There are good guides for DVD playback, but nothing for lower-quality video files.
I've been playing with FFDshow post-processing for the best quality playback without killing my cpu. Any C2D should be able to use these settings very smootly.
First of all, get the latest ffdshow-tryout, because it has better deblocking post-processing features which are not needed for DVDs but essential for divx. i use the v. 1523 dated 5 oct.
Enable the raw video processing, with wmp11 support:
Suggestion: activate the OSD, it will help fine-tuning. The cpu% detection is not accurate (for an euophemism), so open task manager, minimize it and look there instead.Order of filters:
-resize & aspect
For better quality, the blur and sharpen must be done AFTER the resize. I wouldnt do the postprocessing after the resize because is a gratious burden to the cpu. Ideally, the noise reduction should have been done before the resize, but its in the same page. I didnt try to use the blur in the resize page, maybe it's a better option. Anyway, with my settings the PQ of a GOOD dvd (especially if using h.264) rip is indistinguishable from a real DVD. A decent rip has a quality close to a DVD.
1) Postprocessing: This is essential, because it does the deblocking of the compressed file. The best option (SPP deblocking) unfortunately is too much stressing for the cpu. I can speculate that only a QX6800 is able to use is and have a smooth playback. Anyway, the settings on this page provide an excellent result with low cpu use.The settings:
Enable presets, slider at max, tick automatic quality control (this doesn't make a difference if not easying the cpu a 2-3%)
Processing method: mplayer with accurate deblocking
2) Resize: Considering that avi files comes to many different non-standard resolutions, i preferred a fixed size instead of the classic 2x that works wonder on dvd or HDTV rips. Here you can choose between DVD size (720x480) and HD size (1080x720). It depends on the resolution of the source, for very small videos, 720 is more than enough, and you may try SPP deblocking instead if you want 1080 (and have a fast quad core), which is the only thing that can improve the PQ of something as low as 350x240-ish.The settings:
Specify horizontal size: 1080 (or 720)
tick keep original aspect ratio
Resize if x < 1080 (or 720) and y < 720 (or 480 or put 576 for pal and 3:2 letterbox rips)
tick process pixel aspect ratio internally
2b) Resize settings page: The Spline does a much better work than Lanczos on compressed movies. Click on lock to enable it also for chroma. Some of you may want to experiment with the blur and sharpen here so the noise reduction can be done before.The settings:
Luma method: Spline
Click on Lock and enable chroma method, select Spline
Tick accurate rounding
3) Blur & NR: Too much blur causes bad results on dirty compressed sources as xvid. Also the gradual denoise causes ghosts and must be avoided.The settings:
Soften: 10 -is more than enough
tick only denoise 3d and HQ. leave the sliders at defaults
4) Sharpen: Xsharpen is my favourite. Unsharp mask have similar results but it makes the video less natural IMO.The settings:
Select Xsharpen, strenght 20, treshold 150 (default).
I also enable the subtitles, with vobsub. I have already all my subs in the moviename.srt format (for playback in stand-alone dvd player), but ffdshow allows for different names and for more subtitles to be used.