When coding the frame that corresponds to the midpoint frame
defining an ARF, do not update the last reference frame buffer.
Previously this buffer was updated meaning that when coding the next
ARF all the reference buffers were the same (or nearly so).
Turning the update off means that the frame before is still available
as an alternative predictor and for use in compound prediction.
Also fixed inconsistency in test for mismatch (patch from JK).
Net average gains (derf 0.049, yt 0.163, yt-hd 0.207, std-hd 0.286)
Change-Id: Ifee21da21ccbb1648ac2eafe890d3ce60562c7bc
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.
Change-Id: I5951c3a0742a767b20bc9fb5af685d9892c2c96f
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.
Change-Id: I7324a75acd96eafd9e0f9b8633d782e390d5dc21
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.
Change-Id: I7334445158b7666f9295d2a2dd22aa03f4485f58
Do reference counting the same way on the encoder as the decoder does,
rather than maintaining the 'flags' member of YV12_BUFFER_CONFIG.
Change-Id: I91dc210ffca081acaf9d5c09a06e7461b3c3139c
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.
Change-Id: I5945b5ce6cc3582c495102b4e7eed4f08c44d5a1
This commit did a couple of minor cleanup/refactoring to prepare for
futher loop filter experiments. It merged y_only version of loop filter
function into the regular one, which makes sure that same logic is used
for functions for picking level and for actual loop filtering.
Change-Id: Id10c94dccd45f58e5310bacfdf6ee63cbb60b86f
For coefficients, use int16_t (instead of short); for pixel values in
16-bit intermediates, use uint16_t (instead of unsigned short); for all
others, use uint8_t (instead of unsigned char).
Change-Id: I3619cd9abf106c3742eccc2e2f5e89a62774f7da
Only declare the functions in vpx_scale RTCD and include the relevant
header.
Remove unused files and functions in vpx_scale to avoid wasting time
renaming. vpx_scale/win32/scaleopt.c contains functions which have not
been called in a long time but are potentially optimized.
The 'vp8' functions have not been renamed yet. That is for after the
cleanup.
Change-Id: I2c325a101d60fa9d27e7dfcd5b52a864b4a1e09c
Support for gyp which doesn't support multiple objects in the same
static library having the same basename.
Change-Id: Ib947eefbaf68f8b177a796d23f875ccdfa6bc9dc
