JP2001268511A - Method and system for digital broadcast - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital broadcast method and a system capable of solving the author's distrust about digital recording itself and enabling a viewer to re-view the digitally recorded contents by the same analog broadcast sense as conventional one. SOLUTION: A transmitting station generates picture and voice data of high quality and picture and voice data of low quality lower than the picture and voice data of the high quality from the same picture and voice and adds discrimination information for discriminating the picture and voice data of high quality from the picture and voice data of low quality to either one of these data or to both of the data. Then the picture and voice data of high quality and the picture and voice data of low quality are digitally broadcasted. A receiving station receives these data and selects the picture and voice data of high quality and the picture and voice data of low quality so as to record only the picture and sound data of low quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcasting method and system for digitally broadcasting images and sounds, and more particularly to digital broadcasting of high-quality and low-quality images and sounds at the receiving station side. The present invention relates to a digital broadcasting method and system for controlling recording.

[0002]

2. Description of the Related Art In recent years, digital broadcasting has been actively studied, and its realization is imminent. This digital broadcast has a feature that, since an image signal and an audio signal are broadcast as digital signals, the received image signal and audio signal are recorded on a recording medium with little deterioration.

[0003]

However, due to the above-mentioned characteristics, digital broadcasting has a possibility of so-called unauthorized use, which is recorded on a recording medium and then reused without consent of a copyright holder. I have. In order to prevent such unauthorized use, a technique of inserting a copy control signal into the header of a digital signal has been proposed, but the distrust of the copyright holder of the digital recording itself still remains, and problems in program production remain. was there. Furthermore, many recording devices that are widely used cannot record low bits, that is, a large amount of information.
Therefore, high-quality images and sounds have to be recorded with a large amount of information, and in many cases, cannot be recorded by a generally used recording device.

Therefore, the present invention has been made in view of the above problems, and digitally broadcasts the same image and sound as low quality separately from the high quality image and high sound quality digitally broadcasted. By controlling recording on the receiving side, it is possible to eliminate the distrust of the copyright holder of the digital recording itself, and to provide a digital broadcasting method and a system for allowing the viewer to re-listen with the same analog broadcasting feeling as before. Is to do. Further, an object of the present invention is to digitally broadcast a low-quality image and sound separately from the high-quality image and high-quality sound digitally broadcasted,
It is an object of the present invention to provide a technique capable of recording even a recording device which cannot record a low bit, that is, a large amount of information, which is widely used.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a digital broadcasting method, wherein the same image and sound are of lower quality than the high quality image and sound and the high quality image and sound. Digitally broadcasting low-quality images and sounds; and receiving the high-quality images and sounds and the low-quality images and sounds, and recording the received low-quality images and sounds. This is achieved by a digital broadcasting method.

It is another object of the present invention to provide a digital broadcasting method, wherein high-quality image data and high-quality data and low-quality low-quality images and voices are obtained from the same image and voice. Generating image data and audio data, and identifying information for identifying the high-quality image data and audio data and the low-quality image data and audio data, the high-quality image data and audio data Adding one or both of the low-quality image data and the audio data, and digitally broadcasting the high-quality image data and the audio data and the low-quality image data and the audio data to which the identification information is added. Receiving the high-quality image data and audio data and the low-quality image data and audio data, and based on the identification information. Selecting the high-quality image data and audio data from the low-quality image data and audio data, and recording only the selected low-quality image data and audio data. This is achieved by a digital broadcasting method characterized by the following.

As an example of generating high-quality image data and audio data and low-quality image data and audio data, the same image and audio are compressed at a low bit rate and a high bit rate, respectively. Image data and audio data and low-quality image data and audio data are generated.

Further, high-quality image data and audio data and low-quality image data and audio data are converted into different modulation methods, for example, high-quality image data and audio data.
Digital broadcasting is carried out by modulating with the 8PSK method which can transmit a large amount of information at a high bit rate but is weak against noise, and modulating by the QPSK method which can transmit a small amount of information at a low bit rate but is strong against noise. By doing so, it is possible to view and record (record) low-quality image data and audio data even when high-quality image data and audio data cannot be received. Further, as identification information, scrambling of a high-quality image or addition of a marker for identifying image quality to a low-quality image can be considered.

An object of the present invention is a digital broadcasting system, which encodes a broadcast image and audio with a high quality encoder, and encodes the broadcast image and audio with a lower quality than the high quality encoder. Low-quality encoder, identification information for identifying the high-quality image data and audio data and the low-quality image data and audio data, the high-quality image data and audio data and the low-quality image data and audio Identification information adding means for adding to one or both of the data, and the encoded high-quality image data and audio data,
Modulating means for modulating the encoded low-quality image data and audio data; transmitting high-quality image data and audio data, and low-quality image data and audio data modulated by the modulation means; A transmitting station having transmitting means, a recording means for recording images and sounds, a receiving means for receiving the high-quality image data and sound data and the low-quality image data and sound data, and The high-quality image data and audio data received by the receiving unit and the low-quality image data and audio data, and only the selected low-quality image data and audio data are stored in the storage unit. And a receiving station having a selection means for outputting to the digital broadcasting system.

As an example of a low-quality encoder, encoding is performed at a bit rate lower than that of a high-quality encoder with an increased compression rate. Also, the modulating means
Different modulation schemes for high-quality image data and audio data and low-quality image data and audio data, such as high-quality image data and audio data, can transmit a lot of information at a high bit rate, but are susceptible to noise. Modulation is performed by the 8PSK method, and modulation is performed by the QPSK method, which has a small amount of information that can be transmitted at a low bit rate but is strong against noise. By doing so, there is an effect that even when high-quality image data and audio data cannot be received, low-quality image data and audio data can be viewed. The digital broadcast system according to claim 7, wherein modulation is performed by:

As means for adding identification information, the transmitting station has scrambling means for scrambling, as identification information, an image input to a high-quality encoder, or the transmitting station comprises a low-quality encoder. Means for adding a marker for identifying image quality as identification information to the image input to the image forming apparatus.

[0012]

Embodiments of the present invention will be described.

FIG. 1 is a block diagram of an embodiment of the present invention. This embodiment mainly includes a broadcasting station and a receiver (receiving station).

In FIG. 1, reference numeral 1 denotes a scramble device. This scramble device 1 is a device for scrambling an input image A, and if there is no scramble key on the receiving side, the scramble applied to the image cannot be released and cannot be viewed. Further, as described later, it also has a role as identification information for distinguishing between high quality and low quality.

Reference numeral 2 denotes a high-quality encoder that encodes an image scrambled by the scrambler 1. The high image quality encoder 2 encodes an image with a higher bit rate and a lower compression ratio than a low image quality encoder described later.

Reference numeral 3 denotes a high sound quality encoder for encoding a sound to be added to the image A. A multiplexing device 4 multiplexes the high-quality image encoded by the high-quality encoder 2 and the high-quality sound encoded by the high-quality encoder 3.

Reference numeral 5 denotes a low image quality encoder. The low image quality encoder 5 is an encoder that compresses the image A at a lower bit rate and higher than the high image quality encoder 2. Therefore, the image output from the low image quality encoder 5 has a lower image quality than the image output from the high image quality encoder 2.

Reference numeral 6 denotes a low sound quality encoder for encoding a sound added to the image A. This low sound quality audio encoder is an encoder that performs a high compression at a low bit rate as compared with the audio encoder 3. Therefore, the audio output from the low-quality encoder 6 has a lower quality than the audio output from the audio encoder 3. A multiplexing device 7 multiplexes the low-quality image encoded by the low-quality encoder 5 and the low-quality sound encoded by the low-quality encoder 6.

Reference numeral 8 denotes a first modulator. The first modulator 8 modulates the data output from the multiplexer 4 by the 8PSK method. The 8PSK method has an advantage that a large amount of information can be transmitted at a high bit rate, but has a weak point that it is susceptible to noise and cannot be normally received during rainfall.

Reference numeral 9 denotes a second modulator. The second modulator 9 modulates data output from the multiplexer 7 by the QPSK method. This QPSK system has a lower bit rate and a smaller amount of information that can be transmitted than the 8PSK system,
It has the advantage of being resistant to noise and capable of receiving accurately even during rain.

Reference numeral 10 denotes a transmitter, which transmits the modulated signal of the modulator 8 and the modulated signal S of the modulator 9 simultaneously (on different channels). A receiving circuit 11 receives the high-quality image data and audio data and the low-quality image data and audio data transmitted from the broadcasting station.

Reference numeral 12 is a recording device such as a VTR, and 13 is a monitor. A selection circuit 14 selects high-quality image data and audio data and low-quality image data and audio data based on the identification information of the received data, and records only low-quality image data and audio data. Output to the device 12. The display 13 outputs not only low-quality image data and audio data but also high-quality image data and audio data.

Next, the operation of the above configuration will be described. The image A to be digitally broadcast is first input to the scrambler 1 and scrambled. Then, the scrambled image A is input to the high image quality encoder 2 and encoded.

On the other hand, the image A is also input to the low image quality encoder 5 and is encoded with a lower image quality than the high image quality encoder 2, for example, at a low bit rate and a high compression rate. Similarly, the sound added to the image A is encoded by the high sound quality encoder 3 and the low sound quality encoder 6.

The output of the high-quality encoder 2 and the output of the high-quality encoder 3 are input to a multiplexer 4 and multiplexed. Similarly, the output of the low image quality encoder 5 and the output of the low sound quality encoder 6 are input to the multiplexer 7 and multiplexed.

The output of the multiplexing device 4 is input to the modulator 8 and is subjected to 8PSK modulation. Since 8PSK modulation can transmit a larger amount of information than QPSK modulation, it is suitable as a modulation method for transmitting high-quality images.

On the other hand, the output of the multiplexer 7 is input to the modulator 9 and QPSK-modulated. This QPSK modulation is 8
Although the amount of information that can be transmitted is smaller than PSK modulation, it is resistant to rainfall and the like, and even when high-quality images and sounds modulated by 8PSK cannot be viewed,
There is an advantage that low-quality images and sounds can be viewed. Each of the modulated signals modulated as described above, that is, the output of the modulator 8 and the output of the modulator 9 are transmitted by the transmitter 10.

On the receiver side, the digitally broadcasted signal is received by the receiving circuit 11 (set top box). Then, the scrambling is canceled by the selecting circuit 14, and the scrambled image data and the unscrambled image data are selected.

From the selection circuit 14 to the monitor 13, not only the scrambled image data, that is, the high-quality image data and the high-quality sound data, but also the non-scrambled image data, that is, the low-quality image data Image data and audio data of low sound quality are also output.
Then, when the viewer wants to view and record the image and sound displayed on the monitor, only low-quality image data and low-quality sound data are output from the selection circuit 14 to the recording device 12 by a predetermined operation, The recording device 12 records low-quality image data and low-quality audio data.

In the above-described embodiment, when a predetermined content usage fee is paid for high-quality images and sounds, the recording apparatus 12 is also configured to output high-quality image data and sound data. You may.

Next, another embodiment will be described.
FIG. 2 is a block diagram of another embodiment.

Another embodiment is characterized in that, in addition to the above-described embodiment, a marker adding device 21 for adding a marker indicating a low-quality image to an image is added. The marker adding device 21 adds a marker indicating that the image A is a low-quality image before the image A is input to the low-quality encoder 5. With this marker,
The selection circuit 14 can not only select low-quality image data and audio data, but also recognize the viewer that the image displayed on the monitor 13 is of low image quality.

The marker may be added not only in a form that can be visually recognized on the image, but also embedded in the data so as not to be seen as an image. In this case, the marker is the sorting circuit 1
4 plays a role as identification information for selection.

[0034]

According to the present invention, digital broadcasting of high-quality images and audios and low-quality images and audios simultaneously is performed, and recording is controlled on the receiving side, so that the broadcasting station can easily obtain the consent of the copyright holder. This has the effect of making it easier to obtain as many materials. Further, according to the present invention, the viewer side can use a low-bit recording device that is widely used, without relying on a recording device capable of recording a large amount of information, to reproduce low-quality images and sounds in the same manner as in analog broadcasting. There is an effect that recording and re-viewing can be performed with a simple feeling. Further, by modulating high-quality images and sounds and low-quality images and sounds by different modulation methods, there is an effect that even if one cannot be viewed, the other can be viewed and recorded.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scrambler 2 High-quality encoder 3 High-quality sound encoder 4 Multiplexer 5 Low-quality encoder 6 Low-quality sound encoder 7 Multiplexer 8 Modulator (8PSK modulation) 9 Modulator (QPSK modulation) 10 Transmitter 11 Receiving circuit 12 Recording device 13 Monitor 14 Sorting circuit

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Claims (11)

[Claims] 1. A digital broadcasting method, wherein the same image and sound are digitally broadcasted with a high quality image and sound and a low quality image and sound with lower quality than the high quality image and sound. And a step of receiving the high-quality image and sound and the low-quality image and sound, and recording the received low-quality image and sound. 2. A digital broadcasting method, comprising: from the same image and audio, high-quality image data and audio data, and low-quality image data and audio data of lower quality than the high-quality image and audio. Generating the identification information for identifying the high-quality image data and audio data and the low-quality image data and audio data, the high-quality image data and audio data and the low-quality image data and Adding to one or both of audio data; digitally broadcasting high-quality image data and audio data and low-quality image data and audio data to which the identification information is added; And the low-quality image data and the audio data, and the high-quality image data based on the identification information. Digital broadcasting comprising the steps of: selecting data and audio data from the low-quality image data and audio data; and recording only the selected low-quality image data and audio data. Method. 3. The same image and sound are compressed at a low bit rate and a high bit rate, respectively, to generate high-quality image data and audio data and low-quality image data and audio data. The digital broadcasting method according to claim 1. 4. The digital broadcast according to claim 1, wherein high-quality image data and audio data and low-quality image data and audio data are modulated by different modulation schemes and digitally broadcast. Digital broadcasting method described in 1. 5. The digital broadcasting method according to claim 1, wherein scrambling is performed on high-quality images as identification information. 6. The digital broadcasting method according to claim 1, wherein a marker for identifying image quality is added to low-quality images as identification information. 7. A digital broadcasting system, comprising: a high-quality encoder for encoding images and sounds to be broadcast; a low-quality encoder for encoding the images and sounds to be broadcast at a lower quality than the high-quality encoder; Identification information for identifying the high-quality image data and audio data and the low-quality image data and audio data may be any one of the high-quality image data and audio data and the low-quality image data and audio data. Identification information adding means for adding to one or both; modulating means for modulating the encoded high-quality image data and sound data; and the encoded low-quality image data and sound data; and Transmit modulated high quality image and audio data and low quality image and audio data A transmitting station having a transmitting means, a recording means for recording images and sounds, a receiving means for receiving the high-quality image data and sound data and the low-quality image data and sound data, and The high-quality image data and audio data received by the receiving unit and the low-quality image data and audio data, and only the selected low-quality image data and audio data are stored in the storage unit. A digital broadcasting system comprising: a receiving station having a selection unit that outputs the received signal to a digital broadcasting system. 8. The digital broadcasting system according to claim 7, wherein the low-quality encoder is configured to encode at a lower bit rate than a high-quality encoder with an increased compression rate. 9. The apparatus according to claim 7, wherein the modulating means modulates high-quality image data and audio data and low-quality image data and audio data using different modulation schemes. Digital broadcasting system. 10. The digital transmission device according to claim 7, wherein said transmitting station further comprises a scrambling means for scrambling, as identification information, an image input to the high-quality encoder. Broadcast system. 11. The transmitting station according to claim 6, further comprising: a unit for adding a marker for identifying image quality to the image input to the low-quality encoder as identification information. The digital broadcasting system according to any one of the above.