[FFmpeg-devel] [PATCH] Properly store sampling rate for FLAC in mp4

[Jean-Yves Avenard]

hi

On 26 August 2017 at 12:08, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
> 2017-08-25 13:25 GMT+02:00 Jean-Yves Avenard <jyavenard at gmail.com>:
>
>> +            if (track->par->codec_id == AV_CODEC_ID_FLAC) {
>
> Why does this only apply to flac?
>

Sorry, I had missed your reply.

The specification on how sampling rate is to be stored should it be
greater than INT16_MAX is a FLAC in ISOBMFF requirement:

https://git.xiph.org/?p=flac.git;a=blob;f=doc/isoflac.txt;h=574df9f54a779fca2e62c726703fc7be199d4c05;hb=refs/heads/master#l165

It definitely could be applied to other codecs, but I haven't seen
such requirements clearly defined.

ISOBMFF only defines that AudioSampleEntryV1 should be used instead,
in which case the sampling_rate is a 32 bits integer (ISO 14496-12
12.2.3.2)

JY