[FFmpeg-devel] [PATCH 2/8] avformat/mpegts: simplify nb_packets code

[Marton Balint]

On Sat, 19 Dec 2020, Michael Niedermayer wrote:

> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
> libavformat/mpegts.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
> index 1122455f66..cc292ab929 100644
> --- a/libavformat/mpegts.c
> +++ b/libavformat/mpegts.c
> @@ -3090,7 +3090,6 @@ static int mpegts_read_header(AVFormatContext *s)
>         AVStream *st;
>         int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;
>         int64_t pcrs[2], pcr_h;
> -        int packet_count[2];
>         uint8_t packet[TS_PACKET_SIZE];
>         const uint8_t *data;
> 
> @@ -3116,7 +3115,6 @@ static int mpegts_read_header(AVFormatContext *s)
>                 parse_pcr(&pcr_h, &pcr_l, data) == 0) {
>                 finished_reading_packet(s, ts->raw_packet_size);
>                 pcr_pid = pid;
> -                packet_count[nb_pcrs] = nb_packets;
>                 pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;
>                 nb_pcrs++;
>                 if (nb_pcrs >= 2) {
> @@ -3126,7 +3124,6 @@ static int mpegts_read_header(AVFormatContext *s)
>                     } else {
>                         av_log(ts->stream, AV_LOG_WARNING, "invalid pcr pair %"PRId64" >= %"PRId64"\n", pcrs[0], pcrs[1]);
>                         pcrs[0] = pcrs[1];
> -                        packet_count[0] = packet_count[1];
>                         nb_pcrs--;
>                     }
>                 }
> @@ -3138,8 +3135,8 @@ static int mpegts_read_header(AVFormatContext *s)
>
>         /* NOTE1: the bitrate is computed without the FEC */
>         /* NOTE2: it is only the bitrate of the start of the stream */
> -        ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);
> -        ts->cur_pcr  = pcrs[0] - ts->pcr_incr * packet_count[0];
> +        ts->pcr_incr = pcrs[1] - pcrs[0];
> +        ts->cur_pcr  = pcrs[0] - ts->pcr_incr * (nb_packets - 1);
>         s->bit_rate  = TS_PACKET_SIZE * 8 * 27000000LL / ts->pcr_incr;
>         st->codecpar->bit_rate = s->bit_rate;
>         st->start_time      = ts->cur_pcr;

LGTM for this and the preivous as well.

(BTW did anybody hear of anyone ever using the mpegts raw demuxer?)

Thanks,
Marton