JPWO2008050427A1 - Information data receiving apparatus, information data receiving method, information data receiving program, and recording medium storing information data receiving program - Google Patents

Abstract

Information data is transmitted in a packet format. For example, when transmitting information data such as audio and video in an MPEG system, even if an error due to missing or changed data occurs, the effect of the error is minimized during playback. Be able to keep it to the limit. When an error is detected when a PES packet is restored or when an error is detected during decoding by a voice decoding unit 203, interpolation data generation unit 202 generates interpolation data for one frame time, and voice decoding control unit 201 However, the selector 204 is switched so as to output the interpolated data to the audio output buffer 104, and the next frame is decoded. If no error is detected, the data is output as it is. [Selection] Figure 4

Description

  The present invention relates to an information data receiving apparatus, an information data receiving method, an information data receiving program, and a recording medium storing an information data receiving program for receiving information in which video or audio is encoded.

  MPEG (Moving Picture Experts Group) is known as an encoding method for encoding audio and moving images when digitized and transmitted.

  In MPEG, in addition to audio and video encoding methods, each bit stream as information data such as encoded video, audio, and additional data is multiplexed, and transmitted and played back while being synchronized with each other. An MPEG system is defined.

  In the MPEG system, each encoded bit stream is stored in a packet called a PES (Packetized Elementary Stream) packet. FIG. 1 shows the structure of the PES packet. The PES packet is a variable-length packet including a PES packet header including time information called PTS (Presentation Time Stamp), and a PES packet payload in which encoded data such as audio and video is stored.

  Then, the PES packet is divided into packets that are divided into fixed lengths called TS (Transport Stream) packets and output to a transmission path or the like. On the receiving side, the PES packet is restored from the received TS packet, encoded data such as audio and video is extracted from the PES packet payload, and decoding and reproduction are performed based on time information such as PTS extracted from the PES packet header. .

  In such transmission by the MPEG system, data may be lost or unintended changes may occur during transmission over a wireless or wired transmission path. In this case, the receiving side recognizes this as an error, and discards or interpolates the data. As a method for dealing with a receiving side when an error occurs, for example, a receiving device of an information data transmission system described in Patent Document 1 has been proposed.

The receiving device of the information data transmission system described in Patent Document 1 compares the PTS inserted in the PES packet with the PTS inserted in the previous PES packet to determine whether there is a missing PES packet. When the missing is detected, the audio data for the missing PES packet is interpolated.
JP 2001-111610 A

  The receiving device of the information data transmission system described in Patent Document 1 described above determines whether a PES packet is missing from the PTS and interpolates in units of PES. For example, in the case of audio data, the frame included in the missing PES packet If there are many, the sound may be interrupted during playback or the sound may become unnatural.

  Accordingly, the present invention provides an information data receiving apparatus capable of minimizing the influence of errors during reproduction even if errors due to data loss or changes occur when transmitting audio or video in an MPEG system, for example. An object is to provide an information data receiving method, an information data receiving program, and a recording medium storing the information data receiving program.

  In order to solve the above problems, the invention according to claim 1 is characterized in that a minimum coding unit to which time information for decoding and reproduction is added and the minimum coding unit to which the time information is not added. Receiving means for receiving mixed information data, decoding means for decoding the information data received by the receiving means for each minimum coding unit, and playing back the decoded data decoded by the decoding means If the decoding means detects an error when decoding the minimum coding unit, interpolated data for the time of the minimum coding unit is generated. After interpolating means and the reproducing means outputting the interpolation data generated by the interpolating means instead of the information data of the minimum coding unit in which an error is detected, and after outputting the interpolating data Error is characterized in that and a control means for outputting to said reproducing means is decoded in said decoding means continues the minimum coding units was detected.

  The invention according to claim 4 receives information data in which the minimum coding unit to which time information for decoding and reproduction is added and the minimum coding unit to which the time information is not added are mixed. In the information data receiving method for decoding the received information data for each minimum coding unit and reproducing the decoded data, if an error is detected when decoding the minimum coding unit, Generating the interpolation data for the time of the minimum coding unit, reproducing the interpolation data instead of the information data of the minimum coding unit in which an error is detected, and outputting the interpolation data, Control is performed so that the minimum coding unit in which no error is detected is decoded and reproduced continuously.

  The invention according to claim 7 receives information data in which the minimum coding unit to which time information for decoding and reproduction is added and the minimum coding unit to which the time information is not added are mixed. A receiving means, a decoding means for decoding the information data received by the receiving means for each minimum coding unit, and a reproducing means for reproducing the decoded data decoded by the decoding means, and a computer In the information data receiving program to be operated on, when the decoding means detects an error when decoding the minimum coding unit, an interpolation means for generating interpolation data for a time of the minimum coding unit; After causing the reproduction means to output the interpolation data generated by the interpolation means instead of the information data of the minimum coding unit in which an error is detected, and after outputting the interpolation data Errors are characterized and control means for outputting to said reproducing means is decoded in said decoding means continues the minimum coded unit that were not found, and that to function to the computer.

It is explanatory drawing of the PES packet in a prior art. It is a block diagram of the information data receiver concerning one Example of this invention. FIG. 2 is a block diagram of an audio decoder of the information data receiving device shown in FIG. 1. It is the flowchart explaining operation | movement of the audio | voice decoder. It is explanatory drawing which showed the input and output of the audio | voice decoder. It is explanatory drawing which showed the input and output of the audio | voice decoder.

Explanation of symbols

100 information data receiving apparatus 101 TS demultiplexer (receiving means)
103 audio decoder 105 D / A converter (reproducing means)
201 Audio decoding control unit (control means)
202 Interpolation data generation unit (interpolation means)
203 Speech decoding unit (decoding means)

  Hereinafter, an information data receiving apparatus according to an embodiment of the present invention will be described. An information data receiving apparatus according to an embodiment of the present invention generates interpolation data for a time corresponding to a minimum coding unit by the interpolation unit when the decoding unit detects an error when decoding the minimum coding unit. Then, the interpolated data is output to the reproducing means in place of the decoded data of the minimum coding unit in which the error is detected by the control means. Then, after the interpolation data generated by the interpolation means is output, the minimum coding unit in which no error is detected is continuously decoded by the decoding means and output to the reproduction means. In this way, information data can be interpolated when an error occurs regardless of the presence or absence of time information, and decoding of the minimum coding unit can be continued immediately thereafter. Therefore, since the interpolation is performed immediately when an error occurs in the minimum coding unit, the influence of the error can be minimized.

  Further, the control means may detect the missing of the minimum coding unit from the time information, cause the interpolation means to generate information data for the missing time, and output it to the reproducing means. By doing in this way, the interpolation for the missing time can be performed when the time information is detected after the interpolation of the minimum coding unit, so that the time axis shift at the time of reproducing the information data can be reduced.

  In addition, the control means detects the lack of the minimum coding unit by comparing the time calculated from the interpolation number and the decoding number of the minimum coding unit from the previous time information with the currently detected time information. You may do it. By doing this, the time is calculated in advance from the number of interpolations and the number of decodings of the minimum coding unit from the previous time information, and the minimum coding unit to which the current time information is added is detected. If the comparison is made at this point, the missing of the minimum coding unit can be easily detected.

  The information data receiving method according to an embodiment of the present invention generates interpolation data for a time corresponding to the minimum coding unit when an error is detected when decoding the minimum coding unit, and the interpolation data Are output instead of the decoded data of the minimum coding unit in which the error is detected. After the interpolation data is output, the minimum coding unit in which no error is detected is continuously decoded and reproduced. In this way, information data can be interpolated when an error occurs regardless of the presence or absence of time information, and decoding of the minimum coding unit can be continued immediately thereafter. Therefore, since the interpolation is performed immediately when an error occurs in the minimum coding unit, the influence of the error can be minimized.

  Further, it is possible to detect the missing of the minimum coding unit from the time information, and generate and reproduce information data for the missing time. By doing in this way, the interpolation for the missing time can be performed when the time information is detected after the interpolation of the minimum coding unit, so that the time axis shift at the time of reproducing the information data can be reduced.

  In addition, the time calculated from the number of interpolations and the number of decodings of the minimum coding unit from the previous time information may be compared with the currently detected time information to detect the lack of the minimum coding unit. good. By doing this, the time is calculated in advance from the number of interpolations and the number of decodings of the minimum coding unit from the previous time information, and the minimum coding unit to which the current time information is added is detected. If the comparison is made at this point, the missing of the minimum coding unit can be easily detected.

  The information data receiving program according to an embodiment of the present invention interpolates interpolation data for a time corresponding to the minimum coding unit when the decoding unit detects an error when decoding the minimum coding unit. And the interpolation data is output to the reproduction means instead of the decoded data of the minimum coding unit in which the error is detected, and after the interpolation data is output, the minimum error is not detected. The computer is caused to function so that the encoding unit is continuously decoded by the decoding unit and output to the reproducing unit. In this way, information data can be interpolated when an error occurs regardless of the presence or absence of time information, and decoding of the minimum coding unit can be continued immediately thereafter. Therefore, since the interpolation is performed immediately when an error occurs in the minimum coding unit, the influence of the error can be minimized.

  It is also possible to detect the missing of the minimum coding unit from the time information, generate information data for the missing time in the interpolation means, and output it to the reproduction means. By doing in this way, the interpolation for the missing time can be performed when the time information is detected after the interpolation of the minimum coding unit, so that the time axis shift at the time of reproducing the information data can be reduced.

  In addition, the time calculated from the number of interpolations and the number of decodings of the minimum coding unit from the previous time information may be compared with the currently detected time information to detect the lack of the minimum coding unit. good. By doing this, the time is calculated in advance from the number of interpolations and the number of decodings of the minimum coding unit from the previous time information, and the minimum coding unit to which the current time information is added is detected. If the comparison is made at this point, the missing of the minimum coding unit can be easily detected.

  Further, the information data receiving program according to any one of claims 7 to 9 may be stored in a recording medium. In this way, the information data receiving program can be distributed alone as well as being incorporated into the device.

  An information data receiving apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS. The information data receiving device 100 is a device that receives a bit stream as information data input from an input terminal, extracts audio data, decodes it, and reproduces it. As shown in FIG. 2, the information data receiving apparatus 100 includes a TS demultiplexer 101, an audio input buffer 102, an audio decoder 103, an audio output buffer 104, a D / A converter 105, and a speaker 106. .

  A TS demultiplexer 101 as a receiving means restores a PES packet from a TS-format bit stream input from an input terminal, extracts audio data, detects PTS as time information from the PES packet header, and detects audio data error The PTS and error detection information are output to the audio input buffer 102 together with the audio data. At this time, the error detection information is output so as to match the error detection position of the audio data so that the PTS matches the head of the audio data of the PES packet.

  The audio input buffer 102 accumulates the audio data, PTS, and error detection information input from the TS demultiplexer 101, and outputs the audio data, PTS, and error information in response to a request from the audio decoder 103.

  The audio decoder 103 decodes the audio data read from the audio input buffer 102 and outputs it to the audio output buffer 104. If there is error detection information, the audio data is interpolated based on the decoding result and the PTS.

  As shown in FIG. 3, the audio decoder 103 includes an audio decoding control unit 201, an interpolation data generation unit 202, an audio decoding unit 203, and a selector 204.

  The audio decoding control unit 201 as a control unit reads out from the audio input buffer 102 for each frame as a minimum encoding unit which is a decoding processing unit. If the read frame has a PTS, the time is calculated from the number of frames decoded or interpolated from the PTS and the PTS output immediately before, and the missing frame is detected from the time. When error detection information is attached to the read frame, or when a frame loss is detected from the PTS or when an error has been notified from the audio decoding unit 203, the interpolation data generation unit 202 generates interpolation data. Instruct. If no frame is detected from the error detection and PTS, the frame is output to the audio decoding unit 203. Further, the selector 204 is switched depending on which of the interpolation data generation unit 202 and the audio decoding unit 203 has been instructed to process.

  The interpolation data generation unit 202 as an interpolation unit generates complementary data for one frame time corresponding to an error frame or a missing frame while referring to the result of the audio decoding unit 203 in accordance with an instruction from the audio decoding control unit 201. To the selector 204.

  The audio decoding unit 203 as a decoding unit decodes the frame data input from the audio decoding control unit 201 and outputs the decoded data to the selector 204. When a decoding error occurs during decoding, the decoding process is stopped, and the audio decoding control unit 201 outputs that the decoding error has occurred.

  The selector 204 is in response to an instruction from the audio decoding control unit 201. The output of either the interpolation data generation unit 202 or the audio decoding unit 203 is output to the audio output buffer 104. If the output frame has a PTS, the PTS is also output.

  The operation of the audio decoder 103 will be described with reference to the flowchart of FIG.

  First, in step S101, the number of interpolations and the number of frames as decoding numbers counted in the audio decoding control unit 201 are cleared to 0, and the process proceeds to step S102.

  Next, in step S102, the audio decoding control unit 201 reads audio data, PTS, and error detection information in units of frames from the audio input buffer 102, and proceeds to step S103.

  Next, in step S103, it is determined whether or not there is PTS in the data read by the audio decoding control unit 201. If there is PTS (in the case of Y), the process proceeds to step S110, and if not (in the case of N). Advances to step S104.

  Next, in step S104, it is determined whether or not there is error detection information in the data read by the audio decoding control unit 201. If there is error detection information (in the case of Y), the process proceeds to step S107; In the case of N), the process proceeds to step S105.

  Next, in step S105, the frame data read by the audio decoding unit 203 is decoded, and the process proceeds to step S106.

  Next, in step S106, it is determined whether or not an error has occurred during decoding by the audio decoding unit 203. If an error has occurred (in the case of Y), the process proceeds to step S107, and otherwise (in the case of N). Advances to step S108.

  Next, in step S107, when the data read from the audio input buffer 102 includes an error or when a decoding error occurs from the audio decoding unit 203, the audio decoding control unit 201 causes the interpolation data generation unit 202 to receive one frame time. Minute interpolation data is generated, and the process proceeds to step S108. One frame time is acquired from the input bit stream, and the interpolation method may be to output the previous frame again, or generate interpolation data based on a plurality of past frame data. You may do it.

  In step S108, the audio decoding control unit 201 switches the selector 204 to output the decoded or interpolated audio data and PTS to the audio output buffer 104, and the process proceeds to step S109.

  Next, in step S109, the number of frames in the audio decoding control unit 201 is incremented, and the process returns to step S102.

  In step S110, the audio decoding control unit 201 determines whether or not the PTS obtained in step S103 is larger than the value obtained by multiplying the PTS obtained immediately before and the number of frames counted in the audio decoding control unit 201 by one frame time. If it is larger (in the case of Y), the process proceeds to step S111. If not (in the case of N), the process proceeds to step S114. That is, a frame loss is detected by comparing the time calculated from the number of interpolated frames and the number of decoded frames from the previous PTS with the currently detected PTS.

  Next, in step S111, since the PTS detected in step S103 is larger than the value obtained by multiplying the number of frames counted in the immediately preceding PTS and the audio decoding control unit 201 by one frame time, there is a missing frame. Then, the audio decoding control unit 201 causes the interpolation data generation unit 202 to generate interpolation data for one frame time, and the process proceeds to step S112. One frame time is acquired from the input bit stream, and the interpolation method may be to output the previous frame again, or generate interpolation data based on a plurality of past frame data. You may do it.

  In step S112, the audio decoding control unit 201 switches the selector 204 to output the interpolated audio data and PTS to the audio output buffer 104, and the process proceeds to step S113.

  Next, in step S113, the number of frames in the audio decoding control unit 201 is incremented, and the process returns to step S110.

  In step S114, the number of frames in the audio decoding control unit 201 is cleared to 0, and the process proceeds to step S104.

  Here, an example of the operation according to the above-described flowchart will be described with reference to FIGS.

  First, FIG. 5 is a diagram in which a part of the bit stream input to the information data receiving apparatus 100 is extracted. When an input frame sequence is input in order from frame 1, frame 1 indicates the last frame of the previous PES packet, frames 2 to 6 form a PES packet, and frame 7 indicates the next PES packet It is an example. As shown in FIG. 5, PTS is added to frames 2 and 7 which are the top frames of the PES packet. In the following description, a PES packet including frames 2 to 6 will be mainly described.

  In FIG. 5, if an error is detected during decoding in frame 3 and error detection information is included when frame data is read in frame 5, first, in the case of frame 2 which is the head of the PES packet, step S102 is performed. S103 and PTS are added, so if there is no error in the PES packet before proceeding to S110 and proceeding to steps S114, S104, S105, S106, and S108, the decoded audio data is output, and the process proceeds to step S109. Proceed, set the number of frames to 1, and return to step S102. In step S102, frame 3 is read, and the process proceeds to step S103, step S104, step S105, and step S106. An error is detected, the process proceeds to step S107, and interpolation data is generated for one frame time, and the process proceeds to step S108 and step S109. 2 and returns to step S102. In step S102, frame 4 is read, and the process proceeds to step S103, step S104, step S105, step S106, step S108, and step S109. The number of frames is set to 3, and the process returns to step S102.

  Subsequently, frame 5 is read in step S102, and the process proceeds to steps S103 and S104, and error detection information is included. Therefore, the process proceeds to step S107, and interpolation data is generated for one frame time, and the process proceeds to steps S108 and S109. The number is set to 4, and the process returns to step S102. In step S102, frame 6 is read, and the process proceeds to step S103, step S104, step S105, step S106, step S108, and step S109. The number of frames is set to 5, and the process returns to step S102.

  Then, in step S102, the frame 7 that is the head of the next PES packet is read, and the process proceeds to steps S103 and S110. In step S110, the PTS included in the frame 7 is replaced with the number of frames and one frame in the PTS included in the frame 2. It is determined whether or not it is greater than the time obtained by adding the value multiplied by time. As described above, the time obtained by adding the number of frames multiplied by one frame time to the PTS included in frame 2 is the PTS + 5 × 1 frame time of frame 2, and the PTS included in frame 7 is shown in FIG. Thus, since the time is advanced by 5 frame times from frame 2, step S110 becomes N, and the process proceeds to step S114. That is, since no frame loss is detected, no frame interpolation is performed.

  Next, the case of FIG. 6 will be described. FIG. 6 is different from FIG. 5 in that an error occurs in frame 3 and the head of frame 4 cannot be recognized due to the error.

  First, in the case of frame 2 which is the head of the PES packet, the process proceeds to steps S102 and S103, and since the PTS is added, if there is no error in the previous PES packet, the process proceeds to step S110 and steps S114, S104, S105 and S106. In step S108, the decoded audio data is output. In step S109, the number of frames is set to 1, and the process returns to step S102. In step S102, frame 3 is read, and the process proceeds to step S103, step S104, step S105, and step S106. An error is detected, the process proceeds to step S107, and interpolation data is generated for one frame time, and the process proceeds to step S108 and step S109. 2 and returns to step S102. Since frame 4 cannot be detected in step S102, frame 5 in which the head can be detected is read, and the process proceeds to step S103, step S104, step S105, step S106, step S108, and step S109. The number of frames is set to 3, and the process returns to step S102. That is, the decoded data of the frame in which no error is detected after interpolation for one frame time is continuously output.

  Subsequently, in step S102, the frame 6 is read, and the process proceeds to step S103, step S104, step S105, step S106, step S108, and step S109. The number of frames is set to 4, and the process returns to step S102.

  Then, in step S102, the frame 7 that is the head of the next PES packet is read, and the process proceeds to steps S103 and S110. In step S110, the PTS included in the frame 7 is replaced with the number of frames and one frame in the PTS included in the frame 2. It is detected whether or not it is larger than the time obtained by adding the value multiplied by time. As described above, the time obtained by adding the number of frames multiplied by one frame time to the PTS included in frame 2 is the PTS + 4 × 1 frame time of frame 2, and the PTS included in frame 7 is shown in FIG. Thus, since it is the time advanced by the time of 5 frames from frame 2, step S110 becomes Y, advances to steps S111 and S112, outputs interpolation data and PTS, sets the frame to 5 in step S113, and returns to step S110. In step S110, it is detected again whether the PTS included in the frame 7 is larger than the time obtained by adding the number of frames multiplied by one frame time to the PTS included in the frame 2, and the PTS included in the frame 2 is detected. The time obtained by adding the value obtained by multiplying the number of frames by one frame time is PTS + 5 × 1 frame time of frame 2 and coincides with the PTS of frame 7, so the process proceeds to step S114. In other words, frame missing is detected from the PTS, and frame interpolation is performed.

  In the case of FIG. 6, the same operation is performed when the error detection information is added to the frame 3 instead of the error detection during decoding and the head of the frame 4 cannot be recognized.

  The audio output buffer 104 accumulates decoded or interpolated audio data and PTS input from the audio decoder 103 and outputs them to the D / A converter 105 in accordance with the PTS.

  A D / A converter 105 serving as a reproduction unit converts the digital audio data input from the audio output buffer 104 into an analog signal and outputs the analog signal to the speaker 106.

  The speaker 106 amplifies the analog signal output from the D / A converter 105 to a predetermined level by an amplifier (not shown), and then emits it as sound.

  According to the present embodiment, in the information data receiving apparatus 100, the PES packet is restored from the input bit stream by the TS demultiplexer 101, and decoded by the audio decoder 103 for each frame. If an error is detected during PES packet restoration or an error is detected during decoding by the audio decoding unit 203 in the audio decoder 103, the interpolation data generation unit 202 in the audio decoder 103 generates interpolation data for one frame time. The audio decoding control unit 201 switches the selector 204 so as to output the interpolation data to the audio output buffer 104 instead of the error frame, decodes the next frame, and outputs it as it is if no error is detected. When error is detected, the voice data for one frame time can be immediately interpolated. Since the next frame is decoded and output if normal, it can be interpolated in units of frames, so that the influence of errors can be kept to a minimum and the audio information of subsequent frames can be output.

  Further, when the PTS is detected, the PTS is compared with the time calculated from the previous PTS and the number of frames that have been interpolated or decoded. As a result, if the current PTS is large, it is determined that there is a missing frame. Thus, since the frames corresponding to the missing time are interpolated, it is possible to easily determine the presence or absence of the missing frame when the PTS is detected and perform the interpolation. Therefore, it is possible to reduce the deviation of the time axis of the decoded data.

  In the above-described embodiment, the lack of frames is determined by comparing the PTS with the time calculated from the number of interpolations and the number of frames from the previous PTS. An internal clock function may be provided, and a missing frame may be detected from the clock and the PTS. In other words, it may be determined that a frame is missing if the frame has not arrived at the time when it should have arrived.

  Further, in the above-described embodiment, the lack of a frame is determined by comparing the PTS with the time calculated from the number of interpolations and the number of frames from the previous PTS, but considering the fluctuation of the PTS. A determination may be made. For example, in FIG. 5, the time between two PTSs is 5 frame times, but in actual MPEG system transmission, the PTS added to frame 7 may not necessarily be the time after 5 frames from frame 2 ( Judgment may be made in consideration of that amount.

  In the above-described embodiments, audio has been described. However, not only audio but also video, for example, when a picture is the minimum coding unit, there are cases where time information is added to a picture and what is not added. In this case, the present invention can be applied.

  The information data receiving apparatus described above may be a program that operates on a computer. In that case, the function of each block shown in the block diagram of FIG. 2 is functioned by the CPU and the memory, whereby a computer-readable information data receiving program can be obtained.

  Further, if the present invention is applied to a receiver that receives terrestrial digital broadcasting, CATV, broadcasting via the Internet, etc., the influence of errors during transmission can be minimized. In particular, the present invention is very effective when applied to mobile devices and in-vehicle devices that are mobile receivers that transmit information by radio waves.

  According to the embodiment described above, the following information data receiving apparatus, information data receiving method, and information data receiving program can be obtained.

(Supplementary note 1) TS demultiplexer 101 that receives a bitstream in which a frame to which PTS is added and a frame to which PTS is not added is mixed, and the bitstream received by TS demultiplexer 101 is decoded for each frame. In the information data receiving apparatus 100 having the audio decoding unit 203 that performs and the D / A converter 105 that reproduces the audio data decoded by the audio decoding unit 203,
When the audio decoding unit 203 detects an error when decoding a frame, an interpolation data generation unit 202 that generates interpolation data for one frame time;
The interpolation data generated by the interpolation data generation unit 202 is output to the D / A converter 105 instead of the audio data of the frame in which the error is detected, and after the interpolation data is output, the frame in which no error is detected is output. An audio decoding control unit 201 that subsequently decodes the audio decoding unit 203 to output to the D / A converter 105;
An information data receiving apparatus characterized by comprising:

  According to the information data receiving apparatus 100, the audio data can be interpolated for one frame when an error occurs regardless of the presence or absence of the PTS, and thereafter the decoding in units of frames can be continued immediately. Therefore, since the interpolation is performed immediately when an error occurs in the frame, the influence of the error can be minimized.

(Supplementary note 2) A bitstream in which a frame to which a PTS is added and a frame to which a PTS is not added is mixed is received, the received bitstream is decoded for each frame, and the decoded audio data is reproduced. In the information data receiving method,
If an error is detected when decoding a frame, interpolated data for one frame time is generated, the interpolated data is reproduced instead of the audio data of the frame in which the error is detected, and the interpolated data is output. An information data receiving method comprising: performing control so that a frame in which no error is detected is subsequently decoded and reproduced.

  According to this information data receiving method, audio data can be interpolated for one frame when an error occurs regardless of the presence or absence of PTS, and thereafter, decoding in units of frames can be continued immediately. Therefore, since the interpolation is performed immediately when an error occurs in the frame, the influence of the error can be minimized.

(Supplementary note 3) TS demultiplexer 101 that receives a bitstream in which a frame to which PTS is added and a frame to which PTS is not added is mixed, and the bitstream received by TS demultiplexer 101 is decoded for each frame In an information data receiving program that causes a computer to function as an audio decoding unit 203 that performs audio data decoding by the audio decoding unit 203 and a D / A converter 105 that reproduces audio data decoded by the audio decoding unit 203,
When the audio decoding unit 203 detects an error when decoding a frame, an interpolation data generation unit 202 that generates interpolation data for one frame time;
The interpolation data generated by the interpolation data generation unit 202 is output to the D / A converter 105 instead of the audio data of the frame in which the error is detected, and after the interpolation data is output, the frame in which no error is detected is output. An audio decoding control unit 201 that subsequently decodes the audio decoding unit 203 to output to the D / A converter 105;
And a computer-readable information data receiving program which causes the computer to function.

  According to this information data receiving program, it is possible to interpolate audio data for one frame when an error occurs regardless of the presence or absence of PTS, and then continue decoding in units of frames immediately thereafter. Therefore, since the interpolation is performed immediately when an error occurs in the frame, the influence of the error can be minimized.

  In addition, the Example mentioned above only showed the typical form of this invention, and this invention is not limited to an Example. That is, various modifications can be made without departing from the scope of the present invention.

[0002]
An information data transmission system receiver has been proposed.
[0007]
The receiving device of the information data transmission system described in Patent Document 1 compares the PTS inserted in the PES packet with the PTS inserted in the previous PES packet to determine whether there is a missing PES packet. When the missing is detected, the audio data for the missing PES packet is interpolated.
Patent Document 1: Japanese Patent Laid-Open No. 2001-111610 Disclosure of Invention [0008]
The receiving device of the information data transmission system described in Patent Document 1 described above determines whether a PES packet is missing from the PTS and interpolates in units of PES. For example, in the case of audio data, the frame included in the missing PES packet If there are many, the sound may be interrupted during playback or the sound may become unnatural.
[0009]
Accordingly, the present invention provides an information data receiving apparatus capable of minimizing the influence of errors during reproduction even if errors due to data loss or changes occur when transmitting audio or video in an MPEG system, for example. An object is to provide an information data receiving method, an information data receiving program, and a recording medium storing the information data receiving program.
Means for Solving the Problems [0010]
In order to solve the above problems, the invention according to claim 1 is characterized in that a first minimum coding unit to which time information for decoding and reproduction is added and a second unit to which the time information is not added. Receiving means for receiving information data in which the minimum encoding units are mixed, decoding means for decoding the information data received by the receiving means for each minimum encoding unit, and decoding by the decoding means An information data receiving device for reproducing decoded data, wherein the decoding means detects an error when decoding the first minimum encoding unit or the second minimum encoding unit. In this case, the interpolation means for generating the interpolation data for the time of the first minimum encoding unit or the second minimum encoding unit, and the first minimum encoding unit or the second minimum detected error. Information data of minimum coding unit Instead by outputting the interpolated data, outputs the interpolated data to said reproducing means

[0003]
The second minimum coding unit, which is the information data decoded by the decoding means and no error is detected, after the decoding is performed, for each minimum coding unit without waiting for the arrival of the time information. Based on the time information added to the first minimum coding unit that arrives after the second minimum coding unit in which the error is not detected. And control means for complementing the missing first minimum coding unit or second minimum coding unit.
[0011]
The invention according to claim 4 is a mixture of a first minimum coding unit to which time information for decoding and reproduction is added and a second minimum coding unit to which the time information is not added. An information data receiving method for receiving received information data, decoding the received information data for each minimum coding unit, and reproducing the decoded data, wherein the first minimum coding unit or the first coding unit If an error is detected when decoding the second minimum encoding unit, interpolation data for the time of the first minimum encoding unit or the second minimum encoding unit is generated, and the error is detected. The interpolation data is output instead of the information data of the first minimum coding unit or the second minimum coding unit, and the information data is decoded after the interpolation data is output, and no error is detected. The second minimum mark The first minimum code that arrives after the second minimum encoding unit in which the error is not detected and reproduced, and is decoded for each minimum encoding unit without waiting for the arrival of the time information. On the basis of the time information added to the encoding unit, control is performed to complement the missing first minimum encoding unit or second minimum encoding unit.
[0012]
The invention according to claim 7 is a mixture of the first minimum coding unit to which time information for decoding and reproduction is added and the second minimum coding unit to which the time information is not added. Receiving means for receiving information data to be received, decoding means for decoding the information data received by the receiving means for each minimum coding unit, and reproducing means for reproducing the decoded data decoded by the decoding means And an information data receiving program that causes a computer to function, and when the decoding unit detects an error when decoding the first minimum encoding unit or the second minimum encoding unit, Interpolation means for generating interpolation data for the time of the first minimum encoding unit or the second minimum encoding unit, and the first minimum encoding unit or the second minimum encoding unit in which an error is detected Information data Instead, the interpolation data is output, and the second minimum encoding unit in which no error is detected in the information data decoded by the decoding means after outputting the interpolation data to the reproducing means, Without waiting for the arrival of the time information, the decoding means decodes and outputs to the reproduction means for each minimum coding unit, and arrives after the second minimum coding unit in which the error is not detected. Based on the time information added to the first minimum encoding unit, the computer functions as control means for complementing the missing first minimum encoding unit or the second minimum encoding unit. It is characterized by that.
BRIEF DESCRIPTION OF THE DRAWINGS [0013]
FIG. 1 is an explanatory diagram of a PES packet in the prior art.
FIG. 2 is a block diagram of an information data receiving apparatus according to an embodiment of the present invention.
FIG. 3 is a block diagram of an audio decoder of the information data receiving device shown in FIG.
FIG. 4 is a flowchart illustrating the operation of the audio decoder.

[0004]
[FIG. 5] It is explanatory drawing which showed the input and output of the audio | voice decoder.
[FIG. 6] It is explanatory drawing which showed the input and output of the audio decoder.
Explanation of symbols [0014]
100 information data receiving apparatus 101 TS demultiplexer (receiving means)
103 audio decoder 105 D / A converter (reproducing means)
201 Audio decoding control unit (postnatal means)
202 Interpolation data generation unit (interpolation means)
203 Speech decoding unit (decoding means)
BEST MODE FOR CARRYING OUT THE INVENTION [0015]
Hereinafter, an information data receiving apparatus according to an embodiment of the present invention will be described. The information data receiving apparatus according to an embodiment of the present invention is configured to detect the first and second minimum encodings when the decoding unit detects an error when decoding the first and second minimum encoding units. Interpolation data is generated by the interpolation means for the time corresponding to the unit, and the interpolation data is replaced with the decoded data of the first minimum encoding unit or the second minimum encoding unit in which the error is detected by the control means. The second minimum coding unit which is the information data decoded by the decoding means after the interpolation data is output to the reproducing means and no error is detected is minimized without waiting for the arrival of time information. Time information added to the first minimum coding unit that arrives after the second minimum coding unit in which no error was detected by causing the decoding unit to decode and output to the reproduction unit for each coding unit Based on the missing second Or doing a complementary second minimum coded unit. In this way, information data can be interpolated when an error occurs regardless of the presence or absence of time information, and decoding of the second minimum coding unit can be continued immediately thereafter. Therefore, since the interpolation is performed immediately when an error occurs in the first or second minimum coding unit, the influence of the error can be minimized.
[0016]
Further, the control means detects the lack of the first minimum coding unit and the second minimum coding unit from the time information, causes the interpolation means to generate information data for the missing time, and outputs the information data to the reproduction means. Anyway. By doing in this way, it is possible to perform the interpolation for the missing time when the time information is detected after the interpolation of the first minimum coding unit and the second minimum coding unit. Time axis deviation can be reduced.
[0017]
In addition, the control means compares the time calculated from the first minimum coding unit, the number of interpolations and the number of decoding of the second minimum coding unit from the previous time information, and the currently detected time information. Then, the lack of the first minimum coding unit and the second minimum coding unit may be detected. In this way, the time is calculated in advance from the number of interpolations and the number of decodings of the first minimum coding unit and the second minimum coding unit from the previous time information, and the current time If the first minimum coding unit to which the information is added is detected and compared, the missing of the first minimum coding unit and the second minimum coding unit can be easily detected.

[0005]
[0018]
In addition, the information data receiving method according to the embodiment of the present invention, when an error is detected when decoding the first and second minimum encoding units, the first and second minimum encoding units. Is generated in place of the decoded data of the first minimum coding unit or the second minimum coding unit in which an error is detected, and the interpolation data is output and then decoded. The second minimum coding unit that has been converted into information data and no error was detected is decoded and reproduced for each minimum coding unit without waiting for the arrival of time information, and no error is detected. The missing first or second minimum coding unit is complemented based on the time information added to the first minimum coding unit that comes after the two minimum coding units. In this way, information data can be interpolated when an error occurs regardless of the presence or absence of time information, and decoding of the second minimum coding unit can be continued immediately thereafter. Therefore, since the interpolation is performed immediately when an error occurs in the first minimum encoding unit or the second minimum encoding unit, the influence of the error can be minimized.
[0019]
Further, the lack of the first minimum coding unit and the second minimum coding unit may be detected from the time information, and information data for the missing time may be generated and reproduced. By doing in this way, it is possible to perform the interpolation for the missing time when the time information is detected after the interpolation of the first minimum coding unit and the second minimum coding unit. Time axis deviation can be reduced.
[0020]
Also, the time calculated from the first minimum coding unit from the previous time information, the number of interpolations and the number of decoding of the second minimum coding unit is compared with the currently detected time information. The missing of the first minimum coding unit and the second minimum coding unit may be detected. By doing this, the time is calculated in advance from the number of interpolations and the number of decoding of the first minimum coding unit and the second minimum coding unit from the previous time information, and the current time If the first minimum coding unit to which the time information is added is detected at the time of detection, the missing of the first minimum coding unit and the second minimum coding unit can be easily detected.
[0021]
In addition, the information data receiving program according to the embodiment of the present invention has the first and second minimums when the decoding unit detects an error when decoding the first and second minimum encoding units. Interpolation data for the time corresponding to the coding unit is generated by the interpolation means, and the interpolation data is replaced with the decoded data of the first minimum coding unit or the second minimum coding unit in which the error is detected by the control means. Interpolation data is output, and after the interpolation data is output to the reproduction means, the second minimum coding unit which is the information data decoded by the decoding means and no error is detected, without waiting for the arrival of time information Is decoded by the decoding means for each minimum coding unit and output to the reproduction means, and added to the first minimum coding unit that comes after the second minimum coding unit in which no error is detected. Based on time information

[0006]
Cause the computer to function to complement the missing first or second minimum coding unit. In this way, information data can be interpolated when an error occurs regardless of the presence or absence of time information, and decoding of the second minimum coding unit can be continued immediately thereafter. Therefore, since the interpolation is performed immediately when an error occurs in the first or second minimum coding unit, the influence of the error can be minimized.
[0022]
Further, the missing of the first minimum coding unit and the second minimum coding unit may be detected from the time information, and information data for the missing time may be generated by the interpolation means and output to the reproduction means. . By doing in this way, it is possible to perform the interpolation for the missing time when the time information is detected after the interpolation of the first minimum coding unit and the second minimum coding unit. Time axis deviation can be reduced.
[0023]
In addition, the time calculated from the number of interpolations and the number of decoding of the first minimum encoding unit and the second minimum encoding unit from the previous time information is compared with the currently detected time information, The missing of the minimum coding unit and the second minimum coding unit may be detected. In this way, the time is calculated in advance from the number of interpolations and the number of decodings of the first minimum coding unit and the second minimum coding unit from the previous time information, and the current time If the first minimum coding unit to which the information is added is detected and compared, the missing of the first minimum coding unit and the second minimum coding unit can be easily detected.
[0024]
Further, the information data receiving program according to any one of claims 7 to 9 may be stored in a recording medium. In this way, the information data receiving program can be distributed alone as well as being incorporated into the device.
Example [0025]
An information data receiving apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS. The information data receiving device 100 is a device that receives a bit stream as information data input from an input terminal, extracts audio data, decodes it, and reproduces it. As shown in FIG. 2, the information data receiving apparatus 100 includes a TS demultiplexer 101, an audio input buffer 102, an audio decoder 103, an audio output buffer 104, a D / A converter 105, and a speaker 106. .
[0026]
The TS demultiplexer 101 as a receiving means is in the TS format input from the input terminal.

[0013]
It is possible to easily determine the presence or absence of a missing frame at the time of extraction and perform interpolation. Therefore, it is possible to reduce the deviation of the time axis of the decoded data.
[0064]
In the above-described embodiment, the lack of frames is determined by comparing the PTS with the time calculated from the number of interpolations and the number of frames from the previous PTS. An internal clock function may be provided, and a missing frame may be detected from the clock and the PTS. That is, if the frame has not arrived at the time when it should have arrived, it may be determined that the frame is missing.
[0065]
In the above-described embodiment, the lack of a frame is determined by comparing the PTS with the time calculated from the number of interpolations and the number of frames from the previous PTS. A determination may be made. For example, in FIG. 5, the time between two PTSs is 5 frame times, but in actual MPEG system transmission, the PTS added to frame 7 may not necessarily be the time after 5 frames from frame 2 ( Judgment may be made in consideration of that amount.
[0066]
In the above-described embodiments, audio has been described. However, not only audio but also video, for example, when a picture is a minimum coding unit, there are cases in which time information is added to a picture and information that is not added. In this case, the present invention can be applied.
[0067]
The information data receiving apparatus described above may be a program that operates on a computer. In that case, the function of each block shown in the block diagram of FIG. 2 is functioned by the CPU and the memory, whereby a computer-readable information data receiving program can be obtained.
[0068]
Further, if the present invention is applied to a receiver that receives terrestrial digital broadcasting, CATV, broadcasting via the Internet, etc., the influence of errors during transmission can be minimized. In particular, the present invention is very effective when applied to mobile devices and in-vehicle devices that are mobile receivers that transmit information by radio waves.
[0069]
According to the embodiment described above, the following information data receiving apparatus, information data receiving method, and information data receiving program can be obtained.
[0070]
(Supplementary note 1) TS demultiplexer 101 that receives a bit stream in which a frame to which a PTS is added and a frame to which a PTS is not added are mixed, and TS demultiplexer 1

[0014]
In the information data receiving apparatus 100 having the audio decoding unit 203 that decodes the bit stream received by 01 for each frame and the D / A converter 105 that reproduces the audio data decoded by the audio decoding unit 203, the audio decoding When the unit 203 detects an error when decoding the frame, the interpolation data generation unit 202 that generates interpolation data for one frame time, and outputs the interpolation data instead of the audio data of the frame in which the error is detected Thus, after the interpolated data is outputted to the D / A converter 105, the frame which is the information data decoded by the audio decoding unit 203 and to which no error is detected is added without waiting for the arrival of the PTS. The audio decoder 203 decodes each frame and outputs it to the D / A converter 105. And an audio decoding control unit 201 for complementing the missing frame based on the PTS added to the frame to which the PTS that arrives after the frame to which no PTS is not added is detected. An information data receiving apparatus characterized by comprising:
[0071]
According to the information data receiving apparatus 100, the audio data can be interpolated for one frame when an error occurs regardless of the presence or absence of the PTS, and thereafter the decoding in units of frames can be continued immediately. Therefore, since the interpolation is performed immediately when an error occurs in the frame, the influence of the error can be minimized.
[0072]
(Supplementary note 2) A bitstream in which a frame to which a PTS is added and a frame to which a PTS is not added is mixed is received, the received bitstream is decoded for each frame, and the decoded audio data is reproduced. In the information data reception method, when an error is detected when decoding a frame, interpolation data for one frame time is generated, and the interpolation data is output instead of the audio data of the frame in which the error is detected. A frame that is information data decoded after data is output and has no PTS added is decoded and reproduced for each frame without waiting for the arrival of PTS, and no error is detected. To a PTS added to a frame to which a PTS arrives after a frame to which no PTS is added Zui, the information method for receiving data and controlling to perform complement missing frames.
[0073]
According to this information data receiving method, audio data can be interpolated for one frame when an error occurs regardless of the presence or absence of PTS, and thereafter, decoding in units of frames can be continued immediately. Therefore, since the interpolation is performed immediately when an error occurs in the frame, the influence of the error can be minimized.
[0074]
(Supplementary note 3) TS demultiplexer 101 that receives a bitstream in which a frame to which PTS is added and a frame to which PTS is not added is mixed, and the bitstream received by TS demultiplexer 101 is decoded for each frame Audio decoding unit 203 that performs

[0015]
In the information data reception program that causes the computer to function as the D / A converter 105 that reproduces the audio data decoded by the decoding unit 203, when the audio decoding unit 203 detects an error when decoding the frame, An interpolation data generation unit 202 that generates interpolation data for one frame time, and outputs interpolation data in place of the audio data of the frame in which the error is detected, and outputs the interpolation data to the D / A converter 105 and then decodes the audio The frame which is the information data decoded by the unit 203 and is not added with the PTS to which no error is detected is decoded by the audio decoding unit 203 for each frame without waiting for the arrival of the PTS, and the D / A converter 105 To which no error is detected and no PTS is added Computer-readable information data that causes a computer to function as an audio decoding control unit 201 that complements a missing frame based on a PTS added to a frame to which a later PTS is added Receiving program.
[0075]
According to this information data receiving program, it is possible to interpolate audio data for one frame when an error occurs regardless of the presence or absence of PTS, and then continue decoding in units of frames immediately thereafter. Therefore, since the interpolation is performed immediately when an error occurs in the frame, the influence of the error can be minimized.
[0076]
In addition, the Example mentioned above only showed the typical form of this invention, and this invention is not limited to an Example. That is, various modifications can be made without departing from the scope of the present invention.

Claims (10)

Receiving means for receiving information data in which a minimum coding unit to which time information for decoding and reproduction is added and the minimum coding unit to which the time information is not added are mixed; and the receiving means In an information data receiving apparatus comprising: decoding means for decoding received information data for each minimum coding unit; and reproduction means for reproducing decoded data decoded by the decoding means.
If the decoding means detects an error when decoding the minimum coding unit, an interpolation means for generating interpolation data for the time of the minimum coding unit;
The interpolation data generated by the interpolation means is output to the reproduction means instead of the information data of the minimum coding unit in which an error is detected, and the error is not detected after the interpolation data is output. Control means for continuously decoding a minimum coding unit by the decoding means and outputting to the reproduction means;
An information data receiving apparatus characterized by comprising:   2. The control unit according to claim 1, wherein the control unit detects missing of the minimum coding unit from the time information, causes the interpolation unit to generate information data corresponding to a missing time, and outputs the information data to the reproduction unit. The information data receiving device described.   The control means compares the time calculated from the number of interpolations and the number of decoding of the minimum coding unit from the previous time information with the currently detected time information, and detects the lack of the minimum coding unit. The information data receiving apparatus according to claim 2, wherein the information data receiving apparatus is detected. Receiving information data in which the minimum coding unit to which time information for decoding and reproduction is added and the minimum coding unit to which the time information is not added are received, and the received information data is In the information data receiving method of decoding for each coding unit and reproducing the decoded data,
When an error is detected when decoding the minimum coding unit, interpolated data for the time of the minimum coding unit is generated, and instead of the information data of the minimum coding unit in which the error is detected, the data A method of receiving information data, comprising: reproducing interpolated data, and outputting the interpolated data, and then performing control so that the minimum coding unit in which no error is detected is continuously decoded and reproduced.   5. The information data receiving method according to claim 4, wherein a missing of the minimum coding unit is detected from the time information, and interpolation data corresponding to the missing time is generated and reproduced.   Comparing the time calculated from the number of interpolations and the number of decoding of the minimum coding unit from the previous time information with the currently detected time information to detect the lack of the minimum coding unit. The information data receiving method according to claim 5, wherein: Receiving means for receiving information data in which a minimum coding unit to which time information for decoding and reproduction is added and the minimum coding unit to which the time information is not added are mixed; and the receiving means In an information data receiving program for causing a computer to function as a decoding means for decoding received information data for each minimum coding unit and a reproducing means for reproducing decoded data decoded by the decoding means,
If the decoding means detects an error when decoding the minimum coding unit, an interpolation means for generating interpolation data for the time of the minimum coding unit;
The interpolation data generated by the interpolation means is output to the reproduction means instead of the information data of the minimum coding unit in which an error is detected, and the error is not detected after the interpolation data is output. Control means for continuously decoding a minimum coding unit by the decoding means and outputting to the reproduction means;
And a computer-readable information data receiving program which causes the computer to function.   8. The control unit according to claim 7, wherein the control unit detects missing of the minimum coding unit from the time information, causes the interpolation unit to generate information data for a missing time, and outputs the information data to the reproduction unit. The information data receiving program described.   The control means compares the time calculated from the interpolation number and decoding number of the minimum coding unit from the previous time information with the currently detected time information and lacks the minimum coding unit. 9. The information data receiving program according to claim 8, wherein the information data receiving program is detected.   A computer-readable recording medium storing the information data receiving program according to any one of claims 7 to 9.

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