In lossless coding, tx_size can be larger than 4x4 when transform
skipping is activated. Compared to regular vp9 lossless coding,
performance improvement for derf is about 5%; gain is larger
for screen content videos.
Change-Id: Ib20ece7e117f29fb91543612757302a2400110b4
This patch improves the non-transform coding mode. At this
point, the coding gain on screen content videos is about
12% for lossless, an 15% for lossy case.
1. Encode tx_skip flags with context. Y tx_skip flag context is
whether the prediction mode is inter or intra. UV flag context
is Y flag.
2. Transform skipping is less helpful when the Q-index is high.
So it is enabled only when the Q-index is smaller than a
threshold. Currently the threshold is set as 255 for intra blocks,
and 0 for inter blocks.
3. The shift of the prediction residue, when copying them to the
coeff buffer, is set as 3 when the Q-index is larger than a
threshold (currently set as 0), and 2 otherwise.
Change-Id: I372973c7518cf385f6e542b22d0f803016e693b0
Reimplements the supertx experiment from the playground branch.
Makes it work with other experiments.
Results:
With --enable-superttx
derflr: +0.958
With --enable-supertx --enable-ext-tx
derflr: +2.25%
With --enable-supertx --enable-ext-tx --enable-filterintra
derflr: +2.73%
Change-Id: I5012418ef2556bf2758146d90c4e2fb8a14610c7
Extends the ext-tx experiment to include regular and flipped
DST variants. A total of 9 transforms are thus possible for
each inter block with transform size <= 16x16.
In this patch currently only the four ADST_ADST variants
(flipped or non-flipped in both dimensions) are enabled
for inter blocks.
The gain with the ext-tx experiment grows to +1.12 on derflr.
Further experiments are underway.
Change-Id: Ia2ed19a334face6135b064748f727fdc9db278ec
Non-transform option is enabled in both intra and inter modes.
In lossless case, the average coding gain on screen content
clips is 11.3% in my test.
Change-Id: I2e8de515fb39e74c61bb86ce0f682d5f79e15188
Preliminary 64x64 transform implementation.
Includes all code changes.
All mismatches resolved.
Coding results for derf and stdhd are within noise. stdhd is slightly
higher, derf is slightly lower.
To be further refined.
Change-Id: I091c183f62b156d23ed6f648202eb96c82e69b4b
mi_grid_* are arrays of pointer to pointer. They save the pointers that point
to the MIs in cm->mi. But they are unnecessary and complicated. The original
goal was to remove MODE_INFO_t copy. But with an extra MODE_INFO_t pointer
inside MODE_INFO_t, same goal could be achieved.
This commit totally removes the mi_grid_* structures. But there are still
many dummy MODE_INFO_t inside cm->mi which are a waste of memory. Next commit
will do on-demand MODE_INFO_t allocation in order to save these memories.
Change-Id: I3a05cf1610679fed26e0b2eadd315a9ae91afdd6
A previous change, https://gerrit.chromium.org/gerrit/#/c/70632,
introduced a size validation for reference frames to insuare the
input stream is a valid VP9 stream. However, the logic requiring
all reference frames have valid size turned out to be too strict.
In this commit, we modify the validation to require one of the
reference frame has valid dimension. In addition, the decoder
reports error whenever it detects the use of reference frame
with invalid scalig ratio.
Change-Id: If8efc312244087556cfe00f1fcbdff811268ebad
Reimplementing sub8x8-reading of intra block modes in
read_intra_frame_mode_info() and read_intra_block_mode_info(). Code looks
more readable as well.
Change-Id: Ia42fc7d0dad708bc0c7a8bff1f8b37809b843f40
This commit removes the use of best_mv in the decoding process. This
variable can be replaced with nearest_mv. It saves a few cycles on
assigning the values for best_mv.
Change-Id: Ic183f9c1fb615c54efd7e6ccfedcf09d493435e4
