[FFmpeg-devel] [PATCH 1/2] avformat/demux: Restore pkt->stream_index assert check

[Andreas Rheinhardt]

Andreas Rheinhardt:
> It has been moved after "st  = s->streams[pkt->stream_index]"
> in b140b8332c617b0eef4f872f3ef90c469e99920f.
> Deduplicate ff_read_packet() and ff_buffer_packet()
> while fixing this.
> This also fixes shadowing in ff_read_packet().
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
>  libavformat/demux.c | 75 +++++++++++++++++++--------------------------
>  1 file changed, 31 insertions(+), 44 deletions(-)
> 
> diff --git a/libavformat/demux.c b/libavformat/demux.c
> index 4c50eb5568..4345ed4c8c 100644
> --- a/libavformat/demux.c
> +++ b/libavformat/demux.c
> @@ -532,9 +532,6 @@ static void update_timestamps(AVFormatContext *s, AVStream *st, AVPacket *pkt)
>  {
>      FFStream *const sti = ffstream(st);
>  
> -    av_assert0(pkt->stream_index < (unsigned)s->nb_streams &&
> -               "Invalid stream index.\n");
> -
>      if (update_wrap_reference(s, st, pkt->stream_index, pkt) && sti->pts_wrap_behavior == AV_PTS_WRAP_SUB_OFFSET) {
>          // correct first time stamps to negative values
>          if (!is_relative(sti->first_dts))
> @@ -555,13 +552,24 @@ static void update_timestamps(AVFormatContext *s, AVStream *st, AVPacket *pkt)
>          pkt->dts = pkt->pts = av_rescale_q(av_gettime(), AV_TIME_BASE_Q, st->time_base);
>  }
>  
> -int ff_buffer_packet(AVFormatContext *s, AVPacket *pkt)
> +/**
> + * Handle a new packet and either return it directly if possible and
> + * allow_passthrough is true or queue the packet (or drop the packet
> + * if corrupt).
> + *
> + * @return < 0 on error, 0 if the packet was passed through,
> + *         1 if it was queued or dropped
> + */
> +static int handle_new_packet(AVFormatContext *s, AVPacket *pkt, int allow_passthrough)
>  {
>      FFFormatContext *const si = ffformatcontext(s);
> -    AVStream *st  = s->streams[pkt->stream_index];
> -    FFStream *sti = ffstream(st);
> +    AVStream *st;
> +    FFStream *sti;
>      int err;
>  
> +    av_assert0(pkt->stream_index < (unsigned)s->nb_streams &&
> +               "Invalid stream index.\n");
> +
>      if (pkt->flags & AV_PKT_FLAG_CORRUPT) {
>          av_log(s, AV_LOG_WARNING,
>                 "Packet corrupt (stream = %d, dts = %s)",
> @@ -569,13 +577,19 @@ int ff_buffer_packet(AVFormatContext *s, AVPacket *pkt)
>          if (s->flags & AVFMT_FLAG_DISCARD_CORRUPT) {
>              av_log(s, AV_LOG_WARNING, ", dropping it.\n");
>              av_packet_unref(pkt);
> -            return 0;
> +            return 1;
>          }
>          av_log(s, AV_LOG_WARNING, ".\n");
>      }
>  
> +    st  = s->streams[pkt->stream_index];
> +    sti = ffstream(st);
> +
>      update_timestamps(s, st, pkt);
>  
> +    if (sti->request_probe <= 0 && allow_passthrough && !si->raw_packet_buffer.head)
> +        return 0;
> +
>      err = avpriv_packet_list_put(&si->raw_packet_buffer, pkt, NULL, 0);
>      if (err < 0) {
>          av_packet_unref(pkt);
> @@ -585,14 +599,18 @@ int ff_buffer_packet(AVFormatContext *s, AVPacket *pkt)
>      pkt = &si->raw_packet_buffer.tail->pkt;
>      si->raw_packet_buffer_size += pkt->size;
>  
> -    if (sti->request_probe <= 0)
> -        return 0;
> -
>      err = probe_codec(s, st, pkt);
>      if (err < 0)
>          return err;
>  
> -    return 0;
> +    return 1;
> +}
> +
> +int ff_buffer_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    int err = handle_new_packet(s, pkt, 0);
> +
> +    return err < 0 ? err : 0;
>  }
>  
>  int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
> @@ -612,9 +630,6 @@ FF_ENABLE_DEPRECATION_WARNINGS
>  
>      for (;;) {
>          PacketListEntry *pktl = si->raw_packet_buffer.head;
> -        AVStream *st;
> -        FFStream *sti;
> -        const AVPacket *pkt1;
>  
>          if (pktl) {
>              AVStream *const st = s->streams[pktl->pkt.stream_index];
> @@ -656,36 +671,8 @@ FF_ENABLE_DEPRECATION_WARNINGS
>              return err;
>          }
>  
> -        if (pkt->flags & AV_PKT_FLAG_CORRUPT) {
> -            av_log(s, AV_LOG_WARNING,
> -                   "Packet corrupt (stream = %d, dts = %s)",
> -                   pkt->stream_index, av_ts2str(pkt->dts));
> -            if (s->flags & AVFMT_FLAG_DISCARD_CORRUPT) {
> -                av_log(s, AV_LOG_WARNING, ", dropping it.\n");
> -                av_packet_unref(pkt);
> -                continue;
> -            }
> -            av_log(s, AV_LOG_WARNING, ".\n");
> -        }
> -
> -        st  = s->streams[pkt->stream_index];
> -        sti = ffstream(st);
> -
> -        update_timestamps(s, st, pkt);
> -
> -        if (!pktl && sti->request_probe <= 0)
> -            return 0;
> -
> -        err = avpriv_packet_list_put(&si->raw_packet_buffer,
> -                                     pkt, NULL, 0);
> -        if (err < 0) {
> -            av_packet_unref(pkt);
> -            return err;
> -        }
> -        pkt1 = &si->raw_packet_buffer.tail->pkt;
> -        si->raw_packet_buffer_size += pkt1->size;
> -
> -        if ((err = probe_codec(s, st, pkt1)) < 0)
> +        err = handle_new_packet(s, pkt, 1);
> +        if (err <= 0) /* Error or passthrough */
>              return err;
>      }
>  }

Will apply this patchset tomorrow unless there are objections.

- Andreas