[x265] [PATCH] Add real-time VBV fullness based QP tuning in VBV 2 pass

Kirithika Kalirathnam kirithika at multicorewareinc.com
Fri Sep 4 14:13:52 CEST 2020


>From f1391f094c9c3c0502624532f751219d126905aa Mon Sep 17 00:00:00 2001
From: Kirithika <kirithika at multicorewareinc.com>
Date: Fri, 28 Aug 2020 09:20:47 +0530
Subject: [PATCH] Add real-time VBV fullness based QP tuning in VBV 2 pass

This commit enables real-time VBV fullness based 2nd pass QP  tuning.
Experimental feature.Default disabled
---
 doc/reST/cli.rst               |   9 +++
 source/CMakeLists.txt          |   2 +-
 source/common/param.cpp        |  12 ++++
 source/encoder/ratecontrol.cpp | 100 ++++++++++++++++++---------------
 source/encoder/slicetype.cpp   |  14 +++--
 source/x265.h                  |   4 ++
 source/x265cli.cpp             |   1 +
 source/x265cli.h               |   2 +
 8 files changed, 92 insertions(+), 52 deletions(-)

diff --git a/doc/reST/cli.rst b/doc/reST/cli.rst
index e6c628c36..2a4b25aca 100755
--- a/doc/reST/cli.rst
+++ b/doc/reST/cli.rst
@@ -1977,6 +1977,15 @@ Quality, rate control and rate distortion options

    **Range of values:**  0 to 10

+.. option:: --realtime-vbv-2pass, --no-realtime-vbv-2pass
+
+   It enables the Qp tuning at frame level based on real time VBV Buffer
fullness
+   in the ratecontrol second pass to reduce the VBV violations.
+   It could only be enabled with rate control pass 2 encodes with VBV and
ABR
+   rate control mode.
+
+   Default disabled. **Experimental feature**
+
 Quantization Options
 ====================

diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
index d9ed3983e..5738c861c 100755
--- a/source/CMakeLists.txt
+++ b/source/CMakeLists.txt
@@ -29,7 +29,7 @@ option(NATIVE_BUILD "Target the build CPU" OFF)
 option(STATIC_LINK_CRT "Statically link C runtime for release builds" OFF)
 mark_as_advanced(FPROFILE_USE FPROFILE_GENERATE NATIVE_BUILD)
 # X265_BUILD must be incremented each time the public API is changed
-set(X265_BUILD 196)
+set(X265_BUILD 197)
 configure_file("${PROJECT_SOURCE_DIR}/x265.def.in"
                "${PROJECT_BINARY_DIR}/x265.def")
 configure_file("${PROJECT_SOURCE_DIR}/x265_config.h.in"
diff --git a/source/common/param.cpp b/source/common/param.cpp
index 845c38bd2..fc0425905 100755
--- a/source/common/param.cpp
+++ b/source/common/param.cpp
@@ -288,6 +288,7 @@ void x265_param_default(x265_param* param)
     param->bResetZoneConfig = 1;
     param->reconfigWindowSize = 0;
     param->decoderVbvMaxRate = 0;
+    param->rc.bRealtimeVBV2pass = 0;

     /* Video Usability Information (VUI) */
     param->vui.aspectRatioIdc = 0;
@@ -1375,6 +1376,7 @@ int x265_param_parse(x265_param* p, const char* name,
const char* value)
             sscanf(value, "%d,%d,%d", &p->hmeRange[0], &p->hmeRange[1],
&p->hmeRange[2]);
             p->bEnableHME = true;
         }
+        OPT("realtime-vbv-2pass") p->rc.bRealtimeVBV2pass = atobool(value);
         else
             return X265_PARAM_BAD_NAME;
     }
@@ -1817,6 +1819,15 @@ int x265_check_params(x265_param* param)
     CHECK(param->confWinRightOffset < 0, "Conformance Window Right Offset
must be 0 or greater");
     CHECK(param->confWinBottomOffset < 0, "Conformance Window Bottom
Offset must be 0 or greater");
     CHECK(param->decoderVbvMaxRate < 0, "Invalid Decoder Vbv Maxrate.
Value can not be less than zero");
+    if (param->rc.bRealtimeVBV2pass)
+    {
+        CHECK((param->rc.bStatRead == 0), "Real time VBV in 2 pass option
requires rate control 2 pass to be enabled");
+        if ((param->rc.vbvMaxBitrate <= 0 || param->rc.vbvBufferSize <= 0))
+        {
+            param->rc.bRealtimeVBV2pass = 0;
+            x265_log(param, X265_LOG_WARNING, "Real time VBV enabled
without VBV settings.Disabling real time VBV in 2 pass\n");
+        }
+    }
     return check_failed;
 }

@@ -2593,6 +2604,7 @@ void x265_copy_params(x265_param* dst, x265_param*
src)

     dst->confWinRightOffset = src->confWinRightOffset;
     dst->confWinBottomOffset = src->confWinBottomOffset;
+    dst->rc.bRealtimeVBV2pass = src->rc.bRealtimeVBV2pass;
 #ifdef SVT_HEVC
     memcpy(dst->svtHevcParam, src->svtHevcParam,
sizeof(EB_H265_ENC_CONFIGURATION));
 #endif
diff --git a/source/encoder/ratecontrol.cpp b/source/encoder/ratecontrol.cpp
index 82d7c4f2a..ebf374759 100644
--- a/source/encoder/ratecontrol.cpp
+++ b/source/encoder/ratecontrol.cpp
@@ -1755,34 +1755,32 @@ double RateControl::rateEstimateQscale(Frame*
curFrame, RateControlEntry *rce)
                      g_sliceTypeToChar[m_sliceType],
g_sliceTypeToChar[rce->sliceType]);
         }
     }
-    else
+
+    if ((m_param->rc.bRealtimeVBV2pass && m_param->rc.rateControlMode ==
X265_RC_ABR) || m_isAbr)
     {
-        if (m_isAbr)
+        int pos = m_sliderPos % s_slidingWindowFrames;
+        int addPos = (pos + s_slidingWindowFrames - 1) %
s_slidingWindowFrames;
+        if (m_sliderPos > s_slidingWindowFrames)
         {
-            int pos = m_sliderPos % s_slidingWindowFrames;
-            int addPos = (pos + s_slidingWindowFrames - 1) %
s_slidingWindowFrames;
-            if (m_sliderPos > s_slidingWindowFrames)
-            {
-                const static double base = pow(0.5, s_slidingWindowFrames
- 1);
-                m_movingAvgSum -= m_lastRemovedSatdCost * base;
-                m_movingAvgSum *= 0.5;
-                m_movingAvgSum += m_satdCostWindow[addPos];
-            }
-            else if (m_sliderPos == s_slidingWindowFrames)
-            {
-                m_movingAvgSum += m_satdCostWindow[addPos];
-            }
-            else if (m_sliderPos > 0)
-            {
-                m_movingAvgSum += m_satdCostWindow[addPos];
-                m_movingAvgSum *= 0.5;
-            }
-
-            rce->movingAvgSum = m_movingAvgSum;
-            m_lastRemovedSatdCost = m_satdCostWindow[pos];
-            m_satdCostWindow[pos] = rce->lastSatd;
-            m_sliderPos++;
+            const static double base = pow(0.5, s_slidingWindowFrames - 1);
+            m_movingAvgSum -= m_lastRemovedSatdCost * base;
+            m_movingAvgSum *= 0.5;
+            m_movingAvgSum += m_satdCostWindow[addPos];
+        }
+        else if (m_sliderPos == s_slidingWindowFrames)
+        {
+            m_movingAvgSum += m_satdCostWindow[addPos];
         }
+        else if (m_sliderPos > 0)
+        {
+            m_movingAvgSum += m_satdCostWindow[addPos];
+            m_movingAvgSum *= 0.5;
+        }
+
+        rce->movingAvgSum = m_movingAvgSum;
+        m_lastRemovedSatdCost = m_satdCostWindow[pos];
+        m_satdCostWindow[pos] = rce->lastSatd;
+        m_sliderPos++;
     }

     if (m_sliceType == B_SLICE)
@@ -1887,7 +1885,7 @@ double RateControl::rateEstimateQscale(Frame*
curFrame, RateControlEntry *rce)
                 qScale = x265_clip3(lqmin, lqmax, qScale);
             }

-            if (!m_2pass)
+            if (!m_2pass || m_param->rc.bRealtimeVBV2pass)
             {
                 /* clip qp to permissible range after vbv-lookahead
estimation to avoid possible
                  * mispredictions by initial frame size predictors */
@@ -1955,7 +1953,9 @@ double RateControl::rateEstimateQscale(Frame*
curFrame, RateControlEntry *rce)
                 else
                     q /= zone->bitrateFactor;
             }
-            q /= x265_clip3(0.5, 2.0, (double)(abrBuffer - diff) /
abrBuffer);
+            /*Existing ABR conformance check may not be valid with real
time VBV*/
+            if(!m_param->rc.bRealtimeVBV2pass)
+                q /= x265_clip3(0.5, 2.0, (double)(abrBuffer - diff) /
abrBuffer);
             if (m_expectedBitsSum > 0)
             {
                 /* Adjust quant based on the difference between
@@ -1988,24 +1988,34 @@ double RateControl::rateEstimateQscale(Frame*
curFrame, RateControlEntry *rce)

             if (m_isVbv)
             {
-                /* Do not overflow vbv */
-                double expectedSize = qScale2bits(rce, q);
-                double expectedVbv = m_bufferFill + m_bufferRate -
expectedSize;
-                double expectedFullness = rce->expectedVbv / m_bufferSize;
-                double qmax = q * (2 - expectedFullness);
-                double sizeConstraint = 1 + expectedFullness;
-                qmax = X265_MAX(qmax, rce->newQScale);
-                if (expectedFullness < .05)
-                    qmax = lmax;
-                qmax = X265_MIN(qmax, lmax);
-                while (((expectedVbv < rce->expectedVbv/sizeConstraint) &&
(q < qmax)) ||
+                if (!m_param->rc.bRealtimeVBV2pass)
+                {
+                    /* Do not overflow vbv */
+                    double expectedSize = qScale2bits(rce, q);
+                    double expectedVbv = m_bufferFill + m_bufferRate -
expectedSize;
+                    double expectedFullness = rce->expectedVbv /
m_bufferSize;
+                    double qmax = q * (2 - expectedFullness);
+                    double sizeConstraint = 1 + expectedFullness;
+                    qmax = X265_MAX(qmax, rce->newQScale);
+                    if (expectedFullness < .05)
+                        qmax = lmax;
+                    qmax = X265_MIN(qmax, lmax);
+                    while (((expectedVbv < rce->expectedVbv /
sizeConstraint) && (q < qmax)) ||
                         ((expectedVbv < 0) && (q < lmax)))
+                    {
+                        q *= 1.05;
+                        expectedSize = qScale2bits(rce, q);
+                        expectedVbv = m_bufferFill + m_bufferRate -
expectedSize;
+                    }
+                }
+                else
                 {
-                    q *= 1.05;
-                    expectedSize = qScale2bits(rce, q);
-                    expectedVbv = m_bufferFill + m_bufferRate -
expectedSize;
+                        /*  clip qp to permissible range after
vbv-lookahead estimation to avoid possible
+                        * mispredictions by Rate Control pass 1 statistics
analysis */
+                        q = clipQscale(curFrame, rce, q);
                 }
             }
+
             q = x265_clip3(lmin, lmax, q);
         }
         else
@@ -2301,7 +2311,7 @@ double RateControl::clipQscale(Frame* curFrame,
RateControlEntry* rce, double q)
     double lmin = m_lmin[rce->sliceType];
     double lmax = m_lmax[rce->sliceType];
     double q0 = q;
-    if (m_isVbv && m_currentSatd > 0 && curFrame)
+    if ((m_isVbv || m_param->rc.bRealtimeVBV2pass) && curFrame &&
m_currentSatd > 0 )
     {
         if (m_param->lookaheadDepth || m_param->rc.cuTree ||
             (m_param->scenecutThreshold || m_param->bHistBasedSceneCut) ||
@@ -2379,7 +2389,7 @@ double RateControl::clipQscale(Frame* curFrame,
RateControlEntry* rce, double q)
                     }
                     /* Try to get the buffer not more than 80% filled, but
don't set an impossible goal. */
                     targetFill = x265_clip3(m_bufferSize * (1 - 0.2 *
finalDur), m_bufferSize, m_bufferFill - totalDuration * m_vbvMaxRate * 0.5);
-                    if (m_isCbr && bufferFillCur > targetFill &&
!m_isSceneTransition)
+                    if ((m_isCbr || m_2pass) && bufferFillCur > targetFill
&& !m_isSceneTransition)
                     {
                         q /= 1.01;
                         loopTerminate |= 2;
@@ -2432,7 +2442,7 @@ double RateControl::clipQscale(Frame* curFrame,
RateControlEntry* rce, double q)
          * lookahead vbv reduces its qscale by half its value. Be on safer
side and avoid drastic
          * qscale reductions for frames high in complexity */
         bool mispredCheck = rce->movingAvgSum && m_currentSatd >=
rce->movingAvgSum && q <= q0 / 2;
-        if (!m_isCbr || (m_isAbr && mispredCheck))
+        if (!m_isCbr || ((m_isAbr || m_2pass) && mispredCheck))
             q = X265_MAX(q0, q);

         if (m_rateFactorMaxIncrement)
@@ -2442,7 +2452,7 @@ double RateControl::clipQscale(Frame* curFrame,
RateControlEntry* rce, double q)
             return x265_clip3(lmin, qmax, q);
         }
     }
-    if (m_2pass)
+    if (!curFrame && m_2pass)
     {
         double min = log(lmin);
         double max = log(lmax);
diff --git a/source/encoder/slicetype.cpp b/source/encoder/slicetype.cpp
index 4e52e584c..69f3b0ad1 100644
--- a/source/encoder/slicetype.cpp
+++ b/source/encoder/slicetype.cpp
@@ -1497,14 +1497,15 @@ void Lookahead::slicetypeDecide()
         }
     }

-    if (m_lastNonB && !m_param->rc.bStatRead &&
+    if (m_lastNonB &&
         ((m_param->bFrameAdaptive && m_param->bframes) ||
          m_param->rc.cuTree || m_param->scenecutThreshold ||
m_param->bHistBasedSceneCut ||
          (m_param->lookaheadDepth && m_param->rc.vbvBufferSize)))
     {
-        slicetypeAnalyse(frames, false);
+        if(!m_param->rc.bStatRead)
+            slicetypeAnalyse(frames, false);
         bool bIsVbv = m_param->rc.vbvBufferSize > 0 &&
m_param->rc.vbvMaxBitrate > 0;
-        if (m_param->analysisLoad && m_param->scaleFactor && bIsVbv)
+        if ((m_param->analysisLoad && m_param->scaleFactor && bIsVbv) ||
m_param->rc.bRealtimeVBV2pass)
         {
             int numFrames;
             for (numFrames = 0; numFrames < maxSearch; numFrames++)
@@ -1749,7 +1750,7 @@ void Lookahead::slicetypeDecide()
         }
     }

-    bool isKeyFrameAnalyse = (m_param->rc.cuTree ||
(m_param->rc.vbvBufferSize && m_param->lookaheadDepth)) &&
!m_param->rc.bStatRead;
+    bool isKeyFrameAnalyse = (m_param->rc.cuTree ||
(m_param->rc.vbvBufferSize && m_param->lookaheadDepth));
     if (isKeyFrameAnalyse && IS_X265_TYPE_I(m_lastNonB->sliceType))
     {
         m_inputLock.acquire();
@@ -1764,9 +1765,10 @@ void Lookahead::slicetypeDecide()
         m_inputLock.release();

         frames[j + 1] = NULL;
-        slicetypeAnalyse(frames, true);
+        if (!m_param->rc.bStatRead)
+            slicetypeAnalyse(frames, true);
         bool bIsVbv = m_param->rc.vbvBufferSize > 0 &&
m_param->rc.vbvMaxBitrate > 0;
-        if (m_param->analysisLoad && m_param->scaleFactor && bIsVbv)
+        if ((m_param->analysisLoad && m_param->scaleFactor && bIsVbv) ||
m_param->rc.bRealtimeVBV2pass)
         {
             int numFrames;
             for (numFrames = 0; numFrames < maxSearch; numFrames++)
diff --git a/source/x265.h b/source/x265.h
index 0ffa600b0..bcd1d4e58 100644
--- a/source/x265.h
+++ b/source/x265.h
@@ -1486,6 +1486,10 @@ typedef struct x265_param
         /* internally enable if tune grain is set */
         int      bEnableConstVbv;

+        /*Enables Qp tuning with respect to real time VBV buffer fullness
in rate
+        control 2 pass. Experimental.Default is disabled*/
+        int      bRealtimeVBV2pass;
+
     } rc;

     /*== Video Usability Information ==*/
diff --git a/source/x265cli.cpp b/source/x265cli.cpp
index 6e8e0e661..0b17a8d3a 100755
--- a/source/x265cli.cpp
+++ b/source/x265cli.cpp
@@ -221,6 +221,7 @@ namespace X265_NS {
             "                                   - 3 : Nth pass, overwrites
stats file\n");
         H0("   --[no-]multi-pass-opt-analysis   Refine analysis in 2 pass
based on analysis information from pass 1\n");
         H0("   --[no-]multi-pass-opt-distortion Use distortion of CTU from
pass 1 to refine qp in 2 pass\n");
+        H0("   --[no-]realtime-vbv-2pass     Enable realtime VBV in rate
control 2 pass.Default %s\n", OPT(param->bLossless));
         H0("   --stats                       Filename for stats file in
multipass pass rate control. Default x265_2pass.log\n");
         H0("   --[no-]analyze-src-pics       Motion estimation uses source
frame planes. Default disable\n");
         H0("   --[no-]slow-firstpass         Enable a slow first pass in a
multipass rate control mode. Default %s\n",
OPT(param->rc.bEnableSlowFirstPass));
diff --git a/source/x265cli.h b/source/x265cli.h
index 311f06935..89840d9af 100644
--- a/source/x265cli.h
+++ b/source/x265cli.h
@@ -284,6 +284,8 @@ static const struct option long_options[] =
     { "no-multi-pass-opt-analysis",    no_argument, NULL, 0 },
     { "multi-pass-opt-distortion",     no_argument, NULL, 0 },
     { "no-multi-pass-opt-distortion",  no_argument, NULL, 0 },
+    { "realtime-vbv-2pass",           no_argument, NULL, 0 },
+    { "no-realtime-vbv-2pass",        no_argument, NULL, 0 },
     { "slow-firstpass",       no_argument, NULL, 0 },
     { "no-slow-firstpass",    no_argument, NULL, 0 },
     { "multi-pass-opt-rps",   no_argument, NULL, 0 },
-- 
2.28.0.windows.1

*Thanks,*
*Kirithika*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/x265-devel/attachments/20200904/82e4c8ea/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: patch-vbv-exp.patch
Type: application/octet-stream
Size: 16360 bytes
Desc: not available
URL: <http://mailman.videolan.org/pipermail/x265-devel/attachments/20200904/82e4c8ea/attachment-0001.obj>


More information about the x265-devel mailing list