[FFmpeg-devel] [PATCH]Higher default mpeg muxrate for large dimensions

[Carl Eugen Hoyos]

Hi!

I don't know what negative effects attached patch may have, but it is 
currently not possible to specify a -bufsize for constant (low) quantiser - 
specifying a bufsize automatically increases the quantiser to max - and for 
high resolution, the current default bufsize is too low.
See "mpeg2 bufsize question" on -user.

Please comment, Carl Eugen
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diff --git a/libavformat/mpegenc.c b/libavformat/mpegenc.c
index dce1786..f3bae32 100644
--- a/libavformat/mpegenc.c
+++ b/libavformat/mpegenc.c
@@ -374,7 +374,7 @@ static int mpeg_mux_init(AVFormatContext *ctx)
                 stream->max_buffer_size = 6*1024 + st->codec->rc_buffer_size/8;
             else {
                 av_log(ctx, AV_LOG_WARNING, "VBV buffer size not set, muxing may fail\n");
-                stream->max_buffer_size = 230*1024; //FIXME this is probably too small as default
+                stream->max_buffer_size = FFMAX(st->codec->width * st->codec->height, 230*1024);
             }
 #if 0
                 /* see VCD standard, p. IV-7*/