Copied from: http://article.gmane.org/gmane.comp.video.ffmpeg.devel/84145/match=

mov_edit_lists.patch

Index: libavformat/mov.c
===================================================================
--- libavformat/mov.c	(revision 17434)
+++ libavformat/mov.c	(working copy)
@@ -104,6 +104,11 @@
     unsigned flags;
 } MOVTrackExt;
 
+typedef struct {
+  unsigned int track_duration;
+  unsigned int media_time;
+} MOVElst;
+
 typedef struct MOVStreamContext {
     ByteIOContext *pb;
     int ffindex; /* the ffmpeg stream id */
@@ -118,6 +123,8 @@
     MOVStsc *stsc_data;
     int ctts_index;
     int ctts_sample;
+    unsigned int elst_count; /* number of 'edit' (elst atom) */
+    MOVElst *elst_table;
     unsigned int sample_size;
     unsigned int sample_count;
     int *sample_sizes;
@@ -125,7 +132,6 @@
     int *keyframes;
     int time_scale;
     int time_rate;
-    int time_offset; ///< time offset of the first edit list entry
     int current_sample;
     unsigned int bytes_per_frame;
     unsigned int samples_per_frame;
@@ -1222,6 +1228,85 @@
     return 0;
 }
 
+/* This is a little support function used to process the edit list when
+ * building a frame table. */
+#define MAX_DURATION 0x7FFFFFFFFFFFFFFFLL
+static void get_next_edit_list_entry(MOVStreamContext *msc,
+                                     unsigned int *edit_list_index,
+                                     unsigned int *edit_list_media_time,
+                                     int64_t *edit_list_duration,
+                                     int64_t global_timescale) {
+  /* if there is no edit list, set to max duration and get out */
+  if (!msc->elst_table || (msc->elst_count <= 0)) {
+    *edit_list_media_time = 0;
+    *edit_list_duration = MAX_DURATION;
+    return;
+
+  } else while (*edit_list_index < msc->elst_count) {
+
+    /* otherwise, find an edit list entries whose media time != -1 */
+    if (msc->elst_table[*edit_list_index].media_time != -1) {
+      *edit_list_media_time =
+        msc->elst_table[*edit_list_index].media_time;
+      *edit_list_duration =
+        msc->elst_table[*edit_list_index].track_duration;
+
+      /* duration is in global timescale units; convert to msc timescale */
+      *edit_list_duration *= msc->time_scale;
+      *edit_list_duration /= global_timescale;
+
+      *edit_list_index = *edit_list_index + 1;
+      break;
+    }
+
+    *edit_list_index = *edit_list_index + 1;
+  }
+
+  /* on the way out, check if this is the last edit list entry; if so,
+   * don't let the duration expire (so set it to an absurdly large value)
+   */
+  if (*edit_list_index == msc->elst_count)
+    *edit_list_duration = MAX_DURATION;
+}
+
+static void mov_fix_index(MOVContext *mov, AVStream *st) {
+  MOVStreamContext *msc = st->priv_data;
+  AVIndexEntry *e = st->index_entries;
+
+  unsigned int edit_list_media_time = 0;
+  int64_t edit_list_duration = 0;
+  int64_t frame_duration = 0;
+  unsigned int edit_list_pts_counter = 0;
+  unsigned int edit_list_index = 0;
+  int i;
+
+  /* initialize edit list considerations */
+  get_next_edit_list_entry(msc, &edit_list_index,
+    &edit_list_media_time, &edit_list_duration, mov->time_scale);
+
+  /* fix up pts information w.r.t. the edit list table */
+  for (i = 0; i < st->nb_index_entries; i++, e++) {
+    int64_t timestamp = e->timestamp;
+    if (timestamp * msc->time_rate < edit_list_media_time) {
+      e->timestamp = edit_list_pts_counter/msc->time_rate;
+    } else {
+      if (i < st->nb_index_entries - 1)
+        frame_duration =
+            ((e + 1)->timestamp - e->timestamp) * msc->time_rate;
+
+      e->timestamp = edit_list_pts_counter/msc->time_rate;
+      edit_list_pts_counter += frame_duration;
+      edit_list_duration -= frame_duration;
+    }
+
+    /* reload media time and duration */
+    if (edit_list_duration <= 0) {
+      get_next_edit_list_entry(msc, &edit_list_index,
+        &edit_list_media_time, &edit_list_duration, mov->time_scale);
+    }
+  }
+}
+
 static void mov_build_index(MOVContext *mov, AVStream *st)
 {
     MOVStreamContext *sc = st->priv_data;
@@ -1232,12 +1317,6 @@
     unsigned int stss_index = 0;
     unsigned int i, j;
 
-    /* adjust first dts according to edit list */
-    if (sc->time_offset) {
-        assert(sc->time_offset % sc->time_rate == 0);
-        current_dts = - (sc->time_offset / sc->time_rate);
-    }
-
     /* only use old uncompressed audio chunk demuxing when stts specifies it */
     if (!(st->codec->codec_type == CODEC_TYPE_AUDIO &&
           sc->stts_count == 1 && sc->stts_data[0].duration == 1)) {
@@ -1334,6 +1413,7 @@
  out:
     /* adjust sample count to avindex entries */
     sc->sample_count = st->nb_index_entries;
+    mov_fix_index(mov, st);
 }
 
 static int mov_read_trak(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
@@ -1767,24 +1847,25 @@
 static int mov_read_elst(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
     MOVStreamContext *sc = c->fc->streams[c->fc->nb_streams-1]->priv_data;
-    int i, edit_count;
+    MOVElst *elst;
+    int i;
 
     get_byte(pb); /* version */
     get_be24(pb); /* flags */
-    edit_count = get_be32(pb); /* entries */
+    sc->elst_count = get_be32(pb);     /* entries */
+    if (sc->elst_count <= 0)
+      return 0;
 
-    for(i=0; i<edit_count; i++){
-        int time;
-        get_be32(pb); /* Track duration */
-        time = get_be32(pb); /* Media time */
+    sc->elst_table = elst =
+        av_mallocz(sc->elst_count*sizeof(*sc->elst_table));
+
+    for(i=0; i<sc->elst_count; i++, elst++){
+        elst->track_duration = get_be32(pb); /* Track duration */
+        elst->media_time = get_be32(pb); /* Media time */
         get_be32(pb); /* Media rate */
-        if (i == 0 && time != -1) {
-            sc->time_offset = time;
-            sc->time_rate = av_gcd(sc->time_rate, time);
-        }
     }
 
-    if(edit_count > 1)
+    if(sc->elst_count > 1)
         av_log(c->fc, AV_LOG_WARNING, "multiple edit list entries, "
                "a/v desync might occur, patch welcome\n");