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

Carl Eugen Hoyos ceffmpeg at gmail.com
Thu Oct 26 00:57:26 EEST 2017


2017-10-25 16:52 GMT+02:00 Jean-Yves Avenard <jyavenard at gmail.com>:
> 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)

Not sure I understand:
In ticket #6609, I asked if this is a flac-only issue.
You answered: "The issue can be reproduced with any codec."

So why does your patch only fix the issue for flac?
Or do I misunderstand?

Thank you, Carl Eugen


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