization bits may be changed. When input from the decoder unit 2 to the encoder unit 4, for example, when converting the input sound from a sampling frequency of 32 kilohertz to a sampling frequency of recording sound to 48 kilohertz, a semiconductor element such as a sampling rate converter, digital These conversions can be realized by arithmetic processing using a filter, a combination of a digital / analog conversion element and an analog / digital conversion element, or the like.
[0047]
FIG. 9 shows the configuration of the encode information storage unit 6. The recoded information is stored in the codec information unit 61.
[0048]
Next, using the synchronization information extracted in step A105, the synchronization information is added to the re-encoded audio data. In step A107, the synchronization information for the audio data synchronized with the original video data is used, and the synchronization information is added so that the re-encoding data for the same video matches in consideration of the delay time from decoding to re-encoding. Synchronization information is stored in the synchronization time information section 62 of the encode information storage section 6. For example, a semiconductor memory for temporarily storing the decoded data once in the memory and taking in the saved data for re-encoding is required. However, if the time for this conversion is 33 milliseconds (NTSC system image update cycle), the decoded PCM data will have a sampling frequency of 48 kilohertz, quantized 16 bits, and converted to about 2 channels. 6400 bytes.
[0049]
In step A108, the re-encoded audio encoded data is recorded in the primary recording B unit 5, and the encoded information and synchronization information created by the encoding unit 4 during encoding are stored in the encoded information storage unit 6. Further, the content of the encoding information storage unit 6 may be recorded in the primary recording B unit 5. Later, when synchronized playback of encoded video data and re-encoded audio data is performed, if the synchronization information is in the same primary recording B section 5, data maintenance management is easy.
[0050]
At the time of re-encoding, when digitally encoded AV signals are input, the input data is decoded to extract the encoded information and synchronization information, and the audio decoding data is decoded with the same or less bit amount as the encoded information extracted simultaneously with the audio decoding. If re-encoding is performed, the re-encoded audio data amount is less than or equal to the original audio data amount if the re-encoded data is created by adding the extracted synchronization information, so that the re-encoded audio data recording capacity can be suppressed. . For example, when conversion is performed from input data recorded on a certain recording medium to another recording medium, an increase or decrease in recording capacity is likely to be made. This is particularly effective when recording on a recording medium having a smaller recording capacity is assumed.
[0051]
Also, in order to obtain a bit rate that can be reproduced by an external recording medium, the bit amount may be the same as or less than the encoded information extracted from the input data. For example, in a portable audio player, the recording capacity and the recording time are often restricted due to the shape of the player or recording medium, the battery capacity, and the like. For this reason, re-encoding may be performed to increase the degree of compression encoding, and recording may be performed at a reduced bit rate.
[0052]
In some cases, the number of audio channels is reduced and re-encoding is performed due to restrictions on playback equipment. Re-encoding is performed with the same or fewer number of audio channels as the encoded information extracted at the same time as audio decoding. This is based on the playback specifications and functions of the player, and when there is no 5.1 channel surround playback function, or one channel (for example, Japanese / English is recorded) in a so-called dual monaural system for playing bilingual broadcasts. If only selective playback is not possible, audio signal processing is performed after decoding, the number of channels is reduced, re-encoding is performed in advance, and recording is performed on the recording medium B unit 6. As signal processing to reduce the number of channels, the AAC method, etc., for each change of 5.1 channels to 2 stereo channels, adds each coefficient so that each phase does not shift. do it.
[0053]
In the current analog bilingual broadcast of terrestrial, separate language sounds (English and Japanese etc.) are inserted in the left and right channels, so when recording monophonic sound of one language sound from the bilingual broadcast etc. Conversion of the number of channels to may occur. Also, when the source on the input side is dual monaural sound, conversion of only one sound to monaural occurs. For example, one may be selected from left audio (hereinafter abbreviated as L) and right audio (hereinafter abbreviated as R), and monaural recording is performed only on the selected side. Alternatively, it can also be realized by copying data to the R side so that one of the L selected voices is not out of phase.
[0054]
In this case, at the time of re-encoding, re-encoding is performed by limiting the number of audio channels due to the limitation of the playback device. However, if the recording capacity on the recording side is the same as the input data, even if the total number of channels is reduced, for example The per bit rate can be increased and recorded. For example, when the input is 5.1 channels (total 256 kilobits / second and the re-encoding side is two channels (total 256 kilobits / second), recording can be performed by increasing the bit rate per channel.
[0055]
Further, when re-encoding is performed by synthesizing each audio channel signal and re-encoding is performed by adding a new acoustic effect, the recording can be performed by increasing the processing of the volume in the low frequency range and the surround effect. If there is only a poor sound device on the playback device side, emphasizing the dialogue that plays the leading role in the movie makes it easier to hear speech that is likely to be erased in the background music. On the other hand, if the re-encoding is performed after the surround effect signal processing is performed, for example, when it is desired to emphasize the music reflected in the recording of the live music program, a pseudo stage feeling can be enjoyed. For example, if a certain delay element such as an echo and signal processing for multiplying the delayed signal by a specific gain coefficient are added, a reverberant sound can be created.
[0056]
Thus, the present invention is effective not only when changing the encoding method, but also when creating another audio stream to which an acoustic effect is added. Furthermore, since synchronized playback with the original video data is possible, it is also possible to switch between playback audio streams using the original input audio stream and the re-encoded audio stream. Since it is possible to synchronize the same video stream, only the audio output can be switched in the middle without stopping the video output. In this way, when a stream that has been re-encoded with respect to the original stream is used as a recording medium, it is possible to perform playback with an audio stream that can be played back according to the environment of the playback device.
[0057]
When the amount of audio data re-encoded with respect to the original data is small, stuffing bits defined by the MPEG method are added as necessary.
[0058]
The number of encoding units 4 is not limited to one, and a plurality of encoding units 4 may be provided so as to correspond to the number of encoding methods to be re-encoded. For each re-encoding, the number of primary recording B sections 5 may be increased or recorded in another file, and each information in the encoded information storage section 6 may be stored separately. The number is not limited as long as the amount of calculation by hardware resources or software and the data transfer, recording speed and recording capacity are within the allowable range.
[0059]
Of course, there may be a plurality of primary recording A sections 7. For example, when a multi-stream for the same program is input from the input unit 1 such as a multi-angle stream, a plurality of primary recording A units 7 may correspond to the same primary recording B unit 5. However, in a plurality of multi-streams, an audio stream having the same identification number is used for each video stream, or an audio stream having the same synchronization information and the same contents although having different identification numbers It is necessary to limit such cases. The primary recording A section 7 and the primary recording B section 5 can be linked by common information called synchronization information.
[0060]
Furthermore, there may be a plurality of primary recording A sections 7 and a plurality of primary recording B sections 5 each. However, as long as the common time information is used as the synchronization information, any combination can be used for synchronized reproduction. There may be two or more types of audio streams for one video stream. On the other hand, if the management is performed based on time information common to the original audio streams, synchronized playback is possible even if a plurality of audio streams are decoded and each re-encoded audio stream is created. .
[0061]
Next, the creation of secondary recording data or external output data from primary recording data will be described using the block diagram of FIG. 2 and the flowchart of FIG.
[0062]
In FIG. 2, the primary recording A section 7, the primary recording B section 5, and the encoding information storage section 6 are the same as those in FIG. In addition, a system encoding unit 11 that performs system encoding based on information in the encoding information storage unit 6, a secondary recording unit 13 that records a digitally encoded AV signal generated by the system encoding unit 11, and a system encoding unit 11 The separate device output unit 14 that outputs the digitally encoded AV signal to the external connection device, and the output destination information setting unit 12 that sets the system encoding as the secondary recording unit 13 or the selection or both of the separate device output unit 14 And consists of
[0063]
In step A201, secondary recording start (or external device output start) is selected. In step A202, the original data input and recorded from the primary recording A section 7 is read. In step A203, it is determined whether the encoding method to be recorded in the secondary recording unit 13 may be the same as that in the primary recording A unit 7. If they are the same, the read data is recorded as it is. It is not necessary to use the information of the re-encoded primary recording B section 5 described later.
[0064]
On the other hand, if the encoding method needs to be changed, information necessary for system encoding is read from the encoded information storage unit 6 in step A204. The encoding information storage unit 6 stores the encoding method (AAC method, Dolby digital method, etc.), the number of channels, the bit rate, the sampling frequency information, and the number of quantization bits that are the encoded information (audio) from the codec information unit 61. The synchronization time information unit 62 stores synchronization information, time information, and the like during audio encoding. By reading which VPTS of the original video stream of the primary recording A section 7 and the APTS of the re-encoded audio stream of the primary recording B section 5, the system encoding synchronized with AV in both temporary recording sections is realized in step A205 can do.
[0065]
For the reference to video data, the association between VPTS and APTS is given priority. Originally, VPTS is assigned to a video stream and APTS is assigned to an audio stream for AV synchronized playback. Therefore, when only the audio side is replaced, no operation is performed on the VPTS side, and APTS suitable for the re-encoded audio data is assigned to realize AV synchronized reproduction.
[0066]
That is, the system encoding unit 11 replaces the original audio stream of the primary recording A unit 7 with the re-encoded audio stream of the primary recording B unit 5 using the encoded information and the synchronization information stored in the encoding information storage unit 6. Encoding is performed. In the present invention, since it is not necessary to re-encode the video stream at the time of re-encoding, a buffer memory for video encoding, arithmetic processor resources, and the like are not necessary. If the audio stream is basically assumed to be replaced, a recording capacity larger than that of the original data is not required, and a large transmission band and speed are not required for transmission to an external device.
[0067]
Depending on the input of the output destination information setting unit 12, it is selected whether or not to output to the secondary recording unit 13 in step A206. If recording to the secondary recording unit 13 is selected, in step A207, recording to the secondary recording unit 13 is executed until a recording end determination is made in step A208. As the recording end determination, when there is no data to be recorded, when there is no remaining recording capacity on the recording medium, when recording stop is instructed by a user instruction, recording due to some trouble (for example, scratches, etc.) Such as when it becomes impossible to continue. On the other hand, when the output to the external device side is selected, the output from the separate device output unit 14 is executed until the output end determination is made in step A209. As for the output end determination, when there is no data to be output, when an output stop instruction is received from the counterpart device side, when output stop is instructed by a user instruction, some failure of the output interface (for example, transmission path For example, it is impossible to continue output due to disconnection.
[0068]
As an example of the configuration of the output destination information setting unit 12, for example, when the secondary recording unit 13 is inserted and there is a recordable capacity, or when the separate device output unit 14 confirms the connection with the counterpart device, it is automatically determined. A selection button setting by a user, a menu selection method by GUI, and the like.
[0069]
Therefore, referring to both the original data in which the digitally encoded AV input signal is recorded as it is and the re-encoded data, a part of the original data, the re-encoded data, the respective synchronization information, and the encoded information are used. By performing system encoding, digitally encoded data for output is generated.
[0070]
If the buffer model information for normal playback of the video stream and the audio stream at the time of decoding is stored in the buffer model information section 33 of the decode information storage section 3, the following effects can be obtained. . At the time of re-encoding, encoding is performed with reference to the buffer model information 33 created at the time of decoding, and as a result, a buffer model information unit 63 is created in the encoding information storage unit 6. Then, in system encoding, even when audio data and video data are decoded together, system encoding can be performed in consideration of division of the video stream and audio stream so that overflow and underflow do not occur. If normal decoding is possible when the originally input data is decoded, create buffer model information for re-encoding according to the buffer model information at the time of decoding and leave it as a buffer model at the time of system encoding. Easy to manage.
[0071]
In particular, if the video encoding is a variable rate control method in which a large amount of bits is allocated when the change is severe, the bit allocation amount per unit time of the video stream and the audio stream constantly changes. On the other hand, it is important to manage the buffer model so that system-encoded data can be reproduced without causing underflow or overflow of one of video and audio. Therefore, since the buffer model information unit 63 created at the time of re-encoding is used at the time of system encoding, it can be known in advance where the bit allocation amount of the video stream increases. System encoding can be controlled such as
[0072]
On the other hand, when the video encoding is a fixed bit rate that is the same bit allocation amount every time, the bit allocation amount per unit time does not change, so that the buffer model management becomes easy. If an allocation is performed by overflow or underflow at the beginning, it is not necessary to control the allocation change by the system encoder until the recording is completed.
[0073]
Therefore, referring to both the original data in which the digitally encoded AV input signal is recorded as it is and the re-encoded data, a part of the original data, the re-encoded data, the respective synchronization information, the encoded information, and the buffer model By performing system encoding using information, digital encoded data for output is generated.
[0074]
The part of the original data refers to the part of the data that can be replaced with the re-encoded data described so far. For example, audio data and accompanying audio reproduction synchronization information, encoding information, and the like.
[0075]
However, although the present invention has been described with respect to audio re-encoding, the data to be replaced is not limited to audio data, as will be described below. For the convenience of the playback device that plays back the recording medium, video re-encoding according to the output setting can also be realized in the same manner as the present invention. For example, image cutout when the video output aspect ratio is converted from 16: 9 to 4: 3, conversion from a 24 frame / second movie source to a video signal suitable for playback of a 30-frame / second TV broadcast, etc. Can be achieved by re-encoding the video in the same way. In other words, even if the encoding method is not changed, it is effective when the original video reproduction information is changed and recorded. Furthermore, the present invention can be applied to other than audio streams and video streams. It can also be applied to uses such as changing only a sub-picture stream including subtitle information.
[0076]
There may also be more than one video input stream for the same audio input stream. Multi-angle video is broadcast on digital satellite and cable broadcasts. In such a case, synchronization information is added to the video data obtained by re-encoding the other stream with respect to the decoded video of one stream, and those having the same synchronization information are superimposed and combined into one screen, If synchronization information is added and recorded, playback of two screens and one audio can be played back synchronously at the same time. In addition to the NTSC system, re-encoding to a different playback system such as re-encoding to the PAL system is also effective.
[0077]
Although partial replacement has been described, in the case of complete replacement, since the true video and audio are completely re-encoded, the decoded and reproduced AV signal is re-encoded. For the original AV signal data of the primary recording A section 7, re-encoded independent AV signal data is created in the primary recording B section 5, and the recording to the secondary recording section 13 is re-encoded. Since only the primary recording B section 5 is recorded, it is not the subject of the present invention.
[0078]
So far, a method has been described in which the file of the primary recording A section 7 and the file of the primary recording B section 5 are stored as separate files according to related information relating the respective files.
[0079]
In addition to the purpose of simply responding to the increase in capacity, the primary recording A section 7 is recorded on a large capacity removable disk, and the primary recording B section 5 is recorded on another recording medium such as a hard disk. The primary recording A section 7 in which the recorded data is recorded as it is can be reproduced by being mounted on another device alone, but the primary recording B section 5 is reproduced and output only in combination with the primary recording A section 7. Can be operated effectively. As long as there is related information, the file may be separated when the configuration includes a plurality of primary recording B sections 5.
[0080]
On the other hand, the structure which preserve | saves the file of the primary recording A part 7 and the file of the primary recording B part 5 as a single file is also assumed. If one of them is removed in a removable manner, system encoding with reference to both cannot be performed. When there is a strong demand for managing both files uniquely, storing information such as both encoded data and synchronization information in the same file has the advantage of easy management. Depending on the purpose and application, either of the temporary recording configurations can be taken, but the data creation method of the present invention can meet both requirements.
[0081]
Furthermore, by setting the output information by user input, etc., the re-encoded digital encoded data can be directly converted into a format for recording on the secondary recording medium and recorded, or the specifications of the connected external device interface It may be necessary to convert to output.
[0082]
In order to record in the secondary recording unit 13, the format of the recording medium, creation of a file system, the name of the recorded program, the identifier of the recorded file, information attached to the program, etc. may be attached in consideration of the recording capacity. If necessary, it is necessary to verify the recorded content and determine the end of recording while checking the remaining recording capacity. If there is no remaining recording capacity, it is not necessary to continue system encoding.
[0083]
When recording in the secondary recording unit 13, recording in order from the beginning of the stream is not a big problem. It is only necessary to record from the re-encoded part. It is only necessary that the secondary recording unit 13 is recorded so that it can be reproduced from the beginning. Further, the recording speed may be in accordance with the recording medium of the secondary recording unit 13. That is, if the system encoding is fast and the recording speed can be several times higher than the playback speed required for normal playback, recording can be completed in a shorter time than playback.
[0084]
Furthermore, it is preferable to add various kinds of navigation information for convenience to the user. This includes pointer information to the beginning of a program, jump destination address information when skipping at certain intervals, and the like. Assuming that the secondary recording unit 13 is, for example, a DVD player, if navigation information is added and recorded, skipping is performed for each program or in a certain time unit (forward direction), as in the case of normal DVD playback. , Reverse direction, etc.) are possible. Therefore, at the time of system encoding, the navigation information is generated using information such as the synchronization time information in the decode information storage unit 3 and the encode information storage unit 6.
[0085]
On the other hand, in the case of output to another device, interface connection processing, protocol processing, response processing from the counterpart device, and the like are required. When the other device output unit 14 is decoding and reproducing at the same time as the input, it is necessary to output at a constant transfer rate without being interrupted in order from the beginning of the stream. In other words, since output according to the transmission band and quality is possible, there is an effect that reproduction or recording on the counterpart device side can be guaranteed. Of course, when a recording device is connected to the other device output unit 14, the recording can be performed for a short time by high-speed transfer if reproduction is not required during recording.
[0086]
The primary recording A section 7 and the primary recording B section 5 have been described assuming a hard disk or the like. However, a medium such as a semiconductor memory, an optical disk such as a CD, a DVD, or a Blu-Ray, or a digital signal recording tape is used. Also good. The secondary recording unit 13 corresponds to a detachable tape or disk, a memory unit such as a semiconductor memory, a memory device, or the like.
[0087]
In the present invention, the method of creating re-encoded data at the time of input has been described, but re-encoding is not limited to only at the time of input. AV signal that has been digitally encoded in advance is input and recorded in the primary recording A section 7 and the decoding information storage section 3, and is decoded and stored once at a time when the user does not view such as at night. A configuration for re-encoding data to be recorded in the primary recording B unit 5 while referring to the unit 3 may be used. In addition, an AV signal that has been digitally encoded in advance is input and recorded in the primary recording A section 7, and once decoded and reproduced at a time when the user does not view such as at night, a decoded information storage section 3 is created. However, it may be configured to create data to be re-encoded and recorded in the primary recording B section 5. Re-encoded data is created during the period from input to recording to the secondary recording unit 13 or output from the separate device output unit 14, and system encoding can be easily realized by replacing part of the original data. Is the point.
[0088]
Note that a configuration may be adopted in which the information to be re-encoded is read and the encoding condition setting value is set by recognizing information identifying the counterpart device such as the device ID of the externally connected device. For example, an ID number or the like for knowing the device type on the partner output device side is received, and setting is performed by referring to a table in which the relationship between the ID and the encoding parameter in the main body or the memory card for setting the encoding condition is stored. If the configuration is adopted, it is possible to realize the setting by the playback apparatus without the user's operation. As these externally connected devices, monitor output devices such as a TV, interface devices such as audio output amplifiers and AV amplifiers having an AV selector function, portable output devices, in-vehicle AV playback devices, and the like are assumed.
[0089]
Although the input data has been described as data input from the outside, it may be data existing in the device in advance. The input has been described after the system decoding unit 21 performs AV separation. However, it may be file data that has been previously AV-separated. The audio data may be re-encoded with the reproduction time information related to the compressed video data and the compressed audio data and the reproduction time information as inputs. This is because, as a result of editing a signal photographed by a video camera or the like on a personal computer, playback time information related to compressed video data, compressed audio data and playback time, both in the case of an AV mixed file or an AV independent file This is applicable to all cases where information is reproduced in synchronization with each other.
[0090]
In addition, there is a case of linear PCM in which audio is not compressed as a digital compression encoded stream. In the case of linear PCM, since it is an uncompressed audio frame, no decompression operation is necessary, but AV synchronous reproduction can be handled with the same method according to the synchronous information included in the stream.
[0091]
As an application example of the data creation method and the recording apparatus of the present invention, there are a DVD recorder, a hard disk recorder, a set-top box having an internal recording apparatus, a digital satellite broadcast receiver having the same recording apparatus, a personal computer, and the like. By creating an AV data creation program according to the data creation method of the present invention, an external operation program can be loaded and executed on a personal computer or the like.
[0092]
【The invention's effect】
As described above, according to the present invention, when digitally encoded AV signals are input, input data is decoded to extract synchronization information, and audio decoding data is re-encoded simultaneously with audio decoding. This is characterized in that re-encoded data is created by adding, and synchronized playback using video data and re-encoded audio data is possible later, and system encoding is performed at high speed based on the synchronization information. Therefore, there is an effect that high-speed and short-time recording can be performed on the secondary frame.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration until a temporary record is created according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration for creating a secondary record according to an embodiment of the present invention.
FIG. 3 is a diagram showing a configuration of a decoding unit according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating a decoding method according to an embodiment of the present invention.
FIG. 5 is a diagram showing a configuration of an audio playback time information management unit according to an embodiment of the present invention.
FIG. 6 is a flowchart illustrating a method until a temporary record is created according to an embodiment of the present invention.
FIG. 7 is a flowchart illustrating a method for creating a secondary record according to an embodiment of the present invention.
FIG. 8 is a diagram showing a configuration of a decode information storage unit according to the embodiment of the present invention.
FIG. 9 is a diagram illustrating a configuration of an encoding information storage unit according to the embodiment of this invention.
[Explanation of symbols]
1 Input section
2 Decoding part
3 Decoding information storage
4 Encoding section
5 Primary recording part B
6 Encoding information storage
7 Primary recording section A
11 System encoding part
12 Output destination information setting section
13 Secondary recording section
14 Separate equipment output section

Claims (15)

When digitally encoded AV signals are input, input data is decoded to extract synchronization information, audio decoding data is re-encoded simultaneously with decoding, and the extracted synchronization information is added to create re-encoded data. A data creation method characterized by: When digitally encoded AV signals are input, input data is decoded to extract encoded information and synchronization information, and at the same time as decoding, audio decode data is re-encoded with the same or less bit amount as the extracted encoded information. A data creation method, wherein re-encoded data is created by adding the extracted synchronization information. When digitally encoded AV signal is input, input data is decoded to extract encoded information and synchronization information, and at the same time, buffer model information for decoding is acquired, and the extracted encoded information in the extracted buffer model is extracted. A method of creating data, comprising: re-encoding audio decode data with the same or a smaller bit amount and adding the extracted synchronization information. 3. The encoded data and synchronization information are extracted by decoding input data, and re-encoding is performed at the same or lower bit rate than the extracted encoded information simultaneously with audio decoding. Item 4. The data creation method according to Item 3. The encoded data and the synchronization information are extracted by decoding the input data, and re-encoding is performed at the same time as the extracted encoded information with the same or less number of audio channels as the audio decoding. The data creation method according to claim 3. Decode input data to extract encoded information and synchronization information, and add new acoustic effects by synthesizing each audio channel signal with the same or less number of audio channels as the extracted encoded information at the same time as audio decoding. 4. The data creation method according to claim 2, wherein re-encoding is performed. When the digitally encoded AV signal is input, both the original data in which the input signal is recorded as it is and the re-encoded data in which the data recording according to claim 1, 2 or 3 is performed are referred to, and the original data A data creation method characterized in that digitally encoded data is generated by performing system encoding using a part of the data, the re-encoded data and the respective synchronization information. With reference to both the original data in which the input signal is recorded as it is when the digitally encoded AV signal is input and the re-encoded data in which the data recording according to claim 2 or 3 is performed, a part of the original data A data creation method characterized in that digitally encoded data is generated by performing system encoding using the re-encoded data and the respective synchronization information and encoded information. A part of the original data and the re-encoded data are referred to by referring to both the original data in which the input signal is recorded as it is when the digitally encoded AV signal is input and the re-encoded data in which data recording according to claim 3 is performed And digitally encoded data by generating system encoding using the respective synchronization information, encoding information, and buffer model information. A primary record A file recorded without decoding a digitally encoded AV input signal, and a primary record B file recorded with digitally encoded data generated according to claim 1, claim 2 or claim 3. A data creation method characterized by saving a single file. A primary record A file recorded without decoding a digitally encoded AV input signal, and a primary record B file recorded with digitally encoded data generated according to claim 1, claim 2 or claim 3. And a method of creating data characterized in that each file is stored as a separate file according to related information for associating each file. The digitally encoded data generated according to claim 7, claim 8, or claim 9 is converted into a format to be recorded directly on the secondary recording medium and recorded by setting output information by user input or the like. A data recording method characterized by the above. According to output information setting by an input from a user or the like, the digitally encoded data generated according to claim 7, claim 8, or claim 9 is converted into a specification of a connected external device interface and output. Characteristic data output method. An input unit for inputting a digitally encoded AV signal, a primary recording A unit for recording input data without decoding, a decoding unit for executing decoding of input data, and encoding information and synchronization information by the decoding unit A decoding information storage unit for extracting and storing the data, an encoding unit for re-encoding the decoded data decoded by the decoding unit, a primary recording B unit for recording the encoded data created by the encoding unit, and the encoding unit An encoding information storage unit that stores encoded information and synchronization information created at the time of encoding, a system encoding unit that performs system encoding using information in the primary recording A unit, at least one primary recording B unit, and the encoding information storage unit And the digital encoder created by the system encoding unit A secondary recording unit that records the encoded AV signal, and the system encoding unit uses the encoded information and the synchronization information stored in the encoded information storage unit to partially copy the contents of the primary recording A unit. A data recording apparatus characterized in that system encoding is performed by replacing the contents of the primary recording section B. An input unit for inputting a digitally encoded AV signal, a primary recording A unit for recording input data without decoding, a decoding unit for executing decoding of input data, and encoding information and synchronization information by the decoding unit A decoding information storage unit for extracting and storing the data, an encoding unit for re-encoding the decoded data decoded by the decoding unit, a primary recording B unit for recording the encoded data created by the encoding unit, and the encoding unit An encoding information storage unit that stores encoded information and synchronization information created at the time of encoding, a system encoding unit that performs system encoding using information in the primary recording A unit, at least one primary recording B unit, and the encoding information storage unit And the digital encoder created by the system encoding unit The content of the primary recording A section using the encoded information and the synchronization information stored in the encoding information storage section, comprising a separate device output section for outputting the encoded AV signal to the external connection device. A data output apparatus that performs system encoding by replacing a part of the data with the contents of the primary recording B section.

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