This patch incorporates adaptive entropy coding of coefficient tokens,
and mode/mv information based on distributions encountered in a frame.
Specifically, there is an initial forward update to the probabilities
in the bitstream as before for coding the symbols in the frame, however
at the end of decoding each frame, the forward update to the
probabilities is reverted and instead the probabilities are updated
towards the actual distributions encountered within the frame.
The amount of update is weighted by the number of hits within each
context.
Results on derf/hd/std-hd are all up by 1.6%.
On derf, the most of the gains come from coefficients, however for the
hd and std-hd sets, the most of the gains come from the mode/mv
information updates.
Change-Id: I708c0e11fdacafee04940fe7ae159ba6844005fd
The commit changed how baseline 8x8 coefficient probabilities are
initialized, to be consistent with the initialization of baseline
4x4 coefficient probabilities.
The commit does not have any effect on compression.
Change-Id: Ifb3902b5dc0b0c2e6dc3aa5d4a6589d528e58355
1. block types
There are only three types of blocks for 8x8 transformed MBs, i.e. Y
block with DC does not exist for 8x8 transformed MBs as all MB using
8x8 transform have 2nd order haar transform. This commit introduced
a new macro BLOCK_TYPES_8X8 to reflect such fact.
2. context counters
This commit also fixed the mixed of context_counters between 4x4 and
8x8 transformed MBs. The mixed use of the counters leads me to think
the existing the context probabilities were not properly generated
from 8x8 transformed MBs.
3. redundant collecting in recoding
The commit also corrected the code that accumulates entropy stats by
making sure stats only collected for final packing, not during the
recode loop
Change-Id: I029f09f8f60bd0c3240cc392ff5c6d05435e322c
This commit adjusted slightly the 4x4 coefficents band definition to
better classify coefficients with similar distributions and usages.
It helps derf set about .1%, it is alos slightly positive for std-hd
set, where 4x4 blocks are used less frequently.
The commit also removed a const array not in use.
Change-Id: I78d16905d4036641ec905b0c32c190c1def5b249
Adds differential encoding of prob updates using a subexponential
code centered around the previous probability value.
Also searches for the most cost-effective update, and breaks
up the coefficient updates into smaller groups.
Small gain on Derf: 0.2%
Change-Id: Ie0071e3dc113e3d0d7ab95b6442bb07a89970030
the bug caused the encoder to produce invalid bitstream when configured
with enable_extend_qrange.
Change-Id: I1e81c48b13359d0043cbbd480e679380a2da117c
Removal of configure #ifdefs so that segment features
always available. Removal of code supporting old
segment feature method.
Still a good deal of tidying up to do.
Change-Id: I397855f086f8c09ab1fae0a5f65d9e06d2e3e39f
Modify reference frame segmentation so that ONE or MORE
reference frames may be marked as a available for a given
segment.
Fixed bugs relating to segment coding of INTRA and some
INTER modes at the segment level.
Modified Q boost for static areas based on ambient average Q.
Strong results now on clips with significant static areas.
(some data points in derf set as high as 9% and some static &
slide show type content in YT set > 20%)
Change-Id: Ia79f912efa84b977f35a23683ae3643251e24f0c
Patch 1 to Patch 3 is an initial implementation of 8x8 intra prediction
modes, here are with the following assumptions:
a. 8x8 has 4 prediction modes DC, H, V and TM
b. UV 4x4 block use the same mode as corresponding 8x8 area
c. i8x8 modes are enabled for key frame only for now
Patch 4:
d. removed debug code from previous patches
Patch 5:
e. added stats code to collect entropy stats and further cleaned up
Patch 6:
f. changed mode stats code to collect finer stats of modes
Patch 7:
g. normalized i8x8 modes distribution to total at 256 (8bits).
Patch 8:
h. fixed a bug in decoder and removed debug printf output.
Patch 9:
i. more cleanups to address paul's comment
Patch 10:
j. messy rebase/merges to bring the commit up to date.
Tests on HD clips encoded with all key frame showing consistent gain
on all clips and all metrics:~0.5%(psnr) and 0.6%(ssim):
http://www.corp.google.com/~yaowu/no_crawl/i8x8hd_allkey_fixedq.html
To build and test, configure with:
--enable-experimental --enable-i8x8
Change-Id: I9813fe07ae48cab5fdb5d904bca022514ad01e7f
Some basic plumbing added for a range of segment level features.
MB_LVL_* changed to SEG_LVL_* to better reflect meaning.
Change-Id: Iac96da36990aa0e40afc0d86e990df337fd0c50b
With this fix, the experimental branch now builds and encodes correctly
with the following two configure options respectively:
--enable-experimental --enable-t8x8
--enable-experimental
Change-Id: I3147c33c503fe713a85fd371e4f1a974805778bf
allowing the compiler to inline this function. For real-time
encodes, this gave a boost of 1% to 2.5%, depending on the
speed setting.
Change-Id: I3929d176cca086b4261267b848419d5bcff21c02
There were many instances in the code of vp8_coef_tokens and
vp8_coef_tokens-1, which was a preprocessor macro despite the naming
convention. Replace these with MAX_ENTROPY_TOKENS and ENTROPY_NODES,
respectively.
Change-Id: I72c4f6c7634c94e1fa066cd511471e5592c748da
Adding support in the encoder for generating
independent residual partitions by forcing
equal probabilities over the prev coef entropy
contexts.
Change-Id: I402f5c353255f3ca20eae2620af739f6a498cd21
Per John's previous change, shrink TOKENEXTRA from 20 to 8 bytes
original: b7b1e6fb
reverted: 41f4458a
Also drop unused field from vp8_extra_bit_struct
Update ARM ASM to deal with this change. In particular, Extra is signed
and needs to be sign-extended when loaded.
Change-Id: Ibd0ddc058432bc7bb09222d6ce4ef77e93a30b41
Changed the end of block computation to use pmaxw. Removed
additional pushing and popping of registers that was not needed.
Change-Id: I08cb9b424513cd8a2c7ad8cea53b4e2adc66ef98
Extending the value range of tokens allows further experiments on
extending quantizer range. Encoder and decoder were verified to
produce matching reconstructed buffers by tests with forced
quantized value of 1.
Change-Id: I12faf92832867870b6f71ddeafbf643f1040086d
Changes 'The VP8 project' to 'The WebM project', for consistency
with other webmproject.org repositories.
Fixes issue #97.
Change-Id: I37c13ed5fbdb9d334ceef71c6350e9febed9bbba
When the license headers were updated, they accidentally contained
trailing whitespace, so unfortunately we have to touch all the files
again.
Change-Id: I236c05fade06589e417179c0444cb39b09e4200d
