VisualHub problems

[markwm]

I'm trying to convert xvid files into mpeg1, really stuggling to do it.

The problem is the encoded file just doesn't seek, as if it has no keyframes. The whole file will play but as soon as you seek it just freezes while audio continues. This is depsite the fact I've tried to use the -g n flag for keyframes. Can anyone advise?

[mhar4]

Try ffmpegX. I've always found it an effective mpeg1 encoder.

[markwm]

I've tried it, the problem I have with it is that it won't let me set the resolution I want. Even when set to un-constrained and I specify 384x304 it always ends up 320x240!!!

Always gives me errors too

**ERROR: [mplex] MUX STATUS: Frame data under-runs detected!

[dnix71]

This page on mpeg specs says you have chosen a size which does not meet specs:
http://www.mpeg.org/MPEG/DVD/Book_B/Video.html You are allowed 352x240 or 352x288

[/quote] I've tried it, the problem I have with it is that it won't let me set the resolution I want. Even when set to un-constrained and I specify 384x304 it always ends up 320x240!!!
[quote]

[mhar4]

This probably belongs in the ffmpegX discussion list, but you can select either mpeg2enc or ffmpeg as the encoding engine for mpeg1 under the video tab. I seem to remember generating non-standard image sizes, so one of them should be able to do it.

[markwm]

When I enter 352x288 into ffmpegx, the video comes out 320x240.

Just seems like a weird program that does what it wants with the resolution

[markwm]

Check out the attachment

[dnix71]

If the time markers are broken copy the original file, and rename the extension to an avi and open it with VLC. VLC should offer to fix the time markers. Can you post the original on a free host like megaupload? I have a registered version of ffmpegX.

[Case]

When I enter 352x288 into ffmpegx, the video comes out 320x240.
Just seems like a weird program that does what it wants with the resolution

It is not ffmpegX that is weird here, but QuickTime. The Finder information on the video file comes from QuickTime. QuickTime information gives the default display size for resolution, which is 320x240, while the true resolution of the file may be 352x288. QuickTime is 'compensating' for rectangular pixels and equalizing NTSC and PAL (dumbing down, if you will).
Unfortunately, QuickTime does this on all MPEG-1 and -2 files (VCD/SVCD/DVD).

[timme]

HI,
I have nearly the same Problem. I just want to encode an uncompressed Quicktime to mpeg1 with der size 455x341 but it automaticly changes the size to some 4:3 size ... I tried quicktime, compressor, ffmpeg but seems that all have the same Problem.

Is der any workaround?

[Case]

455x341 is not a valid size for MPEG video, as such video is encoded in macroblocks of 16x16 pixels. 448x336 would be valid, as 448 and 336 are both divisible by 16.

[guns1inger]

You don't have to encode on 16 pixel boundaries for mpeg, however it is more efficient for the encoder to do so. You are also not limited to the resolutions posted above unless you are encoding for VCD or DVD.