[FFmpeg-devel] [PATCH 0/2] avformat movenc add flag to allow disabling limit on timescale

[vectronic]

> On 5 May 2020, at 06:19, Gyan Doshi <ffmpeg at gyani.pro> wrote:
> 
> 
> 
> On 05-05-2020 03:16 am, vectronic wrote:
>> 
>>> On 4 May 2020, at 17:56, Gyan Doshi <ffmpeg at gyani.pro> wrote:
>>> 
>>> 
>>> 
>>> On 04-05-2020 09:54 pm, vectronic wrote:
>>>> I needed to encode to mov/mp4 with a timebase of 1/600 and the output was not as expected.
>>> What was the unexpected output?
>>> 
>>> You can use video_track_timescale to set any custom scale.
>>> 
>>> Gyan
>> The unexpected output is that if you request a timebase of 600 as an argument for ffmpeg on the command line, the output timebase is forced to be greater than 10000.
>> 
>> As far as I can see there is no documentation or message logged that the following logic is applied which means the output differs to what a user has requested and expects:
>> 
>> while(track->timescale < 10000)
>>     track->timescale *= 2;
>> 
>> I believe video_track_timescale applies to all tracks - so you unable to specify timescales per track?
> 
> I believe your flag also disables the scale clamping for all video tracks. In that case, better to extend the min value of video_track_timescale  to -1 to implement this instead of a new flag.
> 
> Gyan
> 

Hello Gyan,

I updated the patch with your feedback here: https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=1138

Do you have any further feedback?

Thanks,

Nick