obs-qsv11: Fix CBR Spike

obsproject · Aug 1, 2024 · 8a8fa0a · 8a8fa0a
1 parent 0f4e33c
commit 8a8fa0a
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Showing 2 changed files with 43 additions and 2 deletions.
diff --git a/plugins/obs-qsv11/QSV_Encoder_Internal.cpp b/plugins/obs-qsv11/QSV_Encoder_Internal.cpp
@@ -177,6 +177,23 @@ mfxStatus QSV_Encoder_Internal::Open(qsv_param_t *pParams, enum qsv_codec codec)
 	return sts;
 }
 
+PRAGMA_WARN_PUSH
+PRAGMA_WARN_DEPRECATION
+static inline bool IsOptimizedBRCSupport(const mfxPlatform &platform,
+					 mfxU16 rateControl)
+{
+#if defined(_WIN32)
+	if (rateControl == MFX_RATECONTROL_CBR &&
+	    (platform.CodeName >= MFX_PLATFORM_LUNARLAKE &&
+	     platform.CodeName != MFX_PLATFORM_ALDERLAKE_N))
+		return true;
+#endif
+	(void)platform;
+	(void)rateControl;
+	return false;
+}
+PRAGMA_WARN_POP
+
 mfxStatus QSV_Encoder_Internal::InitParams(qsv_param_t *pParams,
 					   enum qsv_codec codec)
 {
@@ -233,8 +250,15 @@ mfxStatus QSV_Encoder_Internal::InitParams(qsv_param_t *pParams,
 	switch (pParams->nRateControl) {
 	case MFX_RATECONTROL_CBR:
 		m_mfxEncParams.mfx.TargetKbps = pParams->nTargetBitRate;
-		m_mfxEncParams.mfx.BufferSizeInKB =
-			(pParams->nTargetBitRate / 8) * 2;
+
+		if (IsOptimizedBRCSupport(platform, pParams->nRateControl)) {
+			m_mfxEncParams.mfx.BufferSizeInKB =
+				(pParams->nTargetBitRate / 8) * 1;
+		} else {
+			m_mfxEncParams.mfx.BufferSizeInKB =
+				(pParams->nTargetBitRate / 8) * 2;
+		}
+
 		m_mfxEncParams.mfx.InitialDelayInKB =
 			(pParams->nTargetBitRate / 8) * 1;
 		break;
@@ -304,6 +328,22 @@ mfxStatus QSV_Encoder_Internal::InitParams(qsv_param_t *pParams,
 
 	extendedBuffers.push_back((mfxExtBuffer *)&m_co2);
 
+	if (IsOptimizedBRCSupport(platform, pParams->nRateControl)) {
+		memset(&m_co3, 0, sizeof(mfxExtCodingOption3));
+		m_co3.Header.BufferId = MFX_EXTBUFF_CODING_OPTION3;
+		m_co3.Header.BufferSz = sizeof(m_co3);
+		m_co3.WinBRCSize = pParams->nFpsNum / pParams->nFpsDen;
+
+		if (codec == QSV_CODEC_AVC || codec == QSV_CODEC_HEVC) {
+			m_co3.WinBRCMaxAvgKbps =
+				mfxU16(1.3 * pParams->nTargetBitRate);
+		} else if (codec == QSV_CODEC_AV1) {
+			m_co3.WinBRCMaxAvgKbps =
+				mfxU16(1.2 * pParams->nTargetBitRate);
+		}
+		extendedBuffers.push_back((mfxExtBuffer *)&m_co3);
+	}
+
 	if (codec == QSV_CODEC_HEVC) {
 		if ((pParams->nWidth & 15) || (pParams->nHeight & 15)) {
 			memset(&m_ExtHEVCParam, 0, sizeof(m_ExtHEVCParam));

diff --git a/plugins/obs-qsv11/QSV_Encoder_Internal.h b/plugins/obs-qsv11/QSV_Encoder_Internal.h
@@ -116,6 +116,7 @@ class QSV_Encoder_Internal {
 	mfxU16 m_nPPSBufferSize;
 	mfxVideoParam m_parameter;
 	std::vector<mfxExtBuffer *> extendedBuffers;
+	mfxExtCodingOption3 m_co3;
 	mfxExtCodingOption2 m_co2;
 	mfxExtCodingOption m_co;
 	mfxExtHEVCParam m_ExtHEVCParam{};