pgmtoy4m(1) MJPEG tools manual pgmtoy4m(1)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.
MJPEG Linux Square 16 December 2003 pgmtoy4m(1)
Check Out this Related Man Page
ppmtoy4m(1) MJPEG tools manual ppmtoy4m(1)NAME
ppmtoy4m - Convert PPM images to YUV4MPEG2 stream
SYNOPSIS
ppmtoy4m [options] [ filename ]
DESCRIPTION
ppmtoy4m converts one or more raw PPM images into a YUV4MPEG2 stream ready for further processing by other video tools.
Output is to stdout to facilitate piping to other MJPEG tools. The size of the output frame(s) is determined from the (first) input image.
Input is a 'raw' format PPM image, read from stdin or from the optional filename. The input may contain multiple PPM images concatenated
together; ppmtoy4m will read and process them sequentially. All images must have identical size and format. Input images can be inter-
preted as whole progressive frames, interleaved fields, or (in pairs) as sequential fields. The input images must have 8 bits per channel
(i.e. 'maxval' must be 255).
Input images should be in the usual R'G'B' colorspace. They are converted to the Y'CbCr colorspace (ITU-R BT.601) (and chroma subsampled,
if desired) before output.
ppmtoy4m and y4mtoppm are inverses of each other; you can pipe the output of one into the other, and vice-versa. Note that the subsampling
and colorspace operations are lossy in both directions. And, when converting to PPM, information on interlacing and sample aspect ratio is
lost (but can be reconstructed by supplying command-line arguments to ppmtoy4m).
OPTIONS
ppmtoy4m accepts the following options:
-o num
Frame offset: skip output of the first 'num' frames. (default: 0)
-n num
Output a total of 'num' output frames. Use '0' to specify all frames. (default: 0)
-F n:d
Set framerate encoded in output stream, as an exact integer ratio. (default: 30000:1001) Common rates are:
24000:1001 - NTSC 3:2 pulldown converted film
24:1 - native film
25:1 - PAL/SECAM
30000:1001 - NTSC video
50:1 - PAL field rate
60000:1001 - NTSC field rate
-A n:d
Set pixel aspect ratio encoded in output stream, as an exact integer ratio. (default: 1:1) Common ratios are:
1:1 - square pixels (computer graphics)
10:11 - CCIR-601 NTSC
59:54 - CCIR-601 PAL
-B Interpret data as being BGR rather than RGB.
-I x Set interlacing mode, used to interpret the PPM image(s), and also encoded in output stream. (default: 'p')
p - progressive, non-interlaced
t - top/upper-field-first interlaced
b - bottom/lower-field-first interlaced
-L For interlaced streams, treat each PPM image as two interleaved fields. (Otherwise, two PPM images will be read for each frame; one
per field.)
-r Repeat last input frame until output is complete. If '-n 0' is also specified, last input frame will be repeated forever.
-S mode
Set chroma subsampling mode. (default: 444)
444 - 4:4:4 (no subsampling)
420jpeg - 4:2:0 JPEG/MPEG-1, interstitial cositing
420mpeg2 - 4:2:0 MPEG-2, horizontal cositing
The subsampled modes use a lousy subsampling filter; better results will be achieved by passing the default 4:4:4 output to a scaler
which supports subsampling, such as y4mscaler(1).
-v [0,1,2]
Set verbosity level.
0 = warnings and errors only.
1 = add informative messages, too.
2 = add chatty debugging message, too.
EXAMPLES
To convert a file containing a single PPM file into a stream of 15 (identical) frames:
ppmtoy4m -n 15 -r some-image.ppm
To convert a series of Targa format images (in the current directory) to a YUV4MPEG2 stream displayed by yuvplay:
ls *.tga | xargs -n1 tgatoppm | ppmtoy4m | yuvplay
AUTHOR
This man page was written by Matt Marjanovic.
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 ppm(5), y4mtoppm(1), mjpegtools(1), mpeg2enc(1), y4mscaler(1), yuv2lav(1), yuvplay(1)MJPEG Linux Square 28 April 2004 ppmtoy4m(1)