Leak
12th April 2004, 00:05
Okay, so I went totally nuts and made an encoding probably nobody in their right mind would even think about...
I took Autechre's "Gantz Graf" video (which is all computer-generated and very high motion) and thought I'd try out making it as small as possible, quality be damned. So I configured XviD to use up to 300 B-frames, ratio 1, offset 0 and set the B-frame sensitivity to 10000 while clamping all quantizers to 31... :D
Anyway, the resulting file (at 360x172 - I know, I know... it's not MOD8 or MOD16, but it works anyway) plays, but at some points in the video it just stops for a moment and resumes playing a second or so later - I'd guess it hits an I-frame then and continues from there.
Still, when I play the exact same file with ffdshow using libavcodec, it plays without a hitch; using XviD in ffdshow or looking at it in VirtualDubMod it'll always skip at the exact same positions (for example from frame 232 to 256). Looks like there's something in the file that the decoder really doesn't like... :) (Not that I can blame it... :D But since the CPU load stays around 10% for the whole time it can't be the decoder being overloaded...)
Maybe you want to take a look at it, sysKin? ;)
http://desdemona.ssw.uni-linz.ac.at/GantzGrafSick.avi
(oh, and the audio, though heavily MP3-compressed, is supposed to sound that way... :p)
np: Donnacha Costello - Dry Retch (Pop Ambient 2002 comp.)
I took Autechre's "Gantz Graf" video (which is all computer-generated and very high motion) and thought I'd try out making it as small as possible, quality be damned. So I configured XviD to use up to 300 B-frames, ratio 1, offset 0 and set the B-frame sensitivity to 10000 while clamping all quantizers to 31... :D
Anyway, the resulting file (at 360x172 - I know, I know... it's not MOD8 or MOD16, but it works anyway) plays, but at some points in the video it just stops for a moment and resumes playing a second or so later - I'd guess it hits an I-frame then and continues from there.
Still, when I play the exact same file with ffdshow using libavcodec, it plays without a hitch; using XviD in ffdshow or looking at it in VirtualDubMod it'll always skip at the exact same positions (for example from frame 232 to 256). Looks like there's something in the file that the decoder really doesn't like... :) (Not that I can blame it... :D But since the CPU load stays around 10% for the whole time it can't be the decoder being overloaded...)
Maybe you want to take a look at it, sysKin? ;)
http://desdemona.ssw.uni-linz.ac.at/GantzGrafSick.avi
(oh, and the audio, though heavily MP3-compressed, is supposed to sound that way... :p)
np: Donnacha Costello - Dry Retch (Pop Ambient 2002 comp.)