[SCM] libav/experimental: Try to find out correct start time to make seeking faster and add some extra checks to make sure the seeking function will not hang forever.

[siretart at users.alioth.debian.org]

The following commit has been merged in the experimental branch:
commit 22ffac707e52ce58c0bd71857fe1353f453f78e0
Author: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
Date:   Sun Jul 23 18:19:33 2006 +0000

    Try to find out correct start time to make seeking faster and add some
    extra checks to make sure the seeking function will not hang forever.
    
    Originally committed as revision 5814 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index df87339..8fec18d 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -472,6 +472,7 @@ int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
 int av_add_index_entry(AVStream *st,
                        int64_t pos, int64_t timestamp, int size, int distance, int flags);
 int av_seek_frame_binary(AVFormatContext *s, int stream_index, int64_t target_ts, int flags);
+void av_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
 
 /* media file output */
 int av_set_parameters(AVFormatContext *s, AVFormatParameters *ap);
diff --git a/libavformat/ogg2.c b/libavformat/ogg2.c
index 2af5a4f..254415b 100644
--- a/libavformat/ogg2.c
+++ b/libavformat/ogg2.c
@@ -201,7 +201,6 @@ ogg_new_stream (AVFormatContext * s, uint32_t serial)
         return AVERROR_NOMEM;
 
     av_set_pts_info(st, 64, 1, 1000000);
-    st->start_time = 0;
 
     return idx;
 }
@@ -495,6 +494,16 @@ ogg_get_length (AVFormatContext * s)
 
     ogg->size = size;
     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;
+    }
+    ogg_restore (s, 0);
 
     return 0;
 }
@@ -572,12 +581,14 @@ ogg_read_seek (AVFormatContext * s, int stream_index, int64_t target_ts,
     ogg_t *ogg = s->priv_data;
     ByteIOContext *bc = &s->pb;
     uint64_t min = 0, max = ogg->size;
-    uint64_t tmin = 0, tmax = st->duration;
+    uint64_t tmin = st->start_time, tmax = st->start_time + st->duration;
     int64_t pts = AV_NOPTS_VALUE;
 
     ogg_save (s);
 
-    while (min <= max){
+    if ((uint64_t)target_ts < tmin || target_ts < 0)
+        target_ts = tmin;
+    while (min <= max && tmin < tmax){
         uint64_t p = min + (max - min) * (target_ts - tmin) / (tmax - tmin);
         int i = -1;
 
@@ -599,9 +610,25 @@ ogg_read_seek (AVFormatContext * s, int stream_index, int64_t target_ts,
             break;
 
         if (pts > target_ts){
+            if (max == p && tmax == pts) {
+                // probably our tmin is wrong, causing us to always end up too late in the file
+                tmin = (target_ts + tmin + 1) / 2;
+                if (tmin == target_ts) {
+                    url_fseek(bc, min, SEEK_SET);
+                    break;
+                }
+            }
             max = p;
             tmax = pts;
         }else{
+            if (min == p && tmin == pts) {
+                // probably our tmax is wrong, causing us to always end up too early in the file
+                tmax = (target_ts + tmax) / 2;
+                if (tmax == target_ts) {
+                    url_fseek(bc, max, SEEK_SET);
+                    break;
+                }
+            }
             min = p;
             tmin = pts;
         }
@@ -615,7 +642,8 @@ ogg_read_seek (AVFormatContext * s, int stream_index, int64_t target_ts,
         pts = AV_NOPTS_VALUE;
     }
 
-    return pts;
+    av_update_cur_dts(s, st, pts);
+    return 0;
 
 #if 0
     //later...
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 2c882fa..cefce88 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1097,7 +1097,7 @@ static void av_read_frame_flush(AVFormatContext *s)
  * @param timestamp new dts expressed in time_base of param ref_st
  * @param ref_st reference stream giving time_base of param timestamp
  */
-static void av_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp){
+void av_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp){
     int i;
 
     for(i = 0; i < s->nb_streams; i++) {

-- 
Libav/FFmpeg packaging