IS_PARAMETER_SET_NAL：是不是参数集nal头文件codec_api.h codec_app_def.h codec_def.h codec_ver.hSEncParamExt.iMultipleThreadIdc： lager than 1: count number of threads;typedef enum { CAMERA_VIDEO_REAL_TIME, ///< camera video for real-time communication SCREEN_CONTENT_REAL_TIME, ///< screen content signal CAMERA_VIDEO_NON_REAL_TIME, SCREEN_CONTENT_NON_REAL_TIME, INPUT_CONTENT_TYPE_ALL,} EUsageType;typedef enum { SM_SINGLE_SLICE = 0, ///< | SliceNum==1 SM_FIXEDSLCNUM_SLICE = 1, ///< | according to SliceNum | enabled dynamic slicing for multi-thread SM_RASTER_SLICE = 2, ///< | according to SlicesAssign | need input of MB numbers each slice. In addition, if other constraint in SSliceArgument is presented, need to follow the constraints. Typically if MB num and slice size are both constrained, re-encoding may be involved. SM_SIZELIMITED_SLICE = 3, ///< | according to SliceSize | slicing according to size, the slicing will be dynamic(have no idea about slice_nums until encoding current frame) SM_RESERVED = 4} SliceModeEnum;Step1:setup encoderISVCEncoder* encoder_; int rv = WelsCreateSVCEncoder (&encoder_);assert (rv == 0);assert (encoder_ != NULL);step2:initilize with basic parameter SEncParamBase param; memset (&param, 0, sizeof (SEncParamBase)); param.iUsageType = usageType; //from EUsageType enum param.fMaxFrameRate = frameRate; param.iPicWidth = width; param.iPicHeight = height; param.iTargetBitrate = 5000000; encoder_->Initialize (&param);或Step 2:initialize with extension parameter SEncParamExt param; encoder_->GetDefaultParams (&param); param.iUsageType = usageType; param.fMaxFrameRate = frameRate; param.iPicWidth = width; param.iPicHeight = height; param.iTargetBitrate = 5000000; param.bEnableDenoise = denoise; param.iSpatialLayerNum = layers; //SM_DYN_SLICE don’t support multi-thread now if (sliceMode != SM_SINGLE_SLICE && sliceMode != SM_DYN_SLICE) param.iMultipleThreadIdc = 2; for (int i = 0; i < param.iSpatialLayerNum; i++) { param.sSpatialLayers[i].iVideoWidth = width >> (param.iSpatialLayerNum – 1 – i); param.sSpatialLayers[i].iVideoHeight = height >> (param.iSpatialLayerNum – 1 – i); param.sSpatialLayers[i].fFrameRate = frameRate; param.sSpatialLayers[i].iSpatialBitrate = param.iTargetBitrate; param.sSpatialLayers[i].sSliceCfg.uiSliceMode = sliceMode; if (sliceMode == SM_DYN_SLICE) { param.sSpatialLayers[i].sSliceCfg.sSliceArgument.uiSliceSizeConstraint = 600; param.uiMaxNalSize = 1500; } } param.iTargetBitrate *= param.iSpatialLayerNum; encoder_->InitializeExt (&param); int videoFormat = videoFormatI420; encoder_->SetOption (ENCODER_OPTION_DATAFORMAT, &videoFormat); Step3:set option, set option during encoding process encoder_->SetOption (ENCODER_OPTION_TRACE_LEVEL, &g_LevelSetting); int videoFormat = videoFormatI420; encoder_->SetOption (ENCODER_OPTION_DATAFORMAT, &videoFormat);//changing encoding param SEncParamBase param; //fill in instant param即时参数content encoder_->SetOption (ENCODER_OPTION_SVC_ENCODE_PARAM_BASE, &param);Step4: encode and store ouput bistream int frameSize = width * height * 3 / 2; BufferedData buf; buf.SetLength (frameSize); assert (buf.Length() == (size_t)frameSize); SFrameBSInfo info; memset (&info, 0, sizeof (SFrameBSInfo)); SSourcePicture pic; memset (&pic, 0, sizeof (SsourcePicture)); pic.iPicWidth = width; pic.iPicHeight = height; pic.iColorFormat = videoFormatI420; pic.iStride[0] = pic.iPicWidth; pic.iStride[1] = pic.iStride[2] = pic.iPicWidth >> 1; pic.pData[0] = buf.data(); pic.pData[1] = pic.pData[0] + width * height; pic.pData[2] = pic.pData[1] + (width * height >> 2); for(int num = 0;num<total_num;num++) { //prepare input data rv = encoder_->EncodeFrame (&pic, &info); assert (rv == cmResultSuccess); if (info.eFrameType != videoFrameTypeSkip) { //output bitstream handling } } Step5:teardown encoder if (encoder_) { encoder_->Uninitialize(); WelsDestroySVCEncoder (encoder_); }by https://github.com/starrtc/android-demo