JPH11205740A - Compressed recording device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record a video signal or an audio signal by compress-encoding by a proper or optional compressibility corresponding to the feature of the signal. SOLUTION: A genre code detector 12 detects the category of a video signal 100 and an audio signal 200 to compress from the present time from a inputted code, generates a previously decided encoding parameter showing the compressibility of video and audio corresponding to the detected category from an encoding parameter table 9 and sets this to a picture encoder 1 and an audio encoder 2. The signal 100 or 200 is recorded by a proper compressibility according to its feature by this. As a encoding parameter in an encoding parameter table 10 is optimally set by a setting device 16 by each category, the signal can be recorded by compress-coding by the optimum compressibility by setting the coding parameter in this table 10 to the encoders 1 and 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a compression recording apparatus and method for inputting a video signal and an audio signal which are not compression-encoded, compression-encoding and recording.

[0002]

2. Description of the Related Art In recent years, with the development of image compression technology and audio compression technology, it has become possible to compress video signals and audio signals in real time. For example, as a well-known example of a recording apparatus for compressing and encoding an analog video signal and digitally recording the same, a “moving image data compression storage / playback apparatus” of JP-A-5-137104 and a “digital recording apparatus and digital recording method” of JP-A-8-165616 are known. And so on. The former is to change the recording mode of the video signal by detecting the remaining amount that can be recorded in the recording device, and the latter is to add a video identification code to the input video signal, compress and encode the necessary data if necessary, and store it in the storage device. It is recorded in.

[0003] The current analog broadcasting is expected to shift to digital broadcasting in the future. However, the current analog broadcasting is received and compression-encoded and recorded, or the video signal or audio recorded by the analog signal is received. There is a case where it is desired to input a signal, perform compression encoding, and record the signal. In such a case, by appropriately determining the compression ratio of the video signal and the audio signal and performing compression recording, the quality of the reproduced signal is poor and cannot be watched, or the recording area is insufficient and recording cannot be performed to the end. In order to eliminate the problem, it is required to balance the quantity (recording time) of the recording signal and the quality of the recording signal, but the above-mentioned known example does not solve this problem. Also, even in the case of digital video signals and audio signals, signals which have not been compression-encoded may be compressed and recorded / reproduced. In this case, too, for the same reason, the compression ratio of the video signal and the audio signal should be adjusted appropriately. It is requested to decide.

[0004]

When a video signal or an audio signal which is not compression-encoded as described above is compressed and recorded, the characteristics of the video signal or the audio signal, that is, the genre to which these signals belong, for example, Since the value or quality of the video signal and the audio signal changes depending on this, the recording information amount and the quality of the recording signal cannot be maintained in an appropriate balance unless the compression ratio is changed accordingly.

[0005] For example, in the case of a music program, the sound quality is important. Therefore, it is desirable to lower the compression rate to ensure sound quality of a certain level or more. On the other hand, in the case of a news program, information only needs to be transmitted, and a large amount of information can be recorded by increasing the compression ratio. In a classic program, since there is not much movement in the video, the compression rate of the video signal can be increased. If the information itself, such as news or weather forecast, is valuable, there is no problem even if a large amount of information is recorded by increasing the compression ratio of both the video signal and the audio signal to some extent. However, the conventional compression recording apparatus cannot record a signal by selecting an appropriate compression rate according to the characteristics of the video signal and the audio signal as described above.

[0006] The value of the above-mentioned signal also changes depending on the user's preference. For example, users who like ebo music programs want to record with good image quality and sound quality, so it is also desirable to be able to set the compression ratio in consideration of the user's preference. There was no compression recording device that could be used in a short time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to compress and encode the above signal at an appropriate or arbitrary compression ratio according to the characteristics of a video signal and an audio signal. To provide a compression recording apparatus and method for performing recording.

[0008]

According to a first aspect of the present invention, there is provided a compression recording apparatus for separately encoding and recording a video signal and an audio signal and recording the video signal and the audio signal. Detection means for detecting one or both of the features, and a setting means for determining a compression rate according to the feature detected by the detection means, and setting the determined compression rate for each of the video signal and the audio signal. ,
A compression means for separately compressing and encoding a video signal and an audio signal at a compression ratio set by the setting means is provided.

According to the first aspect, for example, when the video signal and the audio signal are obtained by receiving a broadcast of a music program, for example, a high compression rate is applied to the video signal, and a low compression rate is applied to the audio signal. Are determined and these are set, so that the video signal is compressed and recorded at a high compression rate, and the audio signal is compressed and recorded at a low compression rate. Thereby, the recording area of the video signal is small, and when the audio signal is reproduced, a high quality audio signal can be obtained.

A feature of the second invention is that one or both of the video signal and the audio signal detected by the detecting means is a genre code of a broadcasting station that broadcasts the video signal and the audio signal. .

According to a third feature of the present invention, in a compression recording apparatus for separately compressing and recording a video signal and an audio signal, setting means for arbitrarily setting a compression ratio for each of the video signal and the audio signal; A compression means for separately compressing and encoding a video signal and an audio signal at a compression ratio set by the setting means is provided.

According to the third aspect, the compression ratio of the video signal and the audio signal is separately set by the setting means according to the user's preference, so that the video signal can be compressed at a compression rate that matches the user's preference. And compression recording of the audio signal.

According to a fourth aspect of the present invention, there is provided a compression recording apparatus for separately compressing and recording a video signal and an audio signal, and a recording medium storing a compression ratio of one or both of the video signal and the audio signal. Setting means for reading out the compression ratio recorded on the recording medium and setting each of the video signal and the audio signal; and separately compressing the video signal and the audio signal at the compression ratio set by the setting means. Compression means for encoding.

According to the fourth aspect, for example, when a video signal and an audio signal which have been once compressed and recorded on a DVD or the like before being compressed are received from a broadcast or the like, and are compressed and recorded, the video signal and the audio signal are recorded on the DVD. If the compression ratio is read from a recording medium such as a magnetic card that records the compression ratio at the time of compression recording and is set for each of the video signal and the audio signal,
Video and audio signals are optimally compressed and recorded.

[0015] A feature of the fifth invention is that the compression ratio set for the video signal by the setting means changes with time.

According to the fifth aspect of the present invention, the compression ratio is increased in a scene where the motion is small in the video signal, and the compression ratio is lowered in a portion where the motion is present. More optimal compression recording can be performed.

According to a sixth aspect of the present invention, there is provided a compression recording method for separately compressing and encoding a video signal and an audio signal, and recording the video signal and the audio signal. Obtaining a compression ratio according to the detected feature, setting the obtained compression ratio for each of the video signal and the audio signal, and separately compressing and encoding the video signal and the audio signal at the set compression ratio. And the process of doing it.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the compression recording apparatus of the present invention. The image encoding device 1 encodes and compresses the unencoded video signal 100, and records it on a recording medium such as a disk by an image recording device 3 such as a DVD-RAM.
The image decoding device 5 restores the original video signal by decoding and decompressing the compressed and coded signal read from the image recording device 3, and outputs the original video signal to the video / audio synchronization device 11.

The audio encoding device 2 encodes and compresses an unencoded audio signal 200 and converts it to, for example, a DVD.
-Recording on a recording medium such as a disk by an audio recording device 4 such as a RAM. The audio decoding device 6 is the audio recording device 4
The coded signal read out is decoded and expanded to return to the original audio signal and output to the video / audio synchronizer 11. The video / audio synchronizer 11 synchronizes the input audio signal with the video signal and outputs it as a reproduction signal.

A time code generator 7 generates a time code for synchronizing a video signal and an audio signal at the time of reproduction, and generates recording position information from the time code by the image encoder 1 and the audio encoder 2. Then, the image is recorded by the image recording device 3 and the audio recording device 4, respectively. The genre code detection device 12 receives the input genre code 300
The video signal 100 to be input from now or currently
Alternatively, the genre of the audio signal 200 is detected. The encoding parameter table 9 generates encoding parameters corresponding to the video compression ratio and the audio compression ratio detected by the genre code detection device 12. Encoding parameter table 1
0 generates encoding parameters corresponding to the video compression ratio and audio compression ratio for each genre arbitrarily set by the setting unit 16. The selecting device 8 selects one of the encoding parameters in the encoding parameter table 9 or the encoding parameter table 10, and the selected encoding parameter is set in the image encoding device 1 and the audio encoding device 2.

Next, the operation of this embodiment will be described. For example, a video signal 100 and an audio signal 200 received from a broadcast station are input to the image encoding device 1 and the audio encoding device 2. At this time, the genre code 300
Is transmitted, and the genre code detecting device 12 detects the genre of the program currently being broadcast.

As shown in FIG. 2, the optimum compression ratio of the video signal and the audio signal for each genre is set in advance for the genre thus detected. For example, if the genre is news, both the video compression rate and the audio compression rate are high,
For music, the video compression ratio is set to be medium and the audio compression ratio is set to be low. Accordingly, in the encoding parameter table 9, the encoding parameters of the video signal 100 and the audio signal 200 for each genre corresponding to the compression ratio shown in FIG. 2 are set in advance.

On the other hand, in the encoding parameter table 10, encoding parameters for each genre set arbitrarily by the user are set through the setting unit 16. This is for reflecting the user's preference in the video compression ratio and audio compression ratio of each genre, and for example, setting such that the video compression ratio is set to medium and the video compression ratio is increased for the news genre. be able to.

When the genre code detecting device 12 detects the genre of the video signal 100 or the audio signal 200 to be compressed, the genre code detecting device 12 encodes the genre into the encoding parameter tables 9 and 10.
Inform As a result, the encoding parameter tables 9 and 10 have a high video compression ratio in the encoding parameter table 9 if the genre is news, for example, if the genre is news. The encoding parameter for setting the audio compression rate to be high is output from the encoding parameter table 10 for setting the video compression rate to medium and the audio compression rate to be high.

The selection circuit 8 is set The choice of the encoding parameter table in advance, when was encoded parameters one data table 9, the coding parameters Ichita images from this table 9 If the parameters are set in the encoding device 1 and the audio encoding device 2 and are the encoding parameter table 10, the encoding parameters from the table 10 are stored in the image encoding device 1 and the audio encoding device 2 Is set to

Thereafter, the image coding apparatus 1 sets the input video signal 100 at a compression rate according to the set coding parameter.
The audio encoding device 2 encodes the input audio signal 200 at a compression rate according to the set encoding parameter.
Is encoded and compressed. The compression-encoded video signal is recorded on a recording medium such as a disk by the image recording device 3, and the encoded audio signal is recorded on a recording medium such as a disk by the audio recording device 4.

At this time, in order to synchronize the video signal and the audio signal at the time of decoding, the time code output from the time code generation device 7 is input to the image encoding device 1 and the audio encoding device 2, and the video signal and the audio signal are input. Recording position information for retrieving a signal recording position is generated, and this is recorded in the image recording device 3 and the audio recording device 4.

Thereafter, when the video signal and the audio signal are reproduced, the compressed and coded video signal and the audio signal corresponding to the designated time code are reproduced based on the recording position information.
And the compressed signal is read out from the audio recording device 4, and these compressed signals are decompressed by the image decoding device 5 and the audio decoding device 6 and decoded into the original video signal and audio signal. The decoded video signal and audio signal are reproduced and output in synchronization with the video / audio synchronizer 11.

According to the present embodiment, the video signal 100 or the audio signal 200 is compressed and coded at an appropriate compression rate according to the genre, and is recorded. By lowering the audio compression ratio, compression recording can be performed so that the video quality at the time of reproduction is moderate but the audio quality is high. This makes it possible to easily perform appropriate signal compression at the time of reproduction without failure, such as poor audio quality even though the genre is music. In addition, it is possible to arbitrarily set the compression ratio for each signal according to the user's preference, and to obtain a degree of freedom in setting the signal compression ratio for each genre.

In the above-described embodiment, a case has been described in which a genre code is transmitted from a broadcasting station through a broadcast radio wave. However, a case where the broadcasting station and the receiver are connected by, for example, a telephone line is described. The genre code may be sent using a telephone line, or the received video signal 10
A genre discriminating device 17 as shown by a broken line in FIG. 1 that automatically discriminates the genre of the video signal 100 and the audio signal 200 currently being received based on the level change or interval between 0 and the audio signal 200 and generates a genre code. It may be provided.
In addition, the user determines the video and audio currently being received,
The genre code may be manually input. In particular, when the genre discriminating device 17 is used, the device shown in FIG. 1 can be operated even under the standard of the current broadcasting station.

The setting for changing the compression ratio of the video signal 100 and the audio signal 200 is not limited to the genre of these signals, and the same effect can be obtained by other appropriate classification.

Further, the image recording device 3 and the audio recording device 4 have the same effect in a HDD or a magnetic tape recording / reproducing device for recording an encoded signal, in addition to a DVD.

FIG. 3 is a block diagram showing a second embodiment of the compression recording apparatus of the present invention. However, portions corresponding to those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. This example shows an example in which an uncompressed video signal and an audio signal, which have once been compression-encoded on a DVD or the like and whose optimal compression ratio is known, are compression-encoded and recorded on a disk or the like.

In such a case, since the video signal and the audio signal have already been recorded once at an appropriate compression ratio, the compression ratio reading device 14 for reading the recording data of the magnetic card 80 recording the compression ratio at this time, An encoding parameter calculating device 13 for calculating a corresponding encoding parameter from data read by the compression ratio reading device 14 is provided. The recording / reproducing system for other signals has the same configuration as that of the first embodiment.

Next, the operation of this embodiment will be described. The compression rate of the video signal 100 and the compression rate of the audio signal 200 are recorded on the magnetic card 80. The compression rate of the video signal 100 is variable and the compression rate of the audio signal 200 is compression-coded at a fixed rate. Shall be

The compression ratio reading device 14 reads out the recording data from the magnetic card 80 mounted thereon, outputs the data to the encoding parameter calculating device 13, and outputs the obtained encoding parameters to the image encoding device 1 and the audio encoding device. Output to 2 and set. At this time, the encoding parameters for audio are fixed, but the encoding parameters for video are changed with respect to the time axis as shown in FIG. Recorded in table form.

Accordingly, the compression ratio reading device 14 inputs the time code generated by the time code generation device 15 in order to obtain the time information of the currently input signal,
When the compression ratio changes with time, the time code is compared with the time code recorded on the magnetic card 80,
The compression rate in the current time code is output to the encoding parameter calculation device 13.

The encoding parameter calculating device 13 converts the compression ratio input from the compression ratio reading device 14 into an encoding parameter and outputs it to the image encoding device 1 and the audio encoding device 2. As a result, the image encoding device 1 sequentially compresses the input audio signal at a compression ratio that changes over time. On the other hand, since the audio compression ratio is fixed, the compression ratio once read by the compression ratio
3 to convert them into coding parameters, which are set in the voice coding apparatus 2, and thereafter the voice signal 2 is fixed with fixed coding parameters.
00 compression coding is performed.

The video signal compressed by the image encoding device 1 is recorded on a disk or the like by the image recording device 3, and the audio signal compressed by the audio encoding device 2 is recorded on a disk or the like by the audio recording device 4. At this time, in order to synchronize the decoding of the video signal and the audio signal, the time code is input to the image encoding device 1 and the audio encoding device 2, and the recording for searching the recording position of the video signal and the audio signal is performed. The position information is recorded by the image recording device 3 and the audio recording device 4, respectively. The subsequent video signal,
The operation of reproducing the audio signal is similar to that of the first embodiment, and has the same effect.

According to the present embodiment, since the video signal 100 and the audio signal 200 are compressed and recorded using a known compression ratio, appropriate compression can be performed, and the same effects as those of the first embodiment can be obtained. Can be obtained.

In the above embodiment, the magnetic card 80
Although the example in which the compression ratio data is recorded in the recording medium is described above, the same effect can be obtained with another recording medium such as a floppy disk. Further, when the video signal 100 and the audio signal 200 are transmitted by broadcasting or the like, the same effect can be obtained by transmitting the existing compression ratio data on a broadcast wave or a telephone line.

[0042]

As described in detail above, the first and the second
According to the invention, the signal can be compression-encoded and recorded at an appropriate compression rate according to the characteristics of the video signal or the audio signal, and a reproduced signal having an appropriate quality or the like can be obtained.

According to the third aspect, by manually setting the compression ratio, the video signal or the audio signal can be compressed and recorded at an arbitrary compression ratio suitable for the user's preference.

According to the fourth aspect, it is possible to optimally compress and record a video signal or an audio signal which has already been compressed once using an existing compression ratio.

According to the fifth aspect of the present invention, it is possible to perform an optimal compression with a fine grain by a compression ratio according to the scene of the video signal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a compression recording apparatus according to the present invention.

FIG. 2 is a table showing a signal compression ratio for each genre.

FIG. 3 is a block diagram showing a second embodiment of the compression recording apparatus of the present invention.

FIG. 4 is a graph showing an example of a change in a video compression ratio with time.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image encoding device 2 audio encoding device 3 image recording device 4 audio recording device 5 image decoding device 6 audio decoding device 7 time code generation device 8 selection device 9, 10 encoding parameter table 11 video / audio synchronization device 12 genre code detection Apparatus 13 Encoding parameter calculating apparatus 14 Compression rate reading apparatus 16 Setting device 17 Genre discriminating apparatus 80 Magnetic card

Claims (6)

[Claims] 1. A compression recording apparatus for separately compressing and encoding a video signal and an audio signal and recording the same, comprising: detection means for detecting one or both characteristics of the video signal and the audio signal; Setting means for obtaining a compression rate corresponding to the detected feature and setting the obtained compression rate for each of the video signal and the audio signal; and separately for the video signal and the audio signal at the compression rate set by the setting means. And a compression means for performing compression encoding. 2. The apparatus according to claim 1, wherein one or both of the video signal and the audio signal detected by the detection unit is a genre code of a broadcasting station that broadcasts the video signal and the audio signal. Compression recording device. 3. A compression recording apparatus for separately encoding and recording a video signal and an audio signal, wherein the setting means arbitrarily sets a compression ratio for each of the video signal and the audio signal. Compression means for separately compressing and encoding a video signal and an audio signal at different compression ratios. 4. A compression recording apparatus for separately compressing and encoding a video signal and an audio signal, and recording the compression ratio of either one or both of the video signal and the audio signal; Setting means for reading the recorded compression rate and setting each of the video signal and the audio signal; and compression means for separately compressing and encoding the video signal and the audio signal at the compression rate set by the setting means. A compression recording device, comprising: 5. The compression recording apparatus according to claim 4, wherein the compression ratio set for the video signal by said setting means changes with time. 6. A compression recording method for separately compressing and encoding a video signal and an audio signal, and recording the video signal and the audio signal, wherein: detecting a characteristic of one or both of the video signal and the audio signal; Determining a corresponding compression ratio, setting the determined compression ratio for each of the video signal and the audio signal, and separately compressing and encoding the video signal and the audio signal at the set compression ratio. And a compression recording method.