parse 'stps' atom to set keyframe, partial sync sample for mpeg-2 open gop

Originally committed as revision 18813 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/isom.h

@@ -96,6 +96,8 @@ typedef struct MOVStreamContext {
     MOVStts *ctts_data;
     unsigned int stsc_count;
     MOVStsc *stsc_data;
+    unsigned int stps_count;
+    unsigned *stps_data;  ///< partial sync sample for mpeg-2 open gop
     int ctts_index;
     int ctts_sample;
     unsigned int sample_size;

libavformat/mov.c

@@ -1102,6 +1102,35 @@ static int mov_read_stsc(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
     return 0;
 }
 
+static int mov_read_stps(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
+{
+    AVStream *st;
+    MOVStreamContext *sc;
+    unsigned i, entries;
+
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
+    get_be32(pb); // version + flags
+
+    entries = get_be32(pb);
+    if (entries >= UINT_MAX / sizeof(*sc->stps_data))
+        return -1;
+    sc->stps_data = av_malloc(entries * sizeof(*sc->stps_data));
+    if (!sc->stps_data)
+        return AVERROR(ENOMEM);
+    sc->stps_count = entries;
+
+    for (i = 0; i < entries; i++) {
+        sc->stps_data[i] = get_be32(pb);
+        //dprintf(c->fc, "stps %d\n", sc->stps_data[i]);
+    }
+
+    return 0;
+}
+
 static int mov_read_stss(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
     AVStream *st = c->fc->streams[c->fc->nb_streams-1];
@@ -1300,6 +1329,7 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
     unsigned int stts_index = 0;
     unsigned int stsc_index = 0;
     unsigned int stss_index = 0;
+    unsigned int stps_index = 0;
     unsigned int i, j;
 
     /* adjust first dts according to edit list */
@@ -1320,7 +1350,7 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
           sc->stts_count == 1 && sc->stts_data[0].duration == 1)) {
         unsigned int current_sample = 0;
         unsigned int stts_sample = 0;
-        unsigned int keyframe, sample_size;
+        unsigned int sample_size;
         unsigned int distance = 0;
         int key_off = sc->keyframes && sc->keyframes[0] == 1;
 
@@ -1334,16 +1364,23 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
                 i + 1 == sc->stsc_data[stsc_index + 1].first)
                 stsc_index++;
             for (j = 0; j < sc->stsc_data[stsc_index].count; j++) {
+                int keyframe = 0;
                 if (current_sample >= sc->sample_count) {
                     av_log(mov->fc, AV_LOG_ERROR, "wrong sample count\n");
                     return;
                 }
-                keyframe = !sc->keyframe_count || current_sample+key_off == sc->keyframes[stss_index];
-                if (keyframe) {
-                    distance = 0;
+
+                if (!sc->keyframe_count || current_sample+key_off == sc->keyframes[stss_index]) {
+                    keyframe = 1;
                     if (stss_index + 1 < sc->keyframe_count)
                         stss_index++;
+                } else if (sc->stps_count && current_sample+key_off == sc->stps_data[stps_index]) {
+                    keyframe = 1;
+                    if (stps_index + 1 < sc->stps_count)
+                        stps_index++;
                 }
+                if (keyframe)
+                    distance = 0;
                 sample_size = sc->sample_size > 0 ? sc->sample_size : sc->sample_sizes[current_sample];
                 if(sc->pseudo_stream_id == -1 ||
                    sc->stsc_data[stsc_index].id - 1 == sc->pseudo_stream_id) {
@@ -1492,6 +1529,7 @@ static int mov_read_trak(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
     av_freep(&sc->sample_sizes);
     av_freep(&sc->keyframes);
     av_freep(&sc->stts_data);
+    av_freep(&sc->stps_data);
 
     return 0;
 }
@@ -1861,6 +1899,7 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
 { MKTAG('p','a','s','p'), mov_read_pasp },
 { MKTAG('s','t','b','l'), mov_read_default },
 { MKTAG('s','t','c','o'), mov_read_stco },
+{ MKTAG('s','t','p','s'), mov_read_stps },
 { MKTAG('s','t','s','c'), mov_read_stsc },
 { MKTAG('s','t','s','d'), mov_read_stsd }, /* sample description */
 { MKTAG('s','t','s','s'), mov_read_stss }, /* sync sample */