Xvid decoder problem?

[LilY0da]

Did you check your FourCC in that case Sub? Does it actually set it to XVID? I think I tried that and the file had a fourcc of "DIVX" anyway.

I agree that the file certainly does work, since you're using the mp4 engine in that case, and the mpeg4 codec of FFmpeg produces working files.
However, it produces files a bit bigger.

For the same source file, same quality (quality set to 4, VBR), same options
MP4 384.820.200 SpinMP4Fulloptions.avi
XviD 314.141.936 SpinXvidq4.avi

Hence my interest to get a workaround to that XviD problem until the FFmpeg crew posts a workaround, or corrects the code... I'll let y'all know if I manage to do anything. I the meantime, I'll post tonight the best configs I found so far both for XviD and MPEG4 encoding in FFmpeg

[sub]

Did you check your FourCC in that case Sub? Does it actually set it to XVID? I think I tried that and the file had a fourcc of "DIVX" anyway.

Yes I did check this. Its 'XVID'. If I dont specify the -vtag parameter, then it shows FMP4.

I agree that the file certainly does work, since you're using the mp4 engine in that case, and the mpeg4 codec of FFmpeg produces working files.However, it produces files a bit bigger.

For the same source file, same quality (quality set to 4, VBR), same options
MP4 384.820.200 SpinMP4Fulloptions.avi
XviD 314.141.936 SpinXvidq4.avi

Its good enough for me. You're welcome to try to find an alternative version of ffmpeg and an appropriate command line that does exactly what you want, but I'm sure this will meet the vast majority of user's needs.

[LilY0da]

Yes I did check this. Its 'XVID'. If I dont specify the -vtag parameter, then it shows FMP4.

Interesting.... Then the bug is only in the latest version of FFmpeg. I'll try to the one that comes with GBPVR again tonight.

[sub]

Which version are you using? The one included with GB-PVR was built from CVS on the 7th of December, so you're likely to be using an older one.

[sub]

I should point out the -vtag argument didnt work when I specified the original '-vcodec xvid'. It only worked with '-vcodec mpeg4'.

[LilY0da]

Which version are you using? The one included with GB-PVR was built from CVS on the 7th of December, so you're likely to be using an older one.

Could be: 0.4.9-pre1 CVS 2005-02-22. I could have sworn I tried the GBPVR one before, but I'll admit I ran most of my tests on 0.4.9-pre1 after I read your link to it on another post.
Also, if you use -vcodec mpeg4, you'll create a normal basic MP4, not one with the XviD optimizations, I think. So it's better to force the FourCC to DIVX than XVID. This way you'll use the normal DivX decoder and not the XviD one.
For the next version, maybe replace the menu entry from XviD to DivX?

[sub]

Also, if you use -vcodec mpeg4, you'll create a normal basic MP4, not one with the XviD optimizations, I think.

You make it sounds like this will result in a piss-poor conversion, when that is not the case. You'll be able to produce pretty much identical results, with a possible downside of a file thats maybe up to 5% bigger.

So it's better to force the FourCC to DIVX than XVID. This way you'll use the normal DivX decoder and not the XviD one.
For the next version, maybe replace the menu entry from XviD to DivX?

Hey, it recognizes and plays with the xvid codec, thats good enough for me and most other people. I prefer to use the xvid decoders than the divx decoders, so this gives me what I was trying to achieve.

I'll probably add an additional 'divx' option in the next release, but I'll also leave xvid as an option. You'll most likely be able to produce exactly the same quality movie, even if the file is 5% bigger.

[LilY0da]

You make it sounds like this will result in a piss-poor conversion,

No I don't. I never said anything about quality. Iwas meaning that tagging a file as XVID when it's a regular MP4 is a bit unusual.

I do understand you prefer to play DivX files with the XviD decoder, and that's fine. However, that's an option each user should decide.

You can actually choose when you install the XviD software if you want it to play all MP4. Most people will leave it to "yes" which is the default and end up using the XviD codec to play all MP4 content.

You'll be able to produce pretty much identical results, with a possible downside of a file thats maybe up to 5% bigger.

Yes, if you specify quality settings (-qscale), the quality is exactly the same. But the disk space gain is 20% (384Megs for DivX and 314 for XviD)
That's a saving of 40 Gigs on my 200 Gigs recording drive, and I'm greedy
As long as we can edit the options, I don't really care what is the default, DivX or XviD in the software. Maybe DivX is better since not everyone might have installed XviD? But I'm not sure about that...

The only disagreement I had was that I think that tagging a DivX as XVID is a bad idea. That's all.

[sub]

I do understand you prefer to play DivX files with the XviD decoder, and that's fine

The only disagreement I had was that I think that tagging a DivX as XVID is a bad idea. That's all.

Its no more an divx file than an xvid file. Both XviD and DivX are implementations of the ISO MPEG-4 standard.

[LilY0da]

The reason I raised this was for portability, and logic that's all.
Wasn't sure a file tagged as XVID would play on a PC that doesn't have the XviD software.

Nevermind.