Image Quality Priority for SVCD

[menow]

Just want to get an idea of what everybody else uses for the Image Quality Priority. Do I leave it at 17 or what is the recommended number? thanks

[bb]

CCE's image quality priority defaults at something like 40, I believe. But with that setting you don't spend enough bits to complex scenes, and thus get too many artefacts. I'm not sure why DVD2SVCD uses 17, not 16 or 18 (maybe because 17 is a prime number?). At least it's a good compromise to get better quality for high motion scenes without making still scenes look bad.

The answer in short: Yes, I leave it at 17 (or set it explicitly to 17, if I do it manually in CCE).

bb

[beeebeeebeee]

Before I used 20 (CCE default) and it didn't look that great. Now I use 5 and it looks great.

[tja]

Originally posted by beeebeeebeee
Before I used 20 (CCE default) and it didn't look that great. Now I use 5 and it looks great.

Can you go into more detail about it now looking great as compared to not looking great?

I mostly was reading several threads, then tested IQP 10 and just was living with that ...
20 would be as double as much as my setting - what did you see there? 5 would be exactly halve my my value, so i am quite interested in your experiences :-)

Byebye,

[beeebeeebeee]

Under the default 20 setting, I noticed that CCE SVCD had created slightly more blocks than Tmpgenc. The blocks, strangely enough, appeared in fairly slow moving/non-complex scenes (even though 20 is supposed to assign more than ample bitrate to non-complex scenes).

I've read CCE guides that suggest always using 0 (since fast moving scenes are always a pain to encode block-free so why not assign maximum bitrate to complex scenes) but others warn that the 0 setting assigns too much bitrate to complex scenes (fast moving scenes) making non-complex scenes (normal-slow moving scenes) become bitrate starved thereby creating macroblocks in slow scenes (yikes! I surely didn't want that).

Perhaps, I should have experimented with 0 to see if it actually provided worse or better quality. But, I choose 5 as a flexible compromise (significantly smaller than 20 to make a visible difference but not so extreme as 0) and have noticed that CCE then started producing fewer blocks than Tmpgenc for my SVCDs. Afterwards, I started using setting 5 for all my SVCDs and have been happy with the results (very few blocks and only appearing in really complex/fast scenes--which couldn't be helped under any setting) ever since.

If 10 works well as your default setting, then by all means stay with it. For me, my preferred default setting is 5. It has worked well for my video material (our video material could differ, requiring different optimum settings).

Note: Some have indicated that as the slider setting moves to the left (closer to 0), one's video will contain fewer blocks but more mosquito noise. I did notice fewer blocks but haven't noticed mosquito noise. Then again, mosquito noise is not readily visible, except in frame by frame analysis. And I, as with most others, have no problem trading fewer macroblocks with a bit more mosquito noise (which is not noticeable on video playback).