[FFmpeg-devel] [PATCH] Increase MOV_TIMESCALE for higher precision

[Gyan Doshi]

On 2021-03-24 15:45, Jan Ekström wrote:
> On Wed, Mar 24, 2021 at 7:30 AM Gyan Doshi <ffmpeg at gyani.pro> wrote:
>>
>>
>> On 2021-03-24 03:38, Andrey Rikunov wrote:
>>> ---
>>>    libavformat/movenc.h | 2 +-
>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/libavformat/movenc.h b/libavformat/movenc.h
>>> index cdbc407..8a152c0 100644
>>> --- a/libavformat/movenc.h
>>> +++ b/libavformat/movenc.h
>>> @@ -29,7 +29,7 @@
>>>
>>>    #define MOV_FRAG_INFO_ALLOC_INCREMENT 64
>>>    #define MOV_INDEX_CLUSTER_SIZE 1024
>>> -#define MOV_TIMESCALE 1000
>>> +#define MOV_TIMESCALE 60000
>> Instead of hardcoding it, add an option to allow the user to set it.
> if MOV still needs its timescale override of 1:1000 for some

To be clear, the MOV_TIMESCALE refers to the timescale written in the 
mvhd atom in all products of movenc.c. It is distinct from the 
stream/track timescales. The mvhd value is the basis for the duration 
field in edit list entries but not media time which is denominated in 
terms of track timescale ( what video_track_timescale targets but only 
for video streams). Users in the past have asked for a change (usually 
to 600) because some Apple products (FCP ?) only work well with 600 for 
mvhd timescale. There is no strict inter-relation or constraint across 
mvhd and the trak timescales, so auto_adjust_timescale shouldn't force 
it in any hardcoded manner.

Regards,
Gyan