MJPEG Tools Svn

Check-point prior to final merge of HEAD changes

Little bug fix (missing 'break;'), and more diagnostics.

Saw the new pnmtoy4m and y4mtopnm manpages and program - but noticed the
manpages weren't installed. Couldn't wait so I added them to the Makefile.am :)

(A little code-scrubbing.)

X64 support at the top autoconf level - need to have -fno-PIC and not use nasm.

Change ARCH_X86_64 with __LP64__ which is defined by gcc when compiling in
64bit mode (thanks to Gert Vervoort for all the AMD64 updates!)

update amd64 cpu detection.

o Add "Y channel only" colorspace conversion functions.

o Add two new filters, with documentation: y4mtopnm and pnmtoy4m.

These are intended to (eventually) replace y4mtoppm and ppmtoy4m.
The first handles 444, MONO, and 444ALPHA YUV4MPEG2 streams, and
produces PPM, PGM, and PAM output images. The second does the
inverse.
(These do not handle 4:2:0 input; the [super/sub]sampling of
y4mtoppm and ppmtoy4m was always lousy to begin with. It's a
job better done by, say, a scaler.)

Set-up yuvplay to use the 'new, enhanced' features of YUV4MPEG2 streams.

It still can only display 4:2:0 streams. Anything else will require
more real hacking. (Why doesn't Xv/SDL support any other kind of overlay
mode? I'm sure the graphics card's hardware scalers can handle all kinds
of factors. Perhaps no one in the Xv camp has realized the need?)

o Fix two little bugs involving "spatial sampling mode".
o Break out data-only versions of read/write frame/fields functions
(which are useful when how one accesses a frame is predicated on
what the format of the frame is --- i.e. mixed-mode streams).