If the GOLDEN or ALTREF frame was last updated > x frames in the past,
don't use them for denoising (only consider LAST). Using an old reference
frame for denoising, e.g., if it is a long-term reference or the last key frame,
can cause some visible artifacts, in particular in the aggressive denoising mode.
Change-Id: I239c9fbb092c36cba7e95328f1fa67a58d6a7ed9
Allow for option to apply spatial blur for temporal
denoising, under the aggressive denoising mode.
Change-Id: I41c5fdc0b6cf32d8f8d1d4236b25fa5aa406e89e
On key frame, will always start with normal denoising mode,
but based on a computed noise metric (normalized mse on source diff)
may switch to aggressive mode (and back down again).
Change-Id: I20330b2dcf3056287be37223302b2cab5fc103eb
C version and sse2 version, and off by default.
For the test clip used, the sse2 performance improved by ~5.6%
Change-Id: Ic2d815968849db51b9d62085d7a490d0e01574f6
Allow for an option to selectively apply the deblocking loop filter to the denoised
raw block, based on the denoised state (no-filter, filter with zero motion, or filter with non-zero motion)
of the current block and its upper and left denoised block.
This helps to reduce some blocking artifacts from the motion-compensated denoising.
Change-Id: I0ac4e70076df69a98c5391979e739a2681e24ae6
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
