JPH1188878A - Processor for discontinuous transport stream packet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the quantity of data disabled from being displayed out of data stored in a buffer of a decoder by using calibrated STC immediately as an STC for the decoder if discontinuance occurs in a transport stream. SOLUTION: When there is no discontinuance, an STC inputted from an STC input pin 1 is used for the decoder 6 as it is, and when discontinuance occurs, a PTS filter circuit 4 extracts a PTS generated immediately after the occurrence of the discontinuance correspondingly to a signal inputted from a discontinuance detection signal input pin 2 and an STC delay 5 delays the inputted STC by using the PIS and outputs the delayed STC to the decoder 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discontinuous transport stream packet processing apparatus, and more particularly, to a transport stream in which video data and audio data and time information are multiplexed, and to input the time information. P indicating the time reference at which the data was encoded
The STC, which is a time reference of the decoding and reproducing process, is acquired based on the CR, and when performing the decoding and reproducing process using the STC and the PTS indicating the time at which the data of the time information is reproduced, A discontinuous transport stream packet processing apparatus that performs the decoding and reproduction processing using the calibrated STC when a discontinuity occurs in a transport stream packet that constitutes a transport stream to be processed, particularly a system that complies with the MPEG2 standard. And a discontinuous transport stream packet processing device used in a decoding / reproducing device on the receiving side.

[0002]

2. Description of the Related Art With the advance of digitization and compression techniques of data, use of digital images and digital sounds for recording of images and sounds and transmission including broadcasting has been promoted. The merit of using digitized data for recording and transmission is that various types of data including images, sounds, characters, etc. can be handled in a unified manner, so that services can be integrated. By using compression technology for transmission and reception, it is possible to perform a large number of high-quality broadcasts by utilizing the limited transmission bandwidth, to be able to provide homogeneous service by using error correction technology, There are various advantages, such as that encryption technology can be easily used.

[0003] In transmitting and receiving such digitized data and compression-encoded data, packetization is generally used. A packet is a unit of data obtained by dividing the entire data into a certain size. By transmitting and receiving data as packets, it is possible to increase the efficiency and accuracy of data communication. For example, in the case of performing packet switching in a computer network, each packet arrives at a destination at a different timing through the network and is reconstructed into the original data at the destination. Information for identifying the source, the order of the packets, and the like is added.

When digital data is handled, packetization technology is used to packetize and combine video, audio, and various data such as character information and additional information into multiplexed data. Transport stream (TS) used for transmission (transport
stream). As a method for obtaining such multiplexed data, the MPEG2 system standard (ISO / IEC 13818-1) is widely used.

FIG. 3 is a diagram showing the structure of a TS which is multiplexed data created by a conventional technique conforming to the MPEG2 standard. The video data and the audio data are compression-encoded every fixed number of samples such as one frame corresponding to one screen in the case of video and 1024 in the case of audio (the fixed number of samples is also referred to as one frame). PES for one frame or multiple frames
Create a packet called a (packetized elementarystream) packet. FIGS. 3A, 3B, and 3C are schematic diagrams of the format of a TS packet, which is a packet constituting a TS, including a PES packet. As shown, together with video data and audio data, time information for synchronously reproducing video and audio so that each data is displayed on the receiving side at a timing intended on the transmitting side.
(time information) is also multiplexed. Such time information includes a DTS (decoding time stamp) (decoding time information) and a PTS (presentation time stamp) (presentation time information) relating to the time at which each data is decoded and reproduced, and the same time base (time reference). ), And a PCR (program clock refarence) indicating a time base when video and audio data are encoded.
(Program time reference).

Therefore, on the receiving side (decoding and reproducing side), the TS
By obtaining the STC (system time clock) which is the time base of the decoding / reproducing apparatus based on the PCR in the packet, the time base of the decoding / reproducing apparatus can be made the same as that of the transmitting side (encoding side). , And the PTS added to the video data or the audio data is S
By performing the decoding / reproducing process so as to reproduce when the value matches the TC, it is possible to perform the reproduction according to the intention of the transmission side.

[0007]

SUMMARY OF THE INVENTION The transmitting side encodes
When transmitting the multiplexed TS and decoding / reproducing the TS on the receiving side, there is no problem if the TS is continuously transmitted.
If the processing is continuously performed using C, correct reproduction cannot be performed. Therefore, the conventional decoding / reproducing apparatus detects the discontinuity of the TS packet, calibrates the value of the STC when the detection is detected, and thereafter, corrects the STC value after the calibration.
This has been dealt with by performing processing using C.

However, when the decoding process is performed immediately using the calibrated STC, that is, immediately after the STC of the decoder
In the case where the data to be used is used, the data to be used for the STC before the calibration and the data to use the STC after the calibration are mixed in the data temporarily stored in the buffer by the decoder. This causes a problem that the data that should have been reproduced is not displayed, and the reproduction is interrupted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has been made in consideration of the above-described problems. Discontinuous T for processing equipment
An object is to provide an S packet processing device.

[0010]

To achieve the above object, a discontinuous transport stream packet processing apparatus according to claim 1 comprises a transport stream in which video data, audio data, and time information are multiplexed. Is input, and the STC which is the time reference of the decoding / reproducing process is obtained based on the PCR indicating the time reference in which the data of the input time information is encoded.
When performing the decoding / reproducing process using the PTS indicating the time at which the data of the time information is reproduced, when the transport stream packet constituting the input transport stream has a discontinuity, ,
In the discontinuous transport stream packet processing apparatus for performing the decoding and reproduction processing using the calibrated STC, when a discontinuity detection signal indicating that the discontinuity has occurred is input, the video data and the audio data are output. And a PTS filter for extracting the PTS of the data from the packet containing the data, and when the discontinuity detection signal is not inputted, the inputted STC is outputted as it is,
When the discontinuity detection signal is input, a determination process is performed using the input STC and the extracted PTS, and according to the determination result, the input STC is input.
STC delay means for delaying and outputting the result.

According to a second aspect of the present invention, there is provided the discontinuous transport stream packet processing apparatus according to the first aspect, wherein the STC delay means includes the input STC delay means.
And the extracted PTS is compared with a preset value, and when the difference value reaches the preset value, the input STC is output.

Further, a discontinuous transport stream packet processing apparatus according to claim 3 inputs a transport stream in which video data and audio data and time information are multiplexed, and among the input time information, The STC, which is the time reference of the decoding / reproducing process, is acquired based on the PCR indicating the time reference at which the data is encoded, and the STC and the PTS indicating the time at which the data of the time information is reproduced are used by using the STC. In performing the decoding / reproducing process, when a discontinuity occurs in the transport stream packet constituting the input transport stream, the discontinuous transport for performing the decoding / reproducing process by using the calibrated STC. In the stream packet processing device, a discontinuity detection signal indicating that the discontinuity has occurred is output. A video PTS filter means for extracting a PTS of the data from the packet containing the video data, and a discontinuity detection signal indicating that the discontinuity has occurred. Audio PTS filter means for extracting the PTS of the data,
S and the PTS of the audio data are inputted, and PTS selecting means for selecting and outputting one of them is provided. When the discontinuity detection signal is not inputted, the inputted STC is outputted as it is, When a detection signal is input, an STC delay for performing a determination process using the input STC and the extracted PTS, and delaying and outputting the input STC according to a result of the determination. Means.

According to a fourth aspect of the present invention, there is provided the discontinuous transport stream packet processing apparatus according to the third aspect, wherein the STC delay means includes the input STC delay means.
And the extracted PTS is compared with a preset value, and when the difference value reaches the preset value, the input STC is output.

According to a fifth aspect of the present invention, there is provided the discontinuous transport stream packet processing apparatus according to the third or fourth aspect, wherein the PTS selecting means includes a PTS of the video data. And PTS of the audio data, and outputs one of the predetermined data.

According to a sixth aspect of the present invention, there is provided the discontinuous transport stream packet processing apparatus according to the third or fourth aspect, wherein the PTS selecting means comprises a PTS of the video data. And the PTS of the audio data, the one having a large value is selected and output.

According to a seventh aspect of the present invention, there is provided the discontinuous transport stream packet processing apparatus according to the third or fourth aspect, wherein the PTS selecting means comprises a PTS of the video data. And the PTS of the audio data, the one having a small value is selected and output.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 The discontinuous TS packet processing apparatus according to Embodiment 1 of the present invention does not use the STC after calibration immediately,
This is to reduce troubles in data display. FIG. 1 is a block diagram showing a configuration of the discontinuous TS packet processing device according to the first embodiment. As shown, the discontinuous TS packet processing device 10 according to the first embodiment
Is composed of a PTS filter circuit 4, an STC delay unit 5, and a decoder 6, and the discontinuous TS packet processing device 10
Are connected to the STC input pin 1, the discontinuity detection signal input pin 2, and the PES packet input pin 3 which receive input from the TS decoding / reproducing apparatus including

The STC input pin 1 is used by the TS decoding / reproducing device to acquire the S based on the PCR of the input TS.
Enter TC or calibrated STC. The discontinuity detection signal input pin 2 inputs a discontinuity detection signal output when the TS decoding / reproducing apparatus detects that a TS packet is discontinuous. PES packet input pin 3
Inputs a PES packet including video and audio data obtained from the TS. The PTS filter circuit 4 converts the PES packet into P
Extract TS. The STC delay unit 5 delays the STC by a preset amount according to the input signal. The decoder 6 performs a PES packet decoding process using the STC.

The operation of the thus-configured discontinuous TS packet processing apparatus 10 according to the first embodiment for processing corresponding to TS packet discontinuity will be described below. First, when discontinuity of the TS packet does not occur, there is no input at the discontinuity detection signal input pin 2, and the STC of the TS decoding / reproducing apparatus is inputted from the STC input pin 1. And output to the decoder 6. Then, the PES packet input from the PES packet input pin 3 is
And output to the decoder 6. The decoder 6
By decoding the PES packet input from the pin 3 using the STC input from the pin 1, it is possible to correctly process and display data.

On the other hand, when a discontinuity occurs in the TS packet, the TS decoding / reproducing apparatus performs the discontinuity detection processing by the discontinuity detection processing performed before the processing by the discontinuous TS packet processing apparatus. Is detected. This detection processing is performed by checking a “continuity counter” included in the header portion of the TS packet. At the time of detection, a discontinuity detection signal is input to the discontinuity detection signal input pin 2 of the discontinuous TS packet processing device 10, and is input to the PTS filter circuit 4 and the STC delay device 5. Further, in the former stage, the STC calibration process is performed,
The STC after calibration is input to the C pin 1.

When a discontinuity detection signal is input, the PTS filter circuit 4 extracts the first PTS after the discontinuity and outputs it to the STC delay unit 5. The STC delay unit 5 to which the discontinuity detection signal and the first PTS after the discontinuity are input is connected to the STC input from the pin 1 and the PTS.
And the difference value of “PTS minus STC” is obtained. Further, the STC delay unit 5 performs a comparison process between the above difference value and a preset threshold value, and when the difference value is less than the preset threshold value, the STC delay unit 5
Is not output to the decoder 6.

Thus, for a certain period after the discontinuity of the TS packet occurs, the decoding process in the decoder 6 is performed using the STC before the discontinuity occurs. Then, in the comparison processing by the STC delay unit 5, when the difference value reaches the threshold value, the STC delay unit 5 outputs the STC value at that time to the decoder 6. Therefore, the decoding process in the decoder 6 is performed using the STC after calibration.

In FIG. 1, PE input from pin 3
The S packet is temporarily stored in a buffer provided in the preceding stage. Therefore, immediately after the discontinuity detection signal is inputted from the pin 2, the PES packet before the discontinuity occurs is inputted for a certain period of time, so that the STC after calibration is used immediately in the decoder 6. However, the same problem as in the conventional device occurs. In the discontinuous TS packet processing device according to the first embodiment, a difference value between the first PTS after the discontinuity occurs and the STC after calibration is calculated, and the difference value is determined in advance in accordance with the buffer storage amount and the like. By delaying the output of the calibrated STC to the decoder 6 until the set value is reached, it is possible to greatly reduce the amount of PES packets that are not correctly processed due to the above-described inconvenience.

As described above, according to the discontinuous TS packet processing apparatus according to the first embodiment, the PTS filter circuit 4
And the STC delay unit 5, the STC delay unit 5 refers to the PTS immediately after the discontinuity of the TS packet occurs,
Since the calibrated STC input from the STC pin 1 is output to the decoder 6 with a delay, the trouble of data display due to the PES packet temporarily stored in the buffer being processed using an unsupported STC is avoided. It is possible to greatly reduce it.

Second Embodiment A discontinuous TS packet processing apparatus according to a second embodiment of the present invention delays a calibrated STC and uses it for a decoding process as in the first embodiment. The processing is performed in consideration of the video data and the audio data included in the TS to be executed. FIG. 2 shows the second embodiment.
1 is a block diagram showing a configuration of a discontinuous TS packet processing device according to the first embodiment. As shown, the discontinuous TS packet processing device 20 according to the second embodiment includes a video PTS filter circuit 25, an audio PTS filter circuit 26,
S selection circuit 27, STC delay unit 28, video decoder 2
9, a video PES packet input pin 21, a discontinuity detection signal input pin 22, an audio PES packet input pin 23, which receives an input from a TS decoding / reproducing apparatus including the discontinuous TS packet processing apparatus 20. And the STC input pin 24.

The video PES packet input pin 21 and the audio PES packet input pin 23 input a PES packet containing video data and a PES packet containing audio data obtained from the TS, respectively. The discontinuity detection signal input pin 22 inputs a discontinuity detection signal output when the TS decoding / reproducing apparatus detects that a TS packet is discontinuous. The STC input pin 1 is connected to the input T
The STC acquired based on the PCR of S or the calibrated STC is input. The video PTS filter circuit 25 and the audio PTS filter circuit 26 extract video and audio PTSs according to input signals. The PTS selection circuit 27 responds to the input signal
One of the input PTSs is selected by a preset method. The STC delay unit 28 is the same as in the first embodiment. Video decoder 29 and audio decoder 3
0 is video and audio PE using STC.
The S packet is decoded.

The operation of the thus configured discontinuous TS packet processing apparatus 20 according to the second embodiment at the time of processing corresponding to TS packet discontinuity will be described below. First, if there is no discontinuity in the TS packet,
There is no signal input to the discontinuity detection signal input pin 22, the PES packet input from the video PES packet input pin 21 to the video decoder 29, and the PES packet input from the audio PES packet input pin 23 to the audio decoder 30. Is entered. Furthermore, S
From the TC pin 24, the STC obtained based on the PCR is used.
The STC passes through an STC delay unit 28, and a video decoder 29 and an audio decoder 30
Is input to Since the PES packet and the STC input to the video decoder 29 and the audio decoder 30 correspond to each other, each data is correctly displayed by being correctly decoded.

On the other hand, when a discontinuity occurs in the TS packet, a discontinuity detection signal is input to the discontinuity detection signal input pin 22 in the same manner as in the first embodiment, and this signal is transmitted to the video PTS. Filter circuit 25, audio P
TS filter circuit 26, PTS selection circuit 27, and ST
By being input to the C delay unit 28, each functions as follows. Also, as in the first embodiment, the STC after calibration is input to the STC input pin 24 and transmitted to the STC delay unit 28.

The video PTS filter circuit 25 and the audio PTS filter circuit 26 respectively provide the first video PTS and the audio PTS after discontinuity from the input video PES packet and audio PES packet.
The TSs are extracted and output to the PTS selection circuit 27, respectively. The PTS selection circuit 27 selects one of the input PTSs according to a preset selection method,
This is output to the STC delay unit 28. STC delay unit 28
Performs a determination process using the difference value between the PTS and the STC selected by the PTS selection circuit 27, as in the first embodiment.
The calibrated STC input from the TC input pin 24 is delayed and output to the video decoder 29 and the audio decoder 30. The video decoder 29 and the audio decoder 30 perform processing using the input STC, and display data.

Here, regarding the selection method in the PTS selection circuit 27, the video PTS or the audio PTS is selected.
One of the PTSs is always output. Alternatively, a video PTS and an audio P
It is also possible to perform TS comparison processing and output the smaller PTS or to output the larger PTS. When one PTS is always output, the data (video data or audio data) before the discontinuity occurs can be displayed as much as possible, that is, all of the temporarily stored data can be displayed. . Generally, audio playback interruptions are often more conspicuous than video playback interruptions. Therefore, in many cases, measures are taken to avoid audio playback interruptions as much as possible. In some cases, video playback can be prioritized.
When the smaller value of the PTS is output, all the data after the discontinuity can be displayed.
Is output, the data after the discontinuity is generated can be displayed in a state where both audio and video are aligned. Therefore, it is possible to make settings for missing data in accordance with the image quality and sound quality of data, the state of the system, and the demands of the user.

As described above, in the second embodiment,
Instead of the PTS filter circuit of the first embodiment,
With the provision of the TS filter circuit 25, the audio PTS filter circuit 26, and the PTS selection circuit 27, the delay time until the output of the STC after calibration in the STC delay unit 28 corresponds to video or audio. Therefore, it is possible to perform data loss avoidance processing corresponding to the image quality and sound quality of the data, the state of the system, the user's request, and the like.

[0032]

According to the discontinuous transport stream packet processing device of the first aspect, when the transport stream packet constituting the input transport stream has a discontinuity, the discontinuity occurs. PTS filter means for extracting the PTS of the data from the packet including the video data and audio data when the discontinuity detection signal is input, and the STC input when the discontinuity detection signal is not input.
Is output as it is, and when the discontinuity detection signal is input, a determination process using the input STC and the extracted PTS is performed, and the input STC is determined according to the determination result. With the provision of the STC delay means for delaying and outputting the data, the STC after calibration is used immediately for the decoding process, so that the data and the STC
It is possible to reduce troubles in data display caused by incompatibility with the above.

According to the discontinuous transport stream packet processing device of the second aspect, in the discontinuous transport stream packet processing device of the first aspect,
The STC delay means compares a difference between the input STC and the extracted PTS with a preset value, and when the value of the difference reaches the preset value, By outputting the STC, the trouble of data display can be reduced by setting the delay time of the STC according to the state of the system.

According to the discontinuous transport stream packet processing device of the present invention, when a discontinuity occurs in a transport stream packet constituting an input transport stream, the discontinuity indicates that the discontinuity has occurred. When a continuous detection signal is input, a video P for extracting a PTS of the data from a packet including the video data
TS filter means, audio PTS filter means for extracting a PTS of data from a packet containing audio data when a discontinuity detection signal indicating that the discontinuity has occurred is input, PTS of the video data,
PTS selection means for inputting the PTS of the audio data and selecting and outputting one of them, and when the discontinuity detection signal is not input, outputs the input STC as it is and outputs the discontinuity detection signal. When input, the input STC is compared with the selected PTS, and in the comparison, the input STC is provided with STC delay means for delaying and outputting the input STC. By using the STC after calibration immediately in the decoding process, it is possible to reduce troubles in data display caused by incompatibility between the data and the STC corresponding to the video data or the audio data.

According to the discontinuous transport stream packet processing device of the fourth aspect, in the discontinuous transport stream packet processing device of the third aspect, the STC delay means includes the input STC delay unit.
And comparing the difference between the selected PTS with a preset value, and outputting the input STC when the difference value reaches the preset value. By setting the STC delay time according to the system status, it is possible to reduce data display trouble.

According to the discontinuous transport stream packet processing device of claim 5, in the discontinuous transport stream packet processing device of claim 3 or 4, the PTS selecting means is configured to output the video data of the video data. By outputting a predetermined one of the PTS and the PTS of the audio data, data loss of the video data or the audio data before the discontinuity occurs can be obtained. Can be prevented.

Further, according to the discontinuous transport stream packet processing device of claim 6, in the discontinuous transport stream packet processing device of claim 3 or 4, the PTS selecting means comprises: By selecting and outputting the PTS and the PTS of the audio data having a large value, the data after the discontinuity is generated can be displayed in the same video and audio. It becomes possible.

[0038] According to the discontinuous transport stream packet processing device of claim 7, in the discontinuous transport stream packet processing device of claim 3 or 4, the PTS selecting means includes: By selecting and outputting a PTS and a PTS of the audio data having a small value, it is possible to prevent data loss after the discontinuity occurs.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a discontinuous TS packet processing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a discontinuous TS packet processing device according to a second embodiment of the present invention.

FIG. 3 is a diagram for explaining a configuration of a transport stream, which is multiplexed data created according to MPEG2.

[Explanation of symbols]

 1, 24 STC input pin 2, 22 Discontinuity detection signal input pin 3 PES Packet input pin 4 PTS filter circuit 5 STC delay unit 6 Decoder 21 Video PES Packet input pin 23 Audio PES Packet input pin 25 Video PTS filter circuit 26 Audio PTS Filter circuit 27 PTS selection circuit 28 STC delay unit 29 Video decoder 30 Audio decoder

Claims (7)

[Claims] 1. A transport stream in which video data, audio data, and time information are multiplexed is input, and based on a PCR indicating a time reference in which data of the input time information is encoded. The STC, which is the time reference of the decoding / reproducing process, is obtained, and the STC and PT indicating the time at which the data of the time information is reproduced are obtained.
In performing the decoding and reproducing process using S, when the transport stream packets constituting the input transport stream are discontinuous, the decoding and reproducing process is performed using the calibrated STC. In the discontinuous transport stream packet processing device, when a discontinuity detection signal indicating that the discontinuity has occurred is input, a PTS filter means for extracting a PTS of the data from the packet including the video data and the audio data When the discontinuity detection signal is not input, the input STC is output as it is, and when the discontinuity detection signal is input, the input STC and the extracted PTS are used. A determination process is performed, and the input STC is delayed and output according to the result of the determination. T
A discontinuous transport stream packet processing device comprising: C delay means. 2. The discontinuous transport stream packet processing device according to claim 1, wherein the STC delay unit determines a difference between the input STC and the extracted PTS by a predetermined value. A discontinuous transport stream packet processing device, which outputs the input STC when the difference value reaches the preset value. 3. A transport stream in which video data, audio data, and time information are multiplexed is input, and based on a PCR indicating a time reference at which data of the input time information is encoded. The STC, which is the time reference of the decoding / reproducing process, is obtained, and the STC and PT indicating the time at which the data of the time information is reproduced are obtained.
In performing the decoding and reproducing process using S, when the transport stream packets constituting the input transport stream are discontinuous, the decoding and reproducing process is performed using the calibrated STC. In the discontinuous transport stream packet processing apparatus, when a discontinuity detection signal indicating that the discontinuity has occurred is input, video PTS filter means for extracting a PTS of the data from the packet including the video data; An audio PTS filter for extracting a PTS of the data from the packet containing the audio data when a discontinuity detection signal indicating that the discontinuity has occurred; a PTS of the video data; and a PTS of the audio data And PTS to select and output one
Selecting means, when the discontinuity detection signal is not inputted, the inputted STC is outputted as it is, and when the discontinuity detection signal is inputted, the inputted STC and the extracted PTS are outputted. ST that performs the used judgment processing and delays and outputs the input STC according to the result of the judgment.
A discontinuous transport stream packet processing device comprising: C delay means. 4. The discontinuous transport stream packet processing device according to claim 3, wherein the STC delay means determines a difference between the input STC and the extracted PTS by a predetermined value. A discontinuous transport stream packet processing device, which outputs the input STC when the difference value reaches the preset value. 5. The discontinuous transport stream packet processing device according to claim 3, wherein the PTS selecting means includes one of a PTS of the video data and a PTS of the audio data. A discontinuous transport stream packet processing device for outputting a predetermined one. 6. The discontinuous transport stream packet processing device according to claim 3, wherein the PTS selecting means has a larger value among a PTS of the video data and a PTS of the audio data. A discontinuous transport stream packet processing apparatus for selecting and outputting a packet. 7. The discontinuous transport stream packet processing device according to claim 3, wherein the PTS selecting means has a smaller value among a PTS of the video data and a PTS of the audio data. A discontinuous transport stream packet processing apparatus for selecting and outputting a packet.