pgmtoy4m.1

Motion JPEG编解码器源代码

.TH "pgmtoy4m" "1" "16 December 2003" "MJPEG Linux Square" "MJPEG tools manual"
.SH "NAME"
pgmtoy4m \- Convert mpeg2dec pgm and pgmpipe output to YUV4MPEG2
.SH "SYNOPSIS"
.B pgmtoy4m
.RI [ options ]
.SH "DESCRIPTION"
\fBpgmtoy4m\fP repacks the PGM output from \fBmpeg2dec\fP 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.
.SH "OPTIONS"
\fBpgmtoy4m\fP accepts the following options:
.TP 5
.BI \-v " num"
Set verbosity level.
(default: 0)
.TP 5 
.BI \-h
Print a usage summary and exit.
.TP 5
.BI \-i " t|b|p"
Set the interlacing mode.  Top field first (t), bottom field first (b) or 
progressive/none (p).
(default: t)
.TP 5
.BI \-a " sar"
Set the sample aspect ratio.  
(default: 10:11)
.TP 5
.BI \-r " frame rate"
Set the frame rate.
(default: 30000:1001)
.SH "EXAMPLES"
.nf
mpeg2dec -s -o pgmpipe file.mpg | pgmtoy4m -a 10:11 -r 24000:1001 -i b | yuvplay
.sp
mpeg2dec -s -o pgm file.mpg
cat *.pgm | pgmtoy4m -r 30000:1001 -i t | yuvplay
.fi
.SH "NOTES"
This program is specifically designed to work with the output of mpeg2dec
and is \fBNOT\fP a general PGM (NetPBM) tool!
.sp
From the introduction in the source file:
.sp
.nf
 * 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!
.fi
.SH "AUTHOR"
This manpage was written by Steven Schultz (sms at 2bsd dot com).
.SH "BUGS"
Possible but none known at the present time.