support discarding uninterresting packets

Originally committed as revision 3860 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 10 insertions, 2 deletions

diff --git a/libavformat/nut.c b/libavformat/nut.c
index 010e09c3bf..46fbee8aee 100644
--- a/libavformat/nut.c
+++ b/libavformat/nut.c
@@ -1229,6 +1229,11 @@ static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code, int fram
     if(size < 0)
         return -1;
 
+    if(s->streams[ stream_id ]->discard){
+        url_fskip(bc, size);
+        return 1;
+    }
+
     av_new_packet(pkt, size);
     get_buffer(bc, pkt->data, size);
     pkt->stream_index = stream_id;
@@ -1243,7 +1248,7 @@ static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     NUTContext *nut = s->priv_data;
     ByteIOContext *bc = &s->pb;
-    int i, frame_code=0;
+    int i, frame_code=0, ret;
 
     for(;;){
         int64_t pos= url_ftell(bc);
@@ -1281,8 +1286,11 @@ static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
             reset(s, get_v(bc));
             frame_code = get_byte(bc);
         case 0:
-            if(decode_frame(nut, pkt, frame_code, frame_type, pos)>=0)
+            ret= decode_frame(nut, pkt, frame_code, frame_type, pos);
+            if(ret==0)
                 return 0;
+            else if(ret==1) //ok but discard packet
+                break;
         default:
 resync:
 av_log(s, AV_LOG_DEBUG, "syncing from %lld\n", nut->packet_start[2]+1);