This patch attempts to reduce the peak bitrate hit by the encoder
when using small buffer windows.
Tested on the CIF set over 200-500kbps using these settings:
--buf-sz=500 --buf-initial-sz=250 --buf-optimal-sz=250 \
--undershoot-pct=100
Two pass encodes were tested at best quality. One pass encodes were
tested only at realtime speed 4:
--rt --cpu-used=-4
The peak datarate (over the specified 500ms window) was measured
for each encode, and averaged together to get metric for
"average peak," computed as SUM(peak)/SUM(target). This patch
reduces the average peak datarate as follows:
One pass:
baseline: 1.29715
this patch: 1.23664
Two pass:
baseline: 1.32702
this patch: 1.37824
This change had a positive effect on our quality metrics as well:
One pass CBR:
Min / Mean / Max (pct)
Average PSNR -0.42 / 2.86 / 27.32
Overall PSNR -0.90 / 2.00 / 17.27
SSIM -0.05 / 3.95 / 37.46
Two pass CBR:
Min / Mean / Max (pct)
Average PSNR -4.47 / 4.35 / 35.99
Overall PSNR -3.40 / 4.18 / 36.46
SSIM -4.56 / 6.98 / 53.67
One pass VBR:
Min / Mean / Max (pct)
Average PSNR -5.21 / 0.01 / 3.30
Overall PSNR -8.10 / -0.38 / 1.21
SSIM -7.38 / -0.11 / 3.17
(note: most values here were close to the mean, there were a few
outliers on files that were very sensitive to golden frame size)
Two pass VBR:
Min / Mean / Max (pct)
Average PSNR 0.00 / 0.00 / 0.00
Overall PSNR 0.00 / 0.00 / 0.00
SSIM 0.00 / 0.00 / 0.00
Neither one pass or two pass CBR mode adheres particularly strictly
to the short term buffer constraints, and two pass is less
consistent, even in the baseline commit. This should be addressed
in a later commit. This likely will hurt the quality numbers, as it
will have to reduce the burstiness of golden frames.
Aside: My work on this commit makes it clear that we need to make
rate control modes "pluggable", where you can easily write a new
one or work on one in isolation.
Change-Id: I1ea9a48f2beedd59891f1288aabf7064956b4716
fixed a bug where active_worst_quality could be set
below active_best_quality which could result in an
infinite loop.
Change-Id: I93c229c3bc5bff2a82b4c33f41f8acf4dd194039
This patch collects the twopass specific memebers of VP8_COMP into a
dedicated struct. This is a first step towards isolating the two pass
rate control and aids readability by decorating these variables with
the 'twopass.' namespace. This makes it clear to the reader in what
contexts the variable will be valid, and is a hint that a section of
code might be a good candidate to move to firstpass.c in later
refactoring. There likely will be other rate control modes that need
their own specific data as well.
This notation is probably overly verbose in firstpass.c, so an
alternative would be to access this struct through a pointer like
'rc->' instead of 'cpi->firstpass.' in that file. Feel free to make
a review comment to that effect if you prefer.
Change-Id: I0ab8254647cb4b493a77c16b5d236d0d4a94ca4d
The partition_info struct contains info just for SPLITMV,
so it should be used instead of BLOCKD. Eventually, I want
to reduce the size of B_MODE_INFO struct found in BLOCKD, so
this is the first step toward that goal.
Also, since SPLITMV is not supported in vp8_pick_inter_mode(),
the unnecessary mem copies and checks were removed. For rt
encodes, this gave a slight performance improvement.
Change-Id: I5585c98fa9d5acbde1c7e0f452a01d9ecc080574
The error-concealer is plugged in after any motion vectors have been
decoded. It tries to estimate any missing motion vectors from the
motion vectors of the previous frame. Intra blocks with missing
residual are replaced with inter blocks with estimated motion vectors.
This feature was developed in a separate sandbox
(sandbox/holmer/error-concealment).
Change-Id: I5c8917b031078d79dbafd90f6006680e84a23412
rvct 4.1 was complaining about vstmia.16, store multiple expects 64 data type.
optimized the implementation.
Change-Id: I0701052cabd685c375637bbc3796ff6d88f5972c
This commit restructures the mb activity masking code
to better facilitate experimentation using different metrics
etc. and also allows for adjustment of the zero bin either
for encode only or both the encode and mode selection
stages
It also uses information from the current frame rather than
the previous frame and the default strength has been
reduced.
Change-Id: Id39b19eace37574dc429f25aae810c203709629b
This patch improves the accuracy of frame rate estimation by using a
larger, 1 second window. It also more quickly adapts to step changes
in the input frame rate (ie 30fps to 15fps)
Change-Id: I39e48a8f5ac880b4c4b2ebd81049259b81a0218e
The compiler produces better assembly when using int_mv
for assignments. The compiler shifts and ors the two 16bit
values when assigning MV.
Change-Id: I52ce4bc2bfbfaf3f1151204b2f21e1e0654f960f
Further modification and wrong implementation fix which caused
refining_search and refining_searchx4 result mismatching.
Change-Id: I80cb3a44bf5824413fd50c972e383eebb75f9b6f
This is to reflect the RD improvement in the encoder. The change has a
small positive impact on quality (0.25% by VPXSSIM and 0.05% by PSNR)
Change-Id: Ic66ffc19b10870645088c0624c85556f009fd210
The variable is introduced in commit 2e53e9e53 to make more use of
trellis quantization, but this is no longer necessary after RDMULT
was made adaptive in a number of later commits.
Change-Id: I7420522ec7723f38cf77033466c25afb405d52ae
global values were being referenced, but the GOT was not being set up.
as the GOT is only required for PIC, this issue wasn't caught in the
default configuration.
Change-Id: I8006e53776139362a76f2c80cf9d0f8458602b2f
http://code.google.com/p/webm/issues/detail?id=328
In NEWMV mode, currently, full search is used as the refining search
after n-step search. By replacing it with an iterative diamond search
of radius 1 largely reduced the computation complexity, but still
maintained the same encoding quality since the refining search is
done for every macroblock instead of only a small precentage of
macroblocks while using full search.
Tests on the test set showed a 3.4% encoding speed increase with none
psnr & ssim loss.
Change-Id: Ife907d7eb9544d15c34f17dc6e4cfd97cb743d41
