[MPlayer-users] mencoder+codecs??

[Corey Hickey]

JJ2Dogs wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> Could u send me the txt? I don`t know why but the lavc is going on my machine much slover.. I got PIII 1Ghz and the divx4 is running at 20fps and the lavc I thing is about 7-12..

Ok. Here's the tail end of a few encodes. Actually, it seems that the
divx4 ratecontrol is imprecise on my test file, so I had to mess a bit
to make the two encode at the same bitrates.

AthlonXP, 1890.053 MHz
Linux 2.4.21
MEncoder dev-CVS-030924-14:15-3.3.1



1. For the first test I specified a bitrate of 800, but divx4
undershoots that by a ways.

----
time mencoder bad_boys_source.vob -nosound -ovc lavc -lavcopts \
vcodec=mpeg4:vbitrate=800 -ofps 23.976 -o /dev/null

Pos:  60.4s   1449f (99%)  59fps Trem:   0min   5mb  A-V:0.000 [802:0]]
Writing AVI index...
Fixing AVI header...

Video stream:  802.166 kbit/s  (100270 bps)  size: 6059932 bytes  60.436 
secs  1449 frames

real    0m24.715s
user    0m21.590s
sys     0m0.170s

----
time mencoder bad_boys_source.vob -nosound -ovc divx4 -divx4opts \
br=800 -ofps 23.976 -o /dev/null

Pos:  60.4s   1449f (99%)  39fps Trem:   0min   3mb  A-V:0.000 [474:0]
Writing AVI index...
Fixing AVI header...

Video stream:  474.388 kbit/s  (59298 bps)  size: 3583744 bytes  60.436 
secs  1449 frames

real    0m37.297s
user    0m31.980s
sys     0m0.180s

==============
2. For the second test I spececified vbitrate=475 to make lavc match the
divx4 bitrate.

----
time mencoder bad_boys_source.vob -nosound -ovc lavc -lavcopts \
vcodec=mpeg4:vbitrate=475 -ofps 23.976 -o /dev/null

Pos:  60.4s   1449f (99%)  62fps Trem:   0min   3mb  A-V:0.000 [489:0]
Writing AVI index...
Fixing AVI header...

Video stream:  489.703 kbit/s  (61212 bps)  size: 3699444 bytes  60.436 
secs  1449 frames

real    0m23.639s
user    0m20.200s
sys     0m0.160s

==============
3. For the third test, I specified br=1300 to "trick" divx4 into
encoding an average of 800 kbit/s.

time mencoder bad_boys_source.vob -nosound -ovc divx4 -divx4opts \
br=1300 -ofps 23.976 -o /dev/null
----
Pos:  60.4s   1449f (99%)  36fps Trem:   0min   5mb  A-V:0.000 [797:0]
Writing AVI index...
Fixing AVI header...

Video stream:  797.133 kbit/s  (99641 bps)  size: 6021910 bytes  60.436 
secs  1449 frames

real    0m40.223s
user    0m34.610s
sys     0m0.160s

===============

I ran each test three times, but the variation was at most 1fps.
The data shown above is representative.

So, in summary:

475kbit/s
divx4: 39fps (+/- 0fps)
lavc:  62fps (+/- 1fps)
divx4 / lavc = 0.63

800kbit/s
divx4: 36fps (+/- 0fps)
lavc:  59fps (+/- 1fps)
divx4 / lavc = 0.61


-Corey