Applied better MV prediction in real-time mode, which improves
the encoding quality.
Used quarter-pixel search instead of iterative sub-pixel search
for speed >=5 to improve encoding performance.
Tests on the test set showed:
1. For speed=-5, quality improvement: 1.7% on AvgPSNR and 2.1%
on SSIM, performance improvement: 3.6% (This counts in the
performance lose caused by MV prediction calculation in "Improve
MV prediction in vp8_pick_inter_mode() for speed>3").
2. For speed=-8, quality improvement: 2.1% on AvgPSNR and 2.5%
on SSIM. but, 6.9% performance decrease because of MV prediction
calculation. This should be improved later.
Change-Id: I349a96c452bd691081d8c8e3e54419e7f477bebd
Previously, the DC check is to make sure there is no code-able
DC shift for quantizer Q0, which has been verified rather
conservative. This commit changes the criteria to have two
components, DC and AC, to address the conservativeness. First,
it checks if all AC energy is enough to contribute a single
non-zero quantized AC coefficient. Second, for DC, the decision
to skip further considers two possible scenarios: 1. There is
no code-able 2nd order DC coefficient at all; 2 The residue is
relatively flat, but the uniform DC change is very small, i.e.
less than 1/2 gray level per pixel.
Comparing to previous criteria, the new criteria is about 10%
to 15% faster in encoding time with a very small quality loss.
(threshold ~1000 and quality range 33db-45db)
It should be noted that this commit enables "automatic" static
threshold for encodebreakout if a non-zero small value is passed
in to encoder.
Change-Id: I0f77719a1ac2c2dfddbd950d84920df374515ce3
This function was using a variance metric compared to and SSE metric in
other places (eg. vp8_rd_inter_uv)
Change-Id: I9109fcc5a13bca9db1d7ead500fe14999ab233eb
vp8/encoder/rdopt.c:728: warning: pointer targets in passing argument 3
of 'macro_block_yrd' differ in signedness
vp8/encoder/rdopt.c:541: note: expected 'int *' but argument is of type
'unsigned int *'
distortion is signed when calling macro_block_yrd is both other cases,
as well as for RDCOST
Change-Id: I5e22358b7da76a116f498793253aac8099cb3461
Use the function macro_block_yrd() to calculate error and distortion
in keeping with what is done for inter frames.
The old code was using a variance metric for once case and an
SSE function for measuring distortion in the other case.
The function vp8_encode_intra16x16mbyrd() is no longer used.
Change-Id: Ic228cb00a78ff637f4365b43f58fbe5a9273d36f
This commit also removes artificial RDMULT cap for low quantizers.
The intention is to address some abnormal behavior of mode selections
at the low quantizer end, where many macroblocks were coded with
SPLITMV with all partitions using same motion vector including (0,0).
This change improves the compression quality substantially for high
quality encodings in both PSNR and SSIM terms. Overall effect on
mid/low rate range is also positive for all metrics, but smaller
in magnitude.
Change-Id: I864b29c4bd9ff610d2545fa94a19cc7e80c02667
Adjust checking points in motion vector prediction to better cover
possible movements, and get a better prediction. Tests on test
clips showed a 0.1% improvement in SSIM, and no change in PSNR
and performance.
Change-Id: Ifdab05d35e10faea1445c61bb73debf888c9d2f8
vp8cx_mb_init_quantizer was being called for every mode checked
in vp8_rd_pick_inter_mode. zbin_extra is the only value that
really needs to be recalculated. This calculation is disabled
when using the fast quantizer for mode selection.
This gave a small performance boost (~.5% to 1%).
Note: This needs to be verified with segmentation_enabled.
Change-Id: I62716a870b3c82b4a998bdf95130ff0b02106f1e
Prior to this change, VP8 min quantizer is 4, which caps the
highest quality around 51DB. This experimental change extends
the min quantizer to 1, removes the cap and allows the highest
quality to be around ~73DB, consistent with the fdct/idct round trip
error. To test this change, at configure time use options:
--enable-experimental --enable-extend_qrange
The following is a brief log of changes in each of the patch sets
patch set 1:
In this commit, the quantization/dequantization constants are kept
unchanged, instead scaling factor 4 is rolled into fdct/idct.
Fixed Q0 encoding tests on mobile:
Before: 9560.567kbps Overall PSNR:50.255DB VPXSSIM:98.288
Now: 18035.774kbps Overall PSNR:73.022DB VPXSSIM:99.991
patch set 2:
regenerated dc/ac quantizer lookup tables based on the scaling
factor rolled in the fdct/idct. Also slightly extended the range
towards the high quantizer end.
patch set 3:
slightly tweaked the quantizer tables and generated bits_per_mb
table based on Paul's suggestions.
patch set 4:
fix a typo in idct, re-calculated tables relating active max Q
to active min Q
patch set 5:
added rdmult lookup table based on Q
patch set 6:
fix rdmult scale: dct coefficient has scaled up by 4
patch set 7:
make transform coefficients to be within 16bits
patch set 8:
normalize 2nd order quantizers
patch set 9:
fix mis-spellings
patch set 10:
change the configure script and macros to allow experimental code
to be enabled at configure time with --enable-extend_qrange
patch set 11:
rebase for merge
Change-Id: Ib50641ddd44aba2a52ed890222c309faa31cc59c
Previously when a frame was being overlaid on a previously coded
alt ref frame we only checked the alt ref 0,0 mode. Where there is
a possibility that the alt ref buffer is a filtered frame we should allow
the other prediction modes as normal or at the least allow use of
the last frame buffer.
Change-Id: I4d6227223d125c96b4f3066ec6ec9484fee7768c
Add a flag to always enable block4x4 search for speed=0 (good
quality) to guarantee no quality loss for speed0.
Change-Id: Ie04bbc25f7e6a33a7bfa30e05775d33148731c81
The maximum possible MV in 1/8 pel units is (1<<11), which could
cause mvcost out of its range that is 1023. Change maximum
possible MV in 1/8 pel units to (1<<11)-8 will fix this problem.
Change-Id: I5788ed1de773f66658c14f225fb4ab5b1679b74b
cpi->target_bits_per_mb is currently not being used,
so delete it. Also removed other unused code in rdopt.c.
Change-Id: I98449f9030bcd2f15451d9b7a3b9b93dd1409923
1. Search for block8x16/block16x8 uses block8x8's search results.
2. Check block4x4 only if block8x8 is chosen. (This hurts quality,
which will be improved in another check-in.)
3. In block4x4 search, the previous block's result is used as
MV predictor for next block.
This change improves performance.
Change-Id: I9dc089007ca08129fb6c11fe7692777ebb8647b0
Re-calibrated sad_per_bit16 and sad_per_bit4 tables to linearly
correlated to quantizer values, these two variables are used in
motion search for costing motion vectors. This change has an small
positive effect on compression.
Change-Id: Ic9b5ea6fb8d5078ef663ba4899db019cc51f4166
In SPLITMV, the 8x8 segment will be checked first. If the 8x8 rd
is better than the best, we check the other segments. Otherwise
bail. Adjustments to the thresh_mult were necessary to make
up for the initial quality loss.
The performance improved by 20% (average) for good quality,
speed 0 and speed 1, while the overall quality remained the same.
Change-Id: I717aef401323c8a254fba3e9777d2a316c774cc3
vp8_rd_pick_best_mbsegmentation looks at y only. The new
breakout does not include the frame cost, the prob_skip_false
cost, or the uv rate. Performance improved by a few percent
and the quality remained the same.
Change-Id: I94ff013998ac51e8ecce7130870f7b6600758e15
This fix added MV range checks for NEWMV mode as suggested by Jim.
To reduce unnecessary MV range checks, I tried Yaowu's suggestion.
Update UMV borders in NEWMV mode to also cover MV range check.
Also, in this way, every MV that is valid gets checked in diamond
search function.
Change-Id: I95a89ce0daf6f178c454448f13d4249f19b30f3a
The MV's range is 256. Since the new motion search uses a different
starting MV than the center ref MV, a MV range checking needs to
be done to avoid corruption.
Change-Id: I8ae0721d1bd203639e13891e2e54a2e87276f306
Change I3430820 performed an uninitialized read when
encode_breakout == 0, since the sum and sse wouldn't be set:
if(x->encode_breakout)
VARIANCE_INVOKE(..., get16x16var)(..., &sum, &sse);
if (cpi->active_map_enabled && x->active_ptr[0] == 0) {
...
} else if (sse < x->encode_breakout)
Change-Id: I915eb76d1227b4b6d1137a0dedf2c143860098a2
Moved the code from the segmentation loop into a function
which is now called for each segment. This will allow us
to change the segment order checking more easily.
Change-Id: I9510d26f0acae5a73043fcca8f1984b121d3e052
Add vp8_mv_pred() to better predict starting MV for NEWMV
mode in vp8_rd_pick_inter_mode(). Set different search
ranges according to MV prediction accuracy, which improves
encoder performance without hurting the quality. Also,
as Yaowu suggested, using diamond search result as full
search starting point and therefore adjusting(reducing)
full search range helps the performance.
Change-Id: Ie4a3c8df87e697c1f4f6e2ddb693766bba1b77b6
Small changes to the default zero bin and rounding tables.
Though the tables are currently the same for the Y1 and Y2 cases
I have left them as separate tables in case we want to tune this later.
There is now some adjustment of the zbin based on the prediction mode.
Previously this was restricted to an adjustment for gf/arf 0,0 MV.
The exact quantizer now marginal outperforms and is the default.
The overall average gain is about 0.5%
Change-Id: I5e4353f3d5326dde4e86823684b236a1e9ea7f47
NEON has optimized 16x16 half-pixel variance functions, but they
were not part of the RTCD framework. Add these functions to RTCD,
so that other platforms can make use of this optimization in the
future and special-case ARM code can be removed.
A number of functions were taking two variance functions as
parameters. These functions were changed to take a single
parameter, a pointer to a struct containing all the variance
functions for that block size. This provides additional flexibility
for calling additional variance functions (the half-pixel special
case, for example) and by initializing the table for all block sizes,
we don't have to construct this function pointer table for each
macroblock.
Change-Id: I78289ff36b2715f9a7aa04d5f6fbe3d23acdc29c
Changes 'The VP8 project' to 'The WebM project', for consistency
with other webmproject.org repositories.
Fixes issue #97.
Change-Id: I37c13ed5fbdb9d334ceef71c6350e9febed9bbba
Moved partition_bmi and partition_count out of MB_MODE_INFO and
placed into MACROBLOCK. Also reduced the size of other members
of the MB_MODE_INFO struct. For 1080p, the memory was reduced
by 1,209,516 bytes. The decoder performance appeared to improve
by 3% for the clip used.
Note: The main goal for this change is to improve the decoder
performance. The encoder will be revisited at a later date for
further structure cleanup.
Change-Id: I4733621292ee9cc3fffa4046cb3fd4d99bd14613
The main reason for the change was to reduce cycles in the token
decoder. (~1.5% gain for 32 bit) This layout should be more
cache friendly.
As a result of this change, the encoder had to be updated.
Change-Id: Id5e804169d8889da0378b3a519ac04dabd28c837
Note: dixie uses a similar layout
These copies occurred for each macroblock in the encoder and decoder.
Thetemp MB_MODE_INFO mbmi was removed from MACROBLOCKD. As a result,
a large number compile errors had to be fixed.
Change-Id: I4cf0ffae3ce244f6db04a4c217d52dd256382cf3
The mv_ref and sub_mv_ref token encodings are indexed from NEARESTMV
and LEFT4X4, respectively, rather than being zero-based like the
other token encodings.
Change-Id: I3699c3f84111209ecfb91097c4b900773e9a3ad5
Replace the exponential search for optimal rounding during
quantization with a linear Viterbi trellis and enable it
by default when using --best.
Right now this operates on top of the output of the adaptive
zero-bin quantizer in vp8_regular_quantize_b() and gives a small
gain.
It can be tested as a replacement for that quantizer by
enabling the call to vp8_strict_quantize_b(), which uses
normal rounding and no zero bin offset.
Ultimately, the quantizer will have to become a function of lambda
in order to take advantage of activity masking, since there is
limited ability to change the quantization factor itself.
However, currently vp8_strict_quantize_b() plus the trellis
quantizer (which is lambda-dependent) loses to
vp8_regular_quantize_b() alone (which is not) on my test clip.
Patch Set 3:
Fix an issue related to the cost evaluation of successor
states when a coefficient is reduced to zero. With this
issue fixed, now the trellis search almost exactly matches
the exponential search.
Patch Set 2:
Overall, the goal of this patch set is to make "trellis"
search to produce encodings that match the exponential
search version. There are three main differences between
Patch Set 2 and 1:
a. Patch set 1 did not properly account for the scale of
2nd order error, so patch set 2 disable it all together
for 2nd blocks.
b. Patch set 1 was not consistent on when to enable the
the quantization optimization. Patch set 2 restore the
condition to be consistent.
c. Patch set 1 checks quantized level L-1, and L for any
input coefficient was quantized to L. Patch set 2 limits
the candidate coefficient to those that were rounded up
to L. It is worth noting here that a strategy to check
L and L+1 for coefficients that were truncated down to L
might work.
(a and b get trellis quant to basically match the exponential
search on all mid/low rate encodings on cif set, without
a, b, trellis quant can hurt the psnr by 0.2 to .3db at
200kbps for some cif clips)
(c gets trellis quant to match the exponential search
to match at Q0 encoding, without c, trellis quant can be
1.5 to 2db lower for encodings with fixed Q at 0 on most
derf cif clips)
Change-Id: Ib1a043b665d75fbf00cb0257b7c18e90eebab95e
At the end of the decode, frame buffers were being copied.
The frames are not updated after the copy, they are just
for reference on later frames. This change allows multiple
references to the same frame buffer instead of copying it.
Changes needed to be made to the encoder to handle this. The
encoder is still doing frame buffer copies in similar places
where pointer reference could be done.
Change-Id: I7c38be4d23979cc49b5f17241ca3a78703803e66
Following conversations with Tim T (Derf) I ran a large number of
tests comparing the existing polynomial expression with a simpler
^2 variant. Though the polynomial was sometimes a little better at
the extremes of Q it was possible to get close for most clips and
even a little better on some.
This code also changes the way the RD multiplier is calculated
when the ZBIN is extended to use a variant of the same ^2
expression.
I hope that this simpler expression will be easier to tune further
as we expand our test set and consider adjustments based on content.
Change-Id: I73b2564346e74d1332c33e2c1964ae093437456c
The new fdct lowers the round trip sum squared error for a
4x4 block ~0.12. or ~0.008/pixel. For reference, the old
matrix multiply version has average round trip error 1.46
for a 4x4 block.
Thanks to "derf" for his suggestions and references.
Change-Id: I5559d1e81d333b319404ab16b336b739f87afc79
When the license headers were updated, they accidentally contained
trailing whitespace, so unfortunately we have to touch all the files
again.
Change-Id: I236c05fade06589e417179c0444cb39b09e4200d
