[FFmpeg-user] Create an AAC stream matching the Core Media Audio packet format / priming etc?

Mark Burton mwjburton at gmail.com
Sun Jun 25 12:28:36 EEST 2017

On 19 Jun 2017, at 22:38, Marton Balint <cus at passwd.hu> wrote:
> Can you measure how many samples are the delay before and after my patch? I'd rather do some additional testing now, instead committing something that is only half-correct.

I’ve reached out to the developer who was helping me. I believe he also wrote a second patch of his own. I don’t yet have a binary build I can test with myself, so I would like to test more files to check the results and give you a solid answer.

Essentially Quicktime is still assuming 2112 sample delay even with the patches, its just that it is ever so slightly better than normal, but it is still out of sync. In order to get Quicktime to adhere to a provided delay of 1024, there would be other changes needed in ffmpeg.

It does appear that most (if not all) Quicktime based encoders are setup to output a file for the decoder to assume 2112 sample delay. We have not yet found one which uses the ‘modern’ method.

Thanks for your help on this Marton.

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