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在之前的《SkeyeRTSPLive 高效转码之 SkeyeVideoDecoder 高效解码》系列文章中咱们曾经将视频解码成了原始图像数据（YUV/RGB），而后依据不同的转码需要进行编码。如视频分辨率缩放，调整码率，多码率输入等；为了解决转码过程中编码高分辨率高质量或者高压缩率（如 H265）耗时的问题，咱们采纳 Nvidia 硬件驱动编码器进行编码，以谋求最高效率的转码和最低的推送提早。
SkeyeVideoEncoder 基 Nvidia 独立显卡的硬件编码库 SkeyeNvEncoder
1. 接口申明如下：
class SkeyeNvEncoder
{
public:
//codec: 编码格局 0=h264, 1=h265/hevc
int InitNvEncoder(int width,int height,int fps=25, int bitrate=4096, int gop=50, int qp=28, int rcMode=/*NV_ENC_PARAMS_RC_2_PASS_QUALITY*/NV_ENC_PARAMS_RC_CONSTQP,
char* encoderPreset = "Default", int codec = 0,int nDeviceType=0, int nDeviceID=0 );
//H264 获取 SPS 和 PPS
int GetSPSAndPPS(unsigned char*sps,long&spslen,unsigned char*pps,long&ppslen);
//H265 获取 VPS,SPS 和 PPS
int GetH265VPSSPSAndPPS(unsigned char*vps, long&vpslen, unsigned char*sps, long&spslen, unsigned char*pps, long&ppslen);
// 编码 InputFormat 咱们固定为 YUV420PL（I420），可批改为 NV12，YUY2 等等在 Init（）时进行格局转换，[12/18/2016 dingshuai]
unsigned char* NvEncodeSync(unsigned char* pYUV420, int inLenth, int& outLenth, bool& bKeyFrame);
// 敞开编码器，进行编码
int CloseNvEncoder();};2. SkeyeNvEncoder 编码库调用流程
- 第一步，初始化编码器及其参数
// 初始化编码器参数
int InitNvEncoder(int width,int height,int fps, int bitrate, int gop,
int qp, int rcMode, char* encoderPreset , int codec, int nDeviceType, int nDeviceID)
{
// 初始化设置参数 -- Start
memset(&m_encodeConfig, 0, sizeof(EncodeConfig));
m_encodeConfig.width = width;
m_encodeConfig.height = height;
m_nVArea = width*height;
m_nCheckyuvsize = m_nVArea*3/2;
// 编码器辨认的码率是 bps, 然而咱们输出的是 kbps, so*1024
m_encodeConfig.bitrate = bitrate*1024;
// 多通道编码优化图像品质只有在低提早模式下工作（LOW_LATENCY）m_encodeConfig.rcMode = rcMode;//NV_ENC_PARAMS_RC_2_PASS_QUALITY
m_encodeConfig.encoderPreset = encoderPreset; //NV_ENC_PARAMS_RC_2_PASS_QUALITY;
// 默认指定低延时模式以及图像的压缩格局(HQ,HP,LOSSLESS ......)
m_encodeConfig.presetGUID = NV_ENC_PRESET_LOW_LATENCY_HQ_GUID;
// I 帧距离 [12/16/2016 dingshuai]
m_encodeConfig.gopLength = gop;//NVENC_INFINITE_GOPLENGTH;
//CUDA
m_encodeConfig.deviceType = nDeviceType;
m_encodeConfig.deviceID = nDeviceID;
m_encodeConfig.codec = codec;//NV_ENC_H264;
m_encodeConfig.fps = fps;
m_encodeConfig.qp = qp;
m_encodeConfig.i_quant_factor = DEFAULT_I_QFACTOR;
m_encodeConfig.b_quant_factor = DEFAULT_B_QFACTOR;
m_encodeConfig.i_quant_offset = DEFAULT_I_QOFFSET;
m_encodeConfig.b_quant_offset = DEFAULT_B_QOFFSET;
m_encodeConfig.pictureStruct = NV_ENC_PIC_STRUCT_FRAME;
// 编码异步输入模式，1- 异步 0- 同步
m_encodeConfig.enableAsyncMode = 0;
// 默认输出给编码器的格局为 NV12(所以须要格局转换：YUV420->NV12)
m_encodeConfig.inputFormat = NV_ENC_BUFFER_FORMAT_NV12;
// 暂不晓得这些参数什么用
m_encodeConfig.invalidateRefFramesEnableFlag = 0;
m_encodeConfig.endFrameIdx = INT_MAX;
// 没有 B 帧，且目前编码器也不反对 B 帧，设了也没用
m_encodeConfig.numB = 0;
if (m_encodeConfig.numB > 0)
{//PRINTERR("B-frames are not supported\n");
return -1;
}
// 其余参数，欢送补充...... [12/18/2016 dingshuai]
//
//
// 初始化设置参数 -- END
// 初始化编码器 -- Start
NVENCSTATUS nvStatus = NV_ENC_SUCCESS;
switch (m_encodeConfig.deviceType)
{#if defined(NV_WINDOWS)
case NV_ENC_DX9:
nvStatus = InitD3D9(m_encodeConfig.deviceID);
break;
case NV_ENC_DX10:
nvStatus = InitD3D10(m_encodeConfig.deviceID);
break;
case NV_ENC_DX11:
nvStatus = InitD3D11(m_encodeConfig.deviceID);
break;
#endif
// initialize Cuda
case NV_ENC_CUDA:
InitCuda(m_encodeConfig.deviceID,0);
break;
}
if (nvStatus != NV_ENC_SUCCESS)
return -1;
if (m_encodeConfig.deviceType != NV_ENC_CUDA)
nvStatus = m_pNvHWEncoder->Initialize(m_pDevice, NV_ENC_DEVICE_TYPE_DIRECTX);
else
nvStatus = m_pNvHWEncoder->Initialize(m_pDevice, NV_ENC_DEVICE_TYPE_CUDA);
if (nvStatus != NV_ENC_SUCCESS)
return 1;
//nvStatus = InitCuda(m_encodeConfig.deviceID, 0);
//nvStatus = m_pNvHWEncoder->Initialize((void*)m_cuContext, NV_ENC_DEVICE_TYPE_CUDA);
//if (nvStatus != NV_ENC_SUCCESS)
// return -2;
m_encodeConfig.presetGUID = m_pNvHWEncoder->GetPresetGUID(m_encodeConfig.encoderPreset, m_encodeConfig.codec);
nvStatus = m_pNvHWEncoder->CreateEncoder(&m_encodeConfig);
if (nvStatus != NV_ENC_SUCCESS)
{Deinitialize();
return -3;
}
// 编码缓存帧数 [12/16/2016 dingshuai]
uint32_t uEncodeBufferCount = 1;
// 调配编码缓冲区
nvStatus = AllocateIOBuffers(m_pNvHWEncoder->m_uMaxWidth, m_pNvHWEncoder->m_uMaxHeight, uEncodeBufferCount);
if (nvStatus != NV_ENC_SUCCESS)
return -4;
m_spslen = 0;
m_ppslen = 0;
memset(m_sps, 0x00, 100);
memset(m_pps, 0x00, 100);
m_bWorking = true;
return 1;
}其中，咱们须要设置编码格局（0=H264，1=H265 目前只反对这两种格局），视频分辨率，帧率，码率和 I 帧距离（Gop）, 编码品质以及硬件编码器相干参数，参数详解如下：
//rcMode: Rate Control Modes(编码码率 / 品质管制模式)，详见如下枚举：// typedef enum _NV_ENC_PARAMS_RC_MODE
// {
// NV_ENC_PARAMS_RC_CONSTQP = 0x0, /**< Constant QP mode */
// NV_ENC_PARAMS_RC_VBR = 0x1, /**< Variable bitrate mode */
// NV_ENC_PARAMS_RC_CBR = 0x2, /**< Constant bitrate mode */
// NV_ENC_PARAMS_RC_VBR_MINQP = 0x4, /**< Variable bitrate mode with MinQP */
// NV_ENC_PARAMS_RC_2_PASS_QUALITY = 0x8, /**< Multi pass encoding optimized for image quality and works only with low latency mode */
// NV_ENC_PARAMS_RC_2_PASS_FRAMESIZE_CAP = 0x10, /**< Multi pass encoding optimized for maintaining frame size and works only with low latency mode */
// }
//encoderPreset: 编码预设
// 预设编码器编码图像的延时和清晰度
// if (encoderPreset && (stricmp(encoderPreset, "HQ") == 0))
// else if (encoderPreset && (stricmp(encoderPreset, "LowLatencyHP") == 0))
// else if (encoderPreset && (stricmp(encoderPreset, "HP") == 0))
// else if (encoderPreset && (stricmp(encoderPreset, "LowLatencyHQ") == 0))
// else if (encoderPreset && (stricmp(encoderPreset, "BD") == 0))
// else if (encoderPreset && (stricmp(encoderPreset, "LOSSLESS") == 0))
// else if (encoderPreset && (stricmp(encoderPreset, "LowLatencyDefault") == 0))
// else if (encoderPreset && (stricmp(encoderPreset, "LosslessDefault") == 0))
// 详见 nvEncoderAPI.h /* Preset GUIDS supported by the NvEncodeAPI interface. */
- 第二步，获取编码信息参数
如果编码格局为 H264，咱们通过 GetSPSAndPPS 获取编码信息头 SPS 和 PPS，如下代码段所示：
// 获取 SPS 和 PPS
int GetSPSAndPPS(unsigned char*sps,long&spslen,unsigned char*pps,long&ppslen)
{if (!m_bWorking)
{return -1;}
if (m_spslen == 0 || m_ppslen == 0)
{
unsigned char* pEncData = NULL;
int nDataSize = 0;
bool bKeyFrame = false;
unsigned char* pTempBuffer = new unsigned char[m_nCheckyuvsize];
memset(pTempBuffer, 0x00, m_nCheckyuvsize);
pEncData = NvEncodeSync(pTempBuffer, m_nCheckyuvsize, nDataSize, bKeyFrame);
if (pEncData && nDataSize>0)
{GetH264SPSandPPS((char*)pEncData, nDataSize, (char*)m_sps, (int*)&m_spslen, (char*)m_pps, (int*)&m_ppslen);
}
m_encPicCommand.bForceIDR = 1;
if (pTempBuffer)
{delete[] pTempBuffer;
pTempBuffer = NULL;
}
}
if (m_spslen>0&&m_ppslen>0)
{memcpy(sps, m_sps, m_spslen);
memcpy(pps, m_pps, m_ppslen);
spslen = m_spslen;
ppslen = m_ppslen;
}
return 1;
}
如果编码格局为 H265，咱们通过 GetH265VPSSPSAndPPS 获取编码信息头 VPS,SPS 和 PPS，如下代码段所示：
int GetH265VPSSPSAndPPS(unsigned char*vps, long&vpslen, unsigned char*sps,
long&spslen, unsigned char*pps, long&ppslen)
{if (!m_bWorking)
{return -1;}
if (m_spslen == 0 || m_ppslen == 0)
{
unsigned char* pEncData = NULL;
int nDataSize = 0;
bool bKeyFrame = false;
unsigned char* pTempBuffer = new unsigned char[m_nCheckyuvsize];
memset(pTempBuffer, 0x00, m_nCheckyuvsize);
pEncData = NvEncodeSync(pTempBuffer, m_nCheckyuvsize, nDataSize, bKeyFrame);
if (pEncData && nDataSize>0)
{GetH265VPSandSPSandPPS((char*)pEncData, nDataSize, (char*)m_vps, (int*)&m_vpslen, (char*)m_sps, (int*)&m_spslen, (char*)m_pps, (int*)&m_ppslen);
}
m_encPicCommand.bForceIDR = 1;
if (pTempBuffer)
{delete[] pTempBuffer;
pTempBuffer = NULL;
}
}
spslen = m_spslen;
ppslen = m_ppslen;
vpslen = m_vpslen;
if (m_spslen > 0)
memcpy(sps, m_sps, m_spslen);
if(m_ppslen>0)
memcpy(pps, m_pps, m_ppslen);
if(m_vpslen)
memcpy(vps, m_vps, m_vpslen);
return 1;
}-
第三步，调用编码函数进行视频帧编码
编码输出格局 InputFormat 咱们固定为 YUV420PL（I420），如源图像色调格局为 NV12，YUY2 等，须要在传入编码器时进行格局转换。unsigned char* NvEncodeSync(unsigned char* pYUV420, int inLenth, int& outLenth, bool& bKeyFrame) {if( !m_bWorking || inLenth !=m_nCheckyuvsize)// 初始化尚未实现，或者传入的数据不满足 YUV 数据的长度，则返回谬误 { outLenth = 0; return NULL; } NVENCSTATUS nvStatus = NV_ENC_SUCCESS; bool bError = false; EncodeBuffer* pEncodeBuffer = m_EncodeBufferQueue.GetAvailable(); EncodeFrameConfig stEncodeFrame; memset(&stEncodeFrame, 0, sizeof(stEncodeFrame)); stEncodeFrame.yuv[0] = pYUV420;//Y stEncodeFrame.yuv[1] = pYUV420+m_nVArea;//U stEncodeFrame.yuv[2] = pYUV420+m_nVArea+(m_nVArea>>2);//V int nHelfWidth = m_encodeConfig.width >> 1; stEncodeFrame.stride[0] = m_encodeConfig.width; stEncodeFrame.stride[1] = nHelfWidth; stEncodeFrame.stride[2] = nHelfWidth; stEncodeFrame.width = m_encodeConfig.width; stEncodeFrame.height = m_encodeConfig.height; if (m_encodeConfig.deviceType == 0)//CUDA { //CUDA Lock CCudaAutoLock cuLock((CUcontext)m_pDevice);//m_cuContext nvStatus = PreProcessInput(pEncodeBuffer, stEncodeFrame.yuv, stEncodeFrame.width, stEncodeFrame.height, m_pNvHWEncoder->m_uCurWidth, m_pNvHWEncoder->m_uCurHeight, m_pNvHWEncoder->m_uMaxWidth, m_pNvHWEncoder->m_uMaxHeight); if (nvStatus != NV_ENC_SUCCESS) { outLenth = 0; return NULL; } nvStatus = m_pNvHWEncoder->NvEncMapInputResource(pEncodeBuffer->stInputBfr.nvRegisteredResource, &pEncodeBuffer->stInputBfr.hInputSurface); if (nvStatus != NV_ENC_SUCCESS) {PRINTERR("Failed to Map input buffer %p\n", pEncodeBuffer->stInputBfr.hInputSurface); bError = true; outLenth = 0; return NULL; } } else//DirectX or any others { unsigned char *pInputSurface = NULL; uint32_t lockedPitch = 0; while (pInputSurface == NULL) {nvStatus = m_pNvHWEncoder->NvEncLockInputBuffer(pEncodeBuffer->stInputBfr.hInputSurface, (void**)&pInputSurface, &lockedPitch); if (nvStatus != NV_ENC_SUCCESS) return NULL; if (pInputSurface == NULL) {nvStatus = m_pNvHWEncoder->NvEncUnlockInputBuffer(pEncodeBuffer->stInputBfr.hInputSurface); if (nvStatus != NV_ENC_SUCCESS) return NULL; Sleep(1); } } if (pEncodeBuffer->stInputBfr.bufferFmt == NV_ENC_BUFFER_FORMAT_NV12_PL) {unsigned char *pInputSurfaceCh = pInputSurface + (pEncodeBuffer->stInputBfr.dwHeight*lockedPitch); CmnConvertYUVtoNV12(stEncodeFrame.yuv[0], stEncodeFrame.yuv[1], stEncodeFrame.yuv[2], pInputSurface, pInputSurfaceCh, stEncodeFrame.width, stEncodeFrame.height, stEncodeFrame.width, lockedPitch); } } nvStatus = m_pNvHWEncoder->NvEncEncodeFrame(pEncodeBuffer, &m_encPicCommand, m_encodeConfig.width, m_encodeConfig.height, NV_ENC_PIC_STRUCT_FRAME, m_qpDeltaMapArray, m_qpDeltaMapArraySize); if (nvStatus != NV_ENC_SUCCESS) { bError = true; outLenth= 0; return NULL; } pEncodeBuffer = m_EncodeBufferQueue.GetAvailable(); if (!pEncodeBuffer) {pEncodeBuffer = m_EncodeBufferQueue.GetPending(); // 获取编码的 h264/h265 数据 [12/15/2016 dingshuai] nvStatus = m_pNvHWEncoder->ProcessOutput(pEncodeBuffer, m_pOutputBuffer, m_nOutputBufLen); if(nvStatus != NV_ENC_SUCCESS) { bError = true; outLenth= 0; } if (m_encodeConfig.deviceType == 0)//CUDA { // UnMap the input buffer after frame done if (pEncodeBuffer->stInputBfr.hInputSurface) {nvStatus = m_pNvHWEncoder->NvEncUnmapInputResource(pEncodeBuffer->stInputBfr.hInputSurface); pEncodeBuffer->stInputBfr.hInputSurface = NULL; } //pEncodeBuffer = m_EncodeBufferQueue.GetAvailable();} else {nvStatus = m_pNvHWEncoder->NvEncUnlockInputBuffer(pEncodeBuffer->stInputBfr.hInputSurface); if (nvStatus != NV_ENC_SUCCESS) return NULL; } } else { outLenth= 0; return NULL; } if (m_encPicCommand.bForceIDR) {m_encPicCommand.bForceIDR = 0;} outLenth = m_nOutputBufLen; return m_pOutputBuffer; } - 第四步，敞开编码器，开释编码器申请的内存和显卡资源
int CloseNvEncoder()
{
m_bWorking = false;
NVENCSTATUS nvStatus = NV_ENC_SUCCESS;
ReleaseIOBuffers();
m_pNvHWEncoder->NvEncDestroyEncoder();
if (m_cuContext)
{__cu(cuCtxDestroy(m_cuContext));
}
return nvStatus;
}
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