use custom packet allocation only for DV

Originally committed as revision 1937 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/avidec.c

@@ -297,8 +297,16 @@ static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
 
     memset(d, -1, sizeof(int)*8);
     
-    if (avi->type == 1 && avi->stream_index)
+    if (avi->type == 1 && avi->stream_index) {
-        goto pkt_init;
+        /* duplicate DV packet */
+        av_init_packet(pkt);
+        pkt->data = avi->buf;
+        pkt->size = avi->buf_size;
+        pkt->destruct = __destruct_pkt;
+        pkt->stream_index = avi->stream_index;
+        avi->stream_index = !avi->stream_index;
+        return 0;
+    }
 
     for(i=url_ftell(pb); !url_feof(pb); i++) {
         int j;
@@ -346,31 +354,29 @@ static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
             && n < s->nb_streams
             && i + size <= avi->movi_end) {
         
+            if (avi->type == 1) {
                 uint8_t *tbuf = av_realloc(avi->buf, size + FF_INPUT_BUFFER_PADDING_SIZE);
                 if (!tbuf)
                     return -1;
                 avi->buf = tbuf;
                 avi->buf_size = size;
-	    get_buffer(pb, avi->buf, size);
-	    if (size & 1)
-	        get_byte(pb);
-	    if (avi->type != 1)
-	        avi->stream_index = n;
-	    goto pkt_init;
-        }
-    }
-    
-    return -1;
-
-pkt_init:
                 av_init_packet(pkt);
                 pkt->data = avi->buf;
                 pkt->size = avi->buf_size;
                 pkt->destruct = __destruct_pkt;
-    pkt->stream_index = avi->stream_index;
+                avi->stream_index = n;
+            } else {
+                av_new_packet(pkt, size);
+            }
+            get_buffer(pb, pkt->data, size);
+            if (size & 1)
+                get_byte(pb);
+            pkt->stream_index = n;
             pkt->flags |= PKT_FLAG_KEY; // FIXME: We really should read index for that
-    avi->stream_index = !avi->stream_index;
             return 0;
+        }
+    }
+    return -1;
 }
 
 static int avi_read_close(AVFormatContext *s)