MJPEG Tools Svn

patch from Nicolas Boos

Er, "y4m_accept_extensions()" is not "y4m_feature_level()".

A rose by any other name... generates a linker error.

Fixed ridiculously dumb cut'n'paste error in y4m_si_get_plane_height().
(Thank you, Steven Schultz, you must have gotten more sleep than me.)

Remove compile warning error:
yuvinactive.c:229: warning: no previous prototype for `copy_area'

Use new YUV4MPEG2 y4m_si_set_chroma instead of unofficial 'XYSCSS' tag.

Use the new YUV4MPEG2 API to set the chroma using y4m_si_set_chroma instead of
the unofficial 'XYSCSS' tag.

Get rid of the warning errors:
blend_fields.c:17: warning: no previous prototype for `blend_fields_non_accel'
copy_frame.c:9: warning: no previous prototype for `copy_frame'
interleave.c:10: warning: no previous prototype for `interleave_fields'
main.c:343: warning: no previous prototype for `subsample_frame'
main.c:366: warning: no previous prototype for `search_forward_vector'
main.c:392: warning: no previous prototype for `search_backward_vector'
sinc_interpolation.c:10: warning: no previous prototype for `sinc_interpolation'
transform_block.c:8: warning: no previous prototype for `transform_block_Y'
transform_block.c:27: warning: no previous prototype for `transform_block_UV'

yuv4mpeg2 API changed. Will rewrite this later to use the new enhanced
chroma tags, but for now just get it to build.

New y4m API changes.

This check-in extends the YUV4MPEG2 format to explicitly encode the
type of color subsampling and to allow non-4:2:0 modes. It also
adds a frame header tag so that streams can describe mixed-framing
modes, such as 3:2 pulldown. As before, the stream format is
documented in the yuv4mpeg(5) manpage.

Older code will (for the most part) compile just as before, and these
new extended features will be disabled/disallowed by default. This
default assumes uniform framing (progressive, top-first, or bottom-
-first interlacing throughout) and 4:2:0-JPEG subsampled data. If
the library reads a stream/frame header which goes beyond this default,
it will return a new error to the caller, Y4M_ERR_FEATURE.

The extended API adds another argument to the y4m_read_frame_header()
and the y4m_write_frame_header() functions --- so code using those
functions will need to be tweaked.

Code which directly accessed members of the y4m_stream_info_t and the
y4m_frame_info_t structures will also break, but that is the coder's
fault! The API explicitly said "Use the accessor functions and
don't touch these structures directly."