ffserver: fix prepare_sdp_description() to dynamically allocate streams

Originally committed as revision 25494 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffserver.c

@@ -2930,7 +2930,7 @@ static int prepare_sdp_description(FFStream *stream, uint8_t **pbuffer,
                                    struct in_addr my_ip)
 {
     AVFormatContext *avc;
-    AVStream avs[MAX_STREAMS];
+    AVStream *avs = NULL;
     int i;
 
     avc =  avformat_alloc_context();
@@ -2948,14 +2948,29 @@ static int prepare_sdp_description(FFStream *stream, uint8_t **pbuffer,
         snprintf(avc->filename, 1024, "rtp://0.0.0.0");
     }
 
+#if !FF_API_MAX_STREAMS
+    if (avc->nb_streams >= INT_MAX/sizeof(*avc->streams) ||
+        !(avc->streams = av_malloc(avc->nb_streams * sizeof(*avc->streams))))
+        goto sdp_done;
+#endif
+    if (avc->nb_streams >= INT_MAX/sizeof(*avs) ||
+        !(avs = av_malloc(avc->nb_streams * sizeof(*avs))))
+        goto sdp_done;
+
     for(i = 0; i < stream->nb_streams; i++) {
         avc->streams[i] = &avs[i];
         avc->streams[i]->codec = stream->streams[i]->codec;
     }
     *pbuffer = av_mallocz(2048);
     avf_sdp_create(&avc, 1, *pbuffer, 2048);
+
+ sdp_done:
+#if !FF_API_MAX_STREAMS
+    av_free(avc->streams);
+#endif
     av_metadata_free(&avc->metadata);
     av_free(avc);
+    av_free(avs);
 
     return strlen(*pbuffer);
 }