[FFmpeg-devel] There may be a bug for .mp4 reader.

Devin Heitmueller dheitmueller at ltnglobal.com
Mon Apr 1 20:42:47 EEST 2019

Hello Yufei,

> On Apr 1, 2019, at 1:21 PM, Yufei He <yhe at matrox.com> wrote:
> Hi
> There may be a bug for .mp4 reader.
> On decoding some ntsc mp4 files with my h.264 codec, from actvx I received,
> avctx->framerate.den is 100
> avctx->framerate.num is 2997
> avctx->pkt_timebase.num is 1
> avctx->pkt_timebase.den is 2997
> Duration of every packet I received from ff_decode_get_packet(avctx, &pkt) is 100, which means it's a encoded frame. But actually, it's a encoded field, it's duration should be 50.

Libavcodec doesn’t have any support for delivering individual fields.  Decoders are expected to reassemble fields into frames before providing them back to callers.

Presumably this is some sort of PAFF encoded stream?  Does it decode properly when using the software h.264 decoder?


Devin Heitmueller - LTN Global Communications
dheitmueller at ltnglobal.com

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