[MPlayer-dev-eng] Re: [patch] Documentation update following lavc internal 2-pass mode commit

Rémi Guyomarch rguyom at pobox.com
Mon Apr 22 17:18:04 CEST 2002


On Mon, Apr 22, 2002 at 04:33:59PM +0200, Rémi Guyomarch wrote:
> Comments ?

Disregard the previous, this one fix a few wraps in the man page.

-- 
Rémi
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Index: DOCS/mencoder.1
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/mencoder.1,v
retrieving revision 1.36
diff -u -r1.36 mencoder.1
--- DOCS/mencoder.1	20 Apr 2002 06:40:47 -0000	1.36
+++ DOCS/mencoder.1	22 Apr 2002 15:23:09 -0000
@@ -194,32 +194,96 @@
 Available options:
 
   help           get help
-  vcodec=XXX     use the specified codec
-                 (for full list, see html doc!)
+  vcodec=XXX     use the specified codec :
+                   mjpeg - Motion JPEG
+                   h263 - H263
+                   h263p - H263 Plus
+                   mpeg4 - DivX 4/5
+                   msmpeg4 - DivX 3
+                   rv10 - an old RealVideo codec
+                   mpeg1video - MPEG1 video :)
   vbitrate=XXX   specify bitrate in
                  kbit <4-16000> or
                  bit  <16001-24000000>
+                 (warning: 1kbit = 1000 bits)
+  vratetol=XXX   approximated bitrate tolerance,
+                 same unit as vbitrate.
   keyint=XXX     interval between keyframes
-                 (specify in frames)
-  vhq            very high quality
-  vme=XXX        motion estimation method
-  vqmin=XXX      minimum quantizer
-  vqmax=XXX      maximum quantizer
-  vqdiff=XXX     quantizer difference. Limits the
-                 maximum quantizer difference
-                 between frames.
-  vratetol=XXX   approximated bitrate tolerance
+                 (specify in frames, >300 are not
+                 recommended)
+  vhq            high quality mode, macro blocks
+                 will be encoded multiple times and
+                 the smallest will be used.
+  vme=XXX        [0..5] motion estimation method :
+                   0 - no ME at all
+                   1 - ME_FULL
+                   2 - ME_LOG
+                   3 - ME_PHODS
+                   4 - ME_EPZS
+                   5 - ME_X1
+                 EPZS usually gives best results,
+                 but you can try X1 too. FULL is
+                 very slow and the others are
+                 experimental.
+                 The default is EPZS.
   vqcomp=XXX     if the value is set to 1.0, the
                  quantizer will stay nearly
-                 constant. If it's 0.0, the
+                 constant (high motion scenes will
+                 look bad). If it's 0.0, the
                  quantizer will be changed
-                 to make all frames
-                 approximately equally sized.
+                 to make all frames approximately
+                 equally sized (low motion scenes
+                 will look bad).
   vqblur=XXX     blurs the quantizer graph over
                  time.
                     0.0 : no blur
                     1.0 : average all past
                           quantizers
+  vqscale=XXX    [2..31] gives each frame the same
+                 quantizer (selects fixed quantizer
+                 mode).
+  vrc_strategy=X [0..2] different strategies to
+                 decide which frames should get
+                 which quantizer.
+  v4mv           4 motion vectors per macroblock,
+                 may gives you slightly better
+                 quality, can only be used in HQ
+                 mode and is buggy with B frames
+                 currently.
+  vpass=X        [1,2] select internal first pass
+                 or second pass of 2pass mode.
+
+The next 3 options doesn't apply to B frames, only I & P frames :
+
+  vqmin=XX       [1..31] minimum quantizer
+  vqmax=XX       [1..31] maximum quantizer
+  vqdiff=XX      [1..31] quantizer difference.
+                 Limits the maximum quantizer
+                 difference between frames.
+
+The following options only apply to B frames :
+
+  vmax_b_frames=X  [0..4] maximum number of frames
+                   between each I/P frame.
+  vb_strategy=X    strategy to choose between
+                   I/P/B frames :
+                     0 allways use max B
+                     1 avoid B frames in high
+                       motion / scene change (can
+                       lead to filesize miss
+                       predicton)
+
+In fixed quantizer mode you can use those options :
+  vqscale, vmax_b_frames, vhq, vme, keyint
+
+You can use the following options only in pass 1 of 2-pass mode or in 1-pass mode :
+  vqblur, vqdiff
+
+You can use the following options only in pass 2 of 2-pass mode :
+  vrc_strategy, vb_strategy
+
+All other options can be used in all modes.
+
 .TP
 .B \-lameopts
 If encoding to MP3 with libmp3lame, you can specify its parameters here, like:
Index: DOCS/encoding.html
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/encoding.html,v
retrieving revision 1.37
diff -u -r1.37 encoding.html
--- DOCS/encoding.html	20 Apr 2002 07:02:35 -0000	1.37
+++ DOCS/encoding.html	22 Apr 2002 15:23:10 -0000
@@ -168,6 +168,23 @@
   -divx4opts br=1100 -oac copy -o movie.avi -pass 2</CODE>
 </P>
 
+<P><U><B>2 or 3-pass encoding using internal libavcodec controler</B></U> :
+Optionally you can use libavcodec's internal 2 or 3-pass mode, it may gives you
+better final rate accuracy than using the external, DivX4-inspired 2-pass rate
+controler with libavcodec.<BR>
+<UL>
+<B>2-pass encoding</B> :<BR>
+<CODE>rm -f lavc_stats.txt<BR>
+mencoder -dvd 2 -ovc lavc -lacvopts vpass=1 (audio-options) -o movie.avi<BR>
+mencoder -dvd 2 -ovc lavc -lacvopts vpass=2 (audio-options) -o movie.avi</CODE><BR>
+<BR>
+<B>3-pass encoding</B> :<BR>
+<CODE>rm -f frameno.avi lavc_stats.txt<BR>
+mencoder -dvd 2 -ovc frameno (audio-options) -o frameno.avi<BR>
+mencoder -dvd 2 -ovc lavc -lacvopts vpass=1 -oac copy -o movie.avi<BR>
+mencoder -dvd 2 -ovc lavc -lacvopts vpass=2 -oac copy -o movie.avi</CODE><BR>
+</UL>
+</P>
 
 <P><B><A NAME=2.4.3.2>2.4.3.2.  Rescaling movies</B></P>
 


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