[M4IF Technotes] help on Momusys

[Yang, Wei Jian (Mac)]

hello, Jani:
I have resolved this problem. The key is that you should change the Type of
rate control from None to TM5 (
I have not tried other 2 options as VM4 and VM5+), and change alpha channel
to Rectangular. After that, output
coded video quality will change as target bitrate change.
I have another question:
Is the .bits file as coded output stream, or just description file?
Thanks
Mac
Yang, Wei Jian (Mac)
Bell labs, Shanghai
Lucent Technologies (China) Co., Ltd.
Tel:         8621-5450-4555  ext. 8610
Fax:        8621-5490-2106
E-mail:   yangwj   lucent.com
-----Original Message-----
From: Jani Huoponen [mailto:Jani.Huoponen   hantro.com]
Sent: 2002Äê9ÔÂ7ÈÕ 5:08
To: Yang, Wei Jian (Mac); 'technotes   lists.m4if.org'
Subject: RE: [M4IF Technotes] help on Momusys
Hi Mac,
> -----Original Message-----
> From: Yang, Wei Jian (Mac) [mailto:yangwj   lucent.com]
> Sent: 6. syyskuuta 2002 3:40
> To: 'technotes   lists.m4if.org'
> Subject: [M4IF Technotes] help on Momusys
> 
> 
> hello:
>  
> I debug Momusy-FDIS-v1.0-990812, using akiyo.ctl/cfg to 
> encode akiyo CIF
> YUV. I find out that even if I change the Target bit-rate for 
> vol from 64000
> to 9600, the reconstructed image quality is same. 
>  
> Can any one tell me reason?

Without knowing all the coding parameters you are using (like frame rate) I
would say that the sequence (CIF!)
cannot be simply compressed to a such a low bit rate (9.6 kbits/s), i.e.,
the 64 kbps could be close to being
the lowest bit rate that the encoder can achieve with the parameters you
used. So, even if you put 9.6 kbps as a target rate, the encoder cannot go
that low and thus the quality of the video is more or less the same as for
64 kbps. Check the file sizes of the compressed bit streams and calculate
the true bit rate the encoder used. With normal coding conditions that's the
lowest bit rate (and quality) you get with Momusys.
BR, Jani