freerdp_icon_convert reads ICO data, which is used by RAIL for
window and notify icons. The old implementation incorrectly iterpreted
the green channel, flipped the alpha channel, and ignored alpha padding.
This implementation is much more robust and correctly handles the alpha
channel, even for non-powers-of-two image widths.
Fixes#578.
This will make sure we get an appropriate error message in case of memory allocation error, and not just a "Segmentation Fault"
Added some validation on xzalloc return in serial_tty_new to properly deallocate resources when an error occurs.
o combine colorloss recovery, chroma supersampling and color space conversion
in one step
o define private struct and hide the internal buffer
o make internal buffer reusable in the same session
o the decoded argb buffer can be reused to enhance performance
o pass width, height and bpp through nsc_process_message() call
o rename nsc_context_destroy to nsc_context_free and make it actually free the context
Replaced the non-accelerated rgb to ycbcr encoder (rfx_encode.c) to use 32-bit
integer multiplication with shifted factors: 2 times faster
The accelerated SSE2 rgb to ycbcr encoder (rfx_sse2.c) was completely changed
and simplified in order to make use of the SSE2 signed 16-bit integer
multiplication: 2 times faster
Also modified the non-accelerated ycbcr to rgb decoder (rfx_encode.c) to use
32-bit integer multiplications with shifted factors instead of floating point
multiplications: 3 times faster
The current ycbcr decoder was loosing some bits because cr/cb was multiplied by
the shifted factors.
Instead one should multiply by the non-shifted factors and shift the result.
The effects of these lost bits are easily seen by comparing the colors of a
RemoteFX session with the colors of a plain RDP session - they are just wrong ;)
I've replaced the bit-magic from the non non-accelerated version (rfx_decode.c)
and replaced it with simple float multiplications using the compiler's implicit
integer conversions. On several test machines this was even a little bit faster.
The accelerated SSE2 ycbcr decoder (rfx_sse2.c) was completely changed in order
to make use of the SSE2 signed 16-bit integer multiplication.
Fortunately the factors in the conversion matrix are so small that we can
easily shift them to the maximum possible 16-bit signed integer value without
loosing any information and use _mm_mulhi_epi16 which takes the upper 16 bits
of the 32-bit result.
The SSE2 ycbcr decoder is now much simpler and about 40 percent faster.
