Finding the right AVI encoder settings
July 19, 2009 11:21 PM   Subscribe

How do I encode AVI files in Xvid or Divx according to the fashion often seen on bittorrent, where two hours of US TV, minus commercials, fits on one CD?
posted by Yakuman to Computers & Internet (11 answers total) 8 users marked this as a favorite
Which encoder are you using?

Using Handbrake, available for Mac, Windows and Linux, you can specify a target size (from the sounds of it, you'd want to set it to around 350MB).

I typically use Handbrake to compress videos for the iPod (MP4 format) but it has an option to create AVI files as well, using FFmpeg or Xvid as the video codec.
posted by dumbland at 11:32 PM on July 19, 2009 [2 favorites]

Sorry I just realised my 350MB was a little out of context. When I compress an "hour-long episode" of television (so around 44 minutes) so that I can fit a couple episodes on a 700MB CD, I set the target size for a single episode to around 350MB. Handbrake is useful in this regard, as it lets you queue up multiple episodes off a DVD to encode in one go.

Recent versions also support converting files from sources other than a DVD, if you need to do that.
posted by dumbland at 11:42 PM on July 19, 2009

If you're on Linux, AcidRip is also great.
posted by smoke at 11:42 PM on July 19, 2009

If you're on Windows, try AutoGK. Click a few buttons and away you go.
posted by Solomon at 11:49 PM on July 19, 2009 [2 favorites]

Seconding AutoGK for great.
posted by Duke999R at 1:05 AM on July 20, 2009

Seconding Handbrake (or its upscale cousin VisualHub. Flawless and brimming with "it just works"-ness.)
posted by rokusan at 1:19 AM on July 20, 2009

Handbrake works, but can take forever. Like 2 days for a movie .iso that took 20 minutes to rip. But it appears to be heavily CPU dependent, so your mileage may vary. I'll have to try AutoGK.
posted by hungrysquirrels at 2:01 AM on July 20, 2009

Based on the title of this Q, I suspect the OP already knows of the encoding process & tools, but wishes to know of standards and settings. Many private trackers have a ripping/encoding guide; there's one available at the TheBox which shows how to encode files that conform to 'The Scene'. Get it here.
posted by daksya at 3:26 AM on July 20, 2009

HandBrake is not a good choice for AVI. It used a custom AVI 1.0 muxer that was severely outdated and entirely unmaintained. AVI and XviD have been dropped from the development code altogether and won't be in the next release.

If you're on Windows, well, what the people making those BT encodes you see are using is probably AviSynth + MeGUI with a bunch of plug-ins to do stuff like noise reduction (and requisite sharpening to compensate for it) to make up for the tiny bitrates they use. Also, a lot of them probably start with HD sources and scale them down to around 640*480 or less.
posted by jbrjake at 1:09 PM on July 20, 2009

Another option is doing the math to determine the appropriate bitrate and use whichever encoder you wish. In one of my scripts I use:

VIDEO_BITRATE = ((SIZE * 1024 * 1024) - (ABITRATE * LENGTH * 1000 / 8) - (590 * LENGTH) - (1000 * LENGTH)) / LENGTH * 8 / 1000

SIZE is target size in megabytes (700, 350, etc), ABITRATE is the audio bitrate (128, 64, etc) and LENGTH is how long the movie is in seconds. So, for example, a 90 minute movie with 128kbit audio, you would set your video bitrate to 946.

This formula also accounts for AVI mux overhead and is pretty accurate in general.
posted by cj_ at 7:31 PM on July 26, 2009

And yes, you need to downscale and denoise when you are shrinking it to small bitrates or it will look like crap. Unfortunately, the "right settings" for this depends drastically on the nature of the source material and how much time you want to devote to the encoding. There's no right answer, just a lot of options. If you want a very technical rundown of the process, the MPlayer/MEncoder documentation is very detailed and thorough.
posted by cj_ at 7:36 PM on July 26, 2009

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