[FFmpeg-devel] [PATCH v1 3/6] avformat/dashenc: use local variable and avoid calculate duration multiple times

[Jeyapal, Karthick]

On 4/26/20 3:19 PM, lance.lmwang at gmail.com wrote:
> From: Limin Wang <lance.lmwang at gmail.com>
>
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
>  libavformat/dashenc.c | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
> index 5fbe4dd..96c0ea3 100644
> --- a/libavformat/dashenc.c
> +++ b/libavformat/dashenc.c
> @@ -1916,6 +1916,7 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
>          OutputStream *os = &c->streams[i];
>          AVStream *st = s->streams[i];
>          int range_length, index_length = 0;
> +        int64_t duration;
>  
>          if (!os->packets_written)
>              continue;
> @@ -1955,23 +1956,18 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
>              }
>          }
>  
> -        os->last_duration = FFMAX(os->last_duration, av_rescale_q(os->max_pts - os->start_pts,
> -                                                                  st->time_base,
> -                                                                  AV_TIME_BASE_Q));
> +        duration = av_rescale_q(os->max_pts - os->start_pts, st->time_base, AV_TIME_BASE_Q);
> +        os->last_duration = FFMAX(os->last_duration, duration);
>  
>          if (!os->muxer_overhead && os->max_pts > os->start_pts)
>              os->muxer_overhead = ((int64_t) (range_length - os->total_pkt_size) *
> -                                  8 * AV_TIME_BASE) /
> -                                 av_rescale_q(os->max_pts - os->start_pts,
> -                                              st->time_base, AV_TIME_BASE_Q);
> +                                  8 * AV_TIME_BASE) / duration;
>          os->total_pkt_size = 0;
>          os->total_pkt_duration = 0;
>  
>          if (!os->bit_rate) {
>              // calculate average bitrate of first segment
> -            int64_t bitrate = (int64_t) range_length * 8 * AV_TIME_BASE / av_rescale_q(os->max_pts - os->start_pts,
> -                                                                                       st->time_base,
> -                                                                                       AV_TIME_BASE_Q);
> +            int64_t bitrate = (int64_t) range_length * 8 * AV_TIME_BASE / duration;
>              if (bitrate >= 0)
>                  os->bit_rate = bitrate;
>          }
LGTM