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Re: This is fun!
>
> Made some changes to Scott's qcam.c, and I believe Scott will have a lot
> of fun with people sending him patches to do various things.
>
> PGM files don't have to be greyscaled to 255 levels, so that cuts out a
> lot of multiplication... just output 15 or 63 for greyscale levels.
>
I tried it at first, and I had a lot of problems to I scaled it to 255,
just to be safe. It appears my problems were elsewhere in the code, so
I'll change it back. Thanks, you probably bumped the speed up a few
more percent.
> Secondly... I cloned qc_writepgm() and made a qc_writepgm_p5, the
> RAWBITS format of PGM. xv seems to like the files so I'll post the
> function here. If anything, the disk space used by PGM files is cut by
> quite a bit.
>
> Heat of the hack... I feel good. This is so much fun. Makes the camera
> useful again.
>
> void qc_writepgm_p5(FILE *f,unsigned char *scan,int x, int y, int bpp)
[snip]
Ooh, *bad* timing :-). I just finished changing my qc_writepgm routine
so it always uses raw PGM, and as soon as I finish, yours shows up in
my mailbox. The reason I changed mine: qc_writepgm was using 60% of
the CPU time in the entire program. This is after I discovered that
usleep(1) takes over 1000 times as long as usleep(0) and fixed my
timing loops. I'll release a new version of my program later tonight
that *should* be ~4 times as fast as the last version. I hope to have
a few more features as well, but I'll have to see what I can get done
in the next hour or two.
Scott.
References: