[x265] [PATCH] intra: skip RD analysis when sum of sub CU splitcost bigger than non-split cost
Tom Vaughan
tom.vaughan at multicorewareinc.com
Fri Jul 21 21:33:14 CEST 2017
Ximing - thanks for your contribution!
Pradeep - This early decision optimization certainly looks like it has good
potential to be a smart tradeoff for intermediate presets (like medium).
Sure, the test was only for 2 seconds of video, but for this test case we
see a 10% performance gain with no loss of quality... so that’s very
promising. You’re right; more testing is needed to fully understand the
cost/benefit under a wide range of conditions. Can we ask one of our
engineers to run some tests?
I also think we need to take the lead when it comes to naming CLI options
and parameters. Maybe --splitrdskip?
Thanks,
Tom
*From:* x265-devel [mailto:x265-devel-bounces at videolan.org] *On Behalf
Of *Pradeep
Ramachandran
*Sent:* Tuesday, July 18, 2017 10:10 AM
*To:* Development for x265
*Subject:* Re: [x265] [PATCH] intra: skip RD analysis when sum of sub CU
splitcost bigger than non-split cost
On Fri, Jul 14, 2017 at 10:38 PM, Ximing Cheng <chengximing1989 at foxmail.com>
wrote:
command line:
x265 --input BasketballDrive_1920x1080_50.yuv --input-res 1920x1080 --fps
50 --frames 100 --keyint 0 -o test.265
before patch
encoded 100 frames in 57.28s (1.75 fps), 10496.03 kb/s, Avg QP:34.74
after patch
encoded 100 frames in 51.52s (1.94 fps), 10496.03 kb/s, Avg QP:34.74
Thanks for your test data. Looks like this is an intra-only optimization.
Could you please share more results with longer test sequences at different
resolutions, if you have them? We can also run additional tests before
considering this improvement if the results are more wide-spread.
Also, please add a new param field and cli option that may be used to
exercise this. It is always better to do this instead of affect default
encodes with such performance optimizations. They param should be off by
default, and if we can clearly see the benefits to *all possible encodes* for
a given preset, then we can consider enabling that optimization for that
given preset.
------------------ Original ------------------
*From: * "Ximing Cheng";<chengximing1989 at foxmail.com>;
*Send time:* Saturday, Jul 15, 2017 1:07 AM
*To:* "x265-devel"<x265-devel at videolan.org>;
*Subject: * [x265] [PATCH] intra: skip RD analysis when sum of sub CU
splitcost bigger than non-split cost
# HG changeset patch
# User Ximing Cheng <ximingcheng at tencent.com>
# Date 1500052036 -28800
# Sat Jul 15 01:07:16 2017 +0800
# Node ID 9c2e9f6c6ee73e75b94c2e52f85a64bca628baf0
# Parent 3f6841d271e36dc324936f09846d1f2cb77c63e5
intra: skip RD analysis when sum of sub CU split cost bigger than non-split
cost
This patch will speed up all intra case with almost no BDRATE loss
diff -r 3f6841d271e3 -r 9c2e9f6c6ee7 source/encoder/analysis.cpp
--- a/source/encoder/analysis.cpp Wed Jun 28 10:44:19 2017 +0530
+++ b/source/encoder/analysis.cpp Sat Jul 15 01:07:16 2017 +0800
@@ -485,7 +485,7 @@
md.bestMode->reconYuv.copyToPicYuv(*m_frame->m_reconPic,
parentCTU.m_cuAddr, cuGeom.absPartIdx);
}
-void Analysis::compressIntraCU(const CUData& parentCTU, const CUGeom&
cuGeom, int32_t qp)
+uint64_t Analysis::compressIntraCU(const CUData& parentCTU, const CUGeom&
cuGeom, int32_t qp)
{
uint32_t depth = cuGeom.depth;
ModeDepth& md = m_modeDepth[depth];
@@ -561,6 +561,9 @@
Entropy* nextContext = &m_rqt[depth].cur;
int32_t nextQP = qp;
+ uint64_t curCost = 0;
+ int skipSplitCheck = 0;
+
for (uint32_t subPartIdx = 0; subPartIdx < 4; subPartIdx++)
{
const CUGeom& childGeom = *(&cuGeom + cuGeom.childOffset +
subPartIdx);
@@ -572,7 +575,12 @@
if (m_slice->m_pps->bUseDQP && nextDepth <=
m_slice->m_pps->maxCuDQPDepth)
nextQP = setLambdaFromQP(parentCTU,
calculateQpforCuSize(parentCTU, childGeom));
- compressIntraCU(parentCTU, childGeom, nextQP);
+ curCost += compressIntraCU(parentCTU, childGeom, nextQP);
+ if (m_modeDepth[depth].bestMode && curCost >
m_modeDepth[depth].bestMode->rdCost)
+ {
+ skipSplitCheck = 1;
+ break;
+ }
// Save best CU and pred data for this sub CU
splitCU->copyPartFrom(nd.bestMode->cu, childGeom,
subPartIdx);
@@ -590,14 +598,18 @@
memset(parentCTU.m_cuDepth + childGeom.absPartIdx, 0,
childGeom.numPartitions);
}
}
- nextContext->store(splitPred->contexts);
- if (mightNotSplit)
- addSplitFlagCost(*splitPred, cuGeom.depth);
- else
- updateModeCost(*splitPred);
-
- checkDQPForSplitPred(*splitPred, cuGeom);
- checkBestMode(*splitPred, depth);
+
+ if (!skipSplitCheck)
+ {
+ nextContext->store(splitPred->contexts);
+ if (mightNotSplit)
+ addSplitFlagCost(*splitPred, cuGeom.depth);
+ else
+ updateModeCost(*splitPred);
+
+ checkDQPForSplitPred(*splitPred, cuGeom);
+ checkBestMode(*splitPred, depth);
+ }
}
if (m_param->bEnableRdRefine && depth <= m_slice->m_pps->maxCuDQPDepth)
@@ -620,6 +632,8 @@
md.bestMode->cu.copyToPic(depth);
if (md.bestMode != &md.pred[PRED_SPLIT])
md.bestMode->reconYuv.copyToPicYuv(*m_frame->m_reconPic,
parentCTU.m_cuAddr, cuGeom.absPartIdx);
+
+ return md.bestMode->rdCost;
}
void Analysis::PMODE::processTasks(int workerThreadId)
diff -r 3f6841d271e3 -r 9c2e9f6c6ee7 source/encoder/analysis.h
--- a/source/encoder/analysis.h Wed Jun 28 10:44:19 2017 +0530
+++ b/source/encoder/analysis.h Sat Jul 15 01:07:16 2017 +0800
@@ -145,7 +145,7 @@
void qprdRefine(const CUData& parentCTU, const CUGeom& cuGeom, int32_t
qp, int32_t lqp);
/* full analysis for an I-slice CU */
- void compressIntraCU(const CUData& parentCTU, const CUGeom& cuGeom,
int32_t qp);
+ uint64_t compressIntraCU(const CUData& parentCTU, const CUGeom&
cuGeom, int32_t qp);
/* full analysis for a P or B slice CU */
uint32_t compressInterCU_dist(const CUData& parentCTU, const CUGeom&
cuGeom, int32_t qp);
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