[FFmpeg-devel] Exposing preroll and remainder info for aac and mp3.

Dale Curtis dalecurtis at chromium.org
Mon Jul 9 20:08:07 CEST 2012


On Wed, Jul 4, 2012 at 2:21 PM, Michael Niedermayer <michaelni at gmx.at>wrote:

>
> just posted a patchset implementing initial silence skiping for mp3
> doing the same with mov/mp4 aac should be trivial, id need a reference
> sample though to make sure the aac/mov/mp4 stuff is correct. Its easy
> to get it wrong without a testcase ...
>
> the mp3 code should be compatible with lames way of indicating the
> amount of padding.
>
>
Thanks Michael! The AAC audio files from the demo page are good samples:

MP3:
http://rtoy.github.com/webaudio/codec-tests/resources/media/square3.mp3

AAC:
http://rtoy.github.com/webaudio/codec-tests/resources/media/square3.m4a

WAV reference:
http://rtoy.github.com/webaudio/codec-tests/resources/media/square3.wav

According to the OSX afinfo (sorry don't know of a Linux equivalent)
command, the AAC file should have 44100 valid frames + 2112 priming + 892
remainder.

- dale


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