[FFmpeg-user] an issue on decoding a mxf xavc long gop file.

Carl Eugen Hoyos ceffmpeg at gmail.com
Wed Apr 10 02:16:25 EEST 2019

2019-04-10 0:24 GMT+02:00, Yufei He <yhe at matrox.com>:
> On 04/08/2019 02:03 PM, Carl Eugen Hoyos wrote:
>> 2019-04-08 18:56 GMT+02:00, Yufei He <yhe at matrox.com>:
>>> On 04/07/2019 05:37 PM, Carl Eugen Hoyos wrote:
>>>> 2019-04-05 17:03 GMT+02:00, Yufei He <yhe at matrox.com>:
>>>>> I use avctx->framerate in my codec.
>>>> Why?
>>>> I am not claiming that there is no bug (I opened a ticket)
>>>> but I don't see why you need the value, even more so
>>>> if there is not issue with the native decoder.
>>> The chip needs frame rate to be initialized properly.
>> Does that mean that only (strict) cfr is supported by the chip?

> Chip just needs frame rate to get initialized

So this is only a bug in the chip or the driver
because the initialization data is not used?

> it can go as fast as possible.
> I have a question:
> In line 809 of file ffmpeg_opt.c
>              // avformat_find_stream_info() doesn't set this for us
> anymore.
>              ist->dec_ctx->framerate = st->avg_frame_rate;
> Why is avg_frame_rate assigned to  ist->dec_ctx->framerate ?

> Why not st->r_frame_rate;

Doesn't the documentation answer this question?

Carl Eugen

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