Ffmpeg didn't burn srt subtitle on mkv properly -

`ffmpeg version:git-fc6de70 (2013-07-18) libass , fontconfig support. command line:ffmpeg.exe -i test.mkv -vf subtitles=test.srt out.mkv , got error.:

metadata:     encoder         : lavf55.12.102     stream #0:0(eng): video: h264 (libx264) (h264 / 0x34363248), yuv420p, 1280x5 76 [sar 1:1 dar 20:9], q=-1--1, 1k tbn, 23.98 tbc (default)     stream #0:1: audio: vorbis (libvorbis) (ov[0][0] / 0x566f), 48000 hz, stereo , fltp (default) stream mapping:   stream #0:0 -> #0:0 (h264 -> libx264)   stream #0:1 -> #0:1 (aac -> libvorbis) press [q] stop, [?] [parsed_subtitles_0 @ 00000000027b9960] neither playresx nor playresy defined. ssuming 384x288 

http://tinypic.com/r/2ag52so/5

the message get:

[parsed_subtitles_0 @ 00000000027b9960] neither playresx nor playresy defined. assuming 384x288 

means ssa or srt file doesn't specify playresx , y values. vfilter assume display resolution of 384x288, thats why subtitles looks small on 1280x576 video.

a workaround issue is:

1. convert srt ssa/ass

   ffmpeg -i file.srt file.ass 

2. edit ssa/ass file set correct value. ssa format describe here , it's easy set playres x , y.

   [script info] ; sub station alpha v4 script. .... scripttype: v4.00 collisions: normal playresx: 1280 playresy: 576 playdepth: 0 .... 

3. and finally, launch command again using ass file.