Settings to convert WMV to VCD/DVD-playable format?

[pingosimon]

I'm using a Mac, ffmpegx, and Toast 8 Titanium, iDVD to make video discs. (alternatively, is there a way to "manually" make VCDs or DVDs with the Mac OSX disc burning method?)

I have a big collection of small wmv files that I'd like to watch on my TV. I'm able to make VCDs out of them using the VCD creator in Toast, but I'd like to be able to fit more video on one disc, for example, by putting VCD quality video onto a DVD disc, or maybe even just lowering the quality of the video and audio from the default VCD or DVD standard.

(EDIT) to make that more concise: How can I fit the most wmv videos onto a single tabletop-compatible disc?

[Case]

If VCD quality fits your need, then you can convert the wmv files to VCD mpegs (un-check Split and Author) with 48 kHz audio, then drop those files in Toast (set re-encode to 'never') and burn upto about 7 hours to a DVD.

[pingosimon]

Unfortunately, Toast doesn't have an option to turn off encoding, so I really need to get it right in ffmpegx.

Should I be starting from VCD mpeg2enc or VCD ffmpeg?
Does the video bitrate matter (in terms of compatibility)?
The audio codec and bitrate?

[Case]

Unfortunately, Toast doesn't have an option to turn off encoding, so I really need to get it right in ffmpegx.

Toast's 'reencode never' is really 'automatic': it doesn't re-encode when not needed for DVD, but does re-encode if needed for a valid DVD. When setting Toast to re-encode never here, it is meant to keep the MPEG-1 video and audio as provided and not re-encode to MPEG-2 and AC3.

Should I be starting from VCD mpeg2enc or VCD ffmpeg?
Does the video bitrate matter (in terms of compatibility)?
The audio codec and bitrate?

VCD mpeg2enc or VCD ffmpeg, either one will do, as long as it decodes your WMV.
VCD has a constant and fixed bitrate, but when used in a DVD structure, there is more flexibility.
VCD audio should be in MP2 format, but when used in a DVD structure, there is more flexibility.

[pingosimon]

ahhh there's re-encode never! :P

ffmpegx seems to default to 1150 kbps for the video bitrate. How much lower could I go? For the audio bitrate, would 128kbps work?

[tomlee59]

These are tricky questions, because individual tastes vary. That said, 128kb/s stereo audio is usually ok for most people, for most material. You may notice some hollowness on occasion, and some "watery" artifacts with solo violin, for instance, but generally speaking, it will be fine as long as your expectations are suitably low.

As for video bitrate, the bottom end again depends on your taste. I would state things a bit differently, in terms of duration, with the assumption of 128kb/s audio:

A 2-hour XVCD is generally considered watchable. Quality degrades progressively from there.
A 3-hour XVCD would be considered poor by most people. However, for monochrome TV shows from the 1960s (and a monaural audio track at 64kb/s), the results are better than I'd imagined. That's 7 first-season episodes of Gilligan's Island.

Best results are obtained by allowing VBR encodes, which give you about 10-20% greater duration for about the same subjective quality.

My personal record is 3hrs, 15min of an old Flash Gordon serial, whose source was so poor to begin with that the additional degradation of low bitrate XVCD hardly mattered. This should not be taken as a routine expectation, however. I'm just providing you with some approximate calibration data.

Just try a couple of different encodes, look at the results, and decide, based on your personal taste, what is and is not acceptable to you.

I should add that judging the quality of the result is a strong function of how you display it. If you are looking at the result close-up on a 42" LCD, you are likely to be much more displeased than if you were to look at a 15" CRT TV from a good distance back.