- Used three probability approach for temporal context as follows:
P0 - probability of no change if both above and left not changed
P1 - probability of no change if one of above and left has changed
P2 - probability of no change if both above and left have changed
In addition, a 1 bit/frame has been used to decide whether to use temporal context or to encode directly. The cost of using both the schemes is calculated ahead and the temporal_update flag is set if the cost of using temporal context is lower than encoding the segment ids directly.
This approach has given around 20% reduction in cost of bits needed to encode segmentation ids.
Change-Id: I44a5509599eded215ae5be9554314280d3d35405
This eliminates a large set of warnings exposed by the Mozilla build
system (Use of C++ comments in ISO C90 source, commas at the end of
enum lists, a couple incomplete initializers, and signed/unsigned
comparisons).
It also eliminates many (but not all) of the warnings expose by newer
GCC versions and _FORTIFY_SOURCE (e.g., calling fread and fwrite
without checking the return values).
There are a few spurious warnings left on my system:
../vp8/encoder/encodemb.c:274:9: warning: 'sz' may be used
uninitialized in this function
gcc seems to be unable to figure out that the value shortcut doesn't
change between the two if blocks that test it here.
../vp8/encoder/onyx_if.c:5314:5: warning: comparison of unsigned
expression >= 0 is always true
../vp8/encoder/onyx_if.c:5319:5: warning: comparison of unsigned
expression >= 0 is always true
This is true, so far as it goes, but it's comparing against an enum, and the C
standard does not mandate that enums be unsigned, so the checks can't be
removed.
Change-Id: Iaf689ae3e3d0ddc5ade00faa474debe73b8d3395
Most of the code that actually uses these matrices indexes them as
if they were a single contiguous array, and coverity produces
reports about the resulting accesses that overflow the static
bounds of the first row.
This is perfectly legal in C, but converting them to actual [16]
arrays should eliminate the report, and removes a good deal of
extraneous indexing and address operators from the code.
Change-Id: Ibda479e2232b3e51f9edf3b355b8640520fdbf23
../libvpx/vp8/encoder/bitstream.c: In function ‘pack_inter_mode_mvs’:
../libvpx/vp8/encoder/bitstream.c:1026: warning: array subscript has type ‘char’
Change-Id: Ic77491e0a172fa1821e5b3e914d0dc41fe87c00f
Loopfilter deltas are initialized to zero on keyframes in the decoder.
The values then persist from the previous frame unless an update bit
is set in the bitstream. This data is not included in the entropy
data saved by the 'refresh entropy' bit in the bitstream, so it is
effectively an additional contextual element beyond the 3 ref-frames
and the entropy data.
The encoder was treating this delta update bit as update-if-nonzero,
meaning that the value would be refreshed even if it hadn't changed,
and more significantly, if the correct value for the delta changed
to zero, the update wouldn't be sent, and the decoder would preserve
the last (presumably non-zero) value.
This patch updates the encoder to send an update only if the value
has changed from the previously transmitted value. It also forces the
value to be transmitted in error resilient mode, to account for lost
context in the event of lost frames.
Change-Id: I56671d5b42965d0166ac226765dbfce3e5301868
-Updates by making use of spatial correlation.
-Checks if the segment_id is same as above or left context and encodes only the update to the map instead of updating individual segment_ids.
Change-Id: Ib861df97e8aa2b37516219eeddcdbaf552b6a249
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
Moving the eob structure allows for a non-struct based
function to handle decoding an entire mb of
idct/dequant/recon data. This allows for SIMD functions
to idct/dequant/recon multiple blocks at once.
SSE2 implementation gives 3% gain on Atom.
Change-Id: I8a8f3efd546ea4e0535f517d94f347cfb737c9c2
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
When the license headers were updated, they accidentally contained
trailing whitespace, so unfortunately we have to touch all the files
again.
Change-Id: I236c05fade06589e417179c0444cb39b09e4200d
This patch removes the secondary MV clamping from the MV decoder. This
behavior was consistent with limits placed on non-split MVs by the
reference encoder, but was inconsistent with the MVs generated in the
split case.
The purpose of this secondary clamping was only to prevent crashes on
invalid data. It was not intended to be a behaviour an encoder could or
should rely on. Instead of doing additional clamping in a way that
changes the entropy context, the secondary clamp is removed and the
border handling is made implmentation specific. With respect to the
spec, the border is treated as essentially infinite, limited only by
the clamping performed on the near/nearest reference and the maximum
encodable magnitude of the residual MV.
This does not affect any currently produced streams.
Change-Id: I68d35a2fbb51570d6569eab4ad233961405230a3
