24 lines
1.2 KiB
Text
24 lines
1.2 KiB
Text
From y4msclaer(1):
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y4mscaler is a general-purpose video scaler which operates on YUV4MPEG2
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streams, as produced and consumed by the MJPEGtools such as lav2yuv and
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mpeg2enc(1).
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y4mscaler is meant to be used in a pipeline. Thus, input is from stdin, and
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output is to stdout. The essential function of y4mscaler is to scale a
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specified "active" region of the input stream (the source) into a specified
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active region of the output stream (the target). Pixels outside of the active
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region of the source are ignored; pixels outside of the active region of
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the target are filled with a background color. The source may additionally
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have a matte applied to it; pixels outside the source matte are set to a
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separately specified background color.
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y4mscaler correctly handles chroma sampling, and thus it can also perform
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chroma subsampling conversions. The YUV4MPEG2 stream format currently only
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supports 4:2:0 subsampling, although y4mscaler can process 4:1:1, 4:2:2, and
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4:4:4 modes by abusing the YUV4MPEG2 format a bit.
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Includes preset parameters for popular output streams: DVD, SVCD, VCD, DV,
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CVD, and SVCD/VCD still images.
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WWW: http://www.mir.com/DMG/Software/y4mscaler.html
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