moving nearly identical binary search code from nut/mpeg/asf to utils.c

Originally committed as revision 3003 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 14 insertions, 106 deletions

diff --git a/libavformat/asf.c b/libavformat/asf.c
index 19542e5a0c..b4088c9add 100644
--- a/libavformat/asf.c
+++ b/libavformat/asf.c
@@ -422,6 +422,8 @@ static int asf_get_packet(AVFormatContext *s)
     int rsize = 9;
     int c;
     
+    if((url_ftell(&s->pb) - s->data_offset) % asf->packet_size)
+        return -1;
     assert((url_ftell(&s->pb) - s->data_offset) % asf->packet_size == 0);
     
     c = get_byte(pb);
@@ -705,7 +707,7 @@ static void asf_reset_header(AVFormatContext *s)
     asf->asf_st= NULL;
 }
 
-static int64_t asf_read_pts(AVFormatContext *s, int64_t *ppos, int stream_index)
+static int64_t asf_read_pts(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit)
 {
     ASFContext *asf = s->priv_data;
     AVPacket pkt1, *pkt = &pkt1;
@@ -718,15 +720,19 @@ static int64_t asf_read_pts(AVFormatContext *s, int64_t *ppos, int stream_index)
     for(i=0; i<s->nb_streams; i++){
         start_pos[i]= pos;
     }
-
+    
+    pos= (pos+asf->packet_size-1-s->data_offset)/asf->packet_size*asf->packet_size+ s->data_offset;
+    *ppos= pos;
+    url_fseek(&s->pb, pos, SEEK_SET);
+    
 //printf("asf_read_pts\n");
-    url_fseek(&s->pb, pos*asf->packet_size + s->data_offset, SEEK_SET);
     asf_reset_header(s);
     for(;;){
         if (av_read_frame(s, pkt) < 0){
             av_log(s, AV_LOG_INFO, "seek failed\n");
     	    return AV_NOPTS_VALUE;
         }
+        
         pts= pkt->pts;
 
         av_free_packet(pkt);
@@ -736,10 +742,10 @@ static int64_t asf_read_pts(AVFormatContext *s, int64_t *ppos, int stream_index)
             asf_st= s->streams[i]->priv_data;
 
             assert((asf_st->packet_pos - s->data_offset) % asf->packet_size == 0);
-            pos= (asf_st->packet_pos - s->data_offset) / asf->packet_size;
+            pos= asf_st->packet_pos;
 
             av_add_index_entry(s->streams[i], pos, pts, pos - start_pos[i] + 1, AVINDEX_KEYFRAME);
-            start_pos[i]= pos + 1;
+            start_pos[i]= asf_st->packet_pos + 1;
             
             if(pkt->stream_index == stream_index)
                break;
@@ -755,112 +761,13 @@ static int64_t asf_read_pts(AVFormatContext *s, int64_t *ppos, int stream_index)
 static int asf_read_seek(AVFormatContext *s, int stream_index, int64_t pts)
 {
     ASFContext *asf = s->priv_data;
-    AVStream *st;
-    int64_t pos;
-    int64_t pos_min, pos_max, pts_min, pts_max, cur_pts, pos_limit;
-    int no_change;
-    
-    if (stream_index == -1)
-        stream_index= av_find_default_stream_index(s);
     
     if (asf->packet_size <= 0)
         return -1;
 
-    pts_max=
-    pts_min= AV_NOPTS_VALUE;
-    pos_max= pos_limit= -1; // gcc thinks its uninitalized
-
-    st= s->streams[stream_index];
-    if(st->index_entries){
-        AVIndexEntry *e;
-        int index;
-
-        index= av_index_search_timestamp(st, pts);
-        e= &st->index_entries[index];
-        if(e->timestamp <= pts){
-            pos_min= e->pos;
-            pts_min= e->timestamp;
-#ifdef DEBUG_SEEK
-        printf("unsing cached pos_min=0x%llx dts_min=%0.3f\n", 
-               pos_min,pts_min / 90000.0);
-#endif
-        }else{
-            assert(index==0);
-        }
-        index++;
-        if(index < st->nb_index_entries){
-            e= &st->index_entries[index];
-            assert(e->timestamp >= pts);
-            pos_max= e->pos;
-            pts_max= e->timestamp;
-            pos_limit= pos_max - e->min_distance;
-#ifdef DEBUG_SEEK
-        printf("unsing cached pos_max=0x%llx dts_max=%0.3f\n", 
-               pos_max,pts_max / 90000.0);
-#endif
-        }
-    }
+    if(av_seek_frame_binary(s, stream_index, pts)<0)
+        return -1;
 
-    if(pts_min == AV_NOPTS_VALUE){
-        pos_min = 0;
-        pts_min = asf_read_pts(s, &pos_min, stream_index);
-        if (pts_min == AV_NOPTS_VALUE) return -1;
-    }
-    if(pts_max == AV_NOPTS_VALUE){
-        pos_max = (url_filesize(url_fileno(&s->pb)) - 1 - s->data_offset) / asf->packet_size; //FIXME wrong
-        pts_max = s->duration; //FIXME wrong
-        pos_limit= pos_max;
-    } 
-
-    no_change=0;
-    while (pos_min < pos_limit) {
-        int64_t start_pos;
-        assert(pos_limit <= pos_max);
-
-        if(no_change==0){
-            int64_t approximate_keyframe_distance= pos_max - pos_limit;
-            // interpolate position (better than dichotomy)
-            pos = (int64_t)((double)(pos_max - pos_min) *
-                            (double)(pts - pts_min) /
-                            (double)(pts_max - pts_min)) + pos_min - approximate_keyframe_distance;
-        }else if(no_change==1){
-            // bisection, if interpolation failed to change min or max pos last time
-            pos = (pos_min + pos_limit)>>1;
-        }else{
-            // linear search if bisection failed, can only happen if there are very few or no keyframes between min/max
-            pos=pos_min;
-        }
-        if(pos <= pos_min)
-            pos= pos_min + 1;
-        else if(pos > pos_limit)
-            pos= pos_limit;
-        start_pos= pos;
-
-        // read the next timestamp 
-    	cur_pts = asf_read_pts(s, &pos, stream_index);    
-        if(pos == pos_max)
-            no_change++;
-        else
-            no_change=0;
-
-#ifdef DEBUG_SEEK
-printf("%Ld %Ld %Ld / %Ld %Ld %Ld target:%Ld limit:%Ld start:%Ld\n", pos_min, pos, pos_max, pts_min, cur_pts, pts_max, pts, pos_limit, start_pos);
-#endif
-        assert (cur_pts != AV_NOPTS_VALUE);
-        if (pts < cur_pts) {
-            pos_limit = start_pos - 1;
-            pos_max = pos;
-            pts_max = cur_pts;
-        } else {
-            pos_min = pos;
-            pts_min = cur_pts;
-            /* check if we are lucky */
-            if (pts == cur_pts)
-                break;
-        }
-    }
-    pos = pos_min;
-    url_fseek(&s->pb, pos*asf->packet_size + s->data_offset, SEEK_SET);
     asf_reset_header(s);
     return 0;
 }
@@ -874,6 +781,7 @@ static AVInputFormat asf_iformat = {
     asf_read_packet,
     asf_read_close,
     asf_read_seek,
+    asf_read_pts,
 };
 
 #ifdef CONFIG_ENCODERS