take care to use video track field number as duration

Originally committed as revision 10024 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/gxfenc.c

@@ -679,9 +679,9 @@ static int gxf_write_trailer(AVFormatContext *s)
     for (i = 0; i < s->nb_streams; ++i) {
         if (s->streams[i]->codec->codec_type == CODEC_TYPE_AUDIO) {
             av_fifo_free(&gxf->streams[i].audio_buffer);
-        }
-        if (s->streams[i]->codec->frame_number > gxf->nb_frames)
+        } else if (s->streams[i]->codec->codec_type == CODEC_TYPE_VIDEO) {
             gxf->nb_frames = 2 * s->streams[i]->codec->frame_number;
+        }
     }
 
     gxf_write_eos_packet(pb, gxf);

tests/libav.regression.ref

@@ -28,7 +28,7 @@ f8ad5bd78f4d012a8ce9570aa395ac54 *./tests/data/b-libav.flv
 7820fa85ab86c62028d8dbda94589573 *./tests/data/b-libav.dv
 3600000 ./tests/data/b-libav.dv
 ./tests/data/b-libav.dv CRC=0xf517e829
-15d8f0caadacf67a7e602fd244bc0c71 *./tests/data/b-libav.gxf
+2ba41cf880aa5cb87e8a08fdb735398d *./tests/data/b-libav.gxf
 814640 ./tests/data/b-libav.gxf
 ./tests/data/b-libav.gxf CRC=0xa376c09e
 9a9da315747599f7718cc9a9a09c21ff *./tests/data/b-libav.pbm