pgmtoy4m

Section: MJPEG tools manual (1)
Updated: 16 December 2003
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NAME

pgmtoy4m - Convert mpeg2dec pgm and pgmpipe output to YUV4MPEG2

SYNOPSIS

pgmtoy4m [options]

DESCRIPTION

pgmtoy4m repacks the PGM output from mpeg2dec into YUV4MPEG2 4:2:0p. No actual changes to the data are made. The data is unpacked from the quasi-PGM format and placed in YUV4MPEG2 format with the specified sample aspect, frame rate and field order. Output must be either to a pipe or a file, leaving stdout as a terminal will elicit an error and the program will exit.

OPTIONS

pgmtoy4m accepts the following options:

-v num: Set verbosity level. (default: 0)
-h: Print a usage summary and exit.
-i t|b|p: Set the interlacing mode. Top field first (t), bottom field first (b) or progressive/none (p). (default: t)
-a sar: Set the sample aspect ratio. (default: 10:11)
-r frame rate: Set the frame rate. (default: 30000:1001)

EXAMPLES

mpeg2dec -s -o pgmpipe file.mpg | pgmtoy4m -a 10:11 -r 24000:1001 -i b | yuvplay

mpeg2dec -s -o pgm file.mpg
cat *.pgm | pgmtoy4m -r 30000:1001 -i t | yuvplay

NOTES

This program is specifically designed to work with the output of mpeg2dec and is NOT a general PGM (NetPBM) tool!

From the introduction in the source file:

 * Note: mpeg2dec uses a variation of the PGM format - they're really not
 * "Grey Maps" but rather a catenation of the 420P data (commonly called
 * "YUV").    The type is P5 ("raw") and the number of rows is really
 * the total of the Y', Cb and Cr heights.   The Cb and Cr data is "joined"
 * together.  After the Y' rows you have 1 row of Cb and 1 row of Cr per 
 * "row" of PGM data.

 * NOTE: You MAY need to know the field order (top/bottom field first),
 *      sample aspect ratio and frame rate because the PGM format makes
 *      none of that information available!

AUTHOR

This manpage was written by Steven Schultz (sms at 2bsd dot com).

BUGS

Possible but none known at the present time.