JPH08223575A - Moving image coding system device - Google Patents

Abstract

PURPOSE: To suppress code amount by controlling the coding of the main video signal corresponding to the display area of a sub-video signal based on the mixing ratio with the sub-video signal in the display information signal of sub-video. CONSTITUTION: A coding processing is performed for a main video signal by a main video encoder 51 and main video coded data is obtained. A sub-video signal and the display information signal of the sub-video are superposed by a sub-video encoder 6, the coding processings are performed for the signals and sub-video coded data is obtained. A synchronization and a multiplexing processing are performed for the main video coded data and sub-video coded data by a formatter 8 by the format conformed to a transmission form or a recording form, multiplex stream is obtained and the stream is outputted via an output terminal 9. The code amount control part of the main video encoder 51 then performs a control to suppress generated code amount by performing the coding processing by the main encoder 51 according to the mixing ratio information on the display information signal for the moving image signal of only the area corresponding to the display area information on the sub-video signal in the display information signal.

Description

Detailed Description of the Invention

[0001]

[Object of the invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case where a main video signal and a sub video signal are encoded and multiplexed and then output.
The present invention relates to a moving picture coding system device suitable for suppressing the generated code amount of a main video signal corresponding to a display area of multiplexed sub video signals.

[0003]

2. Description of the Related Art In recent years, digital processing of images has been studied. In particular, various methods are being studied for recording digital image data obtained by compressing a moving image signal in a magnetic recording / reproducing apparatus. Further, recently, a device for recording a moving image signal, which has been subjected to a highly efficient compression encoding process on a CD (Compact Disk) or the like, which has been used frequently as a recording medium, has recently been attracting attention.

Generally, when a video signal is digitized, the amount of information becomes enormous, and it is difficult to transmit or record the information without compressing it in terms of communication speed and cost. Therefore, an image compression technique is indispensable for transmitting or recording a digital video signal, and various standardization plans have been studied in recent years. MPEG for moving images
(Moving Picture Experts Group) method is standardized. In MPEG, DCT (Discrete Cosine)
Transform) Transform, interframe predictive coding, run length coding, and entropy coding are used in combination to code a video signal. That is, in the MPEG system, 1
Not only is compression by DCT (intraframe compression) performed within a frame, but interframe compression that reduces the redundancy in the time axis direction by utilizing the correlation between frames is adopted. The inter-frame compression is to further reduce the bit rate by taking advantage of the fact that a general moving image is very similar to the preceding and following frames and obtaining the difference between the preceding and following frames and encoding the difference value. In particular, motion-compensated interframe predictive coding that reduces prediction error by predicting motion compensation of an image and obtaining a difference between frames is effective.

By the way, there is a case where a moving picture signal subjected to such high efficiency coding processing is mixed or transmitted with a sub-picture signal such as a subtitle for transmission or recording. In this case, when the input moving image signal is the main video signal, the main video signal is subjected to an encoding process by a high-efficiency compression encoding device (hereinafter referred to as an encoder) to obtain encoded data.
When the sub video signal and the audio signal are compressed, the compression processing is performed to obtain compressed data. Then, after performing a multiplexing process adapted to the predetermined format corresponding to the transmission form, the encoded data and each compressed data,
Transmit or record. FIG. 4 shows a system apparatus of a moving picture coding system in which each signal is coded separately and multiplexed and output as described above.

FIG. 4 is a block diagram showing an example of a system device of a conventional moving picture coding system. In FIG. 4, a moving image signal of the main image (hereinafter referred to as the main image signal) is input to the input terminal 1. Further, the sub-picture signal multiplexed with the main picture signal is input through the input terminal 2, and the input terminal 3 displays information for displaying the sub-picture signal with respect to the main picture signal, that is, sub-picture display information. Input the signal. The sub-video display information signal is, for example, a display area information signal (display position information signal) indicating in which area of the main video signal the sub-video signal is displayed, or a mixing ratio indicating a mixing ratio with the main video signal. Is a signal including a mixing ratio signal that specifies On the other hand, an audio signal is input to the input terminal 4.

The main video signal input through the input terminal 1 is applied to the main video encoder 5. Main video encoder 5
Is composed of, for example, the above-mentioned MPEG high-efficiency compression encoding circuit, and the main video encoder 5 performs high-efficiency encoding processing on the input signal to obtain encoded data. The main video encoder 5 will be described in more detail. For example, the coding process is performed using discrete cosine transform (hereinafter referred to as DCT). The main video encoder 5 has a video processing circuit, a DCT circuit, a shuffling circuit, a quantization circuit, a variable length coding circuit, an error correction coding circuit and the like, which are not shown. A video processing circuit (not shown) converts the input analog input main video signal into a digital signal and applies framed main image data to a shuffling circuit (not shown). A shuffling circuit (not shown) performs shuffling processing on the framed main image data to form a block (DCT block) of, for example, 8 pixels × 8 lines, and the block data to a DCT circuit (not shown). give. The DCT circuit (not shown) converts the block data from the shuffling circuit (not shown) into a two-dimensional DCT.
Processing is performed to convert the spatial coordinate axis component into the frequency axis component. The transform coefficient from the DCT circuit (not shown) is supplied to a quantization circuit (not shown) and quantized using a predetermined quantized coefficient. In this case, considering the human visual characteristics,
The higher the frequency component of the transform coefficient, the larger the quantization coefficient is set. This reduces signal redundancy. The quantized output of the quantization circuit (not shown) is supplied to the variable length coding circuit (not shown). A variable length coding circuit (not shown) performs variable length coding on the quantized output based on a predetermined variable length code table, for example, a Huffman code table, and supplies it to an error correction coding circuit (not shown). As a result, short bits are assigned to data having a high appearance probability and long bits are assigned to data having a low appearance probability, thereby further reducing the transmission amount. In this way, the main video encoder 5 performs encoding processing on the main video signal to obtain main video encoded data, and
The main video coded data is given to the formatter 8.

The sub-picture signal input through the input terminal 2 is given to the sub-picture encoder 6. Further, the display information signal input via the input terminal 3 is also given to the sub-picture encoder 6. The sub-picture encoder 6 superimposes the sub-picture signal and the display information signal when the sub-picture signal and the display information signal are separately supplied as in this example, and a predetermined code is applied to the superposed signal. Apply chemical treatment. Although not shown, the sub video signal and the display information signal may already be superimposed and given to the sub video encoder 6. In this case also, the sub-picture encoder 6 similarly performs a predetermined encoding process. As a result, sub-picture encoded data is obtained. This sub-picture encoded data is given to the formatter 8.

On the other hand, the audio signal input through the input terminal 4 is given to the audio encoder 7. Voice encoder 7
Performs A / D conversion of the input audio signal and synchronizes with the video signal, and also performs mixing processing and error correction processing. As a result, audio encoded data is obtained, and this audio encoded data is given to the formatter 8 as well as the main video and sub-video encoded data.

The formatter 8 multiplexes the main video coded data, the sub video coded data, and the audio coded data according to the application and in conformity with the format of the transmission form (storage medium, network, etc.) of the stream (data string). I do. That is, the main video coded data, the sub video coded data, and the audio coded data are synchronized with each other, and a multiplexed stream in a format suitable for the transmission mode is generated and output through the output terminal 9. After that, the multiplexed stream is transmitted by a cable or a radio wave (not shown), or is transmitted and then recorded in a recording medium. Also, when displaying the transmitted multiple streams on the screen,
When playing back the recorded multiple streams,
The multiple stream is decoded by a decoder (hereinafter, referred to as a decoder) corresponding to the compression encoding method at the time of compression, and the main video and the sub video are displayed on the screen and the sound is output. In the device shown in this example, since the display information signal of the sub-video signal is not input to the main video encoder 5, in this case, the sub-video signal is encoded by the main video encoder 5. The same compression coding process as that of the area in the other main video signal is performed on the main video signal corresponding to the display area.

Next, the operation of the moving picture coding system device having such a configuration will be described with reference to FIG.

FIG. 5 is an explanatory view for explaining the problems of the conventional moving picture coding system device, and FIG. 5 (a) is a screen display when only the main video signal is coded and the signal is decoded. FIG. 5B is a screen display diagram showing a sub-video signal display area based on a display information signal in an image based on the main video signal, and FIG. 5C is based on a sub-display information signal based on an image based on the main video signal. It is a screen display figure at the time of displaying a sub-picture signal in a field. It should be noted that the main video in FIGS. 5A to 5C has the same pattern as a final frame image for simplifying the description, and the sub-video is an example of subtitle display. The alphabetic symbols of A, B, C shall be displayed. Further, the description of the audio signal is omitted to simplify the description.

Now, assume that only the main video signal is input through the input terminal 1. In this case, the main video signal is subjected to an MPEG compression coding process by the main video encoder 5 and given to the formatter 8. Then, the main video coded data is synchronized by the formatter 8 with the audio coded data from the audio encoder 7 in a format suitable for the transmission form or the recording form, and further multiplexed to obtain a multiple stream. Then, the multiplexed stream is output via the output terminal 9. Although not shown, the multiplexed stream output via the output terminal 9 is transmitted or recorded on a digital recording medium such as a disk.

For example, it is assumed that a disk on which a multiple stream is recorded is reproduced by a magnetic reproducing device. Then, the reproduction data reproduced by the magnetic reproducing apparatus is decoded by the decoder (decoder) provided in the magnetic reproducing apparatus, and the original main video signal is obtained. In this case, in the decoding process by the decoder, the encoded data is decoded so as to correspond to the compression encoding process method of the encoder. Thereafter, the decoded main video signal is given to a display screen of a monitor or the like via a reproduction signal processing circuit or the like of the device. Then, the image based on the main video signal is displayed on the screen as shown in FIG.

Next, it is assumed that the sub-video signal is input from the input terminal 2 and the display information signal of the sub-video signal is input via the input terminal 3 while the main video signal is being input. Then, the sub-picture signal and the display information signal are coded by the sub-picture encoder 6 and multiplexed with the main-picture coded data by the formatter 8 to obtain a multiplexed stream. Then, this multiplex stream is transmitted and recorded on, for example, a disc. When playing this disc,
For example, if the sub-picture signal is a video signal such as a caption, the display area of the sub-picture signal indicated by the display information signal is the area surrounded by the broken line shown in FIG. 5B. Further, when the image of only the main video signal is displayed as shown in FIG. 5B, the code amount coded by the main video encoder 5 is assigned a predetermined code amount, and the wavy line The main video signal in the area corresponding to the sub video signal display area surrounded by is also assigned with the same code amount as in the encoding of only the main video signal.

An image based on the sub-picture signal, that is, an image such as a subtitle is displayed in the sub-picture display area based on the sub-picture display information. That is, the main video signal is encoded, and further, the sub video signal and the display information signal of the sub video are compressed and multiplexed to generate a multiplexed stream. After that, the multiple streams are transmitted and recorded on a digital recording medium such as a disc. Then, at the time of reproduction by the magnetic reproducing apparatus, the reproduction data is decoded to obtain the main video signal, the sub video signal, and the display information signal of the sub video. After that, when these signals are displayed on the screen, it becomes as shown in FIG. That is, the image based on the sub-picture signal is displayed in the display area and the display position based on the display information signal, and the contrast in the image of the sub-picture is also determined by the mixing ratio with the main picture based on the display information signal.

However, in the conventional moving picture coding system apparatus, the coding processing of the main video signal by the main video encoder 5 is performed regardless of the mixing ratio of the display information signal to the sub video. That is, the main video signal of the area corresponding to the display area of the sub video is similarly coded regardless of the mixing ratio. Therefore, the code amount does not change even if the display ratio of the main video shown in the mixing ratio becomes small, since the same code amount as in the normal encoding is assigned. For example, assuming that the mixing ratio of the display information signal of the sub video signal to the main video signal is extremely 100%, FIG.
In the sub-picture display area shown in (c), only sub-picture signals such as subtitles are displayed, and images based on the main picture signal corresponding to this area are not displayed. That is, in the display area of the sub-picture at this time, subtitles and the like are displayed on a black background screen. In this case, the main video signal in the area corresponding to the sub video signal display area may not be required to be encoded, but the main video encoder 6 may also perform the main video signal in the area corresponding to the sub video signal display area. As a result, the main video signal in the other area is encoded, and as a result, the encoding process according to the mixing ratio is not performed, and the code amount becomes constant.

By the way, in a disc (digital video disc) or the like capable of recording compression-encoded data of a moving image together with voice-encoded data, the capacity for recording is limited as well known. . That is, in order to record the compression-encoded data of the moving image in a longer time, it is desirable to reduce the code amount in the encoding process of the moving image signal as much as possible. However, in the conventional moving image coding system device, even in the impose portion which does not originally require a high quality image for the viewer, that is, the main video signal corresponding to the sub video signal area, Since the encoding is performed regardless of the mixture ratio, the resulting code amount is redundantly assigned. That is, there is a problem that the code amount cannot be suppressed. In addition, recently, a compression encoding method (hereinafter abbreviated as MPEG2) for encoding a higher quality image has also been standardized, and there is a main video encoder 5 adopting the MPEG2 compression encoding method. In this case, the code amount of the unnecessary main video signal is desirably reduced as much as possible since it can be widely utilized especially in the transmission form and the storage medium. Furthermore, by reducing the code amount,
It is desirable to allocate a code amount corresponding to that to the main video signal outside the sub-video signal display area to improve the high image quality, but in the conventional technology, the improvement has not been sufficiently made.

[0019]

As described above, in the conventional moving image coding system apparatus, when the main video signal and the sub video signal are coded, the main area of the area corresponding to the display area for displaying the sub video signal is displayed. There is a problem that the video signal is subjected to the code processing regardless of the mixing ratio of the sub video signal in the sub video display information signal, and the code amount for the main video signal cannot be reduced.

Therefore, the present invention has been made in view of the above problems, and based on the mixing ratio of the sub-picture display information signal to the sub-picture signal, the main picture signal corresponding to the display area of the sub-picture signal is displayed. An object of the present invention is to provide a moving picture coding system device capable of controlling coding and suppressing the code amount.

[0021]

【The invention's effect】

[0022]

According to a first aspect of the present invention, there is provided a moving image coding system apparatus according to the first aspect of the present invention. The moving image coding system device performs a coding process on an input moving image signal to generate main image coded data. From the first encoding means, the encoding means, the second encoding means for performing the encoding process on the sub-image signal to be mixed with the moving image signal for display, and generating the sub-image encoded data. Together with the main image coded data and the sub image coded data from the second coding means, display area information indicating a display area of the sub image signal and mixing ratio information indicating a mixing ratio to the moving image signal. A multiplex stream generation means that multiplexes the display information signal to generate and output a multiplex stream, and the first encoding means that causes the first encoding means to perform an encoding process based on the display information signal. From the means of conversion A code amount control means for controlling so as to suppress the code amount is obtained by including a.

According to a fourth aspect of the present invention, there is provided a moving picture coding system apparatus, wherein a filtering means for filtering an inputted moving picture signal and outputting the filtered moving picture signal, and a coding processing for a moving picture signal output from the filtering means. And a first encoding means for generating main image encoded data and a sub image signal to be mixed with the moving image signal for display to generate sub image encoded data. A display area indicating a display area of the sub-image signal, together with second encoding means, main image encoded data from the first encoding means, and sub-image encoded data from the second encoding means. Information and a multiple stream generating means for generating and outputting a multiple stream by multiplexing a display information signal including mixing ratio information indicating a mixing ratio to the moving image signal, and the filter based on the display information signal. And to perform the filtering by stage, in which anda filter control means for controlling so as to suppress the amount of generated codes in the first encoding means.

[0024]

According to the first aspect of the present invention, the first encoding means performs the encoding process on the input moving image signal to generate main image encoded data. The second encoding means performs an encoding process on the sub-image signal to be mixed with the moving image signal for display and generates sub-image encoded data. The multiple stream generation means, together with the main image encoded data from the first encoding means and the sub image encoded data from the second encoding means, display area information indicating a display area of the sub image signal, A display information signal including mixing ratio information indicating a mixing ratio to the moving image signal is multiplexed to generate and output a multiplexed stream. At this time, the code amount control means causes the first encoding means to perform the encoding process based on the display information signal, and controls so as to suppress the generated code amount in the first encoding means. Accordingly, the code amount of the moving image signal in the area based on the display area of the sub image signal can be suppressed.

According to a fourth aspect of the present invention, the filter means filters the input moving image signal and outputs it. The first encoding means performs encoding processing on the moving image signal output from the filter means to generate main image encoded data. The second encoding means performs an encoding process on the sub-image signal to be mixed with the moving image signal for display and generates sub-image encoded data. The multiple stream generation means, together with the main image encoded data from the first encoding means and the sub-image encoded data from the second encoding means,
A display information signal including display area information indicating a display area of the sub-image signal and mixing ratio information indicating a mixing ratio of the moving image signal is multiplexed to generate and output a multiplexed stream. At this time, the filter control means controls the filter processing by the filter means based on the display information signal so as to suppress the generated code amount in the first encoding means. Accordingly, the code amount of the moving image signal in the area based on the display area of the sub image signal can be suppressed.

[0026]

An embodiment will be described with reference to the drawings.

FIG. 1 is a block diagram showing an example of a moving picture coding system device according to the present invention. The same components as those of the device shown in FIG. 4 are designated by the same reference numerals.

In FIG. 1, a main video signal is input to the input terminal 1. Further, the sub-picture signal multiplexed with the main picture signal is input through the input terminal 2, and the input terminal 3 displays information for displaying the sub-picture signal with respect to the main picture signal, that is, the display of the sub-picture. Input information signal. Similar to the prior art, the display information signal of the sub-picture is, for example, a display area information signal (display position information signal) indicating in which area of the main picture signal the sub-picture signal is displayed, or a mixture with the main picture signal. This is a signal including a mixing ratio signal that specifies a mixing ratio indicating a ratio to perform. On the other hand, an audio signal is input to the input terminal 4. The main video signal input via the input terminal 1 is given to the main video encoder 51. The main video encoder 51 is composed of, for example, a high-efficiency compression encoding circuit of the MPEG system (MPEG1 or MPEG2), and the main video encoder 5
Reference numeral 1 performs high-efficiency encoding processing on an input signal to obtain encoded data. Further, in this embodiment, the sub-video display information signal is also supplied to the main video encoder 51, and the main video encoder 51 is based on the sub-video display information signal (not shown). It has a code amount control unit for controlling the encoding process by the high efficiency compression encoding circuit. The code amount control unit, for example, in the encoding process of the main video signal corresponding to the area based on the sub video display area information signal included in the display information signal of the sub video, based on the mixing ratio signal of the sub video information signal. The code amount is controlled.

The main video encoder 51 will be described in more detail. For example, DCT conversion is used to perform the encoding process. The main video encoder 51 has a video processing circuit, a DCT circuit, a shuffling circuit, a quantization circuit, a variable length coding circuit, an error correction coding circuit, etc., which are not shown, in addition to the code amount control unit described above. There is. A video processing circuit (not shown) converts the input analog input main video signal into a digital signal and applies framed main image data to a shuffling circuit (not shown). A shuffling circuit (not shown) performs shuffling processing on the framed main image data to form a block (DCT block) of, for example, 8 pixels × 8 lines, and the block data to a DCT circuit (not shown). give. The DCT circuit (not shown) performs two-dimensional DCT processing on the block data from the shuffling circuit (not shown) to convert the spatial coordinate axis component into the frequency axis component. The transform coefficient from the DCT circuit (not shown) is supplied to a quantization circuit (not shown) and quantized using a predetermined quantized coefficient. In this case, considering the human visual characteristics, the quantization coefficient is set larger for the higher frequency component of the transform coefficient. This reduces signal redundancy. The quantized output of the quantization circuit (not shown) is supplied to the variable length coding circuit (not shown). A variable length coding circuit (not shown) performs variable length coding on the quantized output based on a predetermined variable length code table, for example, a Huffman code table, and supplies it to an error correction coding circuit (not shown). This assigns short bits to data with a high probability of occurrence,
Longer bits are assigned to the data having a low appearance probability to further reduce the transmission amount.

In the present embodiment, for example, a code amount control unit (not shown) controls so as to change the quantization coefficient based on the display information signal of the sub-picture. This allows
The code amount of the main video signal corresponding to the display area of the sub video signal can be reduced. In this way, the main video encoder 51 performs the encoding process on the main video signal to obtain the main video encoded data, and the main video encoded data is given to the formatter 8.

The sub-picture signal input through the input terminal 2 is given to the sub-picture encoder 6. The display information signal input through the input terminal 3 is supplied to the main video encoder 51 as described above and also to the sub video encoder 6. The sub-picture encoder 6 superimposes the sub-picture signal and the display information signal in the case where the sub-picture signal and the display information signal are separately supplied as in the present embodiment, and a predetermined signal is superimposed on the superposed signal. Encoding processing is performed. Although not shown, the sub video signal and the display information signal may already be superimposed and given to the sub video encoder 6. In this case also, the sub-picture encoder 6 similarly performs a predetermined encoding process. As a result, sub-picture encoded data is obtained. This sub-picture encoded data is given to the formatter 8.

On the other hand, the audio signal input through the input terminal 4 is given to the audio encoder 7. Voice encoder 7
Performs A / D conversion of the input audio signal and synchronizes with the video signal, and also performs mixing processing and error correction processing. As a result, audio encoded data is obtained, and this audio encoded data is given to the formatter 8 as well as the main video and sub-video encoded data.

The formatter 8 multiplexes the main video coded data, the sub video coded data, and the audio coded data according to the application and in conformity with the format of the transmission form (storage medium, network, etc.) of the stream (data string). I do. That is, the main video coded data, the sub video coded data, and the audio coded data are synchronized with each other, and a multiplexed stream in a format suitable for the transmission mode is generated and output through the output terminal 9. After that, the multiple streams are transmitted or recorded by a cable or radio waves (not shown). When the transmitted multiple stream is displayed on the screen or when the recorded multiple stream is played back, the multiple stream is decoded by a decoder (decoder) corresponding to the compression encoding method at the time of compression and displayed on the screen. The main video and sub video are displayed, and the audio is output.

Next, the operation of this embodiment will be described.

Now, it is assumed that the main video signal, the sub video signal, the display information signal of the sub video, and the audio signal are inputted so as to correspond to the input terminals 1 to 4, respectively. Then, the sub-picture signal and the display information signal are coded by the sub-picture encoder 6, and the coded coded data is given to the formatter 8. On the other hand, the main video signal is the main video encoder 51.
By this, the compression coding processing of the MPEG system is performed to obtain the main video coded data. At this time, the code amount control unit in the main video encoder 51, for example, in the encoding process of the main video signal corresponding to the area based on the sub video display area information signal, based on the mixing ratio signal of the sub video information signal. Control the code amount. Specifically, the code amount control unit changes the quantization amount to control the code amount for each block unit to change the code amount. This makes it possible to suppress the code amount of the main video signal corresponding to the display area of the sub video signal.

The main video coded data thus coded is synchronized and multiplexed by the formatter 8 with the main video coded data, the sub video coded data and the audio coded data in a format suitable for the transmission form or the recording form. It is processed to obtain multiple streams. Then, the multiplexed stream is output via the output terminal 9. Although not shown, the multiplexed stream output via the output terminal 9 is transmitted or recorded on a digital recording medium such as a disk.

For example, it is assumed that the disk on which the multiple streams are recorded is reproduced by the magnetic reproducing device. Then, the reproduction data reproduced by the magnetic reproducing apparatus is decoded by the decoder (decoder) provided in the magnetic reproducing apparatus, and the original main video signal is obtained. In this case, in the decoding process by the decoder, the encoded data is decoded so as to correspond to the compression encoding process method of the encoder. After that, the decoded main video signal and sub-video signal are given to a display screen such as a monitor through a reproduction signal processing circuit of the apparatus. Then, the image based on the main video signal is shown in FIG.
The screen is displayed as shown in (c). That is, in the sub-picture signal area surrounded by the diagonal lines in the figure, the sub-picture corresponding to the mixing ratio of the display information signals of the sub-picture is displayed, and the main picture with suppressed image quality is also displayed.

Therefore, according to this embodiment, in the encoding process of the main image signal, the encoding process can be controlled based on the sub-image signal display area and the mixing ratio included in the display information signal of the sub-image. As a result, it becomes possible to perform encoding so as to suppress the code amount of the main video signal corresponding to the display area of the sub video signal. As a result, since the code amount can be reduced as a whole, the recording time can be lengthened when recording on a digital recording medium such as a disk. Further, by allocating the suppressed code amount to the code amount of the main video signal outside the sub video display area, it is possible to improve the image quality of other main video that is not in the impose area.

FIG. 2 is a block diagram showing another embodiment of the moving picture increasing coding system apparatus of the present invention. In the apparatus shown in FIG. 2, the same components as those of the apparatus shown in FIG. And the description is omitted.

In the present embodiment, the main video encoder 6
The pre-filter 10 is arranged in the preceding stage, and a filter control unit for controlling the main video signal in the area shown in the display information signal of the sub-video to suppress the high frequency component is provided in the pre-filter 10. The difference from the above-described embodiment is that the provision of such a configuration suppresses the code amount of the main video signal corresponding to the sub video display area.

In FIG. 2, the main video signal input through the input terminal 1 is given to the prefilter 10. The prefilter 10 is composed of, for example, a low-pass filter that passes low-frequency components of the signal, and suppresses and outputs high-frequency components of the input main video signal. Also, the prefilter 1
The display information signal of the sub-picture input through the input terminal 3 is also supplied to 0. Further, the pre-filter 10 has a filter control unit (not shown) which controls the main video signal in the area shown in the display information signal of the sub video so as to suppress the high frequency component. In this case, the filter control unit controls the prefilter 10 so as to filter the main video signal in the area based on the display area signal including the display information signal of the sub video.
That is, only the main video signal corresponding to the display area of the main video signal sub-video signal is filtered by the pre-filter 10, and the main video signal of the low frequency component is given to the main video encoder 6. At this time, the main video signal outside the sub-video display area may be directly applied to the main video encoder 6 without being subjected to the filtering process.

It is also possible that the prefilter 10 can change the frequency component to be suppressed by the filter coefficient. In this case, the filter control unit controls the filter coefficient of the filter 10 based on the mixing ratio signal of the sub-picture for the main picture signal of the area based on the display area signal including the display information signal of the sub-picture. After that, the main video signal whose predetermined frequency component has been filtered as described above is given to the main video encoder 6.

The main video encoder 6 encodes the supplied main video signal. At this time, since the main video signal corresponding to the sub video display area is composed of low frequency components, the generated code amount can be reduced, and as a result, the code amount in the sub video display area is suppressed. It becomes possible to assign. After that, as in the above-described embodiment, the formatter 9 synchronizes and multiplexes the data and outputs it via the output terminal 9.

Other functions and effects are the same as those in the above embodiment.

Therefore, according to the present embodiment, the pre-filter 10 controls in advance to suppress the high frequency component of the main video signal based on the sub video signal display area included in the display information signal of the sub video. When the main video signal is encoded by the main video encoder, the code amount of the main video signal corresponding to the display area of the sub video signal can be suppressed.

FIG. 3 is a block diagram showing another embodiment of the moving picture coding system apparatus according to the present invention. The apparatus shown in FIG. 3 has the same reference numerals as those in FIGS. 1 and 2. And the description is omitted.

In this embodiment, the apparatus shown in FIGS. 1 and 2 is combined and improved, and the display information signal of the sub-picture input through the input terminal 3 is supplied to the prefilter 10 and the main-picture encoder, respectively. To give to 6,
Although not shown, it is different in that the filter control unit and the code amount control unit are configured to control the encoding amount for the main video signal in the sub video display area based on the display information signal of the sub video.

In FIG. 3, the sub-picture display information signal input through the input terminal 3 is applied to the pre-picture filter 10 and the main picture encoder 6 as well as the sub-picture encoder 6. As in the embodiment shown in FIG. 2, the pre-filter 10 is composed of, for example, a low-pass filter that passes the low frequency component of the signal, suppresses the high frequency component of the input main video signal, and suppresses only the low frequency component. Output a signal. Further, the pre-filter 10 filters the main video signal in the area shown in the display information signal of the sub video by the control of the filter control unit to remove the high frequency component. That is, only the main video signal corresponding to the display area of the main video signal sub-video signal is filtered by the pre-filter 10, and the main video signal of the low frequency component is given to the main video encoder 6. At this time, the main video signal outside the sub-video display area may be directly applied to the main video encoder 6 without being subjected to the filtering process. Further, the pre-filter 10 may be capable of varying the frequency component to be suppressed by the filter coefficient. In this case, the filter control unit controls the filter coefficient of the filter 10 based on the mixing ratio signal of the sub-picture for the main picture signal of the area based on the display area signal including the display information signal of the sub-picture.

On the other hand, the main video encoder 6 performs an encoding process on the main video signal. At this time, the code amount control unit of the main video encoder 6 controls to encode the main video signal corresponding to the sub video display area based on the mixing ratio signal included in the display information signal of the sub video. That is, the main video signal corresponding to the sub video display area is composed of low-frequency components, and further, the encoding process is performed based on the mixing ratio with the sub video signal. ,
The code amount of the main video signal can be suppressed, and as a result, the code amount can be effectively suppressed and assigned. Thereafter, as in the above-described embodiment, the formatter 8 synchronizes and multiplexes the data and outputs it via the output terminal 9.

Other functions and effects are the same as those in the above embodiment.

Therefore, according to the present embodiment, the pre-filter controls so as to suppress the high frequency component of the main video signal based on the sub video signal display area included in the display information signal of the sub video. By controlling the video encoder to encode the main video signal based on the mixing ratio with the sub video signal, it is possible to suppress the code amount of the main video signal corresponding to the display area of the sub video signal. Becomes

In the embodiment according to the present invention, the main video signal is coded based on one of the sub-video display area signal and the mixing ratio signal included in the sub-video display information signal. The moving image coding system device may be configured to perform.

Further, in the embodiment in which the pre-filter is arranged, the filter value of the pre-filter may be varied.

[0054]

As described above, according to the present invention, the encoding process of the main video signal corresponding to the sub video signal display area where the sub video signal is displayed is performed according to the mixing ratio with the sub video signal. The controllability has the effect of suppressing the code amount of only the main video signal corresponding to the sub video signal display area.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a moving picture coding system device according to the present invention.

FIG. 2 is a block diagram showing another embodiment of the moving picture coding system device according to the present invention.

FIG. 3 is a block diagram showing another embodiment of the moving picture coding system device according to the present invention.

FIG. 4 is a block diagram showing an example of a conventional moving image coding system device.

FIG. 5 is an explanatory diagram for explaining a conventional problem.

[Explanation of symbols]

1 to 4 ... Input terminal, 51 ... Main video encoder, 6 ... Sub video encoder, 7 ... Audio encoder, 8 ... Formatter, 9 ... Main terminal, 10 ... Prefilter.

Claims (9)

[Claims] 1. A first encoding means for subjecting an input moving image signal to an encoding process to generate main image encoded data, and a sub-image signal to be mixed with the moving image signal for display. A second method for performing encoding processing to generate sub-image encoded data
And the main image encoded data from the first encoding means and the sub-image encoded data from the second encoding means,
Multiplex stream generation means for generating multiplex stream by outputting a multiplex display information signal including display area information indicating a display area of the sub-image signal and mixing ratio information indicating a mixing ratio to the moving image signal; And a code amount control unit for performing a coding process by the first coding unit on the basis of an information signal and controlling so as to suppress a generated code amount in the first coding unit. Characteristic video coding system device. 2. The code amount control means controls the moving image signal of only the display area corresponding to the display area information so as to suppress the generated code amount in the first encoding means. The moving picture coding system device according to claim 1. 3. The code amount control means suppresses the generated code amount in the first encoding means on the basis of the mixture ratio information with respect to the moving image signal of only the display area corresponding to the display area information. The moving picture coding system device according to claim 1. 4. A filter means for filtering an input moving image signal and outputting the same, and a first means for performing an encoding process on the output moving image signal from the filter means to generate main image encoded data. A second encoding means for generating sub-image encoded data by performing an encoding process on the sub-image signal to be mixed with the moving image signal for display.
And the main image encoded data from the first encoding means and the sub-image encoded data from the second encoding means,
Multiplex stream generation means for generating multiplex stream by outputting a multiplex display information signal including display area information indicating a display area of the sub-image signal and mixing ratio information indicating a mixing ratio to the moving image signal; A video control code, comprising: a filter control means for performing a filtering process by the filter means on the basis of an information signal to control so as to suppress the generated code amount in the first encoding means. System equipment. 5. The moving picture coding system apparatus according to claim 4, wherein said filter means performs a filtering process so as to suppress and output a high frequency component of the inputted moving picture signal. 6. The filter control means causes the moving image signal of only the display area corresponding to the display area information to be filtered by the filter means, and the generated code in the first encoding means. The moving picture coding system apparatus according to claim 4, wherein the moving picture coding system apparatus is controlled so as to suppress the amount. 7. The filter control means causes the moving image signal of only a display area corresponding to the display area information to be filtered by the filter means based on the mixture ratio information, and the first filter 5. The moving picture coding system device according to claim 4, wherein the coding means controls so as to suppress the generated code amount. 8. The first encoding means is an MPEG1 system or an MPEG2 which is a compression encoding system of a moving image signal.
The moving picture coding system apparatus according to claim 1, wherein the moving picture coding system is an encoder configured by one of the compression coding methods. 9. The sub-image signal is a signal including a character image, and is a signal displayed on a display image of the moving image signal, according to any one of claims 1 to 8. The video image coding system device according to item 1.