The denoiser was writing to LAST_FRAME buffer. If LAST_FRAME isn't being
updated, the reference frame buffers were out of sync between the encoder and the
denoised raw buffers. This patch resolves the discrepancy by always writing to a work
buffer (INTRA_FRAME) and then copying from that buffer to any buffers that needs to
be updated.
Change-Id: I6dd855b9749978b542bc3d515914d5f16faf25df
The denoiser function was modified to reduce the computational
complexity.
1. The denoiser c function modification:
The original implementation calculated pixel's filter_coefficient
based on the pixel value difference between current raw frame and last
denoised raw frame, and stored them in lookup tables. For each pixel c,
find its coefficient using
filter_coefficient[c] = LUT[abs_diff[c]];
and then apply filtering operation for the pixel.
The denoising filter costed about 12% of encoding time when it was
turned on, and half of the time was spent on finding coefficients in
lookup tables. In order to simplify the process, a short cut was taken.
The pixel adjustments vs. pixel diff value were calculated ahead of time.
adjustment = filtered_value - current_raw
= (filter_coefficient * diff + 128) >> 8
The adjustment vs. diff curve becomes flat very quick when diff increases.
This allowed us to use only several levels to get a close approximation
of the curve. Following the denoiser algorithm, the adjustments are
further modified according to how big the motion magnitude is.
2. The sse2 function was rewritten.
This change made denoiser filter function 3x faster, and improved the
encoder performance by 7% ~ 10% with the denoiser on.
Change-Id: I93a4308963b8e80c7307f96ffa8b8c667425bf50
Allows building the library with the gcc -pedantic option, for improved
portabilty. In particular, this commit removes usage of C99/C++ style
single-line comments and dynamic struct initializers. This is a
continuation of the work done in commit 97b766a46, which removed most
of these warnings for decode only builds.
Change-Id: Id453d9c1d9f44cc0381b10c3869fabb0184d5966
Compares the sum of differences between the input block and the averaged
block. If they differ too much the block will not be filtered. Negligible
perfomance hit.
Change-Id: Ib1c31a265efd4d100b3abc4a1ea6675038c8ddde
This extends the denoiser to work for temporally scalable
coding.
I believe this also fixes a very rare but really bad bug in the original
implementation.
Change-Id: I8b3593a8c54b86eb76f785af1970935f7d56262a
Make functions only referenced from one translation unit static. Other
symbols with extern linkage get a vp8/vpx prefix.
Change-Id: I928c7e0d0d36e89ac78cb54ff8bb28748727834f
