Make packet interleaving in the muxer not scan through the whole

buffer when simply appending at the end works.
Much faster if one stream ends prematurely.
Fixes issue1379.

Originally committed as revision 19870 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/avformat.h

@@ -450,6 +450,12 @@ typedef struct AVStream {
      */
 #define MAX_PROBE_PACKETS 100
     int probe_packets;
+
+    /**
+     * Number of packets in packet_buffer for this stream when muxing.
+     * used internally, NOT PART OF PUBLIC API, dont read or write from outside of libav*
+     */
+    int num_in_packet_buffer;
 } AVStream;
 
 #define AV_PROGRAM_RUNNING 1

libavformat/utils.c

@@ -2657,14 +2657,25 @@ void ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
     pkt->destruct= NULL;             // do not free original but only the copy
     av_dup_packet(&this_pktl->pkt);  // duplicate the packet if it uses non-alloced memory
 
+    if(!s->packet_buffer_end || compare(s, &s->packet_buffer_end->pkt, pkt)){
     next_point = &s->packet_buffer;
     while(*next_point){
         if(compare(s, &(*next_point)->pkt, pkt))
             break;
         next_point= &(*next_point)->next;
     }
+    }else{
+        next_point = &(s->packet_buffer_end->next);
+        assert(!*next_point);
+    }
     this_pktl->next= *next_point;
+
+    if(!*next_point)
+        s->packet_buffer_end= this_pktl;
+
     *next_point= this_pktl;
+
+    s->streams[pkt->stream_index]->num_in_packet_buffer++;
 }
 
 int ff_interleave_compare_dts(AVFormatContext *s, AVPacket *next, AVPacket *pkt)
@@ -2683,27 +2694,24 @@ int ff_interleave_compare_dts(AVFormatContext *s, AVPacket *next, AVPacket *pkt)
 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush){
     AVPacketList *pktl;
     int stream_count=0;
-    int streams[MAX_STREAMS];
+    int i;
 
     if(pkt){
         ff_interleave_add_packet(s, pkt, ff_interleave_compare_dts);
     }
 
-    memset(streams, 0, sizeof(streams));
+    for(i=0; i < s->nb_streams; i++)
-    pktl= s->packet_buffer;
+        stream_count+= !!s->streams[i]->num_in_packet_buffer;
-    while(pktl){
-//av_log(s, AV_LOG_DEBUG, "show st:%d dts:%"PRId64"\n", pktl->pkt.stream_index, pktl->pkt.dts);
-        if(streams[ pktl->pkt.stream_index ] == 0)
-            stream_count++;
-        streams[ pktl->pkt.stream_index ]++;
-        pktl= pktl->next;
-    }
 
     if(stream_count && (s->nb_streams == stream_count || flush)){
         pktl= s->packet_buffer;
         *out= pktl->pkt;
 
         s->packet_buffer= pktl->next;
+        if(!s->packet_buffer)
+            s->packet_buffer_end= NULL;
+
+        s->streams[out->stream_index]->num_in_packet_buffer--;
         av_freep(&pktl);
         return 1;
     }else{