This is for the bidir-pred experiment. Previously the length of the
bi-predictive frame group interval is fixed at 2, i.e. one
bi-predictive frame may be inserted every other frame. This patch
makes the length adjustable, i.e. any positive number may be
specified, but the use of the backward ref will be turned off if the
bi-predictive frame group interval is larger than the golden frame
group.
Further, an additional rate factor level has been added:
INTER_LOW
, which applies to LAST_BIPRED_UPDATE frames that are not used as
references.
Change-Id: I5514d34a64dd486bbb5756c2d0612946f598a789
Major parts have been implemented as follows:
(1) Added BRF_UPDATE, LASTNRF_UPDATE, and NRF_UPDATE in firstpass.c;
(2) Added the handling for the scenario of
"cpi->common.show_existing_frame == 1" at the encoder;
(3) Added a new reference frame of BWDREF_FRAME;
(4) Have bwd-ref work with upsampled references.
Note that when the experiment of "ext_refs" turned on, this experiment
will be turned off automatically currently.
RD performance in Overall PSNR has been improved, compared against the
VP10 baseline:
lowres: Avg -3.312; BDRate -3.154
derflr: Avg -1.927; BDRate -1.176
midres: Avg -2.149; BDRate -2.001
hdres : Avg -0.567; BDRate -0.588
Change-Id: I4c06ff51cc20194bffbd4d2346e57ba3dcf6b62c
This patch always compares the most recent show frames between
the encoder and the decoder to test the mismatch.
Change-Id: I68a91ad0996a598231450debfd616e24992419b5
This patch changes the encoder only for the ext-refs experiment. For
each newly coded frame to refresh the LAST_FRAME, the decoder is
notified that the LAST4_FRAME is to be refreshed, and read out the
updated reference frame buffer vitural indexes for the next coded
frame in a way that:
LAST4_FRAME => LAST_FRAME,
LAST_FRAME => LAST2_FRAME,
LAST2_FRAME => LAST3_FRAME, and
LAST3_FRAME => LAST4_FRAME.
Compared against the original ext-refs experiment in TOT, a small gain
is achieved in overall PSNR:
lowres Avg: -0.154
lowres BDRate: -0.044
Change-Id: I648810c146a3cd915b408274a9373b7d38324864
The uncompressed frame header contains a bit to signal whether the
frame is encoded using 64x64 or 128x128 superblocks. This can vary
between any 2 frames.
vpxenc gained the --sb-size={64,128,dynamic} option, which allows the
configuration of the superblock size used (default is dynamic). 64/128
will force the encoder to always use the specified superblock size.
Dynamic would enable the encoder to choose the sb size for each
frame, but this is not implemented yet (dynamic does the same as 128
for now).
Constraints on tile sizes depend on the superblock size, the following
is a summary of the current bitstream syntax and semantics:
If both --enable-ext-tile is OFF and --enable-ext-partition is OFF:
The tile coding in this case is the same as VP9. In particular,
tiles have a minimum width of 256 pixels and a maximum width of
4096 pixels. The tile width must be multiples of 64 pixels
(except for the rightmost tile column). There can be a maximum
of 64 tile columns and 4 tile rows.
If --enable-ext-tile is OFF and --enable-ext-partition is ON:
Same constraints as above, except that tile width must be
multiples of 128 pixels (except for the rightmost tile column).
There is no change in the bitstream syntax used for coding the tile
configuration if --enable-ext-tile is OFF.
If --enable-ext-tile is ON and --enable-ext-partition is ON:
This is the new large scale tile coding configuration. The
minimum/maximum tile width and height are 64/4096 pixels. Tile
width and height must be multiples of 64 pixels. The uncompressed
header contains two 6 bit fields that hold the tile width/heigh
in units of 64 pixels. The maximum number of tile rows/columns
is only limited by the maximum frame size of 65536x65536 pixels
that can be coded in the bitstream. This yields a maximum of
1024x1024 tile rows and columns (of 64x64 tiles in a 65536x65536
frame).
If both --enable-ext-tile is ON and --enable-ext-partition is ON:
Same applies as above, except that in the bitstream the 2 fields
containing the tile width/height are in units of the superblock
size, and the superblock size itself is also coded in the bitstream.
If the uncompressed header signals the use of 64x64 superblocks,
then the tile width/height fields are 6 bits wide and are in units
of 64 pixels. If the uncompressed header signals the use of 128x128
superblocks, then the tile width/height fields are 5 bits wide and
are in units of 128 pixels.
The above is a summary of the bitstream. The user interface to vpxenc
(and the equivalent encoder API) behaves a follows:
If --enable-ext-tile is OFF:
No change in the user interface. --tile-columns and --tile-rows
specify the base 2 logarithm of the desired number of tile columns
and tile rows. The actual number of tile rows and tile columns,
and the particular tile width and tile height are computed by the
codec ensuring all of the above constraints are respected.
If --enable-ext-tile is ON, but --enable-ext-partition is OFF:
No change in the user interface. --tile-columns and --tile-rows
specify the WIDTH and HEIGHT of the tiles in unit of 64 pixels.
The valid values are in the range [1, 64] (which corresponds to
[64, 4096] pixels in increments of 64.
If both --enable-ext-tile is ON and --enable-ext-partition is ON:
If --sb-size=64 (default):
The user interface is the same as in the previous point.
--tile-columns and --tile-rows specify tile WIDTH and HEIGHT,
in units of 64 pixels, in the range [1, 64] (which corresponds
to [64, 4096] pixels in increments of 64).
If --sb-size=128 or --sb-size=dynamic:
--tile-columns and --tile-rows specify tile WIDTH and HEIGHT,
in units of 128 pixels in the range [1, 32] (which corresponds
to [128, 4096] pixels in increments of 128).
Change-Id: Idc9beee1ad12ff1634e83671985d14c680f9179a
Decouples interintra modes and probability models from regular
intra modes, to enable creating/optimizing new interintra modes.
Also, fixes interpolation values for 128x128 interintra and obmc.
Change-Id: I5c2016db49b8f029164e5fe84c6274d4e02ff90e
If --enable-ext-partition is used at build time, the superblock size
(sometimes also referred to as coding unit (CU) size) is extended to
128x128 pixels.
Change-Id: Ie09cec6b7e8d765b7555ff5d80974aab60803f3a
If configured with --enable-ext-tile, the codec uses an alternative
tile coding syntax in the bitstream. Changes include::
- The maximum number of tile rows and columns is extended to 1024
each.
- The minimum tile width/height is 64 pixels (1 superblock).
- A tile copy mode is added where a tile directly reuse the coded
data of a previous tile
- The meaning of the tile-columns and tile-rows codec parameters are
overloaded to mean tile-width and tile-height in units of 64
pixels.
- All tiles should now be independent, including rows within the
same columns, so large scale parallel, or independent decoding is
possible.
- vpxdec also gained the options to decode only a particular tile,
tile row, or tile column.
Changes without --enable-ext-tile:
- All tiles should now be independent, including rows within the
same columns, so large scale parallel, or independent decoding is
possible.
- vpxenc default tile configuration changed to use 1 tile column.
Change-Id: I0cd08ad550967ac18622dae5e98ad23d581cb33e
This has been ported under ext_partition_types because it is due
to be combined with the coding_unit_size experiment which is
already being ported under ext_partition
Change-Id: I47af869ae123ddf0aa99160dac644059d14266ee
This commit re-designs the probability model for the syntax elements
of the dynamic motion vector referencing system.
Change-Id: Icfb8203c7e8f64e10e99f5890e25e6f6b15fe5d1
This patch added two features to improve entropy coding efficiency
for coefficient tokens.
1. Choose 1 of 4 default probability tables based on q-index for
key-frames.
It is ported from nextgen branch:
https://chromium-review.googlesource.com/#/c/280586/
2. Do backward update after each superblock (64X64) row using
subframe token counts.
Coding gain: 0.1% on lowres; 0.42% on midres; 0.36% on hdres.
Much larger gain for key-frames: 2.6%, 2.3%, 1.7%.
Design doc: go/huisu-entropy
Change-Id: Ia3b6a615636be09247d70e4c520405637561532b
Using the up-sampled reference frames in sub-pixel motion search is
enabled as a speed feature for good-quality mode speed 0 and speed 1.
Change-Id: Ieb454bf8c646ddb99e87bd64c8e74dbd78d84a50
Up-sampled the reference frames to 8 times in each dimension using
the 8-tap interpolation filter. In sub-pixel motion search, use the
up-sampled reference frames to find the best matching blocks. This
largely improved the motion search precision, and thus, improved
the compression quality. There was no change in decoder side.
Borg test and speed test results:
1. On derflr set,
Overall PSNR gain: 1.306%, and SSIM gain: 1.512%.
Average speed loss on derf set was 6.0%.
2. On stdhd set,
Overall PSNR gain: 0.754%, and SSIM gain: 0.814%.
On hevchd set,
Overall PSNR gain: 0.465%, and SSIM gain: 0.527%.
Speed loss on HD clips was 3.5%.
Change-Id: I300ebaafff57e88914f3dedc8784cb21d316b04f
This commit accounts for the context based probability model for
motion vector cost estimate in rate-distortion optimization.
Change-Id: Ia068a9395dcb4ecc348f128b17b8d24734660b83
This makes all metric computation to locate at some place, also gets
rid of duplicate code between vp9 and vp10.
Change-Id: I24a2707d183a2419cd18a8343010adae185ffcd4
In this experiment, an obmc inter prediction mode is enabled for
>= 8X8 inter blocks. When the obmc flag is on, the regular block-
based motion compensation will be refined by using predictors of
the above and left blocks.
Fixed some compatibility issues with vp9_highbitdepth, supertx,
ref_mv, and ext_interp.
Coding gain (%) on derflr/hevcmr/hevchd
OBMC:
1.047/1.022/0.708
OBMC + SUPERTX:
1.652/1.616/1.137
SUPERTX:
0.862/0.779/0.630
Change-Id: I5d8d3c4729c6d3ccb03ec7034563107893103b7f
This commit enables entropy coding for dynamic reference motion
vector modes. The probability model is contexted on the ranking
categories of the reference motion vector candidates.
Change-Id: I09b58d98a409d63ec1a407331e29f8945b7ef17d
BD-rate performance improvement (on top of ext-intra):
derflr 0.22%
hevclr 0.36%
hevcmr 0.48%
hevchr 0.37%
stdhd 0.19%
Average speed impact on some derf clips is about 40% slower (on
top of ext-intra). Speed improvment is a to-do.
Change-Id: I8fe3fe8c5e4f60d0462778adbcc15c84dfbe7a25
Combinations of different mv modes for two reference frames
are allowed in compound inter modes. 9 options are enabled,
including NEAREST_NEARESTMV, NEAREST_NEARMV, NEAR_NEARESTMV,
NEAREST_NEWMV, NEW_NEARESTMV, NEAR_NEWMV, NEW_NEARMV, ZERO_ZEROMV,
and NEW_NEWMV.
This experiment is mostly deported from the nextgen branch.
It is made compatible with other experiments
Coding gain of EXT_INTER(derflr/hevcmr/hevchd): 0.533%/0.728%/0.639%
Change-Id: Id47e97284e6481b186870afbad33204b7a33dbb0
Current implementation is a bilateral filter whose
parameters are transmitted in the bitstream.
derflr: -0.647% BDRATE
hevcmr: -0.794% BDRATE
This is a prelimary patch. Various other variations are to
be investigated next, that will hopefully be less expensive
on the decoder side.
Change-Id: I50634ae8f5014ad0bf7432306348908a349d81e1
NEW2MV is enabled, representing a new motion vector predicted from
NEARMV. It is mostly ported from nextgen, where it was named
NEW_INTER.
A few fixes are done for sub8x8 RDO to correct some misused
mv references in the original patch.
A 'bug-fix' for encoding complexity is done, reducing the additional
encoding time from 50% to 20%. In sub8x8 case, the old patch
did motion search for every interpolation filter (vp9 only
searches once). This fix also slightly improves the coding gain.
This experiment has been made compatible with REF_MV and EXT_REFS.
Coding gain (derflr/hevcmr/hevchd): 0.267%/0.542%/0.257%
Change-Id: I9a94c5f292e7454492a877f65072e8aedba087d4
The nominal tx_type for a given mode is used as a context
to encode the actual tx_type for intra.
Results:
derflr: -0.241% BDRATE
hevcmr: -0.366% BDRATE
Change-Id: Icfe7b0a58d79bc6497a06e3441779afec6e01e21
For the experiment of EXT_REFS, removed the previous special handling
on the new last 3 references, i.e. LAST2_FRAME, LAST3_FRAME, and
LAST4_FRAME, at the decoder, so that these new last references are
treated the same way as the other 3 references (LAST_FRAME,
GOLDEN_FRAME, and ALTREF_FRAME). Encoder changes have been made
accordingly to realize this flexibility.
Change-Id: Ic6546f9443b4377bb7e7b101bfa3e70a8b8d1c65
This commit re-works the entropy coding scheme of the motion
compensated prediction modes. It allows more flexible hyperplane
partition for precise classification.
Change-Id: Iba5035c76691946cf1386b6c495e399c3d9c8fc5
This change has been imported from VP9 and
alters the nature and use of exhaustive motion search.
Firstly any exhaustive search is preceded by a normal step search.
The exhaustive search is only carried out if the distortion resulting
from the step search is above a threshold value.
Secondly the simple +/- 64 exhaustive search is replaced by a
multi stage mesh based search where each stage has a range
and step/interval size. Subsequent stages use the best position from
the previous stage as the center of the search but use a reduced range
and interval size.
For example:
stage 1: Range +/- 64 interval 4
stage 2: Range +/- 32 interval 2
stage 3: Range +/- 15 interval 1
This process, especially when it follows on from a normal step
search, has shown itself to be almost as effective as a full range
exhaustive search with step 1 but greatly lowers the computational
complexity such that it can be used in some cases for speeds 0-2.
This patch also removes a double exhaustive search for sub 8x8 blocks
which also contained a bug (the two searches used different distortion
metrics).
For best quality in my test animation sequence this patch has almost
no impact on quality but improves encode speed by more than 5X.
Restricted use in good quality speeds 0-2 yields significant quality gains
on the animation test of 0.2 - 0.5 db with only a small impact on encode
speed. On most natural video clips, however, where the step search
is performing well, the quality gain and speed impact are small.
Change-Id: Iac24152ae239f42a246f39ee5f00fe62d193cb98
