KR19990027641A - Digital broadcasting signal receiving method - Google Patents

Abstract

A method of receiving a digital broadcast signal, the method comprising: storing a video stream inputted in a predetermined amount of memory and starting decoding; when the write address increases according to the storage, the repeat play address is increased together with the write address, and the user starts decoding. Reproducing the video stream from the next address of the current write address to the read address if the repetitive reproduction is requested, and the still image frame reproduced when the user's image storage request is input. It consists of creating an image file at, so that the compressed video bitstream can be saved so that the user can replay the screen while watching digital TV.The scene can be created as a file to be viewed again when the user wants to see it. Even bigger It gives the satisfaction to improve the competitiveness of the product.

Description

Digital broadcasting signal receiving method

The present invention relates to a digital signal receiving method, and more particularly, to a digital broadcasting signal receiving method for storing a scene desired by a user in an image file format from a received satellite broadcasting signal.

The ability to integrate video, audio and data to process and reprocess efficiently has become a key technology in the multi-media era.

The development of related technologies and applied technologies will play a key role in securing future international competitiveness in this field.

Therefore, satellite broadcast receivers must secure superiority in terms of image quality and sound as well as multi-media functions.

In this regard, satellite broadcast receivers must be able to support basic screen display and sound as well as additional functions in addition to the existing expensive analog TV.

Referring to the accompanying drawings, the configuration of a digital set-top box for satellite broadcast reception according to the prior art is as follows.

1 is a block diagram illustrating a configuration of a digital satellite set-top box according to the prior art, in which a digital satellite set-top box receives a satellite broadcast signal through an antenna 11 and tunes a repeater signal of a channel to be watched among several repeaters. Analyzes the reception state of each serviced channel and the program guide information in the additional information according to the satellite tuner unit 12 and the additional information in the transport stream, and controls accordingly when a desired channel is input through the remote controller 13. The digital processor outputs the host processor unit 14 for outputting a signal, the first memory unit 15 for storing a database according to the information analyzed by the host processor unit 14, and the satellite tuner unit 12. A transpo that selects and outputs packets of a requested channel according to a control signal for a channel desired by the user of the host processor unit 14 in the stream. A video decoder unit 17 including a demux unit 16 and an OSD processing unit 171 and receiving and decoding an image packet among packets output from the transport demux unit 16 to reproduce an image signal; A second memory unit 18 that is temporarily stored for decoding by the video decoder unit 17 and an audio decoder that receives and decodes a voice packet among packets output from the transport demux unit 16 to reproduce a voice signal. It is composed of a portion 19.

The operation of the digital satellite set-top box according to the prior art configured as described above will be described.

First, the satellite broadcast signal is received by the satellite tuner unit 12 through the satellite antenna 11, and the satellite tuner unit 12 synchronizes the repeater signal of the channel to be watched among the various repeaters for video, audio, and program guide information. Additional information including a is time-divided and output to the transport demux unit 15 as a packet multiplexed transport stream.

The transport stream includes all video and audio information of the repeater to which the stream belongs.

In addition, the host processor 14 receives and analyzes additional information of the transport stream, collects information on each serviced channel, and collects information on which packet of the transport stream is transmitted to which packet. It is stored in the memory unit 15.

Then, a certain program is broadcasted at a certain time of a certain channel, and the program guide information is analyzed from the additional information such as the plot, the rating, the classification, the voice multiplexing, and the price of the paid program.

Thereafter, when the user requests the host processor unit 14 to see which channel through the remote controller 13, the host processor unit 14 selects and outputs packets containing video and audio of the requested channel. The mux part 16 is controlled.

Then, the transport demux unit 16 outputs packets containing the video of the requested channel to the video decoder unit 17 under the control of the host processor unit 14, and transmits packets containing the voice of the requested channel. Output to the audio decoder unit 19.

The video decoder unit 17 and the audio decoder unit 19 decode each digital stream and reproduce them as video signals and audio signals.

The reproduced audio and video signals are transmitted to the monitor and the speaker (not shown) through the output terminal, so that the user can view them.

Here, the video decoder unit 17 receives the video compression stream for the channel selected by the transport demux unit 16 to perform decoding. The compressed stream is temporarily stored in the second memory unit 18 and then bit buffered. Decryption is performed later.

FIG. 2 is a diagram for describing the structure of the set-top box video decoder memory of FIG. 1 and illustrates an internal partition structure of the second memory unit 18.

It consists of a bit buffer area for storing a stream, an OSD area for storing graphic data, and a frame buffer area for generating a motion compensation image during video output and decoding of the decoded screen in the form of CCIR601.

As described above, the digital satellite set-top box according to the prior art does not have a function of replaying images and voices, and storing the scenes in the form of an image file.

Therefore, if the user passes a scene of interest, the user may partially replay for a while, and in some cases, even if the user wants to save the video later, the user may not be able to repeat the playback again.

The present invention has been made in order to solve the problems according to the prior art, and an object thereof is to provide a digital broadcast signal reception method for generating a desired scene as a still image file.

A feature of the digital broadcasting signal receiving method according to the present invention is to store a predetermined amount of streams and then play back the stored streams if repeated playback is required. To create it.

In addition, another feature of the digital broadcast signal receiving method according to the present invention is to record it to an external digital storage medium when it is generated in the form of an image file.

1 is a block diagram for explaining the configuration of a digital satellite set-top box according to the prior art

FIG. 2 is a diagram for describing a structure of the set-top box video decoder memory of FIG. 1. FIG.

3 is a block diagram illustrating a configuration of a digital satellite set-top box according to the present invention.

FIG. 4 is a diagram for describing a structure of the set-top box video decoder memory of FIG. 3. FIG.

5 is a flowchart for explaining a method for video replay and image file generation according to the present invention.

6 is a diagram illustrating a memory structure of a bit buffer of a video decoder memory according to the present invention.

Explanation of symbols for main parts of the drawings

11 antenna 12 satellite tuner unit

13: remote control 314: host processor unit

15, 318: memory section 16: transport demux section

17: video decoder unit 19: audio decoder unit

Hereinafter, a digital broadcast signal receiving method according to the present invention will be described with reference to the accompanying drawings.

3 is a block diagram illustrating the configuration of a digital satellite set-top box according to the present invention. The digital satellite set-top box according to the present invention is the same as the configuration of the digital satellite set-top box of the prior art of FIG. Has a second memory unit 318 consisting of a VBV buffer for storing as many delays as necessary for decoding, an extended memory for storing a predetermined amount of the previous video bitstream for repeat playback, and a program for generating a scene in an image file. The host processor 314 which outputs to the data port is different.

In general, the transmission rate of a broadcast compression stream is 6 to 9 Mbps. Therefore, when the bit buffer area is allocated to 30M bytes, that is, about 240M bits, and used for repeated playback, a video stream of 240M bits / 8Mbps = 30 seconds can be stored when the video stream has a data rate of about 8Mbps.

That is, as shown in FIG. 4, the second memory unit 318 is expanded to increase the bit buffer. With a total size of 32M bytes, 30 seconds of past videos can be viewed again.

The host processor 314 also has a program for generating a still image image file in the second memory unit 318.

The video decoder 17 reconstructs a digital image of 720 * 480 resolution. The reconstructed image is in CCIR601 format, and the luminance 8-bit color difference signal is down-sampled for each pixel and has 8 bits of information.

Therefore, the host processor unit 314 executes a program for converting the pixel information into a suitable image format upon a user's request.

The generated image file is stored in the video library in the set-top box so that the user can extract the image file on demand and display it on the screen.

Alternatively, the generated still picture file can be stored by being transferred to a digital storage medium through a data port, and can also be stored by transferring a stream of bit buffers that are repeatedly reproduced in the form of a file (mpg).

A digital broadcast signal receiving method of a digital satellite set top box according to the present invention as described above will be described with reference to the accompanying flowchart.

FIG. 5 is a flowchart illustrating a method for repetitive video reproduction and image file generation according to the present invention, and FIG. 6 is a diagram for describing a memory structure of a bit buffer of a video decoder memory according to the present invention.

First, the video decoder unit 17 is turned on when the set top box is in the mode for playing the video (S51).

The compressed bitstream of the satellite broadcast signal received by the antenna 11 is input to the transport demux unit 16 through the satellite tuner unit 12, and the transport demux unit 16 receives the input compressed bitstream. Is output to the video decoder unit 17 under the control of the host processor unit 34.

The video decoder unit 17 first stores the input bitstream in the bit buffer of the second memory unit 318 (S52).

As shown in FIG. 6, the repetitive memory pointer of the bit buffer, that is, the initial address value, is set to be equal to the initial value of the write pointer which changes as the bitstream is filled (S53).

After that, when a predetermined bitstream is stored in the second memory unit 318, the video decoder unit 17 starts decoding to output a reconstructed image (S54).

At this time, the write pointer increases as the stream is supplied from the outside, and the read pointer increases as the stream is decoded.

When the write pointer comes to the first position by turning the bit buffer area, it has exceeded the capacity for storing the past image, and since this time, the repeated playback pointer increases with the same value as the write pointer (S55).

When the user requests repeat playback with the remote controller 13 or the like (S56), supply of the bitstream input to the video decoder unit 17 is stopped, and video decoding is performed from the repeat playback pointer, which is the next address of the write pointer, to the read pointer. And store in the frame buffer (S57).

The stored decoded data may be generated as an output signal and transferred to a display device through a video and audio output port to view a repeatedly reproduced screen.

Here, the frame buffer is used by dividing an address as shown in FIG.

If the user views the favorite screen while viewing the repeated playback screen and requests to store the image (S58), the video decoder unit 17 generates the reconstructed image in the form of an image file (S59).

The file generation is performed by a still image compression program included in the host processor 314.

After the file is generated, it may be stored in a still image library inactive memory or a disk device managed by the host processor 314 and viewed again when a user wants to see the file. The file may be moved to an external digital storage medium through a data port.

After that, if the viewer wants to watch normally (S60), the process is repeated from step S52, and if the viewer wants to repeat playback, the viewer repeats from step S56.

In addition, a predetermined amount of past video compressed streams stored in the bit buffer may be stored in the external digital storage medium through the data port by the host processor 314.

The digital broadcasting signal receiving method according to the present invention stores a compressed video bitstream so that the user can replay the screen while watching the digital TV, and can create a scene to be viewed when the user wants to see the file again. It gives a greater satisfaction of the effect of improving the competitiveness of the product.

Claims (4)

Storing the input video stream in a certain amount of memory and starting decoding the video stream; When the write address increased according to the storage is in the first position, increasing the repetitive reproduction address as the write address and determining whether the user requires repetitive reproduction; Reproducing the video stream from the next address of the current write address to the read address if it is requested to repeat playback as a result of the determination; And generating an image file from the reproduced still image frame when a user's image storage request is input. The method of claim 1, wherein the generating of the image file comprises storing the image in a still image library inactive memory or a disk after generating the file so that the stored image can be viewed when the user wants to see the image file. . The method of claim 1, wherein the generating of the image file comprises storing the image in an external digital storage medium after generating the file so that the user can view the stored image again. The digital broadcasting signal receiving method as claimed in claim 1, wherein the compressed video stream is stored in an external digital storage medium.