[FFmpeg-user] Encoding an XSUB (DivX subtitles) stream (from an SRT stream)

[Armen Michaeli]

Hi all,

I am trying to include an XSUB stream in to an AVI container. The source of this stream comes from an SRT file, so I am using the following command line:

ffmpeg -i movie.avi -i movie.srt -scodec xsub output.avi

The subtitle encoding fails with "[xsub @ 0x7fb3f883ea00] No subtitle bitmap available.", as part of the following output:

ffmpeg version 1.2 Copyright (c) 2000-2013 the FFmpeg developers
  built on Mar 15 2013 18:24:17 with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
  configuration: --prefix=/Volumes/Ramdisk/sw --enable-gpl --enable-pthreads --enable-version3 --enable-libspeex --enable-libvpx --disable-decoder=libvpx --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-avfilter --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-filters --enable-libgsm --arch=x86_64 --enable-runtime-cpudetect
  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[srt @ 0x7fb3f8818e00] Estimating duration from bitrate, this may be inaccurate
Input #0, srt, from 'movie.srt':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Subtitle: subrip
Output #0, avi, to 'output.avi':
  Metadata:
    ISFT            : Lavf54.63.104
    Stream #0:0: Subtitle: xsub (DXSB / 0x42535844)
Stream mapping:
  Stream #0:0 -> #0:0 (subrip -> xsub)
Press [q] to stop, [?] for help
[xsub @ 0x7fb3f883ea00] No subtitle bitmap available.
Subtitle encoding failed

Am I doing something wrong, or is ffmpeg incapabale of doing what I am trying to do?

I am on a Macbook Air, Mac OS X 10.8.3, binary downloaded from http://ffmpegmac.net. I don't have much choice of binaries anyway, these are far and scarce for the platform.