Re: [Mjpeg-developer] Re: [ mjpeg-Bugs-1214521 ] ppmtoy4m seems broken in 1.6.3-rc1

[Matto M. <ma...@mi...>]

 >>>     ppmmake white 1024 768 | ppmtoy4m | yuvscaler -n
 >>>ntsc -O DVD
 >>>
 >>>fails in 1.6.3-rc1.  Using the 1.6.2 ppmtoy4m fixes the
...
 >> The ppmtoy4m manpage says:
 >> 
 >>        ppmtoy4m  converts  one  or more raw PPM images into a YUV4MPEG2 stream
 >>        ready for further processing by other video tools.
 >
 >The manpage should also tell you about the default yuv croma format 
 >(4:4:4). And I tried to tell you that.

The default has indeed changed.  Other defaults in other tools have probably
 changed, too --- and the underlying stream format and library has significant
 changes (even though it has mostly retained backwards-compatibility).

The "1.6.3" number is a bit confusing in that regard --- the actual release
 should be something like "1.8.0" (> 1.6, and 'even' for what that's worth),
 and maybe these RC's should be 1.7's (since CVS is permanently "1.7.0"?).

Anyhow, we should cobble together a "1.8 Release Notes" that summarizes
 such changes to defaults and what-not.  If we do, we'll be rewarded with
 everlasting love and bug-reports from the eight other people who use this
 stuff.  (If not, we'll just get the bug-reports.)

 >The error message of yuvscaler is a bit missleading.
 >
 >> Am I wrong?  Is there a more "supported" way to do this that won't
 >> break under 1.6.3?
 >Just tell ppmtoy4m to create 4:2:0 subsampling instead auf the default 
 >4:4:4. (-S option)

I was actually intending to remove 'ppmtoy4m' in favor of 'pnmtoy4m',
 which handles more input types, but only produces 4:4:4 output.  The
 little subsampling routine used by ppmtoy4m is mediocre (although,
 it may not be so very bad after all; I'm poking around with this
 stuff again).

-m

PS:  My big kvetch with that bug-report was that it contained none of the
      copious information and debugging output produced the tools --- which
      would have allowed any one of the developers to diagnose the problem
      instantly without ever touching a command-line.