[FFmpeg-devel] [PATCH] fftools/ffmpeg: remove usage of internal timestamp AVStream fields

[James Almer]

On 6/1/2021 12:48 PM, James Almer wrote:
> They should not be accessed outside of libavformat.
> 
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
>   fftools/ffmpeg.c     | 10 ++++++----
>   fftools/ffmpeg.h     |  1 +
>   fftools/ffmpeg_opt.c |  1 +
>   3 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
> index b3658d8f65..04ddc9e60b 100644
> --- a/fftools/ffmpeg.c
> +++ b/fftools/ffmpeg.c
> @@ -1168,7 +1168,7 @@ static void do_video_out(OutputFile *of,
>       if (frame_rate.num > 0 && frame_rate.den > 0)
>           duration = 1/(av_q2d(frame_rate) * av_q2d(enc->time_base));
>   
> -    if(ist && ist->st->start_time != AV_NOPTS_VALUE && ist->st->first_dts != AV_NOPTS_VALUE && ost->frame_rate.num)
> +    if(ist && ist->st->start_time != AV_NOPTS_VALUE && ist->first_dts != AV_NOPTS_VALUE && ost->frame_rate.num)
>           duration = FFMIN(duration, 1/(av_q2d(ost->frame_rate) * av_q2d(enc->time_base)));
>   
>       if (!ost->filters_script &&
> @@ -2625,9 +2625,11 @@ static int process_input_packet(InputStream *ist, const AVPacket *pkt, int no_eo
>       avpkt = ist->pkt;
>   
>       if (!ist->saw_first_ts) {
> +        ist->first_dts =
>           ist->dts = ist->st->avg_frame_rate.num ? - ist->dec_ctx->has_b_frames * AV_TIME_BASE / av_q2d(ist->st->avg_frame_rate) : 0;
>           ist->pts = 0;
>           if (pkt && pkt->pts != AV_NOPTS_VALUE && !ist->decoding_needed) {
> +            ist->first_dts =
>               ist->dts += av_rescale_q(pkt->pts, ist->st->time_base, AV_TIME_BASE_Q);
>               ist->pts = ist->dts; //unused but better to set it to a value thats not totally wrong
>           }
> @@ -3949,10 +3951,10 @@ static OutputStream *choose_output(void)
>   
>       for (i = 0; i < nb_output_streams; i++) {
>           OutputStream *ost = output_streams[i];
> -        int64_t opts = ost->st->cur_dts == AV_NOPTS_VALUE ? INT64_MIN :
> -                       av_rescale_q(ost->st->cur_dts, ost->st->time_base,
> +        int64_t opts = ost->last_mux_dts == AV_NOPTS_VALUE ? INT64_MIN :
> +                       av_rescale_q(ost->last_mux_dts, ost->st->time_base,
>                                       AV_TIME_BASE_Q);
> -        if (ost->st->cur_dts == AV_NOPTS_VALUE)
> +        if (ost->last_mux_dts == AV_NOPTS_VALUE)
>               av_log(NULL, AV_LOG_DEBUG,
>                   "cur_dts is invalid st:%d (%d) [init:%d i_done:%d finish:%d] (this is harmless if it occurs once at the start per stream)\n",
>                   ost->st->index, ost->st->id, ost->initialized, ost->inputs_done, ost->finished);
> diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
> index 606f2afe0c..e9d30fbd67 100644
> --- a/fftools/ffmpeg.h
> +++ b/fftools/ffmpeg.h
> @@ -316,6 +316,7 @@ typedef struct InputStream {
>       /* predicted dts of the next packet read for this stream or (when there are
>        * several frames in a packet) of the next frame in current packet (in AV_TIME_BASE units) */
>       int64_t       next_dts;
> +    int64_t first_dts;       ///< dts of the first packet read for this stream (in AV_TIME_BASE units)
>       int64_t       dts;       ///< dts of the last packet read for this stream (in AV_TIME_BASE units)
>   
>       int64_t       next_pts;  ///< synthetic pts for the next decode frame (in AV_TIME_BASE units)
> diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
> index 849d24b16d..a63bed54cf 100644
> --- a/fftools/ffmpeg_opt.c
> +++ b/fftools/ffmpeg_opt.c
> @@ -809,6 +809,7 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
>           ist->discard = 1;
>           st->discard  = AVDISCARD_ALL;
>           ist->nb_samples = 0;
> +        ist->first_dts = AV_NOPTS_VALUE;
>           ist->min_pts = INT64_MAX;
>           ist->max_pts = INT64_MIN;

Will apply.