Ticket #892: ogg_get_length.patch

libavformat/ogg2.c

@@ -466 +466 @@
 ogg_get_length (AVFormatContext * s)
 {
     ogg_t *ogg = s->priv_data;
-    int idx = -1, i;
-    offset_t size, end;
+    int i, streams_found;
+    offset_t size, search_start, search_end;
+        int64_t duration;
 
     if(s->pb.is_streamed)
         return 0;
@@ -479 +480 @@
     size = url_fsize(&s->pb);
     if(size < 0)
         return 0;
-    end = size > MAX_PAGE_SIZE? size - MAX_PAGE_SIZE: size;
+    search_start = size > MAX_PAGE_SIZE? size - MAX_PAGE_SIZE: size;
+        search_end = size;
 
     ogg_save (s);
-    url_fseek (&s->pb, end, SEEK_SET);
 
-    while (!ogg_read_page (s, &i)){
-        if (ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0 &&
-            ogg->streams[i].codec)
-            idx = i;
-    }
+        /* Seek back from the end of the file until we find the duration of all of the streams */
+        streams_found = 0;
+        while (streams_found < ogg->nstreams && search_start > 0) {
+                url_fseek (&s->pb, search_start, SEEK_SET);
+                while (!ogg_read_page (s, &i) && url_ftell (&s->pb) < search_end) {
+                        if (ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0 && 
+                                ogg->streams[i].codec) 
+                        {
+                                duration = ogg_gptopts (s, i, ogg->streams[i].granule);
+                                if (s->streams[i]->duration == AV_NOPTS_VALUE) {
+                                        s->streams[i]->duration = duration;
+                                        streams_found++;
+                                } else if (duration > s->streams[i]->duration) {
+                                        s->streams[i]->duration = duration;
+                                }
+                        }
+                }
+                search_start -= MAX_PAGE_SIZE;
+                search_end -= MAX_PAGE_SIZE;
+        }
 
-    if (idx != -1){
-        s->streams[idx]->duration =
-            ogg_gptopts (s, idx, ogg->streams[idx].granule);
-    }
+    ogg->size = size;
 
-    ogg->size = size;
+        /* Go back to the start and find the start time for each stream */
     ogg_restore (s, 0);
     ogg_save (s);
-    while (!ogg_read_page (s, &i)) {
-        if (i == idx && ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0)
-            break;
-    }
-    if (i == idx) {
-        s->streams[idx]->start_time = ogg_gptopts (s, idx, ogg->streams[idx].granule);
-        s->streams[idx]->duration -= s->streams[idx]->start_time;
-    }
+        streams_found = 0;
+        /* Reset the start time to AV_NOPTS_VALUE, just in case it isn't already */
+        for (i = 0; i < ogg->nstreams; i++) {
+                s->streams[i]->start_time = AV_NOPTS_VALUE;
+        }
+    while (!ogg_read_page (s, &i) && streams_found < ogg->nstreams) {
+                if (s->streams[i]->start_time == AV_NOPTS_VALUE && ogg->streams[i].granule != -1) {
+                        streams_found++;
+                        s->streams[i]->start_time = ogg_gptopts (s, i, ogg->streams[i].granule);
+            s->streams[i]->duration -= s->streams[i]->start_time;
+                }
+        }
     ogg_restore (s, 0);
 
     return 0;