add new AQ mode (#17)

add new AQ mode This just adds AQ mode 3's dark bias to AQ mode 4. Because of normal AQ strength values for mode 4 not really working well with the dark bias, an additional bias-strength parameter has been added.
DJATOM · Sep 2, 2024 · 3f2eb5a · 3f2eb5a
1 parent 07556a3
commit 3f2eb5a
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diff --git a/doc/reST/cli.rst b/doc/reST/cli.rst
@@ -1724,7 +1724,7 @@ Quality, rate control and rate distortion options
 	ignored. Slower presets will generally achieve better compression
 	efficiency (and generate smaller bitstreams). Default disabled.
 
-.. option:: --aq-mode <0|1|2|3|4>
+.. option:: --aq-mode <0|1|2|3|4|5>
 
 	Adaptive Quantization operating mode. Raise or lower per-block
 	quantization based on complexity analysis of the source image. The
@@ -1737,6 +1737,7 @@ Quality, rate control and rate distortion options
 	2. AQ enabled with auto-variance **(default)**
 	3. AQ enabled with auto-variance and bias to dark scenes. This is recommended for 8-bit encodes or low-bitrate 10-bit encodes, to prevent color banding/blocking.
 	4. AQ enabled with auto-variance and edge information.
+	5. AQ enabled with auto-variance, edge information, and bias to dark scenes.
 
 .. option:: --aq-strength <float>
 
@@ -1748,6 +1749,13 @@ Quality, rate control and rate distortion options
 	Default 1.0.
 	**Range of values:** 0.0 to 3.0
 
+.. option:: --aq-bias-strength <float>
+
+	Adjust the strength of dark scene bias in AQ modes 3 and 5. Setting this
+	to 0 will disable the dark scene bias, meaning modes will be equivalent to
+	their unbiased counterparts (2 and 4).
+	Default 1.0.
+
 .. option:: --sbrc, --no-sbrc
 
 	To enable and disable segment-based rate control. SBRC controls the overflow with

diff --git a/source/common/frame.cpp b/source/common/frame.cpp
@@ -139,7 +139,7 @@ bool Frame::create(x265_param *param, float* quantOffsets)
         CHECKED_MALLOC_ZERO(m_classifyCount, uint32_t, size);
     }
 
-    if (param->rc.aqMode == X265_AQ_EDGE || (param->rc.zonefileCount && param->rc.aqMode != 0))
+    if (param->rc.aqMode == X265_AQ_EDGE || param->rc.aqMode == X265_AQ_EDGE_BIASED || (param->rc.zonefileCount && param->rc.aqMode != 0))
     {
         uint32_t numCuInWidth = (param->sourceWidth + param->maxCUSize - 1) / param->maxCUSize;
         uint32_t numCuInHeight = (param->sourceHeight + param->maxCUSize - 1) / param->maxCUSize;
@@ -388,7 +388,7 @@ void Frame::destroy()
         X265_FREE_ZERO(m_classifyCount);
     }
 
-    if (m_param->rc.aqMode == X265_AQ_EDGE || (m_param->rc.zonefileCount && m_param->rc.aqMode != 0))
+    if (m_param->rc.aqMode == X265_AQ_EDGE || m_param->rc.aqMode == X265_AQ_EDGE_BIASED || (m_param->rc.zonefileCount && m_param->rc.aqMode != 0))
     {
         X265_FREE(m_edgePic);
         X265_FREE(m_gaussianPic);

diff --git a/source/common/param.cpp b/source/common/param.cpp
@@ -283,6 +283,7 @@ void x265_param_default(x265_param* param)
     param->rc.hevcAq = 0;
     param->rc.qgSize = 32;
     param->rc.aqStrength = 1.0;
+    param->rc.aqBiasStrength = 1.0;
     param->rc.qpAdaptationRange = 1.0;
     param->rc.cuTree = 1;
     param->rc.rfConstantMax = 0;
@@ -829,6 +830,7 @@ int x265_zone_param_parse(x265_param* p, const char* name, const char* value)
     }
     OPT("aq-mode") p->rc.aqMode = atoi(value);
     OPT("aq-strength") p->rc.aqStrength = atof(value);
+    OPT("aq-bias-strength") p->rc.aqBiasStrength = atof(value);
     OPT("nr-intra") p->noiseReductionIntra = atoi(value);
     OPT("nr-inter") p->noiseReductionInter = atoi(value);
     OPT("limit-modes") p->limitModes = atobool(value);
@@ -1130,6 +1132,7 @@ int x265_param_parse(x265_param* p, const char* name, const char* value)
     OPT("qblur") p->rc.qblur = atof(value);
     OPT("aq-mode") p->rc.aqMode = atoi(value);
     OPT("aq-strength") p->rc.aqStrength = atof(value);
+    OPT("aq-bias-strength") p->rc.aqBiasStrength = atof(value);
     OPT("vbv-maxrate") p->rc.vbvMaxBitrate = atoi(value);
     OPT("vbv-bufsize") p->rc.vbvBufferSize = atoi(value);
     OPT("vbv-init")    p->rc.vbvBufferInit = atof(value);
@@ -1728,7 +1731,7 @@ int x265_check_params(x265_param* param)
           "Lookahead depth must be less than 256");
     CHECK(param->lookaheadSlices > 16 || param->lookaheadSlices < 0,
           "Lookahead slices must between 0 and 16");
-    CHECK(param->rc.aqMode < X265_AQ_NONE || X265_AQ_EDGE < param->rc.aqMode,
+    CHECK(param->rc.aqMode < X265_AQ_NONE || X265_AQ_EDGE_BIASED < param->rc.aqMode,
           "Aq-Mode is out of range");
     CHECK(param->rc.aqStrength < 0 || param->rc.aqStrength > 3,
           "Aq-Strength is out of range");
@@ -2310,6 +2313,7 @@ char *x265_param2string(x265_param* p, int padx, int pady)
     }
     s += sprintf(s, " aq-mode=%d", p->rc.aqMode);
     s += sprintf(s, " aq-strength=%.2f", p->rc.aqStrength);
+    s += sprintf(s, " aq-bias-strength=%.2f", p->rc.aqBiasStrength);
     BOOL(p->rc.cuTree, "cutree");
     s += sprintf(s, " zone-count=%d", p->rc.zoneCount);
     if (p->rc.zoneCount)
@@ -2760,6 +2764,7 @@ void x265_copy_params(x265_param* dst, x265_param* src)
     dst->rc.qpStep = src->rc.qpStep;
     dst->rc.aqMode = src->rc.aqMode;
     dst->rc.aqStrength = src->rc.aqStrength;
+    dst->rc.aqBiasStrength = src->rc.aqBiasStrength;
     dst->rc.vbvBufferSize = src->rc.vbvBufferSize;
     dst->rc.vbvMaxBitrate = src->rc.vbvMaxBitrate;
 

diff --git a/source/encoder/frameencoder.cpp b/source/encoder/frameencoder.cpp
@@ -484,7 +484,7 @@ void FrameEncoder::compressFrame(int layer)
     memset(&(m_frame[layer]->m_encData->m_frameStats), 0, sizeof(m_frame[layer]->m_encData->m_frameStats));
     m_sLayerId = layer;
 
-    if (m_param->rc.aqMode != X265_AQ_EDGE && m_param->recursionSkipMode == EDGE_BASED_RSKIP)
+    if (m_param->rc.aqMode != X265_AQ_EDGE_BIASED && m_param->rc.aqMode != X265_AQ_EDGE && m_param->recursionSkipMode == EDGE_BASED_RSKIP)
     {
         int height = m_frame[layer]->m_fencPic->m_picHeight;
         int width = m_frame[layer]->m_fencPic->m_picWidth;

diff --git a/source/encoder/slicetype.cpp b/source/encoder/slicetype.cpp
@@ -524,17 +524,17 @@ void LookaheadTLD::calcAdaptiveQuantFrame(Frame *curFrame, x265_param* param)
                 double bias_strength = 0.f;
                 double strength = 0.f;
 
-                if (param->rc.aqMode == X265_AQ_EDGE)
+                if (param->rc.aqMode == X265_AQ_EDGE || param->rc.aqMode == X265_AQ_EDGE_BIASED)
                     edgeFilter(curFrame, param);
 
-                if (param->rc.aqMode == X265_AQ_EDGE && param->recursionSkipMode == EDGE_BASED_RSKIP)
+                if ((param->rc.aqMode == X265_AQ_EDGE || param->rc.aqMode == X265_AQ_EDGE_BIASED) && param->recursionSkipMode == EDGE_BASED_RSKIP)
                 {
                     pixel* src = curFrame->m_edgePic + curFrame->m_fencPic->m_lumaMarginY * curFrame->m_fencPic->m_stride + curFrame->m_fencPic->m_lumaMarginX;
                     primitives.planecopy_pp_shr(src, curFrame->m_fencPic->m_stride, curFrame->m_edgeBitPic,
                         curFrame->m_fencPic->m_stride, curFrame->m_fencPic->m_picWidth, curFrame->m_fencPic->m_picHeight, SHIFT_TO_BITPLANE);
                 }
 
-                if (param->rc.aqMode == X265_AQ_AUTO_VARIANCE || param->rc.aqMode == X265_AQ_AUTO_VARIANCE_BIASED || param->rc.aqMode == X265_AQ_EDGE)
+                if (param->rc.aqMode == X265_AQ_AUTO_VARIANCE || param->rc.aqMode == X265_AQ_AUTO_VARIANCE_BIASED || param->rc.aqMode == X265_AQ_EDGE || param->rc.aqMode == X265_AQ_EDGE_BIASED)
                 {
                     double bit_depth_correction = 1.f / (1 << (2 * (X265_DEPTH - 8)));
                     for (int blockY = 0; blockY < maxRow; blockY += loopIncr)
@@ -543,7 +543,7 @@ void LookaheadTLD::calcAdaptiveQuantFrame(Frame *curFrame, x265_param* param)
                         {
                             uint32_t energy, edgeDensity, avgAngle;
                             energy = acEnergyCu(curFrame, blockX, blockY, param->internalCsp, param->rc.qgSize);
-                            if (param->rc.aqMode == X265_AQ_EDGE)
+                            if (param->rc.aqMode == X265_AQ_EDGE || param->rc.aqMode == X265_AQ_EDGE_BIASED)
                             {
                                 edgeDensity = edgeDensityCu(curFrame, avgAngle, blockX, blockY, param->rc.qgSize);
                                 if (edgeDensity)
@@ -573,7 +573,7 @@ void LookaheadTLD::calcAdaptiveQuantFrame(Frame *curFrame, x265_param* param)
                     avg_adj_pow2 /= blockCount;
                     strength = param->rc.aqStrength * avg_adj;
                     avg_adj = avg_adj - 0.5f * (avg_adj_pow2 - modeTwoConst) / avg_adj;
-                    bias_strength = param->rc.aqStrength;
+                    bias_strength = param->rc.aqBiasStrength * param->rc.aqStrength;
                 }
                 else
                     strength = param->rc.aqStrength * 1.0397f;
@@ -602,6 +602,17 @@ void LookaheadTLD::calcAdaptiveQuantFrame(Frame *curFrame, x265_param* param)
                             else
                                 qp_adj = strength * (qp_adj - avg_adj);
                         }
+                        else if (param->rc.aqMode == X265_AQ_EDGE_BIASED)
+                        {
+                            inclinedEdge = curFrame->m_lowres.edgeInclined[blockXY];
+                            qp_adj = curFrame->m_lowres.qpCuTreeOffset[blockXY];
+                            double dark_bias = bias_strength * (1.f - modeTwoConst / (qp_adj * qp_adj)) / 10.f;
+                            if(inclinedEdge && (qp_adj - avg_adj > 0))
+                                qp_adj = ((strength + AQ_EDGE_BIAS) * (qp_adj - avg_adj));
+                            else
+                                qp_adj = strength * (qp_adj - avg_adj);
+                            qp_adj += dark_bias;
+                        }
                         else
                         {
                             uint32_t energy = acEnergyCu(curFrame, blockX, blockY, param->internalCsp, param->rc.qgSize);

diff --git a/source/x265.h b/source/x265.h
@@ -594,6 +594,7 @@ typedef enum
 #define X265_AQ_AUTO_VARIANCE        2
 #define X265_AQ_AUTO_VARIANCE_BIASED 3
 #define X265_AQ_EDGE                 4
+#define X265_AQ_EDGE_BIASED          5
 #define x265_ADAPT_RD_STRENGTH   4
 #define X265_REFINE_INTER_LEVELS 3
 /* NOTE! For this release only X265_CSP_I420 and X265_CSP_I444 are supported */
@@ -1730,6 +1731,9 @@ typedef struct x265_param
          * AQ is enabled. Default value: 1.0. Acceptable values between 0.0 and 3.0 */
         double    aqStrength;
 
+        /* Sets the bias towards dark scenes in AQ modes 3 and 5. */
+        double    aqBiasStrength;
+
         /* Delta QP range by QP adaptation based on a psycho-visual model.
          * Acceptable values between 1.0 to 6.0 */
         double    qpAdaptationRange;

diff --git a/source/x265cli.cpp b/source/x265cli.cpp
@@ -280,9 +280,10 @@ namespace X265_NS {
             "                                    - 0 : Disabled.\n"
             "                                    - 1 : Store/Load ctu distortion to/from the file specified in analysis-save/load.\n"
             "                                Default 0 - Disabled\n");
-        H0("   --aq-mode <integer>           Mode for Adaptive Quantization - 0:none 1:uniform AQ 2:auto variance 3:auto variance with bias to dark scenes 4:auto variance with edge information. Default %d\n", param->rc.aqMode);
+        H0("   --aq-mode <integer>           Mode for Adaptive Quantization - 0:none 1:uniform AQ 2:auto variance 3:auto variance with bias to dark scenes 4:auto variance with edge information 5:auto variance with edge information and bias to dark scenes. Default %d\n", param->rc.aqMode);
         H0("   --[no-]hevc-aq                Mode for HEVC Adaptive Quantization. Default %s\n", OPT(param->rc.hevcAq));
         H0("   --aq-strength <float>         Reduces blocking and blurring in flat and textured areas (0 to 3.0). Default %.2f\n", param->rc.aqStrength);
+        H0("   --aq-bias-strength <float>    Sets the bias to dark strength in AQ modes 3 and 5. Default %.2f\n", param->rc.aqBiasStrength);
         H0("   --qp-adaptation-range <float> Delta QP range by QP adaptation based on a psycho-visual model (1.0 to 6.0). Default %.2f\n", param->rc.qpAdaptationRange);
         H0("   --[no-]aq-motion              Block level QP adaptation based on the relative motion between the block and the frame. Default %s\n", OPT(param->bAQMotion));
         H1("   --[no-]sbrc                   Enables the segment based rate control. Default %s\n", OPT(param->bEnableSBRC));
@@ -1486,4 +1487,4 @@ namespace X265_NS {
 
 #ifdef __cplusplus
 }
-#endif
+#endif
diff --git a/source/x265cli.h b/source/x265cli.h
@@ -184,6 +184,7 @@ static const struct option long_options[] =
     { "qp",             required_argument, NULL, 'q' },
     { "aq-mode",        required_argument, NULL, 0 },
     { "aq-strength",    required_argument, NULL, 0 },
+    { "aq-bias-strength", required_argument, NULL, 0 },
     { "sbrc",                 no_argument, NULL, 0 },
     { "no-sbrc",              no_argument, NULL, 0 },
     { "rc-grain",             no_argument, NULL, 0 },