[MEncoder-users] Minimize posterization in areas of low contrast when downscaling HD h.264 to mpeg2video

[L Lee]

On 8/10/09 7:06 AM, "Moritz Barsnick" <barsnick at gmx.net> wrote:

> Hi Laine,
> 
> On Sun, Aug 09, 2009 at 14:38:56 -0500, L Lee wrote:
>> Also, is there a way to crop to get an output file with true 2.35:1
>> proportions rather than just creating 16X9 output with black bars? Thanks.
> 
> Not with standard DVD MPEG2 formats.

Thanks. Is there a way to do it while keeping MPEG2 format but not adhering
to standard DVD restrictions?

Also, I discovered through testing that I can greatly improve output quality
for this process by including a vrc_minrate value along side these
mpeg2video options:
vcodec=mpeg2video:vrc_buf_size=1835:vbitrate=9000:vrc_maxrate=9800.

That appears to work mainly by driving up output bitrate. I've been setting
a vrc_minrate value from 5000 to 5600. But I always get this warning:
"Warning min_rate > 0 but min_rate != max_rate isn't recommended!"
I have two questions about that. First, does the warning actually mean

"Warning min_rate > 0 but min_rate <= max_rate isn't recommended!"

and if not, what does "!=" mean?

Second, am I using an incorrect method to drive up the output bitrate? If I
don't set a value for vrc_minrate, bitrate goes down dramatically, and
quality suffers.

Thanks again.

Laine Lee