Too VBR - how can I avoid playback stuttering by encoding?

[aLu]

I have considerabe stuttering in playback, and neither changing screen res/color depth/player/computer&graphic card changes this, while the CPU load is quite low. The stuttering is very fast and occurs even in quite dark motion scenes, when the bitrate shouldn't be that high (average throughout the movie: 105 k). It must be the rapid bitrate changes that cause this (the curve looked quite alive while encoding in Flask).

My question is what's the best encoding configuration to avoid this, maintaining quality, keeping the bitrate flexible enough but the changes not too fast ("curve smoothing"). I'll test this myself, of course, but any suggestions would be welcome.

Encoding settings are now:
Movie size: 624*352
Global settings:
Motion search precision: 6(Ultra high)
I-frame interval: 75
Quantization: H.263;
FourCC: DivX;
Lumi masking enabled;
Quantization: 1:31
Two-Pass tab:
I-frame boost: 20, min. interval: 6
Curve compression high/low: 25%:10%, payback delay: 240 (with bias)
Alt Curse tab (not used)


Choices (some maybe stupid):

* Redistribute the bits used for fast-/low motion scenes (curve compression)
** Edit the quantization matrix (from 1:31 to 2:12 like DivX, for instance)
*** Use alternate curve agression and set it to "LOW" without changing anything else (Alt curve tab)
**** Reduce motion search precision (requires re-encoding all passes)
***** Re-encoding the movie at a smaller scale (is out of competition by now)

[Teegedeck]

Hi,

I don't really think your problems are XviD-related - perhaps you're putting too high a load on the CPU by something else - what kind of audio-stream do you have?

On the other hand - what the heck does THIS mean:

>I-frame interval: 75
?

BTW, don't use Flask EVER! It's the worst encoder of all, who knows what kind of exotic problems it causes. Encode your video with VirtualDub and your audio with BeSweet or OggMachine and mux them lateron.

[edit:]
- Could also be a driver-problem.

- Are you sure you're not using any post-processing?

[aLu]

... that's right. Haven't looked at this thread for some time, sorry. It's definitely a Flask 5-problem, Flask 6 doesn't have it. And I don't have the slightest idea what might be causing it. I suppose Flask 5 and 6 use mainly the same resizing algorythms-? - if not, that's it maybe.

Flask - for me - it the ONLY app that produces high quality. DVD2AVI is not quite up to standards (tested with very high bitrates and 2-pass), and resizing/cropping in XMPEG is a laugh - you end up with sizes not even divisible by 16!

I had posted a thread (http://forum.doom9.org/showthread.php?threadid=34249) on this subject before to better explain the problem:
-----------------
Flask 5 has some other strange problem with some movies (like 'Highlander' german, 'Die fabelhafte Welt der Amelie'), it repeats/ replaces every 11th frame, although PAL 25 fps, no "force film" is selected ("force file" isn't selected and greyed out, either).
------------------
That's what I have now with "The silence of the lambs" (all movies german versions). It's not connected with clipping sizes, because it also occurs at values divisible by 32 (and not with any other apps!).

Now that I've managed my first successfull 2-pass encoding in Flask 6 (http://forum.doom9.org/showthread.php?threadid=36795), maybe I'll not use Flask 5 anymore - end of problem. I hope ;-/

[Koepi]

Don't use flask!

You're at Doom9's here.

read and follow the XviD guide step by step!

You'll be impressed how good the quality can get (compared to flask).

Please, if you ask for advice, follow it instead oif sticking with flask and thus rendering our help useless.
If you don't wanna be helped, behave that way! If you're _really_ interested in high quality you'd switch immediatly to dvd2avi/avisynth/vdub!

Koepi

[MaTTeR]

Maybe it would be a good idea to post in bold letters "Dont use Flask" in one of the stickies. lol

It's shameful the app is still floating around the net IMHO.

[Didée]

This topic reminds me of something I noticed some days ago:

In a rip of TheCell, there is a scene with full-scene-panning & very high picture detail. My older Athlon700 decided to stutter *noticeably* on this particular scene. I played from HD, and usually that machine is able to play everything pretty smooth, it can even catch up with most 50fps clips).
I could imagine there is some bottleneck with very high bitrate scenes, if going along with "heavy use" of motion vectors ??

[Neo Neko]

Originally posted by MaTTeR
Maybe it would be a good idea to post in bold letters "Dont use Flask" in one of the stickies. lol

It's shameful the app is still floating around the net IMHO.

Don't look now. But someone is trying to resurect flask. Don't ask me why. The whole series of flask and derived apps are less than optimal.