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
Rename MI_BLOCK_SIZE.* -> MAX_MIB_SIZE.* (MIB is for MI Block).
Rename MI_MASK.* -> MAX_MIB_MASK.*
There are no functional changes.
This is in preparation for coding the superblock size at the frame
level, which will require some of these constants to become variables.
The new names better reflect future semantics, and hence make the code
clearer.
Change-Id: Iee08d97554cf4cc16a5dc166a3ffd1ab91529992
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
Merge the functions that generate prediction by above/left predictors
for the encoder and the decoder.
Change-Id: I57e53a8f2eb8d3028c4ed0c9abdcbf00503f95a0
Makes a set of 16 transforms total, adding all 1D
combinations of ADST and FlipADST, and removng all DST
transforms.
lowres, midres both improve by about 0.1% and hdres by
-0.378% in BDRATE but with fewer transforms that are also
simpler.
Further experiments to continue later.
Change-Id: I7348a4c0e12078fdea5ae3a2d36a89a319ffcc6e
This commit re-designs the probability model for the syntax elements
of the dynamic motion vector referencing system.
Change-Id: Icfb8203c7e8f64e10e99f5890e25e6f6b15fe5d1
This commit enables the dynamic motion vector predictor for NEWMV
mode. It allows the codec to select the best motion vector predictor
in a rate-distortion optimization framework for motion vector
residual coding. The compression performance is improved:
lowres 0.14%
midres 0.27%
hdres 0.24%
Change-Id: I6a601c74eb6cb0b71a613336d40363359f2edecd
This is a cosmetic patch that removes a great deal of conditional
compilation around CONFIG_VAR_TX from the partition search function.
Change-Id: I9dcef9d4fe6847b793c77bdf565a5cacbdfacd59
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
This commit fixes the computation of rate_nocoef for situation when
rate_y is uninitialized at INT_MAX for x->skip is true.
Change-Id: If3dde4e4ee16667f4408067d3bb3084f916272f1
Coding gain on screen_content is 12.2% (was 6.6%).
Some features such as frame-level color buffer, adaptive
entropy coding, are coming in future patches.
Change-Id: I2658cf5ec0cbb02cff685475759f3b68c9807697
This commit fixes an encoding issue related to var-tx and ref-mv
experiments that causes the codec to use random values for transform
block skip flag.
Change-Id: I8daa6d6b88ea45b5bbeb81b43dd0eeff545c8e5a
Includes various cosmetic changes and refactoring including
naming the sharp filters differently (since they are no longer
8-tap).
Change-Id: Ida5a19ca0daa9f6a64a6734394c685b2a4a2564a
The interintra experiment, which combines an inter prediction and an
inter prediction have been ported from the nextgen branch. The
experiment is merged into ext_inter, so there is no separate configure
option to enable it.
Change-Id: I0cc20cefd29e9b77ab7bbbb709abc11512320325
Instead of using model_rd_for_sb() to estimate the cost and make the
decision on bmc/obmc, we use super_block_yrd/uvrd() to calculate and
compare the real rd costs of bmc and obmc.
Average bit-rate reduction(%) of obmc experiment:
derflr/derfhd/hevcmr/hevchd
2.353/TBD/TBD/TBD
Before the optimization, the coding gain was:
1.582/1.109/1.600/1.164
Note: there is still some mysterious bug because that compared to
the previous version, the performance at low bit rate drops a lot.
Change-Id: I8dbee04a272190f10516a3953c1ae690f8136766
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
