[FFmpeg-devel] A change in r_frame_rate values after upgrade to FFmpeg 6.1

[Kieran Kunhya]

> On Mon, Sep 23, 2024 at 4:45 PM Kieran Kunhya via ffmpeg-devel <ffmpeg-devel at ffmpeg.org> wrote:
>>
>> On Mon, Sep 23, 2024 at 3:27 PM Anton Khirnov <anton at khirnov.net> wrote:
>> >
>> > Quoting Antoni Bizoń (2024-09-23 10:09:51)
>> > > I understand that the r_frame_rate is the lowest framerate with which
>> > > all timestamps can be represented accurately. And I know it is just a
>> > > guess. But why did the logic behind the calculation change?
>> >
>> > Because you're most likely using a codec like H.264 or MPEG-2 that
>> > allows individually coded fields. In that case the timebase must be
>> > accurate enough to represent the field rate (i.e. double the frame
>> > rate), but the code doing this was previously unreliable, so you'd
>> > sometimes get r_frame_rate equal to the frame rate rather than field
>> > rate. That is not the case anymore.
>>
>> This is bizarre and kafkaesque to say the least.
>
>
> Should we schedule deprecation for one of the two fields? I agree it's confusing for end users to check in two fields.

avg_frame_rate implies it's not precise in some way. I think the OP is
correct here that the behaviour makes no sense.
If something says frame_rate it's the rate of frames, not the rate of
fields or anything else.

Kieran