JP3439421B2 - Digital signal processor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal processing device, and more particularly to a digital signal processing device for reducing the data amount of digital data represented by MPEG2 transport stream and recording it on a recording medium.

[0002]

2. Description of the Related Art In recent years, when digitizing and handling a video signal, a method using intraframe or interframe compression coding represented by MPEG2 has been proposed and has already been put to practical use in satellite broadcasting and the like.

Video signals transmitted by such a system are
Since the data compression rate is high, it is very inefficient to perform the decoding when recording the data, re-encode the data, and then record the data. Therefore, a method has been devised in which a transmitted video signal is directly recorded on a recording medium as it is without being decoded.

However, if the transmitted video signal is recorded transparently on the recording medium as it is, the video signal cannot be correctly reproduced during special reproduction such as fast-forward reproduction or rewind reproduction. This is because if the data picked up by the head during special reproduction is inter-frame compression-encoded data, the frame data before and after it is required to decode the data. Regarding this, in December 1995, HD-DVCR (High Def
"Initial Digital Video Cassette Recorder" standardized "DVB (Digital Video Broadcas
"Ting) Signal recording DVCR standard", the recording format of digital TV broadcast signals using MPEG is standardized, and special reproduction data is detected at a predetermined position on the tape and a special reproduction data recording area. It is defined to record the intra-frame compression-encoded data to enable reliable decoding from the signal.

In the case of satellite broadcasting and the like, the transmitted video signal is packet-like data called MPEG2 transport stream packet. Therefore, when such a video signal is transparently recorded, the packet-like data should be recorded as it is. become. Therefore, when an MPEG2 transport stream packet is recorded as special reproduction data, an MPEG2 transport stream packet containing only intraframe compression-encoded data is selected from the transmitted MPEG2 transport stream packets. There must be.

As described above, the trick play data is recorded in a predetermined recording area. The size of the recording area is equivalent to about 2.7 Mbps, but since the same data is repeatedly recorded so that a good image can be reproduced, it is often substantially 0.5 Mbps or less. However, the video signal encoded in the frame is 2 Mbps at the latest.
In many cases, it is not possible to select intra-frame compression-encoded data from the transmitted video signal and record them all as special reproduction data. Therefore, it is necessary to further select data from an MPEG2 transport stream packet including an intra-frame compression-encoded video signal, reduce the amount of data, and generate a new MPEG2 transport stream packet.

[0007]

As described above, when transparently recording a video signal transmitted by satellite broadcasting or the like, the packet-like data is recorded as it is, and further MPEG2 is used as special reproduction data. When recording a transport stream packet, an MPEG2 transport stream packet containing only data that has been compression-coded in a frame is selected from the transmitted MPEG2 transport stream packets. However, since the recording area of the special reproduction data is limited, there is a case where the recording request cannot be endured if all MPEG2 transport stream packets including only the intra-frame compression encoded data are recorded. . As one of means for solving this, a method of processing an MPEG2 transport stream packet and performing processing such as data amount reduction to generate a new MPEG2 transport stream packet can be considered.

However, in this case, the MPE to be processed
If the G2 transport stream packet contains an error, it may not be possible to normally perform processing such as data amount reduction.

There is a bit indicating the presence or absence of an error in the header part of the MPEG2 transport stream packet, but an error processing method using it is not specified, and how to determine the MPEG2 transport stream packet including the error. Whether to handle it is a matter for the future.

The present invention has been made in view of the above problems, and relates to error processing of an MPEG2 transport stream packet containing an error, and processes the MPEG2 transport stream packet to generate a new MPEG2 transport stream packet. In this case, it is an object to provide a digital signal processing device capable of processing with a small circuit scale.

The present invention also provides a new MPEG error.
It is an object of the present invention to provide a digital signal processing device capable of preventing transmission in a 2-transport stream packet.

[0012]

In order to achieve the above object, a digital signal processing apparatus according to claim 1 is an MPE.
A digital signal processing device for processing a G2 transport stream packet to generate an MPEG2 transport stream packet for recording on a recording medium, wherein the presence or absence of an error is detected from the header of the transmitted MPEG2 transport stream packet. Header analysis part and transmitted MPEG2 transport
Data that reduces the amount of data in the data part of the stream packet.
Data reduction unit and recording MPEG2 transport store
Memory for storing ream packets and the amount of data above
The data output from the reduction unit or the data output from the above memory
Either of the data that is
The second output that switches and outputs based on the detection result of the presence or absence of error
Check whether there is an error by the switch and the header analysis section above.
Based on the detection result, the data output from the second switch is
MPEG2 transport stream for recording
A recording packet generator that generates a packet,
It is characterized by that. This allows the above header
-When the analysis unit detects an error, the MP containing the error
Replaces EG2 transport stream packet data
It can be replaced with data and processed. Therefore,
Generate MPEG2 transport stream containing
Error is not propagated to the recording medium and
The effect that a visually good video signal can be obtained at birth
is there.

According to a second aspect of the present invention, there is provided a digital signal processing apparatus according to the first aspect.
Then, the data amount reduction unit causes the error in the header analysis unit.
Is detected, the operation is stopped.
It is something. As a result, the MPE transmitted above is transmitted.
Data part of G2 transport stream packet
When it is not necessary to reduce the data amount, the data amount reduction unit
The operation of can be stopped. Therefore, reduce power consumption
There is an effect that can be done .

[0014]

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Embodiment 1 of the present invention will be described with reference to FIGS. 1, 3 and 4.
First, the configuration of the digital signal processing device according to the first embodiment will be described. 1 is a block diagram of a digital signal processing device according to a first embodiment of the present invention. Figure 3
It is a block diagram of the MPEG2 transport stream packet which has a standard format. FIG. 4 is a diagram showing a configuration example of MPEG2 transport stream packets S101, S105, and S106 according to the first embodiment of the present invention.

In FIG. 1, the main body 100 of the digital signal processing apparatus includes an MPEG2 transport stream packet input terminal 101, an MPEG2 transport stream packet output terminal 102, and a header analysis unit 1.
03, the first switch 104, and the data amount reduction unit 10
5 and a recording packet generation unit 106, and a standard M
Input PEG2 transport stream packet,
A new MPEG2 transport stream packet is generated and output by, for example, reducing the data amount by deleting the AC component of the video signal data portion.

The MPEG2 transport stream packet input terminal 101 is a terminal for inputting the MPEG2 transport stream packet S101 shown in FIG. MPEG2 transport stream packet S1
01 has a standard format as shown in FIG.
It includes data that has been compression-coded in the frame.

The header analysis unit 103 determines the presence or absence of an error by analyzing the error bit existing in the header of the MPEG2 transport stream packet S101, and the result is recorded by the first switch 104, the data amount reduction unit 105 and the recording unit. It is transmitted to the packet generator 106 for use.

The first switch 104 detects a terminal T1 to which the MPEG2 transport stream packet S101 is input, an output terminal T2 to be connected when an error is detected, and an error based on the error detection result of the header analysis unit. If not provided, an output terminal T3 to be connected is provided, and MP
The input destination of the EG2 transport stream packet S101 is switched.

Based on the result of the header analysis unit 103, the data amount reduction unit 105 searches for end codes such as slices and macroblocks of the input MPEG2 transport stream packet S101, and detects the MPEG2 transport stream packet S101. The data amount of the video signal data portion is reduced and output as the MPEG2 transport stream packet S105 shown in FIG.

The recording packet generation unit 106, based on the detection result of the header analysis unit 103, the first switch 104.
MPEG2 transport stream packet S101 output from the output terminal T2 of the same, or MPEG whose data amount output by the data amount reduction unit 105 is reduced.
2 transport stream packet S105 is input, and a new recording MPEG2 transport stream packet S10 shown in FIG. 4 is input from the input data.
6 is a recording packet generation unit for generating 6. MP for recording
The EG2 transport stream packet S106 is
MPEG2 transport stream packet S101
Of the MPEG2 transport stream packet S101 by deleting the AC component of the data portion of or the video signal data portion and repacking it.

The MPEG2 transport stream packet output terminal 102 is a terminal for outputting the recording MPEG2 transport stream packet S106 to the outside, and the outputted MPEG2 transport stream packet S106 is thereafter recorded on a recording medium (not shown). ) Is recorded in the special reproduction data recording area.

Next, the operation of the digital signal processing apparatus according to the first embodiment will be described. MPEG2 transport stream packet S1 supplied to the input terminal 101
01 is input to the header analysis unit 103. The header analysis unit 103 determines whether or not the MPEG2 transport stream packet S101 includes an error from the error indicator included in the header of the MPEG2 transport stream packet S101, and the result is determined by the first switch 104 and the data amount reduction. Part 105
And to the recording packet generator 106.

The MPE supplied to the input terminal 101
The G2 transport stream packet S101 is also input to the first switch 104. Header analysis part 1
If no error is detected in 03, the first switch 104 is switched to the output terminal T3 side, and the MPEG2 transport stream packet S101 input from the input terminal T1 is output from the output terminal T3 and is sent to the data amount reduction unit 105. Sent. MPEG2 transport stream packet S sent to the data amount reduction unit 105
The data amount of 101 is reduced, for example, by deleting the AC component of the video signal data portion, and then transferred to the recording packet generation unit 106 as an MPEG2 transport stream packet S105.

M sent to the recording packet generator 106
PEG2 transport stream packet S105
Will change to new MPE after header replacement etc.
It is output as a G2 transport stream packet S106 and output from the output terminal 102 to the outside.

When an error is detected in the header analysis unit 103, the first switch 104 is switched to the output terminal T2 side and the M input from the input terminal T1.
The PEG2 transport stream packet S101 is output from the output terminal T2, and the recording packet generation unit 10
Sent to 6.

When the result of error detection is input from the header analysis unit 103, the recording packet generation unit 106 outputs the rest of the MPEG2 transport stream packet S105 being processed as stuffing data and then inputs it. Error detected MPEG
Only the header information of the 2 transport stream packet S101 is replaced and output as a new recording MPEG2 transport stream packet S106.
The output MPEG2 transport stream packet S106 is output from the output terminal 102 to the outside.

At this time, the data amount reduction unit 105 shifts to a mode for searching for an end code such as a slice or macroblock based on the result of the header analysis unit 103. Then, based on the result of the header analysis unit 103, the output terminal T
When the MPEG2 transport stream packet S101 having no error is input from 3, the end code is searched, and at the time when the end code is detected, the mode is changed to the data amount reduction mode and the data is sequentially processed as described above. .

That is, in the first embodiment of the present invention, when an MPEG2 transport stream packet including an error is input, the stuffing data is inserted into the packet being processed to complete the process, and the MPEG2 transport including the error is transmitted. The port stream packet is used as the recording MPEG2 transport stream packet S106 as it is, and the end code of the slice layer or macroblock layer is searched from the MPEG2 transport stream packet to the end code of the MPEG2 transport stream packet having no error. Data operates so as not to perform data amount reduction processing.

As a result, when an error is included in the MPEG2 transport stream packet, the MPEG2
By performing the processing without breaking the context of the two transport stream packets and not performing the specific processing for the error, it is possible to generate the special reproduction data with a small circuit scale.

Further, the data amount reduction unit 105, based on the result of the header analysis unit 103, when the MPEG2 transport stream packet S101 includes an error,
The operation of the data amount reduction unit 105 can be stopped by stopping the clock or the like. As a result, it is possible to reduce the power consumption by stopping the operation of the data amount reduction unit 105 when it is not necessary to reduce the data amount.

(Second Embodiment) The second embodiment of the present invention will be described with reference to FIGS. 2, 3 and 5. First,
The configuration of the digital signal device according to the second embodiment will be described. FIG. 2 is a block diagram of a digital signal processing device according to the second embodiment of the present invention. FIG. 3 is a configuration diagram of an MPEG2 transport stream packet having a standard format. FIG. 5 is a configuration diagram of MPEG2 transport stream packets S111, S114, S116 and S117 according to the second embodiment of the present invention.

In FIG. 2, the main body 110 of the digital signal processing device has an MPEG2 transport stream packet input terminal 111, an MPEG2 transport stream packet output terminal 112, and a header analysis section 11.
3, the data amount reduction unit 114, and the second switch 115.
, A memory 116, and a recording packet generation unit 117, a standard MPEG2 transport stream packet is input, and the data amount is reduced by deleting the AC component of the video signal data portion of the standard MPEG2 transport stream packet.
It generates and outputs a transport stream packet.

The MPEG2 transport stream packet input terminal 111 is a terminal for inputting the MPEG2 transport stream packet S111 shown in FIG. MPEG2 transport stream packet S1
11 has a standard format as shown in FIG.
It includes data that has been compression-coded in the frame.

The header analysis unit 113 determines the presence or absence of an error by analyzing the error bit existing in the header of the MPEG2 transport stream packet S111, and the result is recorded in the data amount reduction unit 114, the second switch 115 and the recording unit. It is transmitted to the use packet generation unit 117.

Based on the result of the header analysis unit 113, the data amount reduction unit 114 searches for end codes such as slices and macroblocks of the input MPEG2 transport stream packet S111, and detects the MPEG2 transport stream packet S111. The data amount of the video signal data portion is reduced and output as the MPEG2 transport stream packet S114 shown in FIG.

The second switch 115 receives the data-reduced MPEG2 transport stream packet S11.
4 is input, a terminal T5 to which the MPEG2 transport stream packet S116 shown in FIG. 5 output from the memory 116 described later is input, and an output terminal T6. Based on this, the connection of the input terminals T4 and T5 with respect to the output terminal T6 is switched. The MPEG2 transport stream packet (S114 or S116) input from either the input terminal T4 or T5 is the MPEG2 transport stream packet S11 from the output terminal T6.
It is output as 5.

The recording packet generator 117 generates a new MPEG2 transport stream packet S117 shown in FIG. 5 by replacing header information with the MPEG2 transport stream packet S115 output by the second switch 115. It is a thing.
MPEG2 transport stream packet S117
Is an MPEG2 transport stream packet S1
By deleting the AC component of the video signal data portion of 11 and repacking it newly, a macro block containing more macroblocks than the MPEG2 transport stream packet S111, or up to the end code of this MPEG2 transport stream packet S117. The data is replaced with stuffing data.

The memory 116 includes the recording packet generator 1
17, which is a memory for storing the MPEG2 transport stream packet S117 generated in step S17.
6 is output to the input terminal T5 of the second switch 115.

The MPEG2 transport stream packet output terminal 112 is an output terminal for outputting the MPEG2 transport stream packet S117 generated by the recording packet generator 117 to the outside, and the output MPEG2 transport stream packet shown in FIG. After that, S117 is recorded in the special reproduction data recording area of the recording medium (not shown).

Next, the operation of the digital signal processing apparatus according to the second embodiment will be described. MPEG2 transport stream packet S1 supplied to the input terminal 111
11 is input to the header analysis unit 113. The header analysis unit 113 determines whether an error is included in the MPEG2 transport stream packet S111 from the error indicator included in the header of the MPEG2 transport stream packet S111,
The result is the data amount reduction unit 114, the second switch 11
5 and the recording packet generator 117.

Further, the MPE supplied to the input terminal 111
The G2 transport stream packet S111 is also input to the data amount reduction unit 114.

When no error is detected in the header analysis unit 113, the MPEG2 transport stream packet S11 input to the data amount reduction unit 114 is input.
1, the data amount is reduced by, for example, deleting the AC component of the video signal data portion, and is output to the second switch 115 as an MPEG2 transport stream packet S114. In the second switch 115, the input terminal is switched to the T4 side based on the error detection result of the header analysis unit 113, and the MPEG2 transport stream packet S114 input from the output terminal T4 is transferred from the output terminal T6 to the MPEG2 transport packet. The stream packet S115 is sent to the recording packet generator 117.

MPEG2 transport stream packet S115 input to the recording packet generator 117
Is a new recording MPEG2 transport stream packet S117 after the header information is replaced.
Is output from the output terminal 112 to the outside. Also, this MPEG2 transport stream packet S11
7 is also output to the memory 116 and stored in the memory 116.

When the header analysis unit 113 detects an error, the second switch 115 is switched to the input terminal T5 side and the MPEG2 transport stream packet S11 read from the memory 116 is read.
6 is input to the input terminal T5, and MP is output from the output terminal T6.
It is sent to the recording packet generation unit 117 as the EG2 transport stream packet S115.

When the result of error detection is input from the header analysis unit 113, the recording packet generation unit 117 inserts the stuffing data into the MPEG2 transport stream packet S115 being processed,
New MPEG2 transport stream packet S
It is output as 117. Then, the start code of the slice block or the like is detected from the MPEG2 transport stream packet S116 read from the memory 116, the start code and the subsequent codes are adopted, and only the header is replaced
New MPEG2 transport stream packet S
It is output as 117. Further, when the header analysis unit 113 detects that the next MPEG2 transport stream packet S111 has no error, the MP being processed
The end code of the EG2 transport stream packet S115 is detected, the data up to the end code is replaced with the stuffing data, and a new MPEG2 transport stream packet S117 is output.
MPEG output by the recording packet generator 117
The 2-transport stream packet S117 is output from the output terminal 112 to the outside. In addition, the MPEG2 transport stream packet S117 is stored in the memory 1
It is also output to 16 and stored in the memory 116.

At this time, the data amount reduction unit 114 shifts to a mode for searching end codes such as slices and macroblocks from the MPEG2 transport stream packet S111 based on the error detection result of the header analysis unit 113. Then, the MPEG2 transport stream packet S1 without error is input from the input terminal 111 again.
When 11 is input, the end code is searched from the MPEG2 transport stream packet S111, and when the end code is detected, the mode is changed to the data amount reduction mode, and the data after the end code is the data as described above. Operates to reduce the amount.

That is, in the second embodiment of the present invention, when an MPEG2 transport stream packet including an error is input, the error is made inconspicuous by replacing this with the neighboring data stored in the memory. To work. As a result, when an error is included in the MPEG2 transport stream packet, the error is not propagated to the recording medium and the image is not significantly deteriorated during special reproduction by performing an appropriate error processing.

The data amount reduction unit 114 can stop the operation by stopping the clock or the like based on the result of the header analysis unit 113 when the MPEG2 transport stream packet S111 contains an error.
As a result, it is possible to reduce the power consumption by stopping the operation of the data amount reduction unit 114 when it is not necessary to reduce the data amount.

[0050]

As described above, according to the digital signal processing apparatus of the first aspect, the digital signal processing for processing the MPEG2 transport stream packet and generating the MPEG2 transport stream packet for recording on the recording medium. A device that has been transmitted
A header analysis unit for detecting the presence or absence of an error from the header of the PEG2 transport stream packet, and transmitting it.
Of MPEG2 transport stream packets
Data amount reduction unit that reduces the amount of data in the data unit, and recording
Store MPEG2 transport stream packet for
Output from the memory and the data amount reduction unit
Either data or data output from the above memory
Is the detection result of the presence or absence of an error by the header analysis unit
The second switch for switching and outputting based on
Based on the detection result of the error analysis section
From the data output from the second switch, the recording MP
Description for generating EG2 transport stream packet
Since it has a recording packet generator,
Error in MPEG2 transport stream packet
If it contains a
Error is not propagated to the recording medium, and
There is an effect that the image is not deteriorated .

According to the digital signal processing device of the second aspect, the digital signal processing device of the first aspect.
In the above, the data amount reduction unit is the header analysis unit.
The feature is to stop the operation when an error is detected in
Therefore, when it is not necessary to reduce the data amount,
Power consumption is reduced by stopping the operation of the data amount reduction unit.
The effect is that you can

[0052]

[Brief description of drawings]

FIG. 1 is a block diagram of a digital signal processing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a digital signal processing device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of an MPEG2 transport stream packet having a standard format.

FIG. 4 is a diagram showing MPEG2 transport stream packets S101, S105 and S according to the first embodiment of the present invention.
The block diagram of 106.

FIG. 5 is a diagram showing MPEG2 transport stream packets S111, S114, S1 according to the second embodiment of the present invention.
16 and the configuration diagram of S117.

[Explanation of symbols]

100 Main Body of Digital Signal Processing Device in First Embodiment 101 MPEG2 Transport Stream Packet Input Terminal 102 in First Embodiment MPEG2 Transport Stream Packet Output Terminal 103 in First Embodiment Header Analysis Unit 104 in First Embodiment Switch 105 Data amount reduction unit 106 according to Embodiment 1 Recording packet generation unit 110 according to Embodiment 1 Main body 111 of digital signal processing device according to Embodiment 2 MPEG2 transport stream packet input terminal 112 according to Embodiment 2 MPEG2 transport stream packet output terminal 113 according to Embodiment 2 Second switch 114 Header analysis unit 115 according to Embodiment 2 Data amount reduction unit according to Embodiment 2 116 memory 117 recording packet generator S101 to S106 in the second embodiment MPEG2 in the first embodiment
Transport Stream Packets S111 to S117 MPEG2 in Embodiment 2
Transport stream packet

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-8-32926 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/76-5/956 H04N 7 / 24-7/68

Claims (2)

(57) [Claims] 1. An MPEG2 for processing an MPEG2 transport stream packet and recording it on a recording medium.
A digital signal processing device for generating a transport stream packet, comprising: a header analysis unit for detecting the presence / absence of an error from a header of the transmitted MPEG2 transport stream packet; and a transmitted MPEG2 transport stream packet.
Data amount reduction unit that reduces the data amount of the data portion of the packet
And MPEG2 transport stream packet for recording
The memory to be stored and the data output from the data amount reduction unit, or the memo
Either of the data output from the
The output is switched based on the detection result of the presence or absence of an error by the analysis unit.
Based on the detection result of the presence or absence of an error by the second switch that operates and the header analysis unit, from the data output from the second switch ,
Record MPEG2 transport stream packet
And a recording packet generation unit for generating the same . 2. A digital signal processing apparatus according to claim 1.
In the above, the data amount reduction unit has an error in the header analysis unit.
A digital signal processing device characterized in that it stops operation when detected .