[Ffmpeg-devel] dvr-ms seek help request

[John Donaghy]

> Could you post this code here ? I could give it a try and tell you the
> results.
>
See attached. I'm not submitting it as a patch yet but you're welcome to try it.
-------------- next part --------------
Index: asf.h
===================================================================
RCS file: /cvsroot/ffmpeg/ffmpeg/libavformat/asf.h,v
retrieving revision 1.70
diff -u -r1.70 asf.h
--- asf.h	20 Jan 2006 23:48:16 -0000	1.70
+++ asf.h	23 Mar 2006 22:28:35 -0000
@@ -98,6 +98,7 @@
     ByteIOContext pb;
     /* only for reading */
     uint64_t data_offset; /* begining of the first data packet */
+    uint64_t index_pos; /* begining of the simple index */
 
     ASFMainHeader hdr;
 
Index: asf.c
===================================================================
RCS file: /cvsroot/ffmpeg/ffmpeg/libavformat/asf.c,v
retrieving revision 1.95
diff -u -r1.95 asf.c
--- asf.c	2 Mar 2006 19:50:21 -0000	1.95
+++ asf.c	23 Mar 2006 22:22:59 -0000

@@ -327,6 +327,7 @@
             pos2 = url_ftell(pb);
             url_fskip(pb, gsize - (pos2 - pos1 + 24));
         } else if (!memcmp(&g, &data_header, sizeof(GUID))) {
+	        asf->index_pos = gsize + url_ftell(pb) - 24; 
             break;
         } else if (!memcmp(&g, &comment_header, sizeof(GUID))) {
             int len1, len2, len3, len4, len5;
 

-static int asf_read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags)
+static int asf_build_simple_index(AVFormatContext *s, int stream_index)
 {
+    GUID g;
     ASFContext *asf = s->priv_data;
+    int64_t gsize, itime;
+    int64_t pos, current_pos, index_pts;
+    int i;
+    int pct,ict;
+    int pktnum,pktct;
+    
+    current_pos = url_ftell(&s->pb);
+    
+    url_fseek(&s->pb, asf->index_pos, SEEK_SET);
+    get_guid(&s->pb, &g);
+    if (!memcmp(&g, &index_guid, sizeof(GUID))) {
+        gsize = get_le64(&s->pb);	
+        get_guid(&s->pb, &g);
+        itime=get_le64(&s->pb);
+        pct=get_le32(&s->pb);
+        ict=get_le32(&s->pb);
+        printf("itime:0x%Lx, pct:%d, ict:%d\n",itime,pct,ict);
+    
+        for (i=0;i<ict;i++){
+            pktnum=get_le32(&s->pb);
+            pktct=get_le16(&s->pb);
+            printf("pktnum:%d, pktct:%d\n", pktnum, pktct);
+	    
+            pos=(int)s->data_offset + asf->packet_size*(pktnum);
+            index_pts=itime/10000*i;    
+	    
+            av_add_index_entry(s->streams[stream_index], pos, index_pts, asf->packet_size, 0, AVINDEX_KEYFRAME);
+        }	
+    		    
+    }
+    url_fseek(&s->pb, current_pos, SEEK_SET);
+}
 
-    if (asf->packet_size <= 0)
-        return -1;
-
-    if(av_seek_frame_binary(s, stream_index, pts, flags)<0)
+static int asf_read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags)
+{
+    ASFContext *asf = s->priv_data;
+    AVStream *st;
+    int64_t index_pts;
+    offset_t pos, key_pos; 
+    AVPacket pkt;
+    ASFStream *asf_st;
+    int index;
+	  
+    if (!s->streams[stream_index]->index_entries) 
+        asf_build_simple_index(s, stream_index);
+    
+    st = s->streams[stream_index];
+    index= av_index_search_timestamp(st, pts, flags);
+    if(index<0)
         return -1;
 
+    /* find the position */
+    pos = st->index_entries[index].pos;
+    pts = st->index_entries[index].timestamp;
+    
+
+// various attempts to find key frame have failed so far        
+//    asf_reset_header(s);
+//    url_fseek(&s->pb, pos, SEEK_SET);
+//    key_pos = pos;
+//     for(i=0;i<16;i++){  
+// 	    pos = url_ftell(&s->pb);
+// 	    if (av_read_frame(s, &pkt) < 0){
+// 	        av_log(s, AV_LOG_INFO, "seek failed\n");
+// 	        return -1;
+// 	    }
+// 	    asf_st = s->streams[stream_index]->priv_data;
+// 	    pos += st->parser->frame_offset;
+// 			
+// 	    if (pkt.size > b) {
+// 	        b = pkt.size;
+// 	        key_pos = pos;
+// 	    }
+// 	          
+// 	    av_free_packet(&pkt);
+//     }
+
+
+    
+    /* do the seek */
+    printf("SEEKTO: %Ld\n", pos);
     asf_reset_header(s);
+    url_fseek(&s->pb, pos, SEEK_SET);
+    
     return 0;
 }
 
@@ -850,7 +936,6 @@
     asf_read_packet,
     asf_read_close,
     asf_read_seek,
-    asf_read_pts,
 };
 
 #ifdef CONFIG_MUXERS