Xvid decoder problem?

[nv40]

Regarding quality, I don't know how to make the file quality as good as a Virtualdub re-encode would do... I don't know the dozens of parameters well enough to say what can be used to improve quality while maintaining a low bitrate.

You should try the DivX syntax I posted above and adv if quality looks OK for you. And if anyone knows enough about all those Q values and the all the other parameters you can adjust in FFmpeg, lemme know, cause I don't really know how to increase the quality of the files FFmpeg produces :-(

That's what I want to change I think. With nero recode, i can adjust the bit rate for quailty, and it also changes the size...obviously. There should be an easy way to adjust the bitrate for xvid?

[sub]

The -b parameter is used to specify the bitrate. You can see it in the original xvid command line:

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -f avi -ab 128 -ac 2 -vcodec xvid -b 1250 {DEST_FILE}" targetExtension=".avi" />

[nv40]

The -b parameter is used to specify the bitrate. You can see it in the original xvid command line:

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -f avi -ab 128 -ac 2 -vcodec xvid -b 1250 {DEST_FILE}" targetExtension=".avi" />

So, would changing this value do what I'm looking for. I was thinking maybe going to 1600, how does that sound? Right now it appears to make the file about a third of the original (300, whereas original is 900). I think I would be happy with just over half (450-500, for an original 900 mb file).

[sub]

So, would changing this value do what I'm looking for.

Yes, it would improve the quality. There are other settings that can be tweaked to also improve the quality, but I'm not a ffmpeg guru yet, so I'm not in a good position to advise what these are.

I was thinking maybe going to 1600, how does that sound?

Try it out and see.

[LilY0da]

Found a command line FourCC changer here: http://sarovar.org/download.php/533/cfou...-win32.zip

You can do a "cfourcc -d xvid -u XVID yourfile.avi", and your XviD file is now A-OK... I guess I'll have to write a batch running every morning after the transcode...

[nv40]

Found a command line FourCC changer here: http://sarovar.org/download.php/533/cfou...-win32.zip

You can do a "cfourcc -d xvid -u XVID yourfile.avi", and your XviD file is now A-OK... I guess I'll have to write a batch running every morning after the transcode...

Can you post your results on here....I'm really interested in getting this to work properly. Thanks

Oh, and I'm sure this is completely wrong and a stupid question, but does it matter that in this command the "xvid" part is lowercase?

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -f avi -ab 128 -ac 2 -vcodec xvid -b 1250 {DEST_FILE}" targetExtension=".avi" />

[nv40]

Hmm...did some research...this is a quote from the ffmpeg web site on xvid conversion:

Both XviD and DivX (version 4+) are implementations of the ISO MPEG-4 standard (note that there are many other coding formats that use this same standard). Thus, use '-vcodec mpeg4' to encode these formats. The default fourcc stored in an MPEG-4-coded file will be 'FMP4'. If you want a different fourcc, use the '-vtag' option. E.g., '-vtag xvid' will force the fourcc 'xvid' to be stored as the video fourcc rather than the default.


: I wonder how media player would handle the file if we pulled out the -vtag option and let it default to a fourcc of "FMP4"? Or, like my last post, if simply capitalizing the "-vtag XVID" option would work?

[LilY0da]

unfortunately the -vtag option doesn't seem to work
And by default, FFmpeg encoding in mpeg-4 puts a FourCC of "DIVX" and not "FMP4"

I think they haven't updated their docs in a long time... A lot of the command line options available in my build aren't in the docs

I tried using the -vtag options a dozen times, couldn't make it work. If you manage to, let me know, cause this is driving me nuts...

EDIT: also for the same quality setting (-qscale 4) using -vcodec xvid produces files smaller. So I'd really like to make XviD works

[nv40]

hmm....well, I'm trying to learn all this on the fly, so that was just a shot....it's driving me nuts too....cause I really need this to work. (and actually i'm working on two things, getting these files to play....but also messing with the settings to get the quality up from the default).

[sub]

You could try editting the line in config.xml to say:

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -f avi -ab 128 -ac 2 -vcodec mpeg4 -vtag XVID -b 1250 {DEST_FILE}" targetExtension=".avi" />

I've just tried this here using the version of ffmpeg included with the GB-PVR distribution, and this seems to result in a working file.