[FFmpeg-devel] [PATCH] avformat/dashenc: use AVCodecContext timebase when computing missing bitrate

[Przemysław Sobala]

On Mon, Jun 1, 2020 at 3:30 PM Jeyapal, Karthick <kjeyapal at akamai.com>
wrote:

>
> On 6/1/20 5:24 PM, Przemysław Sobala wrote:
> > On Mon, Jun 1, 2020 at 10:06 AM Anton Khirnov <anton at khirnov.net> wrote:
> >
> >> Quoting Przemysław Sobala (2020-05-27 17:07:22)
> >>> ---
> >>>  libavformat/dashenc.c | 2 +-
> >>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
> >>> index 0cf0df50ef..00a37b175d 100644
> >>> --- a/libavformat/dashenc.c
> >>> +++ b/libavformat/dashenc.c
> >>> @@ -1959,7 +1959,7 @@ static int dash_flush(AVFormatContext *s, int
> >> final, int stream)
> >>>
> >>>          if (!os->bit_rate) {
> >>>              // calculate average bitrate of first segment
> >>> -            int64_t bitrate = (int64_t) range_length * 8 *
> AV_TIME_BASE
> >> / duration;
> >>> +            int64_t bitrate = (int64_t) range_length * 8 *
> >> (c->use_timeline ? os->ctx->streams[0]->time_base.den : AV_TIME_BASE) /
> >> duration;
> >>
> >> That does not look like an AVCodecContext
> >>
> >
> > Of course not. time_base is AVStream's field. I don't know why I wrote
> > AVCodecContext... Please amend that commit message if possible.
> Amended and Pushed!
>
> Thanks,
> Karthick
>
>
Thanks.
What do you think about computing an average bitrate for all segments, not
only the first one (in case of a static - not dynamic - DASH manifest), if
one would not want to specify bitrate while encoding using x264 CRF rate
control? I could prepare such a patch that, if bitrate is not specified,
it'd be computed at the end, for static manifest, for all segments. It'd be
more accurate comparing to the first segment's bitrate.

--
Regards
Przemysław Sobala