Blind And ImageMagick

[cheznewa]

Hello, is possible to add command blind-imagemagick for run convert imagemagick for each frames. for example ::::::::::: blind-imagemagick -colorspace gray for each frames is :::::::: convert framesSTDIn -colorspace gray frameSTDOut

[maandree]

You can already accomplish this using a loop and already provided tools, and you can use any external command and easily create pipelines. I don't like having commands that are specific to specific external commands, if a tool for running an external command would be added, and I currently don't thing it is a good idea, it should allow you to specify the external command.

You could implement blind-imagemagick as (with reservations for errors):

#!/bin/bash -e
# ksh may also work
read nframes width height pixfmt < <(blind-read-head)
blind-write-head $nframes $width $height $pixfmt
while { set +e; blind-next-frame $width $height $pixfmt;
                status=$?;
        set -e; } | \
      blind-to-image | \
      imagemagick "$@" | \
      blind-from-image -h -p; \
      test $status = 0; do
          :;
done # (-p for `blind-from-image` is optional)
test $status = 1

[cheznewa]

Thanks, I just modify convert pam:- $@ pam:- In Line 9 But Show Two Error :::::::::: blind-imagemagick: ligne 11 : test: = : opérateur unaire attendu blind-imagemagick: ligne 14 : test: = : opérateur unaire attendu

[maandree]

Ok, new attempt:

#!/bin/bash -e
# ksh does not work
read nframes width height pixfmt < <(blind-read-head)
blind-write-head $nframes $width $height $pixfmt
while blind-next-frame $width $height $pixfmt | \
      blind-to-image | \
      convert pam:- "$@" pam:- | \
      blind-from-image -h -p; \
      status=( ${PIPESTATUS[@]} );
      test ${status[0]} = 0; do
          test ${status[1]} = 0;
          test ${status[2]} = 0;
          test ${status[3]} = 0;
          test ${status[4]} = 0;
done # (-p for `blind-from-image` is optional)
test ${status[0]} = 1

A cosmetic imperfection here is that the commands will fail when blind-next-frame says that there are no more frames. This can be solved if you have an implementation of ifne that can peeks the input file (uses tee for pipes, MSG_PEEK for sockets, stat/pread for regular files):

#!/bin/bash -e
# ksh also works
set -o pipefail
read nframes width height pixfmt < <(blind-read-head)
blind-write-head $nframes $width $height $pixfmt
while ifne -n false; do
    blind-next-frame $width $height $pixfmt | \
    blind-to-image | \
    convert pam:- "$@" pam:- | \
    blind-from-image -h -p # (-p is optional)
    test $? = 0 # not needed if using bash
done

(It is not possible to just run the loop $nframes times, as $nframes may be 0. Tools should not depend on the value unless absolutely necessary, as it is not always set because it can be too costly.)

[cheznewa]

I A Problem! I Good You Post My Script But :::::::::::::: blind-from-video without -L Option Input And Output Dont Out The Header File, So The Command blind-read-head Show An Error