Text 5294, 69 rader
Skriven 2006-02-12 21:53:04 av Maurice Kinal (1:261/38.9)
Ärende: mencoder
================
Hey All!

I have found the sweet spot ... finally!!!  The job took under 5 hours on a
dual 933MHz smp system and produced a mpeg4 video, mp3 audio avi just under
650M.  I used xvid for the video and lamemp3 for the audio (2 channel stereo
sound).  The commandline looks like this;

mencoder dvd://1 -alang en -ovc xvid -xvidencopts fixed_quant=5 -oac mp3lame
-vf crop=700:464:10:6 -o test.avi

The 'dvd://1 -alang en' part comes from just playing the original in mplayer
and seeing what the proper integer and language was needed to just play the
damn movie!!!  :-)

The '-ovc xvid -xvidencopts fixed_quant=5' was dervived by expermenting and
seeing what was acceptable quality-wise given the goal of 800M or less.  When I
used a fixed_quant=4 it produced a 806M file and is hardly noticeably better in
quality on a 24-bit, 1280x1024 full screen mga_vid driven framebuffer display. 
Given the savings in bytes, and no noticeable cpu usage/time, I am labeling
this as a keeper.

The '-oac mp3lame' produces the mp3 soundtrack which saves literally 100's of M
to the final result.  Offhand for a 90m movie I am guesstimating just this
alone saved ~700M compared to the original.  I'll be sure to check this out
later and come up with a more conclusive number.

The '-vf crop=700:464:10:6' was derived from doing a 'mplayer -vo mga dvd://1
-alang en -vf cropdetect' and skipping ahead to where the movie is actually
playing (not just the credits) and then playing around with the the actual crop
numbers with 'mplayer -vo mga dvd://1 -alang en -vf crop=700:464:10:6' until I
was happy that I wasn't carrying any extra pixels around the edges of the
display.  The suggestion I read for the first two numbers is that they should
be multiples of 16.  The last two numbers I forget what they are for (as I
write this) but I think it has something to do with centering ... or not. 
Sorry about this but I just want to move on and leave the nitpicking up to the
neighbour who cares more about this then I obviously do.

The '-o test.avi' is the outputted file.  Just for fun a 'avitype test.avi'
produces the following output;

<init> : Avifile RELEASE-0.7.43-060128-11:01-gcc version 4.0.2
<init> : Available CPU flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
pge mca cmov pat pse36 mmx fxsr sse
<init> : 4294.97 MHz Pentium III (Coppermine) processor detected
<reader> : Checking: test.avi
<AVI reader> : MainHeader: MicroSecPerFrame=33366 MaxBytesPerSec=0
 PaddingGranularity=0 Flags=[ HAS_INDEX IS_INTERLEAVED TRUST_CKTYPE ]
TotalFrames=165691
 InitialFrames=0 Streams=2 SuggestedBufferSize=0 WxH=700x464
 Scale=0 Rate=0 Start=0 Length=0
<AVI reader> : StreamHeader: Type=vids Handler=XVID Flags=[ ]
 InitialFrames=0 Scale=1001 Rate=30000 Start=0 Length=165691
 SuggestedBufferSize=82838 Quality=0 SampleSize=0 Rect l,r,t,b=0,700,0,464
<AVI reader> : StreamHeader: Type=auds Handler=0x55 Flags=[ ]
 InitialFrames=21 Scale=1152 Rate=48000 Start=0 Length=230358
 SuggestedBufferSize=768 Quality=0 SampleSize=0 Rect l,r,t,b=0,0,0,0
<AVI reader> : InfoChunk Software:  MEncoder dev-CVS-060124-09:49-4.0.2
<AVI reader> : Reading index from offset: 667384206
<AVI reader> : Stream 0 vids : XVID (0x44495658) 165691 chunks (647.23KB)
<AVI reader> : Stream 1 auds : MPEG Layer-3 (0x55) 230358 chunks (1799.67KB)

I get a real kick out of the '4294.97 MHz Pentium III (Coppermine) processor
detected' part.  I wish!!!  Heh, heh.

Life is good,
Maurice

--- Msged/LNX 6.1.2
 * Origin: The Pointy Stick Society Headquarters - Ladysmith BC Ca (1:261/38.9)