help with divx encode

[lucas-br]

im making a film and it is amost done, the only problem that i have is with divx encoding, codec settings are 1 pass-quality based at 80%.
the size is good but the quality is too low, when i use full screen mode its worst

how can i fix this????
someone can send me some divx configs???
i dont understand about this..

[Enchanter]

I'd like a bit more details on what you did and got. For example, what is the video resolution, AVI final filesize, audio stream format and quality, encoder used and such.

[khp]

Using quality based encodeing for anything but short action filled clips, is generally a bad idear.

80% quality corrosponds to quantizer 8. Which as you say is rather poor quality.

To achive the best overall quality you should use two pass, bitrate controlled encoding.

Of course it's always difficult to know what a good bitrate setting might be.
In your case, I would suggest that you calculate the bitrate need to hit approx. 2 times the size, you get by using 80% quality based encoding. I think this should give you a resonable quality.

[lucas-br]

thx ill try 2 pass now

the configs are :

video - 640 x 480
frame rate - 30fps
each arquive - *.tga 901kb 640x480

the video duration deppends, because im doing a lot of little videos and i will connect all later

an exemple :

video : 640 x 480, 24 Bits, 386 Frames, 30.002 Frames/Sec, 312 KB/Sec, DivX codec

duration : 12s
size : 4,128,768 bytes

without sound

[lucas-br]

im try use 2pass now but i have some doubts
2pass, first pass and 2 pass, second pass´s bitrating can be different???
1.i have to change something in manage settings advanced 2.parameters and general parameters???
3.what configs i have to use in a film with 6mins and 150mb ?? (using 2pass)


thx

[khp]

Originally posted by lucas-br

2pass, first pass and 2 pass, second pass´s bitrating can be different???

Yes, but not by more than 30%. If you change it more than that it will still work, but the ratecontrol mechanism will be less precise.

Originally posted by lucas-br

1.i have to change something in manage settings advanced
2.parameters and general parameters???

No No, the default values should do fine. But you might want to push the Psychovisual Enhancements to strong.

Originally posted by lucas-br

3.what configs i have to use in a film with 6mins and 150mb ?? (using 2pass)

What ? do you want the output to be 150 MB ? Are we still talking 640*480 resolution 30 fps ?.

[lucas-br]

Originally posted by khp
What ? do you want the output to be 150 MB ? Are we still talking 640*480 resolution 30 fps ?.

yes why???
6 min 150 mb 640 x 480 30 fps its impossible???

id try to use 2pass, first pass with 3000 kbps and 2pass, second pass with 4500 kbps

8sec 3mb
looks fine and good quality


how can i get more compression without lose quality???

[khp]

Originally posted by lucas-br
6 min 150 mb 640 x 480 30 fps its impossible???

No no, it's quite possible to do that. But 150 MB for 6 minutes, equals a bitrate of 3500kbps(assuming no audio), which at 640*480*30 fps equals 0.379 bits per pixels. When Ripping DVD's I usually anim for 0.2 - 0.25 bits per pixel. Unless you got a very noisy source you should be able to get good quality at 2000-2500 kbps. And if you got a noisy source you need to apply some noise reduction filters.

Originally posted by lucas-br

id try to use 2pass, first pass with 3000 kbps and 2pass, second pass with 4500 kbps

Why would you intentionally use different bitrates for the first and second pass, that makes no sense.

Originally posted by lucas-br

8sec 3mb
looks fine and good quality

Talking about quality, base on such short clips is a bit difficult, because the bitrate needed to encode a clip at a specific quality depends heavily on the amount of motion in the clip.

Originally posted by lucas-br

how can i get more compression without lose quality???

If your video is noisy, you should apply some noise reduction filters. See This page

http://nickyguides.digital-digest.com/vdub-filters2.htm

And Donald Graft's home page

http://shelob.mordor.net/dgraft/

[lucas-br]

my video is about a game, like conterstrike, quake, quake3 etc... maybe is this the reason that im not losing much quality, the video isnt noisy, but if it happen, ill use these noise reduction filters


about 2pass question, im using different bitrate because if i need a file 8s with 3.6mb i can use 2pass, second pass with 3600kbps, but 2pass, first pass with 5400kbps (50%), if i use 3600 for 2pass, first pass i will lose quality (i think..)


is this correct???

[khp]

Originally posted by lucas-br
my video is about a game, like conterstrike, quake, quake3 etc... maybe is this the reason that im not losing much quality, the video isnt noisy, but if it happen, ill use these noise reduction filters

OK, that's about the cleanst source one can imagene, so no filtering should be needed. Noise filtering is mostly for TV-Captures.

Originally posted by lucas-br

about 2pass question, im using different bitrate because if i need a file 8s with 3.6mb i can use 2pass, second pass with 3600kbps, but 2pass, first pass with 5400kbps (50%), if i use 3600 for 2pass, first pass i will lose quality (i think..)
is this correct???

No, the first pass does not encode the video. The second pass must use the exact same source as the first pass. The first pass only gathers information about the video complexity, which is then used by the second pass ratecontrol mechanism. This works most efficiently if the first and second pass use the same bitrate setting.

[lucas-br]

Originally posted by khp
No, the first pass does not encode the video. The second pass must use the exact same source as the first pass. The first pass only gathers information about the video complexity, which is then used by the second pass ratecontrol mechanism. This works most efficiently if the first and second pass use the same bitrate setting.

ok thx

there is another way to get more quality with same size???
(if im not asking too much )

[khp]

Enable B-Frames and GMC. That should let you use a 20-25% lower bitrate without much loss of quality.

[lucas-br]

Originally posted by khp
Enable B-Frames and GMC. That should let you use a 20-25% lower bitrate without much loss of quality.

sorry but i dont know what it is... can u explain please?

[khp]

In the divx codec properties page main tab, there are three options labled 'MPEG4 Tools', check 'use GMC' and 'use Bidirectional Encoding'

[lucas-br]

these options are disable.. how can turn it on??