ppm2raw (1)


       ppm2raw - Convert a PPM pipe to a Raw DV stream


       ppm2raw [ options ]


       ppm2raw converts a PPM to a Raw DV stream.


       -n     NTSC output required.

       -a     Maintain aspect ratio on images following.

       -s     Scale  following  images  to  the full frame size, regardless of
              aspect ratio

       -k     Keep the image unscaled - centre and crop  output  as  necessary

       -w     Wide screen output (default: off).

       -p number
              Number  of encoder passes (default is 3 and afiact, other values
              are ignored - not sure if this is a bug in smil utils or libdv).

       -q qno Another  funky  encoder  related  param which doesn't seem to do

       -q number
              Number of encoder passes.

       -b colour
              Use the colour triple for backgrounds - default is 000000.  For-
              mat  must  be  a  hex  string representing red, green, blue. For
              example, ffffff would be white.

       -A wav Use the wav to dub the output. The wav file must contain stereo,
              16 bit samples at a frequency of 32khz, 44.1khz or 48khz.

       -2     Two pass encoding (default: off).

       Help Options

       --help Show help message.


       ppm2raw  needs  a  PPM input provided on stdin. Fortunately, many tools
       generate PPM on stdout.

       For example, to re-encode any ffmpeg compatible file or  stream  format
       to  a  PAL  Raw  DV  stream  which rescales the images according to the
       aspect ratio of the input using the following command:

       ffmpeg -i 'some-file' -f ppmpipe - |
       rawmutiltiply command:

       ffmpeg -i 'some-file' -f ppmpipe - |
       rawmultiply 1.666 |
       ppm2raw -a > file.dv

       This  then  gives  us  our  25 frames per second (assuming the original
       input was a 25 fps PAL video which was  encoded  using  3:2  dropdown).
       Knowing  when  to  do  this  is not always easy, but you will find that
       issues in this area come to the fore when you add audio into the mix...

       So,  lets  assume we have an mpeg which has a high quality audio track,
       3:2 dropdown for images and we want to encode that to DV:

       ffmpeg -i 'some-file' -f ppmpipe - output.wav |
       rawmultiply 1.666 -A output.wav |
       ppm2raw -a > file.dv

       Now, the audio from the input is added to our output.

       This works, assuming the audio extracted by ffmpeg is a compatible for-
       mat  for DV (or more specifically, libdv).  Currently, smilutils simply
       rejects incompatible audio.  So if you have problems there, extract the
       wav  separately  (via  ffmpeg or some other tool) and sox or some other
       tool to resample to something DV compatible (stereo, 16 bit samples  of
       32khz, 44.1khz or 48khz). For example:

       ffmpeg -i 'some-file' input.wav
       sox input.wav -r 44100 output.wav
       ffmpeg -i 'some-file' -f ppmpipe - |
       rawmultiply 1.666 -A output.wav |
       ppm2raw -a > file.dv

       Many,  many tools have adopted the highly sensible mjpeg tools yuv for-
       mat for output, and mjpeg tools themselves have provided a highly  sen-
       sible y4mtoppm utility, so you can use a pipe like this to encode mjpeg
       yuv streams:

       lav2wav -o output.wav
       lav2yuv 'lav-input' |
       y4mtoppm |
       ppm2raw -a -A output.wav > file.dv

       Obviously, any of the yuv tools (yuvscaler, yuvdenoise, yuvcorrect etc)
       can be placed prior to the y4mtoppm command.

       Note that the -A switch is used on the ppm2raw tool this time, and raw-
       multiply isn't shown.




       See http://kino.schirmacher.de/ for the latest version.


       ppm2raw was written by Charles Yates <charles.yates@pandora.be>.