Jingning Han [Tue, 5 Feb 2013 20:37:13 +0000 (12:37 -0800)]
Butterfly ADST based hybrid transform
Refactor the 8x8 inverse hybrid transform. It is now consistent
with the new inverse DCT. Overall performance loss (due to the
use of this variant ADST, and the rounding errors in the butterfly
implementation) for std-hd is -0.02.
Fixed BUILD warning.
Devise a variant of the original ADST, which allows butterfly
computation structure. This new transform has kernel of the
form: sin((2k+1)*(2n+1) / (4N)). One of its butterfly structures
using floating-point multiplications was reported in Z. Wang,
"Fast algorithms for the discrete W transform and for the discrete
Fourier transform", IEEE Trans. on ASSP, 1984.
This patch includes the butterfly implementation of the inverse
ADST/DCT hybrid transform of dimension 8x8.
Paul Wilkins [Tue, 5 Feb 2013 12:54:09 +0000 (12:54 +0000)]
Added skip switches for SB32 and SB64
Added switches and code to skip/breakout from
doing SB32 and SB64 tests based on whether
the 16x16 MB tests used split modes. Also to
optionally skip 64x64 if 16x16 was chosen over
32x32.
Impact varies depending on clip from a few %
up to almost 50% on encode speed. Only the
split mode breakout is currently enabled.
This patch adds column-based tiling. The idea is to make each tile
independently decodable (after reading the common frame header) and
also independendly encodable (minus within-frame cost adjustments in
the RD loop) to speed-up hardware & software en/decoders if they used
multi-threading. Column-based tiling has the added advantage (over
other tiling methods) that it minimizes realtime use-case latency,
since all threads can start encoding data as soon as the first SB-row
worth of data is available to the encoder.
There is some test code that does random tile ordering in the decoder,
to confirm that each tile is indeed independently decodable from other
tiles in the same frame. At tile edges, all contexts assume default
values (i.e. 0, 0 motion vector, no coefficients, DC intra4x4 mode),
and motion vector search and ordering do not cross tiles in the same
frame.
t log
Tile independence is not maintained between frames ATM, i.e. tile 0 of
frame 1 is free to use motion vectors that point into any tile of frame
0. We support 1 (i.e. no tiling), 2 or 4 column-tiles.
The loopfilter crosses tile boundaries. I discussed this briefly with Aki
and he says that's OK. An in-loop loopfilter would need to do some sync
between tile threads, but that shouldn't be a big issue.
Resuls: with tiling disabled, we go up slightly because of improved edge
use in the intra4x4 prediction. With 2 tiles, we lose about ~1% on derf,
~0.35% on HD and ~0.55% on STD/HD. With 4 tiles, we lose another ~1.5%
on derf ~0.77% on HD and ~0.85% on STD/HD. Most of this loss is
concentrated in the low-bitrate end of clips, and most of it is because
of the loss of edges at tile boundaries and the resulting loss of intra
predictors.
TODO:
- more tiles (perhaps allow row-based tiling also, and max. 8 tiles)?
- maybe optionally (for EC purposes), motion vectors themselves
should not cross tile edges, or we should emulate such borders as
if they were off-frame, to limit error propagation to within one
tile only. This doesn't have to be the default behaviour but could
be an optional bitstream flag.
Paul Wilkins [Tue, 5 Feb 2013 10:28:26 +0000 (10:28 +0000)]
Change definition of NearestMV.
This commit makes the NearestMV match the chosen
best reference MV. It can be a 0,0 or non zero vector
which means the the compound nearest mv mode can
combine a 0,0 and a non zero vector.
Scott LaVarnway [Tue, 5 Feb 2013 00:49:17 +0000 (16:49 -0800)]
Added vp9_short_idct1_32x32_c
and called this function in vp9_dequant_idct_add_32x32_c when
eob == 1. For the test clip used, the decoder performance improved
by 21+%. Based on Yaowu's 16 point idct work.
Yaowu Xu [Fri, 1 Feb 2013 00:16:28 +0000 (16:16 -0800)]
Changes 16 point idct
This commit changes the inverse 16 point dct to use the same algorithm
as the one for 32 point idct. In fact, now 16 point dct uses the exact
version of the souce code for even portion of the 32 point idct.
Tests showed current implementation has significant better accuracy
than the previous version. With this implementation and the minor bug
fix on forward 16 point dct, encoding tests showed about 0.2% better
compression of CIF set, test results on std-hd setting pending.
Yaowu Xu [Wed, 30 Jan 2013 21:01:49 +0000 (13:01 -0800)]
A fix point implementation of 32x32 idct
This commit changes the 32x32 idct to use integer only. The algorithm
was taken directly from "A Fast Computational Algorithm for the
Discrete Cosine Tranform" by W. Chen, et al., which was published in
IEEE Transaction on Communication Vol. Com.-25 No. 9, 1977. The signal
flow graph in the original paper is for a 32 point forward dct, the
current implementation of inverse DCT was done by follow the graph in
reversed direction.
With this implementation, the 32 point inverse dct contains a 16 point
inverse dct in its even portion, similarly the 16 point idct further
contains 8 point and 4 point inverse dcts.
As of patch 4, encoding tests showed there is no compression loss when
compared against the floating point baseline. Numbers even showed very
small postives. (cif: .01%, std-hd: .05%).
Ronald S. Bultje [Wed, 30 Jan 2013 05:46:31 +0000 (21:46 -0800)]
Default superblock skip flag to 32x32 for skip-blocks.
This is identical to the later decisions made in encode_superblock().
This commit doesn't actually change anything, but makes the mbmi state
more consistent between the RD loop and the final encode result.
Ronald S. Bultje [Sat, 26 Jan 2013 00:08:19 +0000 (16:08 -0800)]
Fix block pointer corruption in intra8x8 prediction with 4x4 transform.
The RD loop would change the pointer after the first mode (DC) was tested,
leading to corrupt block objects being provided for the others. This
would essentially render the i8x8 predictor useless.
Paul Wilkins [Tue, 29 Jan 2013 13:33:17 +0000 (13:33 +0000)]
Remove eob_max_offset markers.
Remove eob_max_offset markers and replace
with the generic skip_block flag to indicate
to the quantizer that all coeffs to be set to 0
and eob position set to 0;
Paul Wilkins [Thu, 24 Jan 2013 18:28:33 +0000 (18:28 +0000)]
Simplify Zero bin and zero bin run code.
Simplification to eliminate a number of very large data
data structures. All zero run, zbin boosts for different
transform sizes are now limited to a maximum run length
of 15 before they max out the boost.
Some further work still needs be done to refactor, rationalize
and optimize the multiple quantizer functions.
The simplification coupled with tweaks to the 16 element array
now used for all transform sizes, has minimal effect on quality.
Deb Mukherjee [Fri, 25 Jan 2013 19:30:28 +0000 (11:30 -0800)]
Adding a frame parallel decoding mode
Adds a flag to disable features that would inhibit frame parallel
decoding. This includes backward adaptation and MV sorting based
on search in ref frame buffer.
Deb Mukherjee [Tue, 15 Jan 2013 14:43:35 +0000 (06:43 -0800)]
Adds an error-resilient mode with test
Adds an error-resilient mode where frames can be continued
to be decoded even when there are errors (due to network losses)
on a prior frame. Specifically, backward updates are turned off
and probabilities of various symbols are reset to defaults at
the beginning of each frame. Further, the last frame's mvs are
not used for the mv reference list, and the sorting of the
initial list based on search on previous frames is turned off
as well.
Also adds a test where an arbitrary set of frames are skipped
from decoding to simulate errors. The test verifies (1) that if
the error frames are droppable - i.e. frame buffer updates have
been turned off - there are no mismatch errors for the remaining
frames after the error frames; and (2) if the error-frames are non
droppable, there are not only no decoding errors but the mismatch
PSNR between the decoder's version of the post-error frames and the
encoder's version is at least 20 dB.
John Koleszar [Fri, 18 Jan 2013 19:51:12 +0000 (11:51 -0800)]
Support multiple codecs in test infrastructure
This commit starts to convert the tests to a system where the codec
to be used is provided by a factory object. Currently no tests are
instantiated for VP9 since they all fail for various reasons, but it
was verified that they're called and the correct codec is
instantiated.
John Koleszar [Tue, 22 Jan 2013 16:31:55 +0000 (08:31 -0800)]
Merge changes Ia82cef79,I7324a75a,I7b66daad,I73344451,I91dc210f,I5945b5ce into experimental
* changes:
Use alt-ref frame context for keyframes
Preserve the previous golden frame on golden updates
Generalize and increase frame coding contexts
Start to anonymize reference frames
Update encoder to use fb_idx_ref_cnt
Remove buffer-to-buffer copy logic
John Koleszar [Fri, 18 Jan 2013 22:35:20 +0000 (14:35 -0800)]
Use alt-ref frame context for keyframes
This matches the behavior prior to generalizing the frame context
selection, and intuitively makes sense in that the first forward ref
is immediately after the keyframe, so it's quality is improved a bit
by using the keyframe's entropy context rather than the default.
Yaowu Xu [Thu, 17 Jan 2013 21:26:24 +0000 (13:26 -0800)]
a minor change to a portion of loop filtering
The loop filtering used for MB edge or internal edge of a MB using 8x8
tranform was reading 5 pixel each side and writting 3 pixel each side.
With suggestion from Aki and Scott on hardware&software performance,
this commit changed to read 4 pixel each side and write 3 pixel each
side.
John Koleszar [Wed, 16 Jan 2013 20:19:42 +0000 (12:19 -0800)]
Preserve the previous golden frame on golden updates
This commit restores the quality lost when the buffer-to-buffer copy
logic was removed. Note that this is specific to the current use of
golden frames and will need rework when RTC functionality is added.
John Koleszar [Tue, 15 Jan 2013 23:57:11 +0000 (15:57 -0800)]
Generalize and increase frame coding contexts
Previously there were two frame coding contexts tracked, one for normal
frames and one for alt-ref frames. Generalize this by signalling the
context to use in the bitstream, rather than tieing it to the alt ref
refresh bit. Also increase the number of contexts available to 4, which
may be useful for temporal scalability.
John Koleszar [Tue, 15 Jan 2013 21:49:44 +0000 (13:49 -0800)]
Start to anonymize reference frames
Remove lst_fb_idx, gld_fb_idx, alt_fb_idx, refresh_last_frame,
refresh_golden_frame, refresh_alt_ref_frame from common. Gold/Alt are
encode side conventions. From the decoder's perspective, we want to be
dealing with numbered references.
Updates to active_ref 2 signal mode context switches, vestigial from
refresh_alt_ref_frame. This needs some clean up to make sense with
increased numbers of reference frames, as well as reimplementing the
swapping of alt/golden which was previously done using the
buffer-to-buffer copy mechanism removed in an earlier commit.
John Koleszar [Mon, 14 Jan 2013 22:44:39 +0000 (14:44 -0800)]
Remove buffer-to-buffer copy logic
This is the first in a series of commits to add additional reference
frames to the codec. Each frame will be able to update any of the
available references, but copying between references is not
supported.
John Koleszar [Mon, 14 Jan 2013 19:49:30 +0000 (11:49 -0800)]
Use INT64_MAX instead of LLONG_MAX
These variables have the type int64_t, not long long. long long could
be a larger type than 64 bits. Emulate INT64_MAX for older versions of
MSVC, and remove the unreferenced vpx_ports/vpxtypes.h
Yaowu Xu [Mon, 14 Jan 2013 17:28:35 +0000 (09:28 -0800)]
changed UV plane loop filtering for TX_8X8
In commit 9a1d73d, loop filtering was added for UV 4x4 boundaries
when TX_8X8 is used by a MB. This commit further refined the decision
to be based on the actual transform used for the UV planes. When
UV planes use 4x4 transform, i.e. when prediction mode used is either
I8X8_PRED or SPLITMV, UV planes are filtered on 4x4 boundaries, and no
filtering is applied on 4x4 block boundaries when UV planes use 8X8
transform.
Ronald S. Bultje [Mon, 14 Jan 2013 20:43:12 +0000 (12:43 -0800)]
Reset x->skip for each iteration in the RD loop.
This prevents ill-defined behaviour, such as setting x->skip for a mode
that is excluded because of frame-level flags (e.g. filter selection,
compound prediction selection), then not breaking out of the RD loop
because the mode is not allowed, but keeping the flag on. Whatever mode
is iterated through next in the RD loop will then carry this flag, and
all sort of bad stuff happens, such as x->skip being set on intra pred
modes.
Deb Mukherjee [Wed, 9 Jan 2013 14:26:54 +0000 (06:26 -0800)]
Further enhancements/fixes on dct/dwt hybrid txfm
Fixes some scaling issues. Adds an option to only compute the
dct on the low-low subband for 32x32 and 64x64 blocks using
only a single 16x16 dct after 1 and 2 wavelet decomposition
levels respectively. Also adds an option to use a 8x8 dct
as building block.
Currenlty with the 2/6 filter and with a single 16x16 dct on
the low low band, the reuslts compared to full 32x32 dct is
as follows:
derf: -0.15%
yt: -0.29%
std-hd: -0.18%
hd: -0.6%
These are my current recommended settings, since the 2/6 filter
is very simple.
Scott LaVarnway [Sat, 12 Jan 2013 01:11:04 +0000 (17:11 -0800)]
WIP: Added sse2 version of vp9_mb_lpf_horizontal_edge_w
and vp9_mb_lpf_vertical_edge_w_sse2. This was quickly done so we can
run some tests over the weekend. Future commits will optimize/refactor these
functions further.
The decoder performance improved by ~17% for the clip used.