Troubleshooting a VCD Problem!!!

[alexjs77]

Hey guys, I've been having a strange problem I haven't been able to pinpoint. OK. So I have a .avi with ac3 audio. I first doctor it with divx doctor. I then pull up ffmpegx. I put the doctored .avi in there and set it to the VCD preset. I toggle to bitrate calculator for 690 of 700 MB on a CD. I then encode it and export it to a bin/cue. I burn the bin/cue with toast 6. should work, RIGHT? AHA, when I put it in my standalone DVD player I get choppy audio and video. It's completely useless. If anyone could help me pinpoint where im doing something wrong that would be great! Thanks again!

-Alex

[terryj]

Switch to VCD Builder 1.13.
Take the Divx Doctored .avi to .mov convert,
play it in QT Pro 6. Does it play well?
no choppiness, no drops?

Good.
Then do one of the following:

If you are a toast legacy user, use the Toast Video CD Export plugin,
( do a forum search, I just posted about this last week)
and export to MPEG-1. Then use VCDBuilder 1.13 to author it.

or

Buy Toast 6 and author it to VCD under their Video Tab setting.

This way ( either way via VCDB and Toast) produces cleaner
exports, and canfix any lingering issues with the audio and or video.

[alexjs77]

oops! I totally forgot something. Divx Doctor doesnt convert ac3 audio tracks. I used mencoder instead to change the audio to pcm. sorry for the bad info!

[sdm]

What is the framerate of your avi?
If it isn't 29.97, 23.976 or 25 frames per second, you will get choppiness.
If it is one of these framerates, but you encode to a different framerate, you will also get choppiness.

You shouldn't need to use Divx Doctor at all. I havent found a need for it for the past year or so.

--sdm

[alexjs77]

well the video is 25fps and it encoded the video to PAL which is 25fps and its still choppy.

[sdm]

sorry, I don't know what the problem is.
Maybe try encoding the avi with ffmpegX instead of encoding the doctored .mov.

[thoughton]

It sounds like the bitrate calculator part that is messing you up. VCD should be a constant bitrate (1150kbps). If you are using the calculator ffmpegx is probably changing the bitrate to something nonstandard. This is probably causing your player to choke.

Just choose VCD preset and then don't mess with the bitrate calculator. See if it works then.

[terryj]

Seems you have two major problems:

You say the video is PAL 25fps.
You say the audio is out of spec, being
that it is AC3 audio, not aiff.


So lets start with the easiest fix first:

1. re-encode the audio to AIFF.

Use Wiretap, Audio Hijack or Audio Hijack Pro to re-encode
/re-record the audio to 48KHZ AIFF 16bit Uncompressed.

Do a forum search on Audio, Audio Hijack, fixing audio,
targeted just to the mac forum.

Once you have re-encoded the audio to AIFF,will be taking
the video and add scaled it to the audio to fix
the file.
Do a forum search on terryj, fast, attention, video, add scaled.
I've posted this before on how to fix this.

2. As for your video, I've posted steps on using ffmpegx with
.avi's that would get you a "compliant" file that you could use in QT
to re-add scaled to the audio to fix the problem .avi.

In the past i've used ffmpegx to re-encode the .avi to MPEG-4[.AVI],
and even on 25fps files, I've managed to get good enough results.
do a search for terryj + ffmpegx.

Once it is done, you will have a QT compliant file that should easily be able to :
1. Burn to VCD using Toast 6.
2. Export out to Video CD MPEG-1 using Toast 5's legacy plug-in,
for which you can then either author in Toast 5 or VCDBuilder 1.13.

good luck!