[Ffmpeg-devel] MPEG2 Encoder Quantization Minimum

[Zhang Jian Feng]

Hello,

I'm using ffmpeg release 0.4.9-pre1

Is there a reason the minimum quantization for MPEG2 encoding is kept at a
minimum of 2?
I?m doing some very high-bitrate encodes and realize that quantization
level of 1 works fine if changed in libavcodec/utils.c [patch below].
It seems to give better results for very high bitrate streams.

- Jeff


cvs diff: Diffing .
Index: utils.c
===================================================================
RCS file: /cvsroot/ffmpeg/ffmpeg/libavcodec/utils.c,v
retrieving revision 1.112
diff -u -r1.112 utils.c
--- utils.c     27 Jun 2004 11:07:05 -0000      1.112
+++ utils.c     12 Sep 2005 07:42:01 -0000
@@ -366,9 +366,9 @@
     s->av_class= &av_codec_context_class;
     s->bit_rate= 800*1000;
     s->bit_rate_tolerance= s->bit_rate*10;
-    s->qmin= 2;
+    s->qmin= 1;
     s->qmax= 31;
-    s->mb_qmin= 2;
+    s->mb_qmin= 1;
     s->mb_qmax= 31;
     s->rc_eq= "tex^qComp";
     s->qcompress= 0.5;