On Tue, Jul 9, 2019 at 2:07 PM Marton Balint <c...@passwd.hu> wrote:
> merge_pmt_versions was not usable if multiple programs were present because
> when it was searching for candidate streams it did not make sure that the
> PMT was
> of the same program. This caused the streams of all programs to get merged
> into
> a single (garbled) program.
>
> This patch makes sure that the program number (service ID) is also matching
> with the old streams when parsing the PMT making the feature useful for
> multi
> program streams.
>
> This change might cause issues for single program streams if the program
> number
> changes as well, but I think it is acceptable because the goal of the
> option is
> to make the parsing resilient to PID changes, and that is still working as
> expected.
>
Patch looks good to me. Thanks for catching this!
Aman
>
> Signed-off-by: Marton Balint <c...@passwd.hu>
> ---
> libavformat/mpegts.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
> index 8a84e5cc19..47d8d5f877 100644
> --- a/libavformat/mpegts.c
> +++ b/libavformat/mpegts.c
> @@ -2130,7 +2130,7 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc,
> AVStream *st, int stream_type
> return 0;
> }
>
> -static AVStream *find_matching_stream(MpegTSContext *ts, int pid,
> +static AVStream *find_matching_stream(MpegTSContext *ts, int pid,
> unsigned int programid,
> int stream_identifier, int
> pmt_stream_idx)
> {
> AVFormatContext *s = ts->stream;
> @@ -2139,6 +2139,8 @@ static AVStream *find_matching_stream(MpegTSContext
> *ts, int pid,
>
> for (i = 0; i < s->nb_streams; i++) {
> AVStream *st = s->streams[i];
> + if (st->program_num != programid)
> + continue;
> if (stream_identifier != -1) { /* match based on "stream
> identifier descriptor" if present */
> if (st->stream_identifier == stream_identifier+1) {
> found = st;
> @@ -2309,7 +2311,7 @@ static void pmt_cb(MpegTSFilter *filter, const
> uint8_t *section, int section_len
> if (ts->pids[pid] && ts->pids[pid]->type == MPEGTS_PES) {
> pes = ts->pids[pid]->u.pes_filter.opaque;
> if (ts->merge_pmt_versions && !pes->st) {
> - st = find_matching_stream(ts, pid, stream_identifier, i);
> + st = find_matching_stream(ts, pid, h->id,
> stream_identifier, i);
> if (st) {
> pes->st = st;
> pes->stream_type = stream_type;
> @@ -2331,7 +2333,7 @@ static void pmt_cb(MpegTSFilter *filter, const
> uint8_t *section, int section_len
> mpegts_close_filter(ts, ts->pids[pid]); // wrongly added
> sdt filter probably
> pes = add_pes_stream(ts, pid, pcr_pid);
> if (ts->merge_pmt_versions && pes && !pes->st) {
> - st = find_matching_stream(ts, pid, stream_identifier, i);
> + st = find_matching_stream(ts, pid, h->id,
> stream_identifier, i);
> if (st) {
> pes->st = st;
> pes->stream_type = stream_type;
> @@ -2353,7 +2355,7 @@ static void pmt_cb(MpegTSFilter *filter, const
> uint8_t *section, int section_len
> st = ts->stream->streams[idx];
> }
> if (ts->merge_pmt_versions && !st) {
> - st = find_matching_stream(ts, pid, stream_identifier, i);
> + st = find_matching_stream(ts, pid, h->id,
> stream_identifier, i);
> }
> if (!st) {
> st = avformat_new_stream(ts->stream, NULL);
> --
> 2.16.4
>
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