RT_Stats, Compile-time/Runtime Functions v1.43 - 08 Oct 2014

[StainlessS]

Here An updated QueryBorderCrop(), unfortunately, the site screws up at a simple 16K script, so
I'm splitting it into several posts.

Here Some of the Text I will have to strip out of the AVS file.

Function QueryBorderCrop(clip c,int "Samples",Float "Thresh",bool "Laced",int "XMod",int "YMod",int "WMod",int "HMod", \
    bool "Relative", String "Prefix",int "RLBT",bool "DEBUG",float "Ignore",int "Matrix") {
# QueryBorderCrop v1.08, By StainlessS, Requires GScript & RT_Stats v1.01 Plugins.
# http://forum.doom9.org/showthread.php?p=1586858#post1586858 
#
# Prescan function to get coords for eg cropping black borders. Planar, YUY2, RGB.
# Simultaneously returns 4 sets of strings holding crop coords, here is one set: "QBCropX=8 QBCropY=8 QBCropW=640 QBCropH=480".
# String sets are Chr(10) separated, the 'exact found' coords set as above, not rounded at all and possibly  throwing an error if
# you try to crop, although could use in eg resize.
# Second set using eg "QBCropXL=8", which is CropLess("L" trailer), ie when rounding for Xmod,WMod etc may leave some black border.
# Third set using eg "QBCropXM=8", which is CropMore, ie when rounding for Xmod,WMod etc may crop some image.
# Forth set using eg "QBCropXP=8", which is CropPlus, moves border positions an extra 2 pixels inwards on each edge and then as CropMore.
# The non-exact coords try to center the coords when cropping for larger WMod/HMod's so as to evenly crop from eg both left and right instead of
# just one side. Also returned in the return string is the used Threshold, perhaps set by AutoThresh, as eg "QBCropThresh=32.0"
# You can use eg Eval(QueryBorderCrop()) to set values into QBCropX, QBCropY,QBCropW,QBCropH etc variables.
#
# Args:-
#
# Samples=24, Number of frames to sample from source clip c.
#
# Thresh= -32.0, Average luma value below or equal to which is considered possible black border, above considered possible image
#  (if 3 adjacent pixel rows/columns above Thresh, then taken as image).
#  A zero or negative value is 'AutoThresh', will prescan 'Samples' frames looking for minimum pixel luma value (but ignoring a percentage
#  of the darkest pixels, see Ignore) and set 'Thresh' to that value plus the negated AutoThresh value, ie defaults sets Thresh to minimum
#  found Y value + 32.0.
#  Auto cropping will likely fail on END CREDITS ONLY clips, where on black background, and will probably crop off the sides that are no
#  different in average luma to any letterbox borders, if you cannot see the borders, then neither can QueryBorderCrop(), even setting the
#  auto Thresh to eg -1.0 or 0.0 is quite likely to fail. (See RLBT edge bitflags).
#  v1.08, If 'samples' < 12 [samples would have been reduced if greater than framecount], and Thresh is not specified, then default
#     AutoThresh will be adjusted.
#        Thresh = -(((samples - 1) * (31.5/(12-1))) + 0.5)      # samples==1 comes out as -0.5 : samples==12 would come out at -32.0
#     So if eg single frame, would use an AutoThresh of -0.5
#     If RGB and user specified a PC matrix then AutoThresh would also be scaled up a little (by (255.0/(235-16)).
#     The adjustment to auto Thresh where samples < 12, is to reduce the possibility of overcropping on eg a dark single 'Samples' clip,
#     but could result in not cropping enough border, its a bit of a balancing act really.
#     As an observation, most clips have good border recogition within the 1st 2 sampled frames using the default -32 AutoThresh
#     although have noticed some dark clips that required ~8 samples (or more) for full recognition @ default Thresh = -32.
#     We use a default Samples=24, because we are intrinsically paranoid.
#     To speed up, you may want to leave Auto-Thresh alone and reduce samples, but there is danger that it will not detect all borders
#     (overcrop).
#     NOTE, The plugin AutoCrop() uses a Thresh of 40.0 and samples == 5 by default (No AutoThresh), but the logic is not too dissimilar. 
#   
# Laced=true, set true for Interlaced.  (Modifies defaults for YMod,HMod, explicit YMod/HMod will override).
#
# XMod, Default: Planar 2, YUY2=2, RGB=1
# YMod, Default: Planar=2, YUY2=1, RGB=1: BUT, Doubled if laced=true.
# WMod, Default: Planar=4, YUY2=2, RGB=1
# HMod, Default: Planar=2, YUY2=1, RGB=1: BUT, Doubled if laced=true.
#  The above XMod etc set rounding for the non-exact cropping coords.
#  The only real reason for default planar WMod=4 is VirtualDubMod dont like it less than that (Vdub latest, OK).
#
# Relative=false, False returns Width and Height, true returns Width/Height relative eg QBCropW=-6 QBCropH=-4.
#
# Prefix="QBCrop", string for returned variable names, only use valid variable name characters eg NO SPACES. Default returns eg "QBCropX".
#
# RLBT=15=All Borders, Bitflags of edges to crop, 15 ($0F) crops all four. Each letter in the name 'RLBT' represents an edge and bit position
#  starting with 'R' in bit 3 representing the value 8 (2^3=8). 'L' = bit 2=4 (2^2=4), 'B' = bit 1=2 (2^1=2), 'T' = bit 0=1 (2^0=1).
#  To calculate the RLBT bitflags, for 'R'(Right) add 8, for 'L'(Left) add 4, for 'B'(Bottom) add 2, and for 'T'(Top) add 1. 
#  Add all of the bit flags together 8+4+2+1 (=15) crops all four edges, 8+4 crops only Right & Left, and 2+1 crops only Bottom & Top.
#
# DEBUG=False=No Debug. Set True for debugging info, need DebugView: http://technet.microsoft.com/en-gb/sysinternals/bb545027
#
# Ignore=0.2, percentage of darkest pixels to ignore during Full image AutoThresh scan. 
#
# Matrix, For conversion of RGB to YUV-Y, 0 = Rec601, 1 = Rec709, 2 = PC601, 3 = PC709
#  Default for RGB is 2(PC601) if width <= 720 else 1(PC709) : YUV not used 
#  The defaults are for PC601 & PC709 range 0-255.
#  So as to not require different Thresh for RGB, if clip c is RGB and matrix is PC range, then Thresh will be scaled
#  to RGB full range ie Thresh = Thresh * (255.0/(235.0-16.0))
#
# If cropping too much border, then increase Samples or reduce Thresh 
# If not cropping enough border then border is being seen as image, increase Thresh.

The Bare Script Follows In next post