This patch will make sure the use of the BWDREF_FRAME for the
encoding of both the two types of bipredictive frames, namely
LAST_BIPRED_UPDATE and BIPRED_UPDATE. To realize it, the
updates on the cpi->ref_frame_flags have been moved to before
the encoding of one frame, instread of originally handled after
the encoding of one frame.
RD performance has been improved slightly, approximately by 0.17%
compared to before the applying of this patch:
lowres: Avg -3.474; BDRate -3.324
derflr: Avg -2.097; BDRate -1.353
Change-Id: I0aa19afd752293e345489fbff104c4351ca5498c
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
Weighted single motion search is implemented for obmc predictor.
When NEWMV mode is used, to determine the MV for the current block,
we run weighted motion search to compare the weighted prediction
with (source - weighted prediction using neighbors' MVs), in which
the distortion is the actual prediction error of obmc prediction.
Coding gain: 0.404/0.425/0.366 for lowres/midres/hdres
Speed impact: +14% encoding time
(obmc w/o mv search 13%-> obmc w/ mv search 27%)
Change-Id: Id7ad3fc6ba295b23d9c53c8a16a4ac1677ad835c
In VP10, REFRESH_FRAME_CONTEXT_OFF mode is only set when the error
resillient mode is on. Instead of being used to decide how to update
the frame contexts, it is used to decide if or not to reset the
frame contexts.
To verify, ran borg test on lowres set. The result is neutral.
Overall PSNR: -0.006%; SSIM: -0.006%.
Change-Id: Ic48265cf7488e80c6f5aab3eef7ba1c273506419
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
This commit enables 1/8 luma component motion vector precision
for all motion vector cases. It improves the compression performance
of lowres by 0.13% and hdres by 0.49%.
Change-Id: Iccfc85e8ee1c0154dfbd18f060344f1e3db5dc18
This will facilitate bringing the zero node into the token set while
allowing its probability to vary independently.
Change-Id: I57b44c0fce44debb8e612021e44713b229d1b3cf
With ext-ref enabled, it is possible that when trying to encode the
first true ALTREF frame after a keyframe, the previous ALTREF frame
(alias for the keyframe) is the same as one of the new LAST{2,3,4}
reference frames, and hence cpi->ref_frame_flags will have the ALTREF
bit clear, as computed by get_ref_frame_flags in encoder.c.
sf->alt_ref_search_fp forces the previous ALTREF frame to
be used as the only possible reference when encoding a new ALTREF
frame, but due to cpi->ref_frame_flags, some buffers will not be
initialized (see rdopt.c:7689 yv12_mb), leading to a segfault.
get_ref_frame_flags in encoder.c has been changed to prefer to keep
the LAST frame, then the ALTREF frame, then any of the LAST{2,3,4}
frames and then the GOLDEN frame in that order of preference in case
any of them are the same. This avoids the segfault and behaves the
same for the baseline.
Change-Id: I4da1991667614009da5d3061a6316c0d5dbc6c0c
The VP8_EFLAG_NO_UPD_LAST and VP8_EFLAG_NO_REF_LAST flags can be
passed to the encoder to signal that it should not update/reference
the LAST ref frame when encoding the current frame. With
--enable-ext-refs turned on, the new LAST2 LAST3 and LAST4 ref frames
could still be used or updated, which causes the
VP10/ErrorResilienceTestLarge.DropFramesWithoutRecovery/{0,1,2}
tests to fail.
With this patch, if --enable-ext-refs is used, then
VP8_EFLAG_NO_UPD_LAST and VP8_EFLAG_NO_REF_LAST also applies to the
new LAST2 LAST3 and LAST4 ref frames, as well as the LAST ref frame.
Change-Id: If482b1c09bbaf914eca8e0348a2367bff261661d
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
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 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
Make the RANS implementation operate on cumulative distribution
functions rather than individual probability distribution functions.
CDFs have shown themselves more flexible to work with.
Reduces decoding memory usage from scaling O(num_distributions *
symbol_resolution) to O(num_distributions).
No bitstream change. This is an purely implementation change.
Change-Id: I4e18d3a0a3d37a36a61487c3d778f9d088b0b374
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
Includes various cosmetic changes and refactoring including
naming the sharp filters differently (since they are no longer
8-tap).
Change-Id: Ida5a19ca0daa9f6a64a6734394c685b2a4a2564a
This commits adds a shift stage for FASTSSIM computaton when source
bit depth is different from working bit depth, to make sure metric
results are calculated in bit_depth consistent with source.
Change-Id: I997799634076ef7b00fd051710544681ed536185
This commit unifies the motion vector cost buffers for full pixel
and sub-pixel motion search. The new motion vector coding system
provides 0.5% coding gains for 720p and above sequences and 0.2%
for lower resolution sets.
Change-Id: I927ec81eadc39d11a3c12b375221a1ddd2e8bf24
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
move to encoder_encode() as vp10_get_compressed_data() allocates data and
would require some modification to make its error return meaningful.
Change-Id: Ia5267c35d16ccd42b6da6d2136402b13e28f9159
Adds a wiener filter based restoration scheme in loop which can
be optionally selected instead of the bilateral filter.
The LMMSE filter generated per frame is a separable symmetric 7
tap filter. Three parameters for each of horizontal and vertical
filters are transmitted in the bitstream. The fourth parameter
is obtained assuming the sum is normalized to 1.
Also integerizes the bilateral filters, along with other
refactoring necessary in order to support the new switchable
restoration type framework.
derflr: -0.75% BDRATE
[A lot of videos still prefer bilateral, however since many frames
now use the simpler separable filter, the decoding speed is
much better].
Further experiments to follow, related to replacing the bilateral.
Change-Id: I6b1879983d50aab7ec5647340b6aef6b22299636
