JPH1198427A - Digital video reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a video data selector circuit having been required for a conventional digital video reproducing device in the case of conducting reproduction of a video image received from an input of another system in addition to conventional reproduction of a video image. SOLUTION: The device is provided with a video data input section 101 that receives coded video data, a video data storage section 102 that stores the video data from the data input section 101, a video data reproduction section 103 that receives the video data from the video data storage section 102 to reproduce the video data, a video data output section 104 that sends data from the video data reproduction section 103 to post-stages, and a host interface section 105 that receives an external control instruction and executes the instruction. Then the host interface section 105 receives also the coded video data and gives the data to the video data storage section 102 to process the video data of two systems.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video reproducing apparatus such as a set-top box or a PC for receiving digital broadcasting.

[0002]

2. Description of the Related Art In recent years, digital broadcast set-top boxes featuring multiple channels have become widespread. Each broadcasting company has proposed still image services such as product guidance to differentiate services. In addition to normal video stream (video data) playback, still image MPEG video streams (hereinafter referred to as MPEG-I streams) ) Regeneration is required. The MPEG standard (Moving Picture
Experts Group) -compliant digital video playback devices include the latest MPEG textbook (ASCII, 199).
It is known to be described in a practical MPEG textbook (ASCII Co., Ltd., first edition issued on November 1, 1995).

[0003]

FIG. 6 is a diagram showing an example of the configuration of a conventional digital video reproducing apparatus. In a conventional digital video reproducing apparatus, when processing two systems of video data, a selector 601 for selecting video data was required at a stage preceding the video data input unit 602. Further, when the two systems of video data are switched by the selector 601, simply by receiving a control command from the outside, a seam occurs at a place other than a break of the video data. The video data reproducing unit 604 is a video data storage unit 6
Since only the video data input from the input device 03 is decoded, the output image of the video data output unit 605 has image distortion and noise.

[0004] An object of the present invention is to solve the above problems. FIG. 1 is a block diagram of a digital video reproducing apparatus according to the present invention.

[0005]

According to a first aspect of the present invention, there is provided a digital video reproducing apparatus comprising: a video data input unit for inputting encoded video data; A video data storage unit that stores video data from an input unit, a host interface unit that receives an external command and executes the command, and a video data playback unit that inputs and plays video data from the video data storage unit And a digital video reproducing apparatus having a video data output section for transmitting data from the video data reproducing section to a subsequent stage. Data is also input and transmitted to the video data storage unit. With the above configuration, two systems of video data,
That is, the video data from the video data input unit and the video data from the host interface unit can be processed.

Further, in the digital video reproducing apparatus according to a second aspect of the present invention, when the encoded video data is input from the host interface unit, the video data input unit is configured to output the video data from the host interface unit. By stopping the input of video data from the outside based on the instruction, the video data from the video data input unit and the video data from the host interface unit do not collide in the video data storage unit, The data storage unit can uniquely select the video data from the host interface unit.

The digital video reproducing apparatus according to a third aspect of the present invention is the digital video reproducing apparatus, wherein the video data input section, the host interface section, the video data storage section, the video data reproducing section and the video data output section Time-division processing, when the encoded video data is input from the host interface unit, the video data input unit, based on an instruction from the host interface unit, by stopping its operation, The video data from the video data input unit and the video data from the host interface unit do not collide in the video data storage unit, the video data storage unit can uniquely select video data from the host interface unit, The number of sets to be subjected to time division processing is also reduced, and as a result, processing efficiency is improved.

In the digital video reproducing apparatus according to a fourth aspect of the present invention, when the input of the encoded video data is switched from the video data input section to the host interface section, the video data output section Stops outputting the video data, the host interface unit sends the input video data to the video data storage unit, and the video data reproduction unit transmits the video data from the host interface unit stored in the video data storage unit. After the reproduction of the video data is started, the video data output unit resumes the data output, so that the image disturbance that occurs when the video data input unit is switched to the host interface unit does not occur.

According to a fifth aspect of the present invention, in the digital video reproducing apparatus according to the fifth aspect, when the input of the encoded video data is switched from the host interface section to the video data input section, the video data output section is provided. Stops outputting video data, the video data input unit sends the input video data to the video data storage unit, and the video data reproduction unit transmits the video data input stored in the video data storage unit. After the reproduction of the video data from the unit is started, the video data output unit resumes the data output, so that the image disturbance that occurs when the host interface unit switches the video data input unit does not occur.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing an embodiment of a digital video reproducing apparatus according to the first invention of the present application. 101 is a video data input unit, 102 is a video data storage unit, 103 is a video data reproduction unit, 104 is a video data output unit, and 105 is a host interface unit.

For normal video reproduction, the video data input unit 10
1 is stored in the video data storage unit 102, the video data reproduction unit 103 at the next stage reproduces the video data from the video data storage unit 102, and the video data output unit 104 Is output. The host interface unit 105 receives a control command from the outside and controls the video data input unit 101, the video data storage unit 102, and the video data output unit 104.

In the video reproduction of another system, instead of inputting the encoded video data to the video data input unit 101, the encoded video data is transmitted to the host interface unit 105.
The host interface unit 105 transmits the video data to the video data storage unit 102, and the video data reproduction unit 103 at the next stage reproduces the video data from the video data storage unit 102, and the video data output unit 104 This is realized by outputting a video. The host interface unit 105 controls each unit in response to an external control command in the same manner as during normal video reproduction.

FIG. 2 is a block diagram showing an example of the configuration of an embodiment of the digital video reproducing apparatus according to claim 1 of the present invention. The PES (Packetized E
A supplementary stream (Packet) packet is obtained by adding various types of control information to an elementary stream (hereinafter, referred to as ES), and a TS (Transport Stream) is a stream having a normal PES packet as a payload. Reference numeral 201 denotes a TS decoder that receives a transport stream (hereinafter referred to as TS) and outputs a video PES packet, 202 denotes an MPEG decoder, 203 denotes an external CPU, and 204 denotes a memory.

An MPEG decoder 202 which receives a PES packet output from the TS decoder 201 or an MPEG-I stream stored in the memory 204 as an input is connected to an external C
The stream input is selected and decoded according to the control information from the PU 203, and an NTSC digital video signal is output.

In the above description, the memory 204 is an MPE
Although the GI stream is stored, the GI stream is not limited to the MPEG-I stream, and may be any stream that can be decoded by the MPEG decoder 202. Therefore, DVD
Streams from storage type storage media such as
As long as the video data is stored in the video buffer 04, the video can be reproduced.

FIG. 3 shows a data flow inside the MPEG decoder 202 when processing a PES packet from the TS decoder 201. 301 is a stream interface, 302 is a PES packet analysis task, 303 is a buffer memory, 304 is a DRAM transfer task, 305 is a DRAM, 306 is an MPEG video decoder unit transfer task, 307 is an MPEG video decoder unit, and 308 is a video output A task, 309 is a video interface, 310 is a host interface, 311 is a host task, and 312 is an internal CPU.

The stream interface 301 receives the PES packet input from the TS decoder 201 of FIG. 2, and the PES packet analysis task 302 analyzes the system layer (ISO / IEC13818-1) of the PES packet received by the stream interface 301. The video elementary stream (hereinafter, referred to as ES) is transferred to the buffer memory 303.

The DRAM transfer task 304 transfers the ES transferred to the buffer memory 303 to the DRAM 305,
The MPEG video decoder unit transfer task 306 transfers the ES existing in the DRAM 305 to the MPEG video decoder unit 307. The MPEG video decoder unit 307 receives the ES of the DRAM 305 as an input and the video layer (ISO / IEC13818-
Decode 2).

The video output task 308 converts the decoding result of the MPEG video decoder unit 307 into NTSC digital data,
9 and output as a video signal. Host task 3
Numerals 301 to 301 indicate control information obtained from the external CPU 203 in FIG.
The operation of 312 is controlled. The internal CPU 312 includes a PES packet analysis task 302, a DRAM transfer task 304,
MPEG video decoder unit transfer task 306,
The video output task 308 and the host task 311 are time-divisionally processed.

(Embodiment 2) An embodiment of a digital video reproducing apparatus according to the second invention of the present application will be described below. FIG. 4 shows a data flow inside the MPEG decoder 202 when processing the MPEG-I stream (ES). Here, only the part that operates differently from FIG. 3 will be described. The numbers in the figure are the same as in the description of FIG. Although FIG. 4 is also used in the description of other embodiments, the characters in parentheses and the arrows in parentheses in FIG. 4 are effective only when describing (Embodiment 2).

The host task 311 stops the stream interface 301 corresponding to the video data input unit according to claim 2 based on the control information from the external CPU 203 of FIG. From the memory 204 of the host interface 31
The MPEG-I stream input to 0 is transferred to the buffer memory 303.

The internal CPU 312 performs time-division processing of a total of five tasks: a PES packet analysis task 302, a DRAM transfer task 304, an MPEG video decoder / unit transfer task 306, a video output task 308, and a host task 311.

The host task 311 shown in FIG. 4 performs not only the processing of control information but also the MP
The difference from the host task 311 in FIG. 3 is that EG-I stream transfer is performed. Although the PES packet analysis task 302 by the internal CPU 312 is operating, the ES is not written to the buffer memory 303 because the stream interface 301 is stopped.

(Embodiment 3) An embodiment of a digital video reproducing apparatus according to the third invention of the present application will be described below. Here, the description will be made with particular emphasis on the difference from (Embodiment 2).

In the third aspect, the video data input unit is P
This corresponds to the ES packet analysis task 302. This PES
When the packet analysis task 302 stops, the internal CPU 3
12 performs time-division processing of a total of four tasks of a DRAM transfer task 304, an MPEG video decoder / unit transfer task 306, a video output task 308, and a host task 311.

FIG. 5 shows the processing status of tasks when the internal CPU 312 performs time-division processing on each task. When the stream is switched from the stream via the stream interface 301 to the stream via the host interface 310, the above-described PES packet analysis task 302 stops, so that the processing of the other tasks in the present embodiment is about ／ times faster.

(Embodiment 4) An embodiment of a digital video reproducing apparatus according to the fourth invention of the present application will be described below. From the PES packet via the stream interface 301 to the MPEG-
The procedure for switching to the I stream (FIGS. 3 to 4) is as follows (step 1) to (step 7). However,
Although FIG. 4 is used in the description of the second embodiment, the characters in parentheses in the figure and the arrows in the parentheses are effective only when the second embodiment is described.

(Step 1) The video output task 308 and the video interface 309 freeze the video output.

(Step 2) The stream interface 301 and the PES packet analysis task 302 are stopped.

(Step 3) The write pointer indicating the start position of the stream written to the buffer memory 303 and the read pointer indicating the read start position are moved to the head position of the buffer memory 303. Further, the write pointer indicating the start position of the stream written to the DRAM 305 and the read pointer indicating the read start position are moved to the head position of the DRAM 305.

(Step 4) Host Interface 31
Then, an MPEG-I stream is input via a line 0, and the stream data is stored from the position of the write pointer in the buffer memory 303.

(Step 5) DRAM transfer task 304
Reads the stream after the position of the read pointer in the buffer memory 303 and transfers the stream data to the position after the position of the write pointer in the DRAM 305.

(Step 6) MPEG video decoder
The unit transfer task 306 reads stream data following the read pointer of the DRAM 305,
Transfer to EG video decoder unit 307.

(Step 7) MPEG video decoder
The decoding result of the unit 307 is output to the video output task 30.
8 converts the video signal into a video signal,
Output through

(Embodiment 5) An embodiment of a digital video reproducing apparatus according to the fifth invention of the present application will be described below. From the MPEG-I stream via the host interface 310 to the P via the stream interface 301
The procedure for switching to the ES packet (from FIG. 4 to FIG. 3) is the following (Step 8) to (Step 14).

(Step 8) The video output task 308 and the video interface 309 freeze the video output.

(Step 9) The stream interface 301 and the PES packet analysis task 302 are activated.

(Step 10) Buffer memory 303
Then, the write pointer indicating the start position of the stream written and the read pointer indicating the read start position are moved to the head position of the buffer memory 303. Further, the write pointer indicating the start position of the stream written to the DRAM 305 and the read pointer indicating the read start position are moved to the head position of the DRAM 305.

(Step 11) A PES packet is input via the stream interface 301, and the stream data is stored from the position of the write pointer in the buffer memory 303.

(Step 12) DRAM transfer task 30
4 reads the stream after the position of the read pointer in the buffer memory 303, and transfers this stream data to the position after the position of the write pointer in the DRAM 305.

(Step 13) The MPEG video decoder / unit transfer task 306 reads out stream data following the read pointer of the DRAM 305,
Transfer to PEG video decoder unit 307.

(Step 14) The decoding result of the MPEG video decoder unit 307 is output to the video output task 3.
08 is converted to a video signal,
Output through 9.

In the above description, the PES packet is used as the input to the stream interface 301, the MPEG-I stream is used as the input to the host interface 310, and the NTSC digital video signal is used as the video output. It is not limited.

[0045]

As described above, the digital video reproducing apparatus according to the present invention does not require a selector circuit which has been conventionally required. Therefore, two streams of input streams can be processed without increasing the circuit scale, and the control of the selector circuit conventionally performed by the external CPU is unnecessary.

Also, by stopping the stream input from the TS decoder in the stream interface, the TS which has been conventionally performed by the external CPU at the time of video switching is used.
There is no need to control the output of the decoder, and the burden on the CPU associated with TS decoder control is reduced.

Further, when processing the stream via the host interface, the P input from the TS decoder is processed.
By stopping the PES packet analysis task for analyzing the ES packet, the CPU occupancy of other tasks processed by the internal CPU of the MPEG decoder increases, and as a result, the processing efficiency of other tasks improves.

When switching from the stream via the stream interface to the stream via the host interface, the output video of the stream via the stream interface is stopped, and then the stream is switched to the stream via the host interface, and the stream via the host interface is reproduced. Then, by outputting the video, it is possible to prevent screen disturbance and noise that occur when the video is switched.

Similarly, when switching from the stream via the host interface to the stream via the stream interface, after stopping the output video of the stream via the host interface, the stream is switched to the stream via the stream interface, and the stream via the stream interface is reproduced. After that, by outputting the video, it is possible to prevent screen disturbance and noise that occur at the time of video switching.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital video reproducing apparatus according to the present invention.

FIG. 2 is a block diagram showing an example of a configuration according to an embodiment of the digital video reproducing apparatus according to claim 1 of the present invention.

FIG. 3 is a block diagram of the MPEG decoder of FIG. 2 according to one embodiment of the present invention when processing a PES packet;

FIG. 4 is a block diagram of the MPEG decoder of FIG. 2 according to an embodiment of the present invention when processing an MPEG-I stream;

FIG. 5 is a diagram showing effects of the digital video reproducing apparatus according to claim 3 of the present invention.

FIG. 6 is a diagram showing an example of the configuration of a conventional digital video reproducing apparatus.

Claims (5)

[Claims] A video data input unit for inputting encoded video data; a video data storage unit for storing video data from the video data input unit; and a video data input unit for receiving video data from the video data storage unit. A video data reproducing apparatus comprising: a video data reproducing unit for reproducing, a video data output unit for transmitting data from the video data reproducing unit to a subsequent stage, and a host interface unit for receiving an external control command and executing the command 3. The digital video reproducing apparatus according to claim 1, wherein the host interface unit also receives encoded video data and transmits the encoded video data to the video data storage unit. 2. The method according to claim 1, wherein when the encoded video data is input from the host interface unit, the video data input unit stops external video data input based on an instruction from the host interface unit. The digital video reproducing apparatus according to claim 1, wherein 3. A video data input unit, a host interface unit, a video data storage unit, a video data reproduction unit, and a video data output unit are time-division processing, and input coded video data from the host interface unit. 2. The digital video reproducing apparatus according to claim 1, wherein when the video data is input, the video data input unit stops its operation based on an instruction from the host interface unit. 4. When the input of encoded video data is switched from the video data input section to the host interface section, the video data output section stops outputting the video data, and the host interface section outputs the input video data to the video interface. Sending to the data storage unit, the video data output unit restarts data output after the video data reproduction unit starts reproducing the video data from the host interface unit stored in the video data storage unit. 2. The digital video playback device according to claim 1, wherein: 5. When the input of encoded video data is switched from the host interface section to the video data input section, the video data output section stops outputting the video data, and the video data input section outputs the input video data. The video data output unit resumes data output after sending to the video data storage unit and starting playback of video data from the video data input unit stored in the video data storage unit. 2. The digital video playback device according to claim 1, wherein