Newbie H264/AC3 Muxing issue

[fishnchips]

Hi all. I'm trying to demux HD MKV files and create an Perian friendly AVI. I have used mkvextract to extract a .x264 and AC3 file successfully but am now trying to mux the two files using ffmpegx. These are the steps I'm going through:

1. Drag/drop the video file into the source
2. Set Video to Passthrough
3. Set Audio to Passthrough and click Add/Audio and select the ac3 audio file
4. Click encode

This is the error message I get:

FFmpeg version CVS, Copyright (c) 2000-2004 Fabrice Bellard
Mon Nov 27 09:56:18 GMT 2006
Mac OSX universal build for ffmpegX
  libavutil version: 49.0.0
  libavcodec version: 51.9.0
  libavformat version: 50.4.0
Input #0, h264, from '/Users/michael/Movies/video.264':
  Duration: N/A, bitrate: N/A
  Stream #0.0, 23.98 fps(r): Video: h264, yuv420p, 1280x720
Input #1, ac3, from '/Users/michael/Movies/audio.ac3':
  Duration: 00:42:16.0, start: 0.000000, bitrate: 384 kb/s
  Stream #1.0: Audio: ac3, 48000 Hz, 5 channels, 384 kb/s
Could not find sync stream #0.1

Any ideas what 'Could not find sync stream' means?

[jpschuck]

Hi all. I'm trying to demux HD MKV files and create an Perian friendly AVI. I have used mkvextract to extract a .x264 and AC3 file successfully but am now trying to mux the two files using ffmpegx. These are the steps I'm going through:

1. Drag/drop the video file into the source
2. Set Video to Passthrough
3. Set Audio to Passthrough and click Add/Audio and select the ac3 audio file
4. Click encode
[...]
Any ideas what 'Could not find sync stream' means?

If I'm not mistaken, ffmpegX is not able to add an audio track to a single video track. The clip must have an existing audio track that will be replaced by the new one. I would suggest you to try avidemux instead (you'll need to install X11 from you MacOX install Disc).

[fishnchips]

Thanks for the link. Will check it out tonight (need the OS X disks to install X).

[jpschuck]

Thanks for the link. Will check it out tonight (need the OS X disks to install X).

In case avidemux wouldn't support raw .x264, first use ffmpegx to create a video only .avi file.