y4mtoppm(1) [suse man page]
y4mtoppm(1) MJPEG tools manual y4mtoppm(1) NAME
y4mtoppm - Convert YUV4MPEG2 stream to PPM images SYNOPSIS
y4mtoppm [options] DESCRIPTION
y4mtoppm converts a YUV4MPEG2 stream into a sequence of raw PPM images. Output is to stdout (but feel free to have the shell redirect to a file). Input is read from stdin, like all other YUV4MPEG2 filters and tools. YUV4MPEG2 streams contain frames using the Y'CbCr colorspace (ITU-R BT.601). y4mtoppm will convert each pixel to the usual R'G'B' colorspace used for computer graphics. YUV4MPEG2 streams may (often!) have subsampled chroma planes. y4mtoppm can upsample "4:2:0 JPEG" streams using a simple, lousy algorithm. Better results will be obtained using a filters such as y4mscaler(1) which are capable of general-purpose subsampling operations. y4mtoppm will fail on streams which have chroma subsampling modes other than 4:4:4 or 4:2:0-JPEG. For interlaced streams, these operations are performed on each field individually. Fields can be output as separate PPM images in time- order (default), or interleaved into full-frame images. If multiple PPM images are generated, they are simply output one after another. If you want to turn such a "multi-image" PPM stream/file into individual files, use pnmsplit. (Some PNM filters can process multi-image files/streams; however, many written before June 2000 will only process the first image.) y4mtoppm and ppmtoy4m are inverses of each other; you can pipe the output of one into the other, and vice-versa. Note that the colorspace (and subsampling) 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
y4mtoppm accepts the following options: -L For interlaced streams, output a single PPM image for each frame, containing two interleaved fields. (Otherwise, two PPM images will be generated for each frame; one per field.) -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 turn the first 15 frames of an (MJPEG or DV) AVI file into individual PPM files: lav2yuv -f 15 your-video.avi | y4mtoppm | pnmsplit - "your-video-%d.ppm" 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), pnm(5), ppmtoy4m(1), mjpegtools(1), mpeg2enc(1), lav2yuv(1), pnmsplit(1), y4mscaler(1) MJPEG Linux Square 28 April 2004 y4mtoppm(1)
Check Out this Related Man Page
pnmtoy4m(1) MJPEG tools manual pnmtoy4m(1) NAME
pnmtoy4m - Convert PNM/PAM images to YUV4MPEG2 stream SYNOPSIS
pnmtoy4m [options] [ filename ] DESCRIPTION
pnmtoy4m converts one or more raw PPM, PGM, PBM, or PAM images into a YUV4MPEG2 stream ready for further processing by other video tools. These three (or four) image formats are collectively referred to as "PNM images". 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 PNM image, read from stdin or from the optional filename. The input may contain multiple PNM images concatenated together; pnmtoy4m will read and process them sequentially. All images must have identical size and format. Input images can be inter- preted as whole progressive frames, pairs of interleaved fields, or as sequential fields (read in pairs of images) to be output as either interlaced or progressive frames. PPM and PGM images must have 8 bits per channel (i.e. 'maxval' must be 255). PPM input images should be in the usual R'G'B' colorspace. They are converted to the Y'CbCr colorspace (ITU-R BT.601) before being output to a "4:4:4" (non-subsampled) YUV4MPEG2 stream. If chroma subsampling is required (e.g. to 4:2:0 for MPEG), the output should be further piped through a program such as y4mscaler. PGM images should be in the standard full-range ([0,255]) grayscale colorspace. PGM and PBM images will be converted to BT.601 luma and output as "MONO" (luma-only) YUV4MPEG2 streams. The PAM format is a newer superset of the PNM formats; the precise contents of a PAM image is defined by the TUPLTYPE header tag. pnmtoy4m handles TUPLTYPE "GRAYSCALE" as PGM, "RGB" as PPM, and "RGB_ALPHA" as PPM with an 8-bit alpha channel. (The alpha channel is converted to BT.601 luma as is appropriate for YUV4MPEG2 streams.) pnmtoy4m and y4mtopnm are inverses of each other; you can pipe the output of one into the other, and vice-versa. Note that the colorspace operations are lossy in both directions. And, when converting to PNM, information on interlacing and sample aspect ratio is lost (but can be reconstructed by supplying command-line arguments to pnmtoy4m). OPTIONS
pnmtoy4m 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) -B Interpret data as being BGR rather than RGB. -r Repeat last input frame until output is complete. If '-n 0' is also specified, last input frame will be repeated forever. -D x Treat each PNM image as a single (de-interleaved) field instead of a full frame. The argument specifies the interpretation: t - the first image is a top-field b - the first image is a bottom-field With this option, two input images will be required per output frame. Be careful: mismatched "-I" and "-D" options can invert the temporal or spatial order of the fields (or both). -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 -I x Set the output interlacing mode, encoded in the output stream. (Default is to match "-D" if given, or 'p' if not.) p - progressive, non-interlaced t - top/upper-field-first interlaced b - bottom/lower-field-first interlaced -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: pnmtoy4m -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 | pnmtoy4m | yuvplay AUTHOR
This manual 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
pam(5), pbm(5), pgm(5), pnm(5), ppm(5), y4mtopnm(1), mjpegtools(1), mpeg2enc(1), y4mscaler(1), yuv2lav(1), yuvplay(1) MJPEG Linux Square 28 April 2004 pnmtoy4m(1)