No timestamps in audio

Krunal Patel_11

Hello TI,

We have DM8148 based custom board and we are using ezsdk_dm814x-evm_5_05_01_04. We have designed our own application using the audio_encode and capture_encode demo provided in the ezsdk package.

We are using IL_ClientOutputBitStreamWriteTask thread to dump the data into the respective audio and video files. Now the problem I am facing is with the timestamps.

When I read the pBufferOut->nTimeStamp parameter I get the timestamp for video but in case of audio I always get '0' value for this parameter.

Further when I investigated the issue, I found out that for audio we don't assign any value to pBufHdr->nTimeStamp in AAC_Read_InputData.

So can anyone please guide me how can I have the timestamp values for the input buffer of audio?

For video we are assigning the value pBufferIn->nTimeStamp in IL_ClientProcessPipeCmdETB.

Please let me know if I am unable to explain the query and you need more information.

Thanks,

Krunal

over 9 years ago

0 Margarita Gashova over 9 years ago

TI__Guru* 80190 points

Hello,

I will check it and I will let you know.

Best Regards,

Margarita

0 Margarita Gashova over 9 years ago

TI__Guru* 80190 points

Hello,

Krunal Patel1 said:
Please let me know if I am unable to explain the query and you need more information.

Correct my understanding if it is wrong. Your use case is capture audio and video right?

For the video capture you are using OMX capture_encode demo (VFCC->...->VENC->...)?

For the audio encode you are using AENC.

What you are using for audio capture? Is it ALSA?

Best Regards,

Margarita

0 Krunal Patel_11 over 9 years ago in reply to Margarita Gashova

Expert 2250 points

Hi Margarita,

Yes you are right. We are using ALSA for audio capture.

Regards,

Krunal

0 Margarita Gashova over 9 years ago in reply to Krunal Patel_11

TI__Guru* 80190 points

Hello,

It seems to me that the video capture component timestamps the frames. The h264 encoder component only copy the timestamps from the input buffer header to the output buffer header, the audio codec component does the same but the alsa capture driver does not add timestamps. Probably this is the problem.

Best Regards,

Margarita

0 Krunal Patel_11 over 9 years ago in reply to Margarita Gashova

Expert 2250 points

Hi Margarita,

Yes may be you are right ALSA capture driver is not adding timestamps. So in order to have the timestamps in audio will it be good to copy the timestamps of video capture component? Or will it be good that ALSA driver should add timestamps?

Please let me know if you need more information.

PS: We want to use same timestamps that HDVICP provides.

Thanks,

Krunal

0 Margarita Gashova over 9 years ago in reply to Krunal Patel_11

TI__Guru* 80190 points

Hello,

Krunal Patel_11 said:
PS: We want to use same timestamps that HDVICP provides.

Should be possible .

Krunal Patel_11 said:
Or will it be good that ALSA driver should add timestamps?

You could check http://www.alsa-project.org/main/index.php/Main_Page

and

http://www.mail-archive.com/alsa-devel@lists.sourceforge.net/msg12590.html

Best Regards,

Margarita

0 Faizel over 9 years ago in reply to Margarita Gashova

Expert 1460 points

Hi,

You can put the time stamps from the application as well. There is not any issue in that. Give the same time stamps as the video, to make sure of the sync. That will be the easier solution.

Regards

Faizel

0 Krunal Patel_11 over 9 years ago in reply to Margarita Gashova

Expert 2250 points

Hi Margarita,

Thanks for responding and this information was helpful.

So is there a way by which we can have same timestamps for audio and video and also where we won't face synchronization issues.

Please let me know if you have any query.

Thanks,

Krunal

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No timestamps in audio