[FFmpeg-devel] [PATCH] matroskadec: Improve TTA duration calculation

[James Almer]

On 16/08/13 5:21 PM, Paul B Mahol wrote:
> On 8/16/13, James Almer <jamrial at gmail.com> wrote:
>> On 16/08/13 7:24 AM, Paul B Mahol wrote:
>>> On 8/15/13, James Almer <jamrial at gmail.com> wrote:
>>>> -            avio_wl32(&b, matroska->ctx->duration *
>>>> track->audio.out_samplerate);
>>>> +            avio_wl32(&b, av_rescale(matroska->ctx->duration,
>>>> track->audio.out_samplerate, AV_TIME_BASE));
>>>
>>> Isn't time base variable thing that can be changed by muxer?
>>>
>>> Perhaps this could be used when muxing tta files to make sure
>>> last packet can always decode.
>>
>> Our muxer already uses 1000000 (aka AV_TIME_BASE) as timescale for every
>> file.
> 
> But this patch does not use time base as used in file, but hardcode it,

It's using matroska->ctx->duration, which is calculated using the duration 
and the timescale of the stream as stored in the file (line 1546).

That line for that matter could use av_rescale() as well instead of 
a plain a*b/c, but that's unrelated.