png2yuv(1)							MJPEG tools manual							png2yuv(1)

NAME

       png2yuv - Convert PNG images to the YUV4MPEG stream format.

SYNOPSIS

       png2yuv [-b num] [-f num] [-I num] [-L num] [-n num] [-l num] [-j filename]

DESCRIPTION

       png2yuv decompresses a sequence of PNG files and pipes the image data to stdout as a YUV4MPEG2 stream.  Any 8bit/pixel PNG format supported
       by libpng can be read.  stdout will be filled with the YUV4MPEG movie data stream, so be prepared to pipe it on to mpeg2enc or to write	it
       into a file.

       This tool is incomplete.  The alternative utility you are probably looking for is ppmtoy4m(1), which is also included in MJPEGtools.

OPTIONS

       png2yuv accepts the following options:

       -b num
	    Frame offset:  skip output of the first 'num' frames.  (default: 0)

       -f num
	    Set the frame rate of stream accepts the same numbers. Not default, this option has to be specified.

       -I num
	    interlacing mode: p = none / progressive
	    t = top field first
	    b = bottom field first
	    No default, this option has to be specified.

       -L num
	    0 = non-interleaved (two successive fields per PNG file)
	    1 = interleaved fields

       -l num
	    Specifies the number of loops (default: 0 loops )

       -S samp_mode
	    chroma subsampling mode, only for professionals, for more info see ppmtoy4m and the YUV guide on http://www.mir.com/DMG/.
	    default: 420_jpeg
	    When  this	option	is not used the given range of images is only processed once. If you use this option and as number 1, jpeg2yv will
	    loop forever writing the image to stdout. When you use n > 1 it will loop. n-time till it finishes.

       -n num
	    Specifies the nummber of frames to process. (default: all = -1)

       -j {1}%{2}d{3}
	    Read PNG frames with the name components as follows:
	     {1} PNG filename prefix (e g: picture_ )
	     {2} Counting placeholder (like in C, printf, eg 06 ))
	     {3} File extension. Something like this: .png A correct description of the files could look like this: picture_%06d.png

       -v num
	    Verbosity level (0, 1 or 2)

BUGS

       The frame rate description does not seem to be up to date. The NTSC integer ratios are not supported (use floating point instead). As work-
       around  specify	a  PAL	(25)  or native FILM (24) and set the right frame rate in mpeg2enc with the -F option.	Interlaced handling is not
       implemented yet.

AUTHOR

       This man page was written by Gernot Ziegler.
       If you have questions, remarks, problems or you just want to contact the developers, the main mailing list for the MJPEG-tools is:
	 mjpeg-users@lists.sourceforge.net

       For more info, see our website at
	      http://mjpeg.sourceforge.net

SEE ALSO

       mjpegtools(1), mpeg2enc(1), ppmtoy4m(1), yuv2lav(1), yuvdenoise(1), yuvmedianfilter(1), yuvscaler(1)

MJPEG Linux Square						  2 February 2003							png2yuv(1)