[game_preservation] Gameplay movies, audio and video compression

[Jim Leonard]

Andrew Armstrong wrote:

> I wondered if anyone here could give me a idea about what kind of file 

> format / dimensions / compressions they use (if anyone does!) for 30FPS 

> video content of gameplay movies.


Your email was akin to attempting to shooting a fly with a shotgun. 
There are so many hits that it may take a few follow-ups to fully answer 
all of your questions :-)


> I intend to do some tests, capturing video gameplay segments to show 

> what a game is, how it is played. At the moment its PC games only. I'm 

> using FRAPs and capturing full screen (1680x1050 usually, although it 

> can be anything else my monitor supports, like square resolutions) at 

> 30FPS. I might go and do half-capture at 60FPS for some parts, if there 

> is a lot of action full screen 30FPS capture can go below 30FPS, thus 

> not looking right.


If you want to truly preserve the gameplay, it might be best to ensure a 
rock-solid 30fps or 60fps by capturing at a smaller resolution.  It 
takes a pretty powerful machine to play back compressed video at the 
capture resolution you listed above, unless your target is "users 5 
years from now".  And that high a res means your own machine will 
struggle to capture it in the first place.


> Therefore, knowing a good video compressor would be great, and perhaps 

> some suggested settings (I am willing to tinker). I'm currently 

> investigating DivX 6.X, XviD 5.X and WMV 9 (although I don't like WMV 

> much), and I'll likely try MPEG-2 as well. I'm looking mainly at full 

> screen conversion - for some reason XviD seems to get corrupted with my 

> test. Not sure why. Not tried any of the H.XXX MPEG's either, not sure 

> entirely what download you need installed to use them in fact (ffdshow 

> perhaps?)


MPEG-4 AAC (H.264) is the way to go.  MPEG-4 is a standards-based 
format, it can be played in Quicktime or VLC or Flash (coming soon, 
already in beta) so that's what your target should be.  H.264 provides 
excellent quality for the size and has encoding profiles that can ease 
the playback demands (ie. "simple profile") at the expense of about 
15%-30% size/quality.

The easiest way to encode MP4 is either Nero Recode (included in Nero 7 
full retail package) or Quicktime Pro ($30).  You can also do it with 
completely free tools, like FFMPEG, but you may have to jump through a 
few more hoops.


> I also would love any information on a good choice for audio conversion. 

> FRAPs captures are 44100Hz PCM WAV, so needs cutting down. I also intend 

> to possibly have a second audio track with commentary (although I've 

> found out its near impossible to do this with one PC, FRAPs and a 

> microphone plugged into the PC), so any ideas on container formats which 

> support this would be welcome.


MPEG-4 and Quicktime easily support multiple audio tracks, although the 
only tools that support it at the moment are probably 
Quicktime-specific.  I believe Premiere Pro CS2 and higher can output 
Quicktime with multiple audio tracks but don't quote me on that.

This is where waiting a year or two will help you significantly, as the 
tools catch up.
-- 
Jim Leonard (trixter at oldskool.org)            http://www.oldskool.org/
Help our electronic games project:           http://www.mobygames.com/
Or check out some trippy MindCandy at     http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/