Increase the first stage dynamic range by 4 times, and reduce it
back with proper rounding before applying the second stage. Hence
it still fits in the given dynamic range and slightly improves
the key frame coding performance.
Change-Id: Ia4c5907446f20a95dc3de079c314b3ad1221d8aa
Rebased.
Remove the old matrix multiplication transform computation. The 16x16
ADST/DCT can be switched on/off and evaluated by setting ACTIVE_HT16
300/0 in vp9/common/vp9_blockd.h.
Change-Id: Icab2dbd18538987e1dc4e88c45abfc4cfc6e133f
Some minor refactoring code relating to estimates of
bits per MB at a given Q and estimating the allowed Q range.
Most of the changes here were included in a previous commit.
This commit seeks to separate out the refactoring from more
the material changes.
Two #define control flags have been added for experimentation.
ONE_SHOT_Q_ESTIMATE force the two pass encoder to
use its initial Q range estimate for the whole clip even if this results
in a miss on the target data rate. In effect this tightens the Q range
seen at the expense of rate control accuracy.
DISABLE_RC_LONG_TERM_MEM is a related flag that disables the
long term memory in the rate control. Local adjustments are still
made to try and better hit the rate target on a per frame basis but
the impact of rate control misses is not propagated to the remainder
of the clip. This means that for example an overshoot early on will not
cause frames later in the clip to be starved of bits. Again the result
of this relaxation amy be less rate control accuracy especially on short
clips.
The flags are disabled by default for now.
Change-Id: I7482f980146d8ea033b5d50cc689f772e4bd119e
This commit added pre/post scaling for first half of fDCT16x16 to
reduce error, by simulation of 100,000 blocks for random inputs,
the average sse reduced from 2.1/block to 0.0498/block.
also enabled tests for 16x16 fDCT and iDCT
Change-Id: Id2a95f0464c6dd4118797d456237ae90274c0f02
This patch alters the balance of context between the
coefficient bands (reflecting the position of coefficients
within a transform blocks) and the energy of the previous
token (or tokens) within a block.
In this case the number of coefficient bands is reduced
but more previous token energy bands are supported.
Some initial rebalancing of the default tables has been
by running multiple derf clips at multiple data rates using
the ENTOPY_STATS macro. Further balancing needs to be
done using larger image formatsd especially in regard to
the bigger transform sizes which are not as well represented
in encodings of smaller image formats.
Change-Id: If9736e95c391e711b04aef6393d26f60f36e1f8a
The commit added a final rounding choice for 8x8 forward dct to get
rid of a sign bias at DC position and improve the accuracry in term
of round trip error for 8x8 fDCT/iDCT.
This commit also enabled forward 8x8 dct test.
Change-Id: Ib67f99b0a24d513e230c7812bc04569d472fdc50
The issue that potentially broke the encoding process was due to the fact
that the length of token link is calculated from the total number of tokens
coded, while it is possible, in high bit-rate setting, this length is
greater than the buffer length initially assigned to the cpi->tok.
This patch increases the initially allocated buffer length assigned to
cpi->tok from
(mb_rows * mb_cols * 24 * 16) to (mb_rows * mb_cols * (1 + 24 * 16)).
It resolves the buffer overflow problem.
Change-Id: I8661a8d39ea0a3c24303e3f71a170787a1d5b1df
Removing redundant 'extern' keywords and parentheses, fixing indentation,
making variable names lower case, using short expressions x *= c
instead of x = x * c, minor code simplifications.
Change-Id: If6a25fcf306d1db26e90d27e3c24a32735c607de
The over quant code was added in VP8 post
bitstream freeze to allow compression to lower
data rates
In VP9 the real qualtizer range has been greatly
extended anyway.
Change-Id: I5d384fa5e9a83ef75a3df34ee30627bd21901526
This patch includes 4x4, 8x8, and 16x16 forward butterfly ADST/DCT
hybrid transform. The kernel of 4x4 ADST is sin((2k+1)*(n+1)/(2N+1)).
The kernel of 8x8/16x16 ADST is of the form sin((2k+1)*(2n+1)/4N).
Change-Id: I8f1ab3843ce32eb287ab766f92e0611e1c5cb4c1
Removing redundant 'extern' keyword from function declarations and making
function arguments lower case.
Change-Id: Idae9a2183b067f2b6c85ad84738d275e8bbff9d9
Refactors the switchable filter search in the rd loop to
improve encode speed.
Uses a piecewise approximation to a closed form expression to estimate
rd cost for a Laplacian source with a given variance and quantization
step-size.
About 40% encode time reduction is achieved.
Results (on a feb 12 baseline) show a slight drop:
derf: -0.019%
yt: +0.010%
std-hd: -0.162%
hd: -0.050%
Change-Id: Ie861badf5bba1e3b1052e29a0ef1b7e256edbcd0
The issue that potentially broke the encoding process was due to the fact
that the length of token link is calculated from the total number of tokens
coded, while it is possible, in high bit-rate setting, this length is
greater than the buffer length initially assigned to the cpi->tok.
This patch increases the initially allocated buffer length assigned to
cpi->tok from
(mb_rows * mb_cols * 24 * 16) to (mb_rows * mb_cols * (1 + 24 * 16)).
It resolves the buffer overflow problem.
Change-Id: I8661a8d39ea0a3c24303e3f71a170787a1d5b1df
The commit changes the coding mode to lossless whenever the lowest
quantizer is choosen.
As expected, test results showed no difference for cif and std-hd
set where Q0 is rarely used. For yt and yt-hd set, Q0 is used for
a number of clips, where this commit helped a lot in the high end.
Average over all clips in the sets:
yt: 2.391% 1.017% 1.066%
hd: 1.937% .764% .787%
Change-Id: I9fa9df8646fd70cb09ffe9e4202b86b67da16765
The 32x32 value in case of splitmv was uninitialized. this leads to
all kind of erratic behaviour down the line. Also fill in dummy values
for superblocks in keyframes (the values are currently unused, but we
run into integer overflows anyway, which makes detecting bad cases
harder). Lastly, in case we did not find any RD value at all, don't
set tx_diff to INT_MIN, but instead set it to zero (since if we couldn't
find a mode, it's unlikely that any particular transform would have made
that worse or better; rather, it's likely equally bad for all tx_sizes).
Change-Id: If236fd3aa2037e5b398d03f3b1978fbbc5ce740e
This issue breaks the encoding process of the codebase. The effect
emerges only in particular test sequence at certain bit-rates and
frame limits.
Change-Id: I02e080f2a49624eef9a21c424053dc2a1d902452
Since there is no Y2, these values are always zero. This changes the
bitstream results slightly, hence a separate commit.
Change-Id: I2f838f184341868f35113ec77ca89da53c4644e0
These allow sending partial bitstream packets over the network before
encoding a complete frame is completed, thus lowering end-to-end
latency. The tile-rows are not independent.
Change-Id: I99986595cbcbff9153e2a14f49b4aa7dee4768e2
This patch abstracts the selection of the coefficient band
context into a function as a precursor to further experiments
with the coefficient context.
It also removes the large per TX size coefficient band structures
and uses a single matrix for all block sizes within the test function.
This may have an impact on quality (results to follow) but is only an
intermediate step in the process of redefining the context. Also the
quality impact will be larger initially because the default tables will
be out of step with the new banding.
In particular the 4x4 will in this case only use 7 bands. If needed we
can add back block size dependency localized within the function, but
this can follow on after the other changes to the definition of the
context.
Change-Id: Id7009c2f4f9bb1d02b861af85fd8223d4285bde5
Reverted part of change
I19981d1ef0b33e4e5732739574f367fe82771a84
That gives rise to an enc/dec mismatch.
As things stand the memsets are still needed.
Change-Id: I9fa076a703909aa0c4da0059ac6ae19aa530db30
This is an initial step to facilitate experimentation
with changes to the prior token context used to code
coefficients to take better account of the energy of
preceding tokens.
This patch merely abstracts the selection of context into
two functions and does not alter the output.
Change-Id: I117fff0b49c61da83aed641e36620442f86def86
