Do mvp clamping in full-pixel precision instead of 1/8-pixel
precision to avoid error caused by right shifting operation.
Also, further fixed the motion vector limit calculation in change:
b748045470
Change-Id: Ied88a4f7ddfb0476eb9f7afc6ceeddbf209fffd7
In this commit I have added an experimental function
that tests prediction quality either side of a central position
to calculate a suggested boost number for an ARF frame.
The function is passed an offset from the current position and
a number of frames to search forwards and backwards.
It returns a forward, backward and compound boost number.
The new code can be deactivated using #define NEW_BOOST 0
In its current default state the code searches forwards and backwards
from the proposed position of the next alt ref.
The the old code used a boost number calculated by scanning forward
from the previous GF up to the proposed alt ref frame position.
I have also added some code to try and prevent placement of a gf/arf
where there is a brief flash.
Change-Id: I98af789a5181148659f10dd5dd2ff2d4250cd51c
I got this idea from Pascal (Thanks). Before encoding a macroblock,
copy it to a 16x16 buffer, and then read source data from there
instead. This will help keep the source data in cache, and help
with the performance.
Change-Id: Id05f4cb601299150511d59dcba0ae62c49b5b757
This reverts commit 212f618373.
Further testing shows that the overshoot accumulation/damping is too
aggressive on some clips. Allowing the accumulated overshoot to
decay and limiting to damping to golden frames shows some promise.
But some clips show significant overshoot in the buffer window, so
I think this still needs work.
Change-Id: Ic02a9ca34f55229f9cc04786f4fab54cdc1a3ef5
Modify the second-pass code to provide a full golden-frame (GF) bit
allocation boost if the past GF group (GFG) had no alt-ref frame (ARF),
even if the current GFG does contain and ARF.
This mostly has no effect on clips, since switching ARFs on/off between
GFGs is not very common. Has a positive effect on e.g. cheer (+0.45 SSIM
at 600kbps) and football (+0.25 SSIM at 600kbps), particularly at high
bitrates. Has a negative effect (-0.04 SSIM at 300kbps) at pamphlet,
which appears only marginally related to this patch, and crew (-0.1 SSIM
at 700kbps).
Change-Id: I2e32899638b59f857e26efeac18a82e0c0b77089
firstpass.c contains some rate adjustment code that assures that the
last few frames in a sequence abide by rate limits. If the second-to-
last group of frames contains an alt-ref frame (ARF), the last golden
frame (GF) is zero bytes, and we will thus spend a ridiculously high
number of bits on regular P-frames trying to hit the target rate. This
does slightly enhance the quality of these last few frames, but has
no perceptual value (other than hitting the target rate).
Disabling this code means we consistently (slightly) undershoot the
target rate and consequently do worse on the last few frames of a
clip, which is particularly noticeable for small clips. The quality-
per-bitrate is generally better, ~0.2% better overall on derf-set,
especially on clips such as garden, tennis, foreman at low bitrates.
Has a negative effect on hallmonitor at high bitrates.
Change-Id: I1d63452fef5fee4a0ad2fb2e9af4c9f2e0d86d23
Moved encode_intra function from firstpass.c to encodeintra.c to
prevent linking problem in real-time only build. Also changed name
of the function to vp8_encode_intra because it is not a static.
Change-Id: Ibf3c6c1de3152567347e5fbef47d1d39564620a5
Some further re-structuring of activity masking code.
Still has various experimental switches.
Supports a metric based on intra encode.
Experimental comparison against a fixed activity target rather
than a frame average, for altering rd and zbin.
Overall the SSIM performance is similar to TT's original
code but there is a much smaller PSNR hit of circa
0.5% instead of 3.2%
Change-Id: I0fd53b2dfb60620b3f74d7415e0b81c1ac58c39a
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
Declared the bmi in BLOCKD as a union instead of B_MODE_INFO.
Then removed B_MODE_INFO completely.
Change-Id: Ieb7469899e265892c66f7aeac87b7f2bf38e7a67
This is basically a slightly modified version of the previous patch,
and it has a moderately positive effect (SSIM/PSNR both +0.08% avg
on derf-set). Most clips show no change, except waterfall/coastguard,
each ~ +0.8% SSIM/PSNR. You can see similar effects in other clips
by shortening their length to terminate at a very short last group
of frames.
Change-Id: I7a70de99ca1f9fe6a8b6ca7a6e30e8a4b64383e4
this commit makes the usage errorperbit and sadperbit consistent for
encoding modes and passes. Removed all different magic weight factors
associated with errorperbit. Now 1/2 is used for both sadperbit16 and
sadperbit4, the /2 operation is merged into initializations of the 2
variables.
Tests on cif set show .23%, 0.18% and 0.19% gain by avg psnr, overall
psnr and ssim respectively.
Change-Id: Ifa285c3e065ce0a5a77addfc9f95aabf54ee270d
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 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
This patch cleans up the source buffer storage and copy mechanism to
allow access through a standard push/pop/peek interface. This approach
also avoids an extra copy in the case where the source is not a
multiple of 16, fixing issue #102.
Change-Id: I05808c39f5743625cb4c7af54cc841b9b10fdbd9
MV sad cost error is only used in full-pixel motion search,
which only need full-pixel resolution instead of quarter-pixel
resolution. This change reduced mvsadcost table size, and
removed unneccessary pamameter passing since this table is
constant once it is generated.
Change-Id: I9f931e55f6abc3c99011321f1dfb2f3562e6f6b0
A large number of functions were defined with external linkage, even
though they were only used from within one file. This patch changes
their linkage to static and removes the vp8_ prefix from their names,
which should make it more obvious to the reader that the function is
contained within the current translation unit. Functions that were
not referenced were removed.
These symbols were identified by:
$ nm -A libvpx.a | sort -k3 | uniq -c -f2 | grep ' [A-Z] ' \
| sort | grep '^ *1 '
Change-Id: I59609f58ab65312012c047036ae1e0634f795779
The firstpass motion map consists of an 8-bit flag for
each MB indicating how strongly the firstpass code
believes it should be filtered during the second pass
ARNR filtering.
For long or large format material the motion map can
become extremely large and hamper the operation of
the encoding process.
This change removes the motion map altogether, leaving
the second pass to rely on the magnitude of the motion
compensated error to determine the filter weight to
use for the MB during ARNR filtering.
Tests on the derf set indicate that the effect of this
change is neutral, with some small wins and losses. The
motion map has therefore been removed based on
a cost/benefit evaluation.
Change-Id: I53e07d236f5ce09a6f0c54e7c4ffbb490fb870f6
The previous calculation of macroblock count (w*h)/256
is not correct when the width/height are not multiples of
16. Use the precalculated macroblock count from
cpi->common instead. This manifested itself as a divide
by zero when the number of pixels was less than 256.
num_mbs updated in estimate_max_q, estimate_q,
estimate_kf_group_q, and estimate_cq
Change-Id: I92ff98587864c801b1ee5485cfead964673a9973
GCC 4.5 and 4.6 both issue a warning about the multi-line format
string introduced in bc9c30a0, which also changed the whitespace
in the associated stt file by line-wrapping the long format string.
Instead, use multiple string constants, which the compiler will
concatenate. This maintains the original formatting, but remains
legible within the standard line length.
Change-Id: I27c9f92d46be82d408105a3a4091f145f677e00e
In some cases where clips have been encoded with
borders (eg. some wide-screen content where there is a
border top and bottom and slide shows containing portrait
format photographs (border left and right)) key frames were
not being correctly detected.
The new code looks to measure cases where a portion of
the image can be coded equally easily using intra or inter
modes and where the resulting error score is also very low.
These "neutral" areas are then discounted in the key frame
detection code.
Change-Id: I00c3e8230772b8213cdc08020e1990cf83b780d8
This code extends what was previously done for GFs, to pick
cases where insertion of a key frame after a fade (or other
transition or complex motion) followed by a still section, will
be beneficial and will reduce the number of forced key frames.
Change-Id: If8bca00457f0d5f83dc3318a587f61c17d90f135
When the modified_error_left accumulator exceeds INT_MAX, an incorrect
cast to int resulted in a negative value, causing the rate control to
allocate no bits to that keyframe group, leading to severe undershoot
and subsequent poor quality.
This error was exposed by the recent change to the rolling target and
actual spend accumulators in commit 305be4e4 which fixed them to
actually calculate the average value rather than be re-initialized
on every frame to the average per-frame bitrate. When this bug was
triggered, the target bitrate could be 0, so the rolling target
becomes small, which causes the undershoot. The code prior to 305be4e4
did not exhibit this behavior because the rolling target was always
set to a reasonable value and was independent of the actual target
bitrate. With this patch, the actual target bitrate is calculated
correctly, and the rate control tracks as expected.
This cast was likely added to silence a compiler warning on a comparison
between a double (modified_error_left) and an int (0). Instead, this
patch removes the cast and changes the comparison to be against 0.0,
which should prevent the warning from reoccuring.
This fixes issue #289. Special thanks to gnafu for his efforts in
reporting and debugging this fix.
Change-Id: Ie5cc1a7b516c578a76c3a50c892a6f04a11621fe
This fixes an overflow problem in the frame error accumulators.
The overflow condition is extreme but did trigger when Frank B.
coded some high motion interlaced HD content.
The observed effect was a catastrophic breakdown of the rate
control leading to massive undershoot and poor bit allocation.
All the error values should really be unsigned but I will look at this
separately.
Change-Id: I9745f5c5ca2783620426b66b568b2088b579151f
Improved the performance of the first pass only
(~6% on 720p test clip) by making use of LUT instead of the
float calculations. Might try a SIMD version later.
Also started to make use of int_mv instead of
MV.
Change-Id: If2a217c7d6b59cd2c25c5553e0ca7e0502403af8
Commit 336aa0b7da incorrectly
declared current_pos as and int, when it should have been
a FIRSTPASS_STATS pointer.
Change-Id: I0a51c7a86ebba8546c95dd5d9d1c1143d4613e40
The old 2 pass code estimated error distribution when coding a
forced (by interval) key frame. The result of this was that in some
cases, when allocating bits at the GF group level within a KF
group there was either a glut of bits or starvation of bits at the end
of the KF group.
Added code to rescan and get the correct data once the position of
a forced key frame has been determined.
Change-Id: I0c811675ef3f9e4109d14bd049d7641682ffcf11
Added code to scan ahead a few frames when we see what
we think is a static scene in the two pass GF loop to see if the
conditions persist.
Moved calculation of decay rate out into a fuunction.
Change-Id: I6e9c67e01ec9f555144deafc8ae67ef25bffb449
These changes are specifically targeted at fade transitions to
static scenes. Here we want to place a GF/ARF immediately
after the fade and prevent an ARF just before the fade.
Also some code lines and comment lines shortened to 80 chars
while I was there.
Change-Id: Iefdc09a4fa7b265048fc017246b73e138693950f
In both vp8_find_next_key_frame and define_gf_group,
motion_pct was initialised at the top of the loop before
next_frame stats had been read in.
This fix sets motion_pct after next_frame stats have
been read.
Change-Id: I8c0bebf372ef8aa97b97fd35b42973d1d831ee73
Incorrect value loop_decay_rate used in GF loop.
The intent was to test the cumulative value decay_accumulator.
Change-Id: I62928c63eb09f4f6936a45ebd1c23784d1c9681b
This code fixes a bug in the calculation of
the minimum Q for alt ref frames.
It also allows an extended gf/arf interval for sections
of clips that completely static (or nearly so).
Change-Id: I1a21aaa16d4f0578e5f99b13bebd78d59403c73b
Where a key frame occurs because of a minimum interval
selected by the user, then these forced key frames ideally need
to be more closely matched in quality to the surrounding frame.
Change-Id: Ia55b1f047e77dc7fbd78379c45869554f25b3df7
Further experiment with restriction of the Q range.
This uses the average non KF/GF/ARF quantizer, instead
of just relying on the initial value. It is not such a strong constraint
but there may be a reduced risk of rate misses.
Change-Id: I424fe782a37a2f4e18c70805e240db55bfaa25ec
