SkewRows

SkewRows(clip clip, int skew)

SkewRows (added in v2.60) skews the rows of a clip by an amount of skew. The skewing is memory layout based, so RGB images are skewed from the bottom up, YUV images are skewed from the top down.

It can be used to read those skewed error messages that some media player users are submitting.

The effect of the algorithm is to paste all of the input rows together as one single very long row, then slice them up based on the new width (= input width + skew). Skew can also be negative in which case the last skew pixels of each line are added to the beginning of the next line and you get some extra lines at the end. The last line is padded with grey pixels when required.

The geometry of the output is calculated as follows:

• OutWidth = InWidth + skew // signed skew values acceptable
• OutHeight = (InHeight*InWidth + OutWidth-1) / OutWidth // rounded up to nearest integer

All interleaved pixel formats are supported (including Y8), though skew should be even for YUY2.

examples:

Original	SkewRows(1)

changelog:

v2.60

Initial release