Dilema ? Problem when converting video with audio track

[doward]

I'm converting MPG4 to any DiVx or DVD or other. The common issue is that when I choose the audio track (1) instead of the default selection - 0, then the conversion takes 1 second and the output file isn't readable.
When I choose audio track 1 I get the audio as well when I click the play button in ffmpegX but the conversion bugs. Choosing Audio Track 0 produces a viewable file without audio.

Can anybody help with the Dilema ?
Thanks

[Case]

1/ If your source file has only one video track and one audio track, then leave the audio track selection at "0".
2/ Possibly the stream mapping is reversed from what ffmpegX expects. To check this, take a look at the log and post that here. You may access the Process Information log by clicking the blue "i" in the ffmpegX Progress window after a conversion/conversion attempt.

[doward]

Thanks for the reply:
Here is the log:
FFmpeg version CVS, Copyright (c) 2000-2004 Fabrice Bellard
Mac OSX universal build for ffmpegX
libavutil version: 49.0.0
libavcodec version: 51.9.0
libavformat version: 50.4.0
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Volumes/WD 300GB/Classes/Audio_Video/FRX/Specification sets.mp4':
Duration: 00:05:35.7, start: 0.000000, bitrate: 643 kb/s
Stream #0.0(eng): Audio: aac, 44100 Hz, stereo
Stream #0.1(eng), 30.00 fps(r): Video: h264, yuv420p, 640x360
Number of stream maps must match number of output streams
Mon Nov 29 17:41:02 EST 2010


I also get this with diffrent options: Codec type mismatch for mapping #0.0 -> #0.0

Funny, it worked once today, and I can't figure out what it was that made it work.

[Case]

Stream #0.0(eng): Audio: aac, 44100 Hz, stereo
Stream #0.1(eng), 30.00 fps(r): Video: h264, yuv420p, 640x360

Notice how the the audio is mentioned before the video. ffmpeg gives the streams a number (#0.0 and #0.1), which is taken from the stream order. We'll use this. read on...

Number of stream maps must match number of output streams

Unfortunately, the log doesn't show the current stream mapping, before giving this error. Maybe for this log you had Audio Track "1" (non-existing stream #0.2) selected?

I also get this with diffrent options: Codec type mismatch for mapping #0.0 -> #0.0

If you don't instruct this version of ffmpeg in ffmpegX otherwise, it tries to convert the first stream (#0.0) to video and the second stream (#0.1) to audio. Obviously (to humans), it needs to convert video to video and audio to audio. Hence, it needs a little help mapping the correct stream to each other, so that this mismatch doesn't occur. To do this in the ffmpegX interface, set the "Invert mapping" checkbox in the Audio tab.

[doward]

Thanks! It works!

I thought I did invert mapping before...
I'm trying to make the screen capture movie more fluid in my output but so far the conversion loses some of that fluidity.

Any way to save a profile so I use the same options next time quickly?
Any advice on what options make sense for screen capture-movies that can go on a USB stick or have plenty of bandwith?

I used Trellies quantization and the output is 5 times bigger and 2 times worse.

[Case]

Any way to save a profile so I use the same options next time quickly?

You may save presets from the File menu.

Any advice on what options make sense for screen capture-movies that can go on a USB stick or have plenty of bandwith?

The easiest way to preserve quality, is to set Qmin=2 and Qmax=2 in the Options tab. The quantizer value sets the compression level. By using the same value for Qmin and Qmax, there will be constant compression throughout the movie, which is close to what viewers perceive as constant quality. With a constant quantizer, the target bitrate will be ignored, so the output size may be unpredictable.