Ticket #9006: 0001-avformat-mpegts-use-stream-index-based-lookup-with-m.patch

libavformat/mpegts.c

@@ -116 +116 @@
     int pmt_found;
 };
 
+struct Stream {
+    int pmt_stream_idx;
+    int stream_identifier;
+    int program_num;
+};
+
 struct MpegTSContext {
     const AVClass *class;
     /* user data */
@@ -2201 +2207 @@
     return 0;
 }
 
-static AVStream *find_matching_stream(MpegTSContext *ts, int pid, unsigned int programid,
+static AVStream* find_matching_stream(MpegTSContext *ts, struct Stream *old_streams, int nb_old_streams, int pid, unsigned int programid,
                                       int stream_identifier, int pmt_stream_idx)
 {
     AVFormatContext *s = ts->stream;
     int i;
     AVStream *found = NULL;
+    AVStream *idxfound = NULL;
 
-    for (i = 0; i < s->nb_streams; i++) {
-        AVStream *st = s->streams[i];
+    for (i = 0; i < nb_old_streams; i++) {
+        struct Stream *st = old_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;
-                break;
+                if (found) { /* fallback to idx based guess if multiple streams have the same identifier */
+                    stream_identifier = -1;
+                    found = NULL;
+                } else {
+                    found = s->streams[i];
+                }
             }
-        } else if (st->pmt_stream_idx == pmt_stream_idx) { /* match based on position within the PMT */
-            found = st;
-            break;
+        }
+        if (st->pmt_stream_idx == pmt_stream_idx) { /* match based on position within the PMT */
+            if (!idxfound)
+                idxfound = s->streams[i];
         }
     }
 
+    if (!found)
+        found = idxfound;
+
     if (found) {
         av_log(ts->stream, AV_LOG_VERBOSE,
                "re-using existing %s stream %d (pid=0x%x) for new pid=0x%x\n",
@@ -2288 +2303 @@
     uint32_t prog_reg_desc = 0; /* registration descriptor */
     int stream_identifier = -1;
 
+    struct Stream *old_streams = NULL;
+    int nb_old_streams = 0;
+
     int mp4_descr_count = 0;
     Mp4Descr mp4_descr[MAX_MP4_DESCR_COUNT] = { { 0 } };
     int i;
@@ -2361 +2379 @@
 
     set_pmt_found(ts, h->id);
 
+    if (ts->merge_pmt_versions) {
+        old_streams = av_malloc_array(sizeof(struct Stream), ts->stream->nb_streams);
+        if (!old_streams)
+            goto out;
+        nb_old_streams = ts->stream->nb_streams;
+        for (i = 0; i < nb_old_streams; i++) {
+            AVStream *st = ts->stream->streams[i];
+            old_streams[i].pmt_stream_idx = st->pmt_stream_idx;
+            old_streams[i].stream_identifier = st->stream_identifier;
+            old_streams[i].program_num = st->program_num;
+        }
+    }
 
     for (i = 0; ; i++) {
         st = 0;
@@ -2382 +2412 @@
         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, h->id, stream_identifier, i);
+                st = find_matching_stream(ts, old_streams, nb_old_streams, pid, h->id, stream_identifier, i);
                 if (st) {
                     pes->st = st;
                     pes->stream_type = stream_type;
@@ -2404 +2434 @@
                 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, h->id, stream_identifier, i);
+                st = find_matching_stream(ts, old_streams, nb_old_streams, pid, h->id, stream_identifier, i);
                 if (st) {
                     pes->st = st;
                     pes->stream_type = stream_type;
@@ -2426 +2456 @@
                 st = ts->stream->streams[idx];
             }
             if (ts->merge_pmt_versions && !st) {
-                st = find_matching_stream(ts, pid, h->id, stream_identifier, i);
+                st = find_matching_stream(ts, old_streams, nb_old_streams, pid, h->id, stream_identifier, i);
             }
             if (!st) {
                 st = avformat_new_stream(ts->stream, NULL);
@@ -2481 +2511 @@
         mpegts_open_pcr_filter(ts, pcr_pid);
 
 out:
+    av_free(old_streams);
     for (i = 0; i < mp4_descr_count; i++)
         av_free(mp4_descr[i].dec_config_descr);
 }