Modified QMF

[defunkt]

If my understanding of XVID is correct one thing it will benefit from is a steady stream of consistant information, allowing it to reuse blocks from other frames particularly I-Frames on scene changes.

In which case, one problem with QMF is that it evaluates the first frame of a new scene (presumably an I-Frame) as high motion, which given its intended use will be a frame with less detail than a low motion frame even when the scene that follows is low motion. So I've messed about with the original script to make it detect scene changes (I find a threshold of 24 pretty accurate) and then treat that frame as it would the frame that follows.

I also added another level of motion but think that this is probably fairly gratuitous and unneccesary.

Thoughts?

function Motion() {
global motion_level = 0
global motion_level = (diff > threshold_zm) ? 1 : motion_level
global motion_level = (diff > threshold_lm) ? 2 : motion_level
global motion_level = (diff > threshold_hm) ? 3 : motion_level
global motion_level = (diff > threshold_sc) ? 4 : motion_level
}

function Change() {
global motion_level = (next > threshold_zm && motion_level > 3) ? 5 : motion_level
global motion_level = (next > threshold_lm && motion_level > 3) ? 6 : motion_level
global motion_level = (next > threshold_hm && motion_level > 3) ? 7 : motion_level
}

function QMF(clip c,
float "threshold_zm",
float "threshold_lm",
float "threshold_hm",
float "threshold_sc",
bool "debug") {
global threshold_zm = default(threshold_zm, 3.0)
global threshold_lm = default(threshold_lm, 6.0)
global threshold_hm = default(threshold_hm, 12.0)
global threshold_sc = default(threshold_sc, 24.0)
global motion_level = 0
global clip = c
c = ConditionalFilter(c, Filter_Motion_Nil(c), c, "motion_level", "=", "0")
c = ConditionalFilter(c, Filter_Motion_Min(c), c, "motion_level", "=", "1")
c = ConditionalFilter(c, Filter_Motion_Mid(c), c, "motion_level", "=", "2")
c = ConditionalFilter(c, Filter_Motion_Max(c), c, "motion_level", "=", "3")
c = ConditionalFilter(c, Filter_Motion_Nil(c), c, "motion_level", "=", "4")
c = ConditionalFilter(c, Filter_Motion_Min(c), c, "motion_level", "=", "5")
c = ConditionalFilter(c, Filter_Motion_Mid(c), c, "motion_level", "=", "6")
c = ConditionalFilter(c, Filter_Motion_Max(c), c, "motion_level", "=", "7")
c = (default(debug, false)) == true ? ScriptClip(c, "Debug()") : c
c = FrameEvaluate(c, "Change()")
c = FrameEvaluate(c, "global next =
(0.50 * YDifferenceToNext(clip)) +
(0.25 * UDifferenceToNext(clip)) +
(0.25 * VDifferenceToNext(clip))")
c = FrameEvaluate(c, "Motion()")
c = FrameEvaluate(c, "global diff =
(0.50 * YDifferenceFromPrevious(clip)) +
(0.25 * UDifferenceFromPrevious(clip)) +
(0.25 * VDifferenceFromPrevious(clip))")
return c
}

function Debug(clip c) {
c = Subtitle(c, "Motion Evaluation: " + string(diff),
x=25, y=150, font="courier new", size=24)
c = (motion_level == 0) ? Subtitle(c, "Zero Motion Frame",
x=25, y=200, font="courier new", size=32, text_color=$FFFFFF) : c
c = (motion_level == 1) ? Subtitle(c, "Low Motion Frame",
x=25, y=200, font="courier new", size=32, text_color=$FFFFFF) : c
c = (motion_level == 2) ? Subtitle(c, "Medium Motion Frame",
x=25, y=200, font="courier new", size=32, text_color=$FFFFFF) : c
c = (motion_level == 3) ? Subtitle(c, "High Motion Frame",
x=25, y=200, font="courier new", size=32, text_color=$FFFFFF) : c
c = (motion_level == 4) ? Subtitle(c, "Scene Change (Zero)",
x=25, y=200, font="courier new", size=32, text_color=$FFFFFF) : c
c = (motion_level == 5) ? Subtitle(c, "Scene Change (Low)",
x=25, y=200, font="courier new", size=32, text_color=$FFFFFF) : c
c = (motion_level == 6) ? Subtitle(c, "Scene Change (Medium)",
x=25, y=200, font="courier new", size=32, text_color=$FFFFFF) : c
c = (motion_level == 7) ? Subtitle(c, "Scene Change (High)",
x=25, y=200, font="courier new", size=32, text_color=$FFFFFF) : c
return c
}

[Dreassica]

Post an example for usage. I May be missing something obvious, but I can't get this script to load.

[Schlumpf]

Is that modification based on the latest Qmf 1.5 b1 ?
'Cause that was apparently the latest released version but all the downloadlinks in the old threads are down and I couldn't find a mirror via Google, that's why I can't compare.

[Dreassica]

Here, attached qmf 1.5b1. I tried comparing screipts to see if i could derive proper usage from modified one. But I'm not good at that kind of scripting.

[defunkt]

The script as posted is only a fragment, it was also line broken on the longer lines (so as not to make the post too wide). You can grap a more complete implementation here (http://www.ionwerks.net/defunkt/ModQMF.avs). Have enabled debug mode QMF(..., debug=true) so you can see what decisions the script is making, runs much faster without this. The functions:

Filter_Motion_Nil(clip base)
Filter_Motion_Min(clip base)
Filter_Motion_Mid(clip base)
Filter_Motion_Max(clip base)

...presently do nothing but return the clip they are passed. Use these to perform your own processing based on the frame type.

Hope this helps.

[Dreassica]

Thanks, got it working. The scenechanges no longer look blurry compared to frames after it in low motion scenes. It does seem to be more switch-happy during scenes itself though, compared to original qmf. Especially apparent when theres sudden motion in relative quiet scenes. Most likely it's a matter of further tweaking.

[defunkt]

Keep in mind that I added a fourth level of motion separation which on reflection I think was probably unnecessary. As you say it's very twitchy between nil/low motion - the two could (should?) probably be treated as one.