Low bitrates with avi.NET

[DeathKing]

Whenever I encoded music videos to XviD, the bitrate is super low (800-1000kbps). It never changes no matter what file size or bitrate I choose. It used to work fine and give me the bitrate I asked for (usually 2300), but now I get really small file sizes with decent quality.

I read somewhere that its a problem with the XviD codec and you need to have the right one. Well right now im using the one that came with the support package. What should I do?

[guns1inger]

I haven't used avi.NET, but if it works like AutoGK then there is a quality based component to the encoding as well. It may simply be that the encoder doesn't believe that such a high bitrate is required to maintain the required quality level.

[manono]

Yeah, if you're using low resolutions, then you'll never be able to achieve those bitrates/sizes. Nothing to do with XviD. Raise the resolution. Also, if you've ever installed a newer version of XviD over an older version without first uninstalling the older version, that could also account for the sizes being off. But my gusss is that you're trying to achieve bitrates the video can't take. You've already maxxed out the quality.

[DeathKing]

I think it had to do with installing the new XviD without uninstalling the old. I just did that and avi.NET put the video up to 2300kbps as I requested!

Sweet, hopefully all is resolved. Many thanks to the both of you.

[RolePlayArtist]

Looks like this dual installed xvid codec was the problem I was having with avi.net too. Avi.net will index and convert a whole movie when you only input the first VOB. Nice feature. But when I was converting a 2h 10m movie, no matter what output file size or forced bitrate I specified, the movie was being converted to sizes ranging from 300-400MB, with obviously poor video resolution. The audio was fine though, whether I kept the AC3 or allowed the conversion to MP3.

I first thought, though the entire movie was being converted, the low filesize was because I was only inputing the first 1G VOB, the resulting avi file being 1/3 of that. But When I input a merged VOB (first taking the movie through pgc.net), the results were the same.

So I tried AutoGK, and it worked! The filesize was 1.1G as I specified, the video was good, and so was the audio. The problem with avi.net gnawed at me though, as I had used it successfuly on a movie AutoGK had problems with.

When looking at the bitrate of the small converted avi files, I discovered the video bitrate was being reduced to the audio bitrate (128 for the 300MB file and 192 for the 400MB file). When I saw this post about a newer xvid codec being installed over an older one, I did find two installed XviD versions on my system. I uninstalled both and installed the newest version. With the merged VOB input, I ran the avi.net conversion again with the following settings:

* Selected .33DVD 1493 MB (avi filesize), which put the bitrate at 1616
* No MP3 conversion (kept movie's AC3)
* Screen size 720 (same as movie)
* Smooth/Sharp on highest setting (far right)
* Autocrop down one level from default (to crop the upper and lower black areas)
* The XviD 1.1.2/3 codec

The converted fileszize was 1.6G and the video was of excellent quality. I could not tell the difference between it and the the ripped movie. Problem solved! Thanks to Videohelp for resolving yet another visdeo issue!

[FulciLives]

I sometimes use avi.NET instead of autoGK only because autoGK will sometimes use a lower bitrate than it really should as it's quality based test thing isn't perfect. I have found that avi.NET will use whatever bitrate you tell it to use.

Also I have noticed that some autoGK encoded files (using XviD and the MTK profile) will NOT work on my PS3 but some do ... so far all avi.NET encoded files (using XviD and run through MPEG4Modifier to "unpack" the bitstream and change the fourcc to DX50) have worked ... 100% ... although I do have more autoGK files than avi.NET files.

I really am confused how some XviD files work on the PS3 while some do not. It isn't as simple as something "odd" like GMC or number of B-frames etc. but rather ... something else. The fact that I use the same parameters on all autoGK encoded files and yet some work and some don't tells me the PS3 firmware for XviD support is a bit "buggy" as all autoGK encoded files work fine on my Philips DVP5140 (a MPEG-4 capable DVD player using the MediaTek chipset).

- John "FulciLives" Coleman