Swap Filters

Set of filters to combine, extract and manipulate the order of channels in YUV(A) clips:

• SwapUV swaps the order of the U/V channels.

• UToY / VToY copies the U/V channel onto the Y (luma) channel and keeps the same color format.

• UToY8 / VToY8 extract the U/V chroma channel to a Y-only greyscale clip.

• YToUV combines individual YUV(A) planes into a new YUV(A) clip.

These filters provide similar functionality to the CombinePlanes, Extract and ShowU/V filters.

SwapUV

Swaps the U and V (chroma) channels. Corrects certain decoding errors – faces blue instead of red, etc.

Syntax and Parameters

SwapUV (clip)

clip

Source clip. All YUV(A) color formats supported.

UToY / VToY

UToY and VToY copy the U or V chroma plane to the Y luma plane and keeps the same color format as the source clip. All color (chroma) information is removed and set to neutral (greyscale). Depending on the color format, the image resolution can be changed – i.e.,

• with a YUV444 source, the output clip will be the same width and height as input clip, but

• with a YUV420 source, the output clip will be half the input clip's width and height.

Syntax and Parameters

UToY (clip)
VToY (clip)

clip

Source clip; all YUV(A) color formats supported.

UToY8 / VToY8

UToY8 and VToY8 extract the U or V chroma channel to a Y-only greyscale clip. Despite the names, all bit depths are supported. Resulting clip will be Y8, Y10 etc. as appropriate.

Syntax and Parameters

UToY8 (clip)
VToY8 (clip)

clip

Source clip; all YUV(A) color formats supported.

YToUV

YToUV combines up to 4 independent clips to create a new YUV(A) clip. The Y channel of each of the supplied clips are then copied onto the respective channel of the output clip. Note that all of the parameters are unnamed, however, only the first two clips are mandatory. Only Y or YUV(A) color formats are accepted.

Syntax and Parameters

YToUV (clip clipU, clip clipV, clip clipY, clip clipA)

clipU, clipV

Source clips; dimensions of both clips must be identical.

The first clip is used for the U channel and the second clip for the V channel.

clipU determines the color format of the output clip unless clipY is defined.

clipY

Source clip; If clipY is given, the Y channel is copied onto the Y channel of the output clip. The dimensions of this clip determines the color format of the output clip, for example:

• If the width and height of clipY are the same as the U/V channels, the output clip will be YUV444.

• If the width and height of clipY are double the size of the U/V channels, the output clip will be YUV420.

• Due to chroma subsampling restrictions, some dimensions are not compatible with YUV420 and YUV422 color formats.

If clipY is not given, the Y channel of the output clip will be set to grey (0x7e).

clipA

Source clip; if clipA is given, the Y channel is copied onto the A channel of the output clip. Dimensions must be identical to clipY.

Examples

Blur the U and V chroma channels different amounts:

video = ColorBars(512, 512, pixel_type="YUV420P8")
u = UToY8(video).Blur(1.5)
v = VToY8(video).Blur(0.5)
YtoUV(u, v, video)

Show U and V channels stacked side by side for illustration purposes.

• Note that with a YUV420 source (like the image below), the U and V images will be half the size of the original.

• In the U and V images, grey will be "neutral" (for example, 128 for 8-bit) and saturated colors will appear brighter or darker.

swap-peppers.jpg

src = FFImageSource("swap-peppers.jpg") srcU = src.UToY().Subtitle("UtoY", align=2) srcV = src.VToY().Subtitle("VtoY", align=2) srcUV = StackHorizontal(srcU, srcV) StackVertical(src, srcUV)

Changelog

Version	Changes
AviSynth+ r2487	Added parameter clipA to YToUV. Added YUVA support to SwapUV. Added support for 10-16 bits and float.
AviSynth 2.6.0	Added UToY8 and VToY8. Added support for Y8, YV411, YV16, YV24.
AviSynth 2.5.3	Added support for YUY2.
AviSynth 2.5.1	Added parameter clipY to YToUV.
AviSynth 2.5.0	Added UToY, VToY, YToUV.

$Date: 2022/09/17 14:12:41 $