Xvid decoder problem?

[Humperdinck]

Ok, heheh, silly me. The 0.4.9-pre1 is even so old that there's no xvid support in it. What's strange is that it encoded to divx anyway, probably trying to use the 'risky codecs'.

Now, I grabbed the latest CVS 25/12 and compiled in the xvid library again (http://www.xvid.org, not xlib as it says on soenkeohde) and got yet another version of ffmpeg.

Let's do it like this instead. Edit the source code for the xvidff.c in the libavcodec directory. Look for the lines that says:

} else {
/* We are claiming to be XviD */
x->quicktime_format = 0;
avctx->codec_tag = ff_get_fourcc("xvid");
}

And change ff_get_fourcc("xvid"); to ff_get_fourcc("XVID");

Compile and run. (I had to omit the --enable-faad and --enable-faac, I'm probably missing some code for it.)

Use it with the below settings in config.xml.

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -f avi -ab 224 -ac 2 -acodec mp3 -vcodec xvid -b 1250 {DEST_FILE}" targetExtension=".avi" />

However, the resulting files are blocky if there's fast motion involved. Maybe this can be tuned away by using another bitrate or some other ffmpeg setting?

I'll try and attach the files to this post later since it's not working now.

Merry Christmas!

[LilY0da]

If that works and it sets the FourCC correctly, I'll take it and try it!!!

[sub]

Let's do it like this instead. Edit the source code for the xvidff.c in the libavcodec directory. Look for the lines that says:

} else {
/* We are claiming to be XviD */
x->quicktime_format = 0;
avctx->codec_tag = ff_get_fourcc("xvid");
}

And change ff_get_fourcc("xvid"); to ff_get_fourcc("XVID");

Thanks for the tip.

[Humperdinck]

Yep, it seems to work fine, been playing all day with the settings for it. I now use the below that seems to give me nice quality. It's a guesswork trying to figure out which settings does what, I'm guessing by looking at the xvid windows settings and trying to translate those to ffmpegs.

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -intra -qmin 2 -qmax 8 -bf 3 -aic -umv -b_qoffset 75 -i_qfactor 250 -me full -g 300 -vcodec xvid -ac 2 -ab 224 -acodec mp3 {DEST_FILE}" targetExtension=".avi" />

[Humperdinck]

Ok, since I have some issue with uploading to the forum I put the files on a web link. You can download them from http://mychat.mine.nu/FFmpeg.zip

Any tips on making the settings improve are welcome. I recorded a 4Gb movie and it packed it to a 725Mb xvid file. The movie was Daredevil and that one is kind of dark in itself but converting to xvid doesn't make it brighter....Anyone know how to compensate for darkness?

[Humperdinck]

Dear Forum,

A small update. I noticed xvid has gone out of beta and reached 1.1.0 so I recompiled xvid and ffmpeg for it. The binaries for those that want to test are at the link in my earlier post. I now use the following line (in config.xml) for the encoding:

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -intra -qmin 3 -qmax 9 -bf 3 -aic -umv -b_qoffset 75 -i_qfactor 250 -me full -g 300 -b 1250 -vcodec xvid -ac 2 -ab 224 -acodec mp3 {DEST_FILE}" targetExtension=".avi" />

It seems to encode to a decent-looking result, although I have noticed that there's some problem with every second line, making movement blurry. Anyone knows how to fix this?

/Humperdinck

[LilY0da]

maybe add "-deinterlace" in your command line?

[Humperdinck]

That's it! Excellent! Thanks for the tip!

/Humperdinck

[Humperdinck]

Dear Forum,

A small update. I noticed xvid has gone out of beta and reached 1.1.0 so I recompiled xvid and ffmpeg for it. The binaries for those that want to test are at the link in my earlier post. I now use the following line (in config.xml) for the encoding:

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -intra -qmin 3 -qmax 9 -bf 3 -aic -umv -b_qoffset 75 -i_qfactor 250 -me full -g 300 -b 1250 -vcodec xvid -ac 2 -ab 224 -acodec mp3 {DEST_FILE}" targetExtension=".avi" />

It seems to encode to a decent-looking result, although I have noticed that there's some problem with every second line, making movement blurry. Anyone knows how to fix this?

/Humperdinck

Dear Forum,

Here is yet another small update. I managed to compile liba52 and libfaac and added support for those in the resulting ffmpeg. I didn't manage to compile in faad though, something is broken there.

With liba52 and libffac and of course libmp3lame I use the following ./configure:

./configure --enable-mp3lame --enable-faac --enable-xvid --enable-mingw32 --enable-a52 --enable-pp --enable-amr_nb --enable-amr_wb --enable-amr_if2 --enable-gpl --enable-memalign-hack --extra-cflags=-I/local/include--extra-ldflags=-L/local/lib


I have also been encoding and trying out the ffmpeg settings to achieve (for my purposes) a good result. For my recordings (Hauppauge PVR 250) I now use the following line in config.xml:

<Conversion name="XviD" cmd="-y -i {SOURCE_FILE} -vcodec xvid -qcomp 0.7 -qblur 0.3 -mbd 2 -qmin 3 -qscale 4 -qmax 31 -qdiff 2 -bt 8000 -bf 3 -aic -umv -b_qoffset 75 -i_qfactor 250 -me full -g 300 -ac 2 -ab 224 -acodec mp3 -deinterlace -ec 2 -b_qoffset 1 {DEST_FILE}" targetExtension=".avi" />

The files are at the link in my earlier post as usual. And if someone has tips on how to optimize the settings, please post in this thread.

Oh, maybe I should mention that I posted my small change in the source to make the fourcc capitalized to the ffmpeg developers mailing list as well, hopefully they will notice it.

Have a good 2006! Thanks for GBPVR and comskip/comclean!

/Humperdinck

[sub]

Cheers, keep us up to date. I'm absorbing all this info for incorporation into the next release of GB-PVR.

Unfortunately I find it difficult to find time to tinker to this low level myself.