Adds command line option --fast-residual-cost=<limit>. When QP is below
the limit, estimates the cost of coding the residual coefficients from
the sum of absolute coefficients. Skipping CABAC is not worth it with
high QPs because there are fewer coefficients so CABAC is not as slow.
- Replaces lcu_dqp_enabled with max_qp_delta_depth in encoder_control_t.
- Fixes set_cu_qps so that it can handle quantization groups of
arbitrary size.
- Fixes computation of QP predictors so that it works for quantization
groups of arbitrary size.
Checks the cost of flushing all coefficients of an inter block to zero.
This is much faster than doing full RDOQ but can still reduce bitrate
significantly. Encoding speed is increased since fewer coefficient bits
have to be coded with CABAC.
SMP/AMP search is performed using a lower work tree level than the
normal inter search so the prediction info must be copied up if an
SMP/AMP mode is chosen. Previously pixels and coefficient were copied as
well. Changed to only copy prediction info.
When 4x4 intra blocks are enabled and inter search is limited to 16x16
and larger blocks, it is possible that inter search is accidentally done
for 4x4 blocks. Fixed by checking that block size is at least 8x8 before
doing inter search.
Changes the work_tree parameter in search.c functions from an array to
a pointer. Fixes "formal parameter with requested alignment of 8 won't
be aligned" errors.
Replaces function kvz_intra_recon_lcu_luma and
kvz_intra_recon_lcu_chroma in intra.c with function kvz_intra_recon_cu.
The new function can handle reconstruction for both luma and chroma.
Removes some duplicated code.
Replaces functions kvz_quantize_lcu_luma_residual and
kvz_quantize_lcu_chroma_residual in transform.c with function
kvz_quantize_lcu_residual. The new function can handle any of the YUV
colors. Removes some duplicated code.
Changes the way coefficients are passed from kvz_search_lcu to
kvz_encode_coding_tree. Drops fields coeff_y, coeff_u and coeff_v in
videoframe_t and instead passes them through field coeff in
endoder_state_t.
When video width or height was not a multiple of the smallest CU size,
no prediction would be performed at the border CUs. Kvazaar would later
crash at an assertion failure when attempting to write the bitstream for
the CU.
Fixed by permitting inter and intra prediction when the CU split is
forced, even if CUs of that size would otherwise be disabled.
Some of the fields in encoder_control_t were simply copies of the
corresponding fields in kvz_config. This commit drops the copied fields
in favor of using the fields in encoder_control_t.cfg directly.
The kvz_config struct is created by the user but kvazaar keeps a pointer
to it. It is easy to break things by modifying the configuration outside
kvazaar. In addition, kvazaar modifies the struct even though it is has
a const modifier.
This commit changes the field cfg in encoder_control_t to be a copy of
the kvz_config struct instead of a pointer, removing modifications to
the const struct and allowing users to do whatever they want with it
after opening the encoder.
Drop a conditional for depth > MAX_DEPTH in search_cu. The depth cannot
be greater than MAX_DEPTH (== 3) since an earlier if-clause checks that
it is less than MAX_PU_DEPTH (== 4).
Adds field lcu_stats to encoder_state_config_frame_t. The following data
is recorded for each LCU:
- number of bits
- squared cost
- used lambda value
- alpha parameter used for rate control
- beta parameter used for rate control
Adds fields lambda, lambda_sqrt and qp to encoder_state_t. Drops field
cur_lambda_cost_sqrt from encoder_state_config_frame_t and renames
cur_lambda_cost to lambda.
Write bitstream without chroma when encoding with --input-format=P400.
This reduces bitstream size by 0-1 %, compared to coding monochrome in
420 format, and speeds up encoding slightly due to not processing
chroma.
Enables search for 2NxN and Nx2N partition modes for 8x8 CUs and 2NxnU,
2NxnD, nLx2N and nRx2N partition modes for 16x16 CUs.
Changes the loop for copying reconstructed luma pixels in
kvz_inter_recon_lcu to use 4 byte chunks instead of 8 byte chunks since
it is now possible to have 4 pixel wide blocks.
