JPH1118050A - Recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve movement in the case of special reproduction again by using a VTR or the like for recording compressed image data, such as special reproduction (image data compressed in units of 2N fields). SOLUTION: A 1st image selection word is received, together with special reproduction compressed data, is recorded on a tape 5, and an image selection means 9 generates a 2nd image selection word in response to a speed at special reproduction. An output image discrimination means 10 generates a 3rd image selection work from the 1st image selection word, reproduced from an error correction means 8 and a 2nd image selection word obtained by the image selection means 9 and provides an output of the selected word together with the reproduced compressed image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to additional information in recording / reproducing, editing and transmitting audio data and image data, and more particularly to a case where image data is compressed in units of 2.times.N (N is a natural number) fields. The present invention relates to a recording / reproducing device effective for:

[0002]

2. Description of the Related Art In recent years, digital processing devices for image data have been rapidly digitized. Among them, devices such as a VTR of an analog recording system, a VTR of a digital uncompressed recording system, and a VTR for compressing and recording digital image data by high-efficiency encoding have been developed and digitized. Equipment.

[0003] On the other hand, fusion of AV equipment and computers is also rapidly progressing. For example, it is becoming common practice to take compressed image data recorded on a VTR and decode the compressed image data into a computer without decoding it, and to start editing. This is due to the efficient coding
Compression technology capable of compressing enormous image data of about Mbit / sec to several tens of Mbit / sec and several Mbit / sec, and advancement of semiconductor technology capable of realizing image compression requiring enormous calculations in real time Thanks.

[0004] As described above, a bit stream for connecting devices with compressed image data is being standardized. Actually, a consumer VTR is a VTR of a system using a consumer DV (Digital Video Cassette (DVC)) standard using the IEEE 1394 standard.
-VTR) has been standardized as an interface for compressed image data based on the compression format.

In a consumer DV, a video signal is compressed and recorded by high-efficiency coding in units of one frame (in units of two fields) and reproduced. During reproduction, the compressed image data is decoded (expanded), and the video signal is restored and output. The compressed image data is output so that it can be taken into a PC. This compressed image data
Since the video signal is compressed in units of one frame, the minimum unit of the output compressed image data is one frame.
A file of compressed image data completed for each frame is transmitted as a digital interface for compression.

However, the VTR has a special reproduction mode such as slow reproduction. For example, if the speed is 1/2 times, it is necessary to output the video signal of the same field twice in one frame period. Therefore, in the DV-VTR, when the compressed image data is output, slow playback and reverse playback are considered,
Two information bits called F and FS are defined as follows, and are output for each frame as data attached to the compressed image data.

When (FF, FS) = (0, 0), 1
The image of the first field is output twice in the frame. (F
When (F, FS) = (0, 1), the image of the second field is output twice in one frame. (FF, FS) =
In the case of (1, 0), an image is output to one frame in the order of the second and first fields. (FF, FS) = (1, 1)
In the case of, an image is output in the order of the first and second fields in one frame.

In normal reproduction, (FF, FS) = (1, 1)
-1 × speed reproduction is (1,0), and 倍 × speed reproduction is (0,0) and (0,1) repetition.

The above signal processing is described in, for example, Japanese Patent Application Laid-Open No. Hei 5-344472.

FIG. 7 is a block diagram of video signal processing on the reproduction side of a conventional VTR. In the figure, 5 is a tape,
Reference numeral 6 denotes a reproducing means for reproducing the compressed image data from the tape;
Is an error correcting means for correcting an error in the compressed image data reproduced by the reproducing means 6, and 9 is a track reference signal which detects a track number inserted in a bit stream of the compressed image data reproduced by the reproducing means 6, and Image selection means for detecting the tape phase of reproduction by comparing the phase with the image data and determining the reference image to be output in consideration of the reproduction direction;
Is transmission means for multiplexing and outputting an image selection word output from the image selection means 9 as a bit stream of compressed image data output from the error correction means 8, and 12 is an output terminal for compressed image data.

The operation of the image data processing device configured as described above will be described. The compressed image data reproduced from the tape 5 by the reproducing means 6 is transmitted to the error correcting means 8.
To correct errors generated in the process of reproduction.
The compressed image data output from the reproducing means 6, the reproduction reference signal, and the direction of tape reproduction (which indicates forward or backward, not shown) are input to the image selecting means 9. The image selection means 9 detects the track number inserted in the bit stream of the compressed image data, compares the phase with the reproduction reference signal, detects the tape phase of reproduction, and considers the reproduction direction of the tape. The image to be output is determined. An image selection word output from the image selection means 9;
The compressed image data output from the error correction means 8 is transmitted to the transmission means 1
1 are multiplexed and output terminal 12
Output more.

[0012] Thereafter, the compressed image data is provided without the intermediary of the decoder (not shown in FIG. 7).
FF, F
An output image is selected by the information bit of S, and slow reproduction is realized.

[0013]

However, in the prior art, a problem arises when the compressed image data subjected to special reproduction such as slow reproduction or the like is not decoded, but is directly recorded on a VTR and then reproduced again in slow reproduction. For example, consider the case where compressed image data reproduced at -1 × speed is recorded again and slow reproduced at 倍 × speed.

FIG. 8 is a timing chart of compressed image data reproduced at -1.times. Speed. FIG. 3A is a timing chart of the compressed image data recorded on the tape.
Indicates a frame. V1 + V2, V3 + V4, V5 + V
6, V7 + V8 is 2 images of 2 fields in each frame.
This indicates that the data is compressed and recorded in field units (one frame unit). FIG. 6B is a timing chart of the output of the compressed image data when the compressed image data recorded at the timing of FIG. FIG. 13C shows an image selection word (FF, FS), and FIG. 14D shows the image selection word based on the compressed image data of FIG. 14B and the image selection word of FIG. The timing of the image when the compressed image data is decoded is shown.

As shown in FIG. 8, V1 + V2, V3 + V
Compressed image data recorded in frames in the order of 4, V5 + V6, V7 + V8 (each number indicates a field number) is reproduced at -1 × speed to obtain V7 + V8, V5
+ V6, V3 + V4, V1 + V2,
(FF, FS) is output as (1, 0) in order to output an image in the order of the second field and the first field in each frame. As described above, when the image data reproduced at -1 × speed is decoded, the images are V8, V7,.
., V1 are generated in order, and a desired -1 × speed image can be obtained.

Next, FIG. 9 shows a timing chart in the case where the compressed image data reproduced at -1 × speed is recorded as a bit stream and reproduced at 倍 × speed. FIG. 3A shows the timing on the tape when the compressed image data reproduced at -1.times. Speed is recorded while being compressed. FIG. 2B shows the timing when the compressed image data recorded on the tape is reproduced at 1/2 speed, and FIG. 3C shows the image selection word when reproduced at 1/2 speed. (D) shows the timing of an image when decoding is performed using the compressed image data in FIG. (B) and the image selection word in (c).

As shown in FIG. 9, the decoded image is in the order of V7, V8, V5, V6, and
There is a problem that a slow image at a double speed cannot be obtained (the time axis of the order of the obtained pictures is reversed).

The present invention solves the above-mentioned problems, and realizes variable-speed playback a plurality of times while maintaining a compressed bit stream. Further, the present invention realizes variable-speed reproduction of audio data input in synchronization with compressed image data a plurality of times.

[0019]

In order to solve the above-mentioned problems, the present invention provides a first image selection word obtained by recording and reproducing data together with compressed data, and a second image selection word generated according to a current tape reproducing speed. The third image selection word is formed from the second image selection word.

As a result, it is possible to obtain a recording / reproducing apparatus capable of realizing appropriate variable speed reproduction even in dubbing or editing with compressed data as it is when special reproduction is repeated.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first invention of the present invention is a method for decoding image data compressed in units of 2.times.N fields (N is a natural number), and for decoding the compressed image data, 2.times.N An apparatus for recording and reproducing a compressed bit stream obtained by multiplexing a first image selection word indicating which image data is to be output from among the pieces of image data, and receiving means for receiving the input compressed bit stream Recording means for recording the compressed image data and the first image selection word of the bit stream received by the receiving means; and variable speed reproduction of the compressed image data and the first image selection word to obtain 2 × N fields A playback unit that outputs in units of unit, detects a playback speed and a playback phase, and indicates which image to output in image data compressed in units of 2 × N fields. An image selection unit that outputs a second image selection word; an output image determination unit that creates a third image selection word to be output from the first image selection word and the second image selection word; Transmitting means for outputting the reproduced compressed image data and the third image selection word as a bit stream of the compressed image data in units of 2 × N fields.

Thus, the compressed image data of the bit stream of the compressed image data and the image selection word received by the receiving means for receiving the bit stream of the compressed image data compressed in units of 2 × N fields are compressed by the recording means. The image data is recorded as a first image selection word. The recorded compressed image data and the first image selection word are reproduced at variable speed by the reproducing means and output in units of 2 × N fields. Further, the image selection means outputs a second image selection word corresponding to the reproduction speed and the reproduction phase. Further, a third image selection word is created from the first image selection word and the second image selection word by the output image determination means. The third image selection word and the compressed image data reproduced by the reproducing means are multiplexed by the transmitting means and output in units of 2 × N fields.

According to a second aspect of the present invention, audio data synchronized with compressed image data transmitted in units of 2 × N fields (N is a natural number) and reproduction speed information of the audio data are multiplexed and transmitted. Receiving means for receiving the input bit stream, and using the playback speed information of the bit stream received by the receiving means as first playback speed information, Recording means for recording the audio data and the first reproduction speed information at a variable speed, and outputting the data in units of 2 × N fields; reproduction speed detection means for detecting the speed of the reproduction means; The second reproduction speed information and the first reproduction speed information output from the reproduction speed detecting means are input and the two are calculated. There is further provided an arithmetic means for generating third reproduction speed information, and a transmission means for multiplexing the audio data reproduced by the reproduction means and the third reproduction speed information and outputting the multiplexed data as a bit stream.

Thus, the audio data synchronized with the image data compressed in units of 2 × N fields and the first reproduction speed information for reproducing the audio data are received and recorded by the receiving means and the recording means. The recorded audio data and the first reproduction speed information are reproduced at a variable speed by the reproduction means and output in units of 2 × N fields. The reproduction speed of the variable speed reproduction is detected as the second reproduction speed information by the reproduction speed detecting means. Further, the first reproducing speed information and the second reproducing speed information reproduced by the variable speed reproducing means are calculated by the calculating means,
And multiplexed with the reproduced audio data as the reproduction speed information.

A third aspect of the present invention is a method for storing image data compressed in units of 2 × N fields (N is a natural number),
When decoding the compressed image data, a first image selection word indicating which image data is to be output among 2 × N image data for each field, and a 2 × N field unit for the compressed image data Audio data synchronized with
An apparatus for recording and reproducing a compressed bit stream obtained by multiplexing the reproduction speed information of the audio data with a receiving means for receiving an input compressed bit stream, and compressed image data of the bit stream received by the receiving means. Recording means for recording the first image selection word, the audio data, and the first reproduction speed information; and variable-speed transmission of the compressed image data, the first image selection word, the audio data, and the first reproduction speed information. Play and 2 × N
Reproducing means for outputting in field units, reproducing speed detecting means for detecting the speed of the reproducing means and outputting it as second reproduction speed information, detecting a reproducing speed and a reproducing phase,
Image selection means for outputting a second image selection word indicating which image is to be output in image data compressed in units of 2 × N fields, the first image selection word, the second image selection Output image determining means for generating a third image selection word to be output from a word; calculating means for calculating the first playback speed information and the second playback speed information and outputting the information as third playback speed information; And transmitting means for outputting the compressed image data and audio data reproduced by the reproducing means and the third image selection word and third reproduction speed information as a bit stream of compressed image data.

Thus, the compressed image data and the first image selection word compressed in units of 2 × N fields, and the audio data and the first reproduction speed information synchronized with the compressed image data are recorded by the recording means. . The recorded compressed image data, the first image selection word, the audio data, and the first reproduction speed information are reproduced in units of 2 × N fields by the reproduction means. The second image selection word corresponding to the reproduction speed and the reproduction phase of the variable speed reproduction and the reproduced first
Is output as a third image selection word by the output image determination means. The second reproduction speed information corresponding to the variable reproduction speed and the reproduced first reproduction speed information are output as third reproduction speed information by the arithmetic means, and the compressed image data and audio data reproduced by the transmission means are output. And the third image selection word and the third reproduction speed information are multiplexed into 2 ×
It is output in units of N fields.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram showing a configuration of a recording / reproducing apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes an input terminal for compressed image data.
A selection word of an image (field) to be output to a frame is inserted and input. 2 is a receiving means for receiving the compressed image data from the input terminal 1; 3 is an error correcting code adding means for adding an error correcting code to the compressed image data and the direction bit, the image selection word, etc. received by the receiving means 2; Is a recording means, 5 is a tape, 6 is a reproducing means for reproducing compressed image data from the tape, 8 is an error correcting means for correcting an error of the compressed image data reproduced by the reproducing means 6, 9 is a reproducing direction and a reproduction reference. Signal and reproduction means 6
The image selecting means for determining the reference image to be output from the result of detecting the track number inserted in the bit stream of the compressed image data reproduced by the above method and outputting the second image selection word, and 10 for error correction The first image selection word recorded with the output of the means 8, the second image selection word of the output of the image selection means 9, and the reproduction direction bit are input, and the third of the compressed image data to be output is output. An output image determining means for determining an image selection word, multiplexes the third image selection word output from the output image determining means as a bit stream of compressed image data output from the error correcting means, and outputs the multiplexed output. Means 12 is an output terminal for compressed image data.

The operation of the recording / reproducing apparatus configured as described above will be described in detail below. First, the compression format of the compressed image data input to the input terminal 1 will be briefly described.

FIG. 2 is a schematic diagram showing a slice for compression. This figure shows a one-frame TV screen, in which the first field is displayed as A and the second field is displayed as B. 480 valid lines of one frame (in case of NTSC signal)
Is divided into 10 and the two fields are combined, and they are divided into (1A + 1B), (2A + 2B),.
10B). The above one division is called one slice. One frame of image data is divided into 10 slices, subjected to DCT conversion, variable-length coding, and the like, and then a direction bit and an image selection word are inserted.

In the present embodiment, two fields are compressed to 1
Since one unit is used, there are four types of image selection words. The image selection word assumes slow reproduction. The unit of compression is two fields, but the unit of slow reproduction is one field. Therefore, unless two bits are added to the compressed image data as an image selection word, the slow reproduction is performed. Can't express.

That is, when the 2-bit image destination selection word is (0,0), the first field is set to 2 in one frame.
Output. Similarly, in the case of (0, 1), the second field is output twice in one frame. In the case of (1, 0), an image is output in the order of the second field and the first field in one frame. In the case of (1, 1), an image is output in the order of the first field and the second field in one frame. Such two bits are added to the compressed image data as an image selection word.

Further, in the present embodiment, the image selection word is defined on the assumption that compressed image data that has been subjected to reverse playback and slow playback on a VTR or the like is input from an input terminal.

The compressed image data and the image selection word output from the receiving means 2 are input to an error correction code adding means 3 where an error correction code such as a Reed-Solomon code is added. The compressed image data to which the error correction code has been added is input to the recording means 4, and is recorded on the tape 5 after processing such as addition of ID (identification data) such as a track ID and 24-25 modulation. In the present embodiment, an image selection word input from the input terminal 1 is recorded together with the compressed image data.

FIG. 3 shows a schematic diagram (conceptual diagram) of the tape pattern of the present embodiment. As shown in the figure, one frame is composed of ten tracks, and one track corresponds to the division of FIG. 2, and the main data of (1A + 1B) to (10A + 10B) of FIG. . Also,
Each track is composed of 135 image data sync blocks and 50 sync blocks for recording additional information, and each sync block records a word indicating an ID indicating a track position. The numbers below the figure are the track numbers of the respective tracks.

Next, the operation of the reproducing system will be described. The compressed image data recorded on the tape 5
Thus, processing such as 24-25 demodulation and track number detection are performed. The compressed image data output from the reproduction means 6 is input to the error correction means 8 and error correction is performed. Further, the error correction means 8 outputs the compressed image data recorded on the tape 5 and an image selection word (hereinafter referred to as a first image selection word). The track number and the reproduction reference signal detected by the reproducing means 6 are inputted to the image selecting means 9 to detect the reproducing direction and the reproducing speed, and to output the second image selecting word.

The technique of detecting the reproduction speed based on the reproduced track number and the reproduction reference signal and selecting an image is described in detail in Japanese Patent Application Laid-Open No. Hei 5-344472 described in the background art, and will be described. Omit.

Next, the operation of the output image judging means 10 will be described. The first image selection word from the error correction unit 8 and the second image selection word and direction bit from the image selection unit 9 are input to the output image determination unit 10. The first image selection word indicates the state of the source (how the reconstructed compressed image data is recorded), and the direction bit and the second image selection word indicate the state of the player (currently how Playback is in progress).

Therefore, the first image selection word is (1,
In the case of 1), since it is the same as that in which a normally reproduced image is recorded, the second image selection word may be output as the image selection word (third image selection word) of the output image.

However, as described above, the state of the source includes the source reproduced in slow motion or the source transmitted in reverse. Therefore, the image selection word of the output image needs to be determined in consideration of the first image selection word.

In this embodiment, the image selection word of the output image is determined according to the matrix shown in FIG. 4, and is output as the third image selection word.

The third image selection word is transmitted by the transmission means 11
And is inserted into the compressed image data that has been error-corrected by the error correction means 8 and output from the output terminal 12.

For example, FIG. 5 shows a timing chart when compressed image data reproduced at -1.times. Speed is recorded and reproduced at 1 / 2.times. Speed. FIG. 4A shows the timing when the compressed image data reproduced at -1 × speed is recorded on the tape as it is, and FIG. 4B shows the timing when the tape recorded at the timing of FIG. The timing of the compressed image data when reproduced at double speed, (c) is the first timing recorded on the tape.
(D) is the second word determined from the reproduction speed.
(E) is a third image selection word generated from the first image selection word and the second image selection word according to the matrix of FIG. 4, and (f) is the compressed image data of (b). The image when decoded from the third image selection word is shown.

As shown in the figure, the compressed image data reproduced at -1.times. Speed is recorded in units of one frame in the reverse time direction, and (1, 0) is sequentially added as an image selection word. When they are reproduced at 1/2, the compressed image data is repeated twice as shown in FIG. 5, and the second image selection word is (0,0) (0,1) (0,0) (0,0 1)
Becomes When they are corrected by the output image determining means 10 in correspondence with the first image selection word, the third image selection word becomes (0,1) (0,0) (0,1) (0,0). .
Therefore, when the compressed image data is decoded, it is output in accordance with the third image selection word, so that it is possible to restore the image as a desired -1/2 speed image as shown in FIG. .

As described above, in the present embodiment, on the recording side, compressed image data compressed in units of two fields,
A first image selection word indicating the order of fields to be output when the compressed image data is restored is recorded. Also,
The second image when the compressed image data recorded normally from the reproduction speed at the time of reproduction (the first image selection word indicates a word for outputting an image in the order of the first field and the second field) Image selection means 9 for selected word
The output image determination means 10 determines the image data to be output by restoring the compressed image data from the first image selection word and the second selection word. Therefore, even when the slow-reproduced or reverse-forward reproduced source is captured and recorded by the compression interface and re-performed in the slow-reproduced or reverse-reproduced reproduction mode, an image having no image quality degradation in the time axis direction can be obtained.

(Embodiment 2) Next, a recording / reproducing apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings. This embodiment relates to audio data synchronized with compressed image data transmitted in units of 2 × N fields.

FIG. 6 is a block diagram showing the configuration of the recording / reproducing apparatus according to the present embodiment. In the figure, reference numeral 1 denotes an input terminal for compressed image data, and in this embodiment, audio data and first reproduction speed information that generated the audio data are inserted in synchronization with image data compressed in units of two fields. Is entered. 2 is a means for receiving the compressed image data, 3 is an error correction code adding means for adding an error correction code to the audio data received by the receiving means 2 and first reproduction speed information of the audio data, 4 is a recording means,
Numeral 5 is a tape, numeral 6 is audio data from the tape, reproduction means capable of variable-speed reproduction of the first reproduction speed information, numeral 8 is an error correction means for correcting an error of the audio data reproduced by the reproduction means 6, and numeral 20 is reproduction. The speed detecting means 21 calculates the first reproducing speed information recorded by the output of the error correcting means 8 and the second reproducing speed information detected by the reproducing speed detecting means 20, and outputs the reproducing speed information. Calculating means for outputting as the third reproduction speed information,
Reference numeral 1 denotes a transmission unit for multiplexing and outputting the third reproduction speed information of the arithmetic unit 21 and audio data output from the error correction unit 8 as a bit stream, and 12 denotes an output terminal of the audio data from the transmission unit 11. .

The operation of the recording / reproducing apparatus configured as described above will be described in detail below. In the present embodiment,
The audio data output from the receiving unit 2 and the first reproduction speed information that generated the audio data are recorded on the tape 5 by the recording unit 4 after the error correction code is added by the error correction adding unit 3.

Next, the operation of the reproducing system will be described. The audio data and the first reproduction speed information recorded on the tape are reproduced at variable speed by the reproduction means 6 and output in units of 2 × N fields. The audio data output from the reproduction means 6 and the first reproduction speed information are input to the error correction means 8 and error correction is performed. The reproduction speed of the variable speed reproduction is detected by the reproduction speed detecting means 20. In the case of a VTR, the capstan FG is used for detecting the reproduction speed. Since the capstan FG generates several pulses per one rotation of the capstan, the reproduction speed can be obtained by measuring the number of the capstan FG pulses. Further, since the direction of reproduction is determined by a command from the front panel of the VTR, it is easy to detect. As described above, the reproduction speed detected by the reproduction speed detection means 20 is output as the second reproduction speed information. The first reproduction speed information output from the error correction means 8 and the second reproduction speed information output from the reproduction speed detection means 20 are input to the calculating means 21 and are (first reproduction speed information) ×
(Second playback speed information) is calculated, and the result is output as third playback speed information.

For example, when audio data reproduced at -1 times speed is recorded and reproduced at 1/3 times speed, the third
Is -−１.

Further, the audio data output from the error correction means 8 and the third reproduction speed information output from the arithmetic means 21 are input to the transmission means 11 and both are multiplexed to obtain 2 data.
The data is output from the output terminal 12 as data in field units.

As described above, in the present embodiment, the audio data synchronized with the compressed image data with two input fields as one unit and the reproduction speed at which the audio data was generated are recorded as the first reproduction speed information. The output reproduction speed (third reproduction speed information) is obtained by multiplying the second reproduction speed information indicating the actual reproduction speed by the first reproduction speed information.

For example, consider the case where the first reproduction speed is 1/2 speed and the second reproduction speed is 1/3. The audio data to be recorded has a reproduction speed of 速, and is recorded twice in two fields as one unit. When these audio data are reproduced at 1/3 times speed, the reproduction is repeated six times with two fields as one unit. Here, as the third reproduction speed, (1/2 ×
By transmitting (), it is possible to reproduce the original sound by stretching it to 1/6 times.

The image and the sound may be simultaneously processed by combining the first and second embodiments of the present invention.

Further, although the present embodiment has been described with respect to a VTR, it goes without saying that the present invention can be applied to a hard disk.

[0055]

As described above, according to the present invention, on the recording side, the first order indicating the order of the compressed image data compressed in units of 2 × N fields and the fields to be output when the compressed image data is decompressed is obtained. Record the image selection word. Also, normal recording was performed based on the reproduction speed at the time of reproduction (first
Indicates a word for outputting an image in the order of the first field and the second field.) When the compressed image data is reproduced, the second image selection word is output from the image selection means, and the output image determination means is output. Thus, based on the first image selection word and the second selection word, the image data to be output after decompressing the compressed image data is determined. Therefore, even when the slow-reproduced or reverse-forward reproduced source is captured and recorded by the compression interface and re-performed in the slow-reproduced or reverse-reproduced reproduction mode, an image having no image quality degradation in the time axis direction can be obtained.

On the recording side, audio data synchronized with image data compressed in units of 2 × N fields and first reproduction speed information that generated the audio data are recorded. On the reproduction side, the second reproduction speed information indicating the reproduction speed of the variable speed reproduction is multiplied by the first reproduction speed information, and output as the third reproduction speed information together with the audio data in units of 2 × N fields. Therefore, even when the source reproduced in the slow reproduction and the reverse reproduction is captured by the compression interface and recorded, and the reproduction in the slow reproduction and the reverse reproduction is performed again, it is possible to obtain the audio synchronized with the image.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a recording / reproducing device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a compressed slice in the recording / reproducing apparatus.

FIG. 3 is a schematic diagram of a tape format in the recording / reproducing apparatus.

FIG. 4 is a generation matrix diagram of a third image selection word in the recording / reproducing apparatus.

FIG. 5 is a timing chart showing the operation of the recording / reproducing apparatus when the compressed image data reproduced at -1x speed is further reproduced at 1 / 2x speed.

FIG. 6 is a block diagram showing a configuration of a recording / reproducing device according to a second embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a conventional recording / reproducing apparatus.

FIG. 8 is a timing chart when the recording / reproducing apparatus reproduces data at a speed of -1.

FIG. 9 is a timing chart when the compressed image data reproduced at −1 × speed is recorded and reproduced at 倍 × speed by the recording / reproducing apparatus.

[Explanation of symbols]

 2 receiving means 4 recording means 5 tape 6 reproducing means 9 image selecting means 10 output image judging means 11 transmitting means

Claims (3)

[Claims] An image data compressed in units of 2.times.N fields (N is a natural number) and, when decoding the compressed image data, which image data out of 2.times.N image data for each field What is claimed is: 1. A device for recording and reproducing a compressed bit stream obtained by multiplexing a first image selection word indicating whether or not to output, a receiving means for receiving an input compressed bit stream, and a bit stream received by said receiving means. Recording means for recording the compressed image data and the first image selection word, variable-speed reproduction of the compressed image data and the first image selection word, and output in units of 2 × N fields; A reproduction phase is detected, and a second image selection word indicating which image is to be output is output from image data compressed in units of 2 × N fields. Image selection means, the first image selection word and the second
Output image judging means for creating a third image selection word to be output from the image selection word, and the compressed image data reproduced by the reproduction means and the third image selection word as a bit stream of compressed image data. A recording / reproducing apparatus comprising: a transmission unit that outputs data in units of × N fields 2. An apparatus for recording and reproducing a bit stream transmitted by multiplexing audio data synchronized with compressed image data transmitted in units of 2 × N fields (N is a natural number) and reproduction speed information of the audio data. Receiving means for receiving an input bit stream; recording means for recording reproduction speed information of the bit stream received by the receiving means as first reproduction speed information together with the audio data; data,
Reproducing means for reproducing the first reproduction speed information at a variable speed and outputting in units of 2 × N fields; reproduction speed detection means for detecting the speed of the reproduction means; and second reproduction of the output of the reproduction speed detection means Calculating means for inputting the speed information and the first reproduction speed information and calculating the both to generate third reproduction speed information; audio data reproduced by the reproduction means; And a transmission means for multiplexing the data and outputting the multiplexed data as a bit stream. 3. An image data compressed in units of 2 × N fields (N is a natural number) and, when decoding the compressed image data, which image data among 2 × N image data for each field Apparatus for recording / reproducing a compressed bit stream multiplexing a first image selection word indicating whether to output, audio data synchronized with the compressed image data in units of 2 × N fields, and reproduction speed information of the audio data Receiving means for receiving the input compressed bit stream, and recording compressed image data, a first image selection word, audio data, and first reproduction speed information of the bit stream received by the receiving means. Recording means for performing compression image data, a first image selection word, audio data,
Reproducing means for reproducing the first reproduction speed information at a variable speed and outputting in units of 2 × N fields; reproduction speed detection means for detecting the speed of the reproduction means and outputting it as second reproduction speed information; And the reproduction phase are detected, and 2 ×
Image selection means for outputting a second image selection word indicating which image is to be output among image data compressed in units of N fields;
Output image judging means for creating a third image selection word to be output from the image selection word, and the first reproduction speed information and the second reproduction speed information are calculated and output as third reproduction speed information Arithmetic means, compressed image data and audio data reproduced by the reproduction means,
A recording / reproducing apparatus comprising: a transmission unit that outputs the third image selection word and the third reproduction speed information as a bit stream of compressed image data.