jon.schaffer
26th December 2005, 13:25
Hi,
I would like to report a case of oversizing despite the old & good "quant 2" method.
The movie encoded is a cartoon : "Clone Wars".
My target size was 653 MB (668672 KB) i.e. a bitrate of 1364 kbps (duration: 1:06:43).
A simple AviSynth script:
MPEG2Source("G:\CLONE_WARS\clones.d2v")
BicubicResize(640,336,0,0.5,0,0,720,576-0-4)
I used XviD.1.1.cvs [2005-12-10] (CelticDruid's build), then I tried 1.0.3 version (Koepi's). I tested this with default values except for Full quality 1st pass and Min quant = 2. All ended up with a ~690 MB file.
Solution: by increasing the max overflow degradation value to 10 (i.e. 5%/5%/10%), I finally got the good final size (simply increasing the overflow control strength to 10 (=0) helped a few but was not enough : I hit 660 MB)
Question: would it be interesting to slightly increase this value by default in order to avoid rare oversizing (despite min quant = 2...)?
I would like to remind you that increasing this value may also help against oversizing with the default min quant=1 setting.
Or... do you think increasing this value could have a negative effect? (I didn't test this extensively)
Or... is this case too rare to justify a modification in the default settings?
Or... maybe a simple "hint/warning" in the 2nd pass tab like "In case of oversizing, you could try to slightly increase the max overflow degradation value. But you at your own risk!" could help?
In your opinions: what could be the culprit? The fact that it is a cartoon... or the low duration of this movie? (though we "all" encoded cartoon and short movies without any problem...) I'm curious to know what disturbed the rate control.
JS
Edit:
just to add that I used H263 quantization type. The oversizing does not happen with MPEG matrix.
I would like to report a case of oversizing despite the old & good "quant 2" method.
The movie encoded is a cartoon : "Clone Wars".
My target size was 653 MB (668672 KB) i.e. a bitrate of 1364 kbps (duration: 1:06:43).
A simple AviSynth script:
MPEG2Source("G:\CLONE_WARS\clones.d2v")
BicubicResize(640,336,0,0.5,0,0,720,576-0-4)
I used XviD.1.1.cvs [2005-12-10] (CelticDruid's build), then I tried 1.0.3 version (Koepi's). I tested this with default values except for Full quality 1st pass and Min quant = 2. All ended up with a ~690 MB file.
Solution: by increasing the max overflow degradation value to 10 (i.e. 5%/5%/10%), I finally got the good final size (simply increasing the overflow control strength to 10 (=0) helped a few but was not enough : I hit 660 MB)
Question: would it be interesting to slightly increase this value by default in order to avoid rare oversizing (despite min quant = 2...)?
I would like to remind you that increasing this value may also help against oversizing with the default min quant=1 setting.
Or... do you think increasing this value could have a negative effect? (I didn't test this extensively)
Or... is this case too rare to justify a modification in the default settings?
Or... maybe a simple "hint/warning" in the 2nd pass tab like "In case of oversizing, you could try to slightly increase the max overflow degradation value. But you at your own risk!" could help?
In your opinions: what could be the culprit? The fact that it is a cartoon... or the low duration of this movie? (though we "all" encoded cartoon and short movies without any problem...) I'm curious to know what disturbed the rate control.
JS
Edit:
just to add that I used H263 quantization type. The oversizing does not happen with MPEG matrix.