Ubuntu Manpage: yuvscaler - UPscales or DOWNscales a YUV4MPEG2 stream to a specified format

Provided by: mjpegtools_2.1.0+debian-6build1_amd64

NAME

       yuvscaler - UPscales or DOWNscales a YUV4MPEG2 stream to a specified format

SYNOPSIS

       yuvscaler [-I input_keyword] [-M mode_keyword] [-O output_keyword] [-n p|s|n] [-v 0-2] [-h]

DESCRIPTION

       yuvscaler  is  a  general  (UP  or  DOWN)  scaling  utility  that is provided to allow conversion between
       different video formats. It reads in a YUV4MPEG2 format stream from  stdin  (such  as  that  produced  by
       lav2yuv)  and  outputs  such  stream to stdout (e.g. to be consumed by mpeg2enc).  The most common use of
       yuvscaler is to generate input suitable for MPEG encoding to VCD or SVCD formats using mpeg2enc(1).

       yuvscaler will automatically take into account PAL/SECAM and NTSC format, as well  as  widescreen  (16:9)
       format and interlacing. Use of yuvscaler was designed to be straightforward.

EXAMPLES

       VCD encoding:
       lav2yuv my-file.avi | yuvscaler -O VCD | mpeg2enc -f 1 -o vcd.%d.m1v

       SVCD encoding:
       lav2yuv my-file.qt | yuvscaler -O SVCD | mpeg2enc -f 4 -o svcd.%d.m2v

       Encoding anamorphic 16:9 as letterboxed VCD:
       lav2yuv my-ana16-9.eli | yuvscaler -M WIDE2VCD | mpeg2enc -f 1 -o letterbox_vcd.%d.m1v

       Encoding anamorphic 16:9 as letterboxed SVCD:
       lav2yuv my-ana16-9.eli | yuvscaler -M WIDE2STD -O SVCD | mpeg2enc -f 4 -o letterbox_svcd.%d.m2v

       Encoding anamorphic 16:9 as letterboxed DVD:
       lav2yuv my-ana16-9.eli | yuvscaler -M WIDE2STD -O DVD | mpeg2enc -f 8 -o letterbox_dvd.%d.m2v

OPTIONS

-I input_keyword

Specifies input processing options. Input options may be combined by using multiple -I flags.
Possible input_keywords are:

USE_WidthxHeight+WidthOffset+HeightOffset to select a useful area of the input frame (all multiple
of 2, Height and HeightOffset multiple of 4 if interlaced), the rest of the image being discarded

ACTIVE_WidthxHeight+WidthOffset+HeightOffset to select an active area of the input frame (all
multiple of 2, Height and HeightOffset multiple of 4 if interlaced), the rest of the image being
made black

-M mode_keyword

Sets the scaling mode options. Scaling mode options can be combined by giving several -M flags.
Possible are:

BICUBIC - to use the (Mitchell-Netravalli) high-quality bicubic upsacling and/or downscaling
algorithm

RESAMPLE - to use a classical resampling algorithm -only for downscaling- that goes much faster
than bicubic. For coherence reason, yuvscaler will use RESAMPLE if only downscaling is necessary,
BICUBIC if not.

WIDE2STD - convert widescreen anamorphic (16:9) input video into letterboxed (4:3), generating
necessary black lines. Note that for MPEG applications if your player can properly decode
anamorphic video you may wish to leave the video unscaled and simply specify the approprate format
during MPEG encoding (see mpeg2enc(1)).

RATIO_WidthIn_WidthOut_HeightIn_HeightOut to specified scaling ratios of WidthIn/WidthOut for
width and HeightIN/HeightOut for height to be applied to the useful area. The output frames that
result from scaling can have a different format than the output format specified using -O
options(s). In this case, yuvscaler automatically generate necessary black lines and columns
and/or skips necessary lines and columns to center the scaled image in the output frame.

WIDE2VCD to scale anamorphic widescreen (16:9) frames into letterboxed VCD format (equivalent to
-M WIDE2STD -O VCD).

FASTVCD to transcode full sized frames to VCD (equivalent to -M RATIO_2_1_2_1 -O VCD, see below).

FAST_WIDE2VCD to transcode full-sized anamorphic (16:9) frames to letter-boxed VCD (equivalent to
-M WIDE2STD -M RATIO_2_1_2_1 -O VCD, see below).

NO_HEADER to suppress stream header generation on output

MMX to use MMX functions for BICUBIC scaling (experimental feature!!)

-O output_keyword

Sets the output frame format options. Output format options can be combined by giving several -O
flags. By default, output frames size will be the same as input frame sizes, as well as output
frames interlacing if coherent with output keyword specification which prevails, top_first if not.

MONOCHROME to generate monochrome frames on output. Chrominance information for the scaled pixels
is set neutral (white). MPEG encoding of black and white video will be both inefficient and show
annonying chrominance artifacts unless this is done.

VCD to generate VCD compliant frames on output (taking care of PAL and NTSC standards). Non-
interlaced output.

SVCD to generate SVCD compliant frames on output (taking care of PAL and NTSC standards). Top-
field-first interlaced frames.

DVD to generate DVD compliant frames on output (taking care of PAL and NTSC standards). Top-field-
first interlaced frames.

SIZE_WidthxHeight to generate frames of size WidthxHeight on output (multiple of 4)

If VCD, SVCD or DVD keywords are not used, output interlacing is taken of the same type as input.
By default, output frames size will be the same as input frame size.

-n p|s|n
(usually not necessary) if norm could not be determined from data flux, specifies the OUTPUT norm
for VCD/SVCD (p=pal,s=secam,n=ntsc).

-v 0|1|2
Specifies the degree of verbosity: 0=quiet, 1=normal, 2=verbose/debug

-h Prints a summary of command line syntax.

Note: The most useful downscaling ratios are handled using dedicated optimised scaling routines. They
are:

RATIO_WidthIn_WidthOut_2_1 => Full-sized frame to VCD downscaling

RATIO_3_2_1_1 => Full-sized frame to SVCD downscaling

RATIO_1_1_4_3 => WIDE2STD downscaling mode

RATIO_WidthIn_WidthOut_1_1 => downscaling only concerns width, not height

RATIO_1_1_HeightIn_HeightOut => downscaling only concerns height, not width

RATIO_2_1_2_1 => FASTVCD, slightly width distorted (real ratio 45 to 22) but faster full-sized
frame to VCD downscaling (-M RATIO_2_1_2_1 -O VCD)

RATIO_WidthIn_WidthOut_8_3 => specific to WIDE2VCD downscaling (-M WIDE2STD -O VCD)

RATIO_2_1_8_3 => specific to (slighly distorted) FAST_WIDE2VCD downscaling (-M WIDE2STD -M
RATIO_2_1_2_1 -O VCD)

RATIO_1_1_1_1 => copy useful input part of possible several files into output frames

AUTHOR