1.gpu解码器的基本调用流程
要做视频流解码，必须要了解cuda自身的解码流，因为二者是一样的底层实现，不一样的上层调用
那cuda的解码流程是如何的呢
在https://developer.nvidia.com/nvidia-video-codec-sdk 下载 Video_Codec_SDK_8.0.14
解压开来
在sampls里面有几个针对不同场景应用的小例子，如果不知道自己该参考哪一个，就需要去看开发文档，doc里面有一个 NVENC_VideoEncoder_API_ProgGuide.pdf 文档
由于我这里使用的是视频流解码，所以最好去查看NvTranscoder这个demo.
在NvTranscoder里面主要关注红框中的这几个文件
NvTranscoder.cpp实现了主函数
VideoDecoder.cpp实现了解码
FrameQueue.cpp实现了gpu解码后的数据回调
先看NvTranscoder.cpp的主要代码（比较冗余，有兴趣可以全部看）
int main(int argc, char* argv[])
{
#if defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
typedef HMODULE CUDADRIVER;
#else
typedef void *CUDADRIVER;
#endif
CUDADRIVER hHandleDriver = ; __cu(cuInit(, __CUDA_API_VERSION, hHandleDriver));
__cu(cuvidInit()); EncodeConfig encodeConfig = { };
encodeConfig.endFrameIdx = INT_MAX;
encodeConfig.bitrate = ;
encodeConfig.rcMode = NV_ENC_PARAMS_RC_CONSTQP;
encodeConfig.gopLength = NVENC_INFINITE_GOPLENGTH;
encodeConfig.codec = NV_ENC_H264;
encodeConfig.fps = ;
encodeConfig.qp = ;
encodeConfig.i_quant_factor = DEFAULT_I_QFACTOR;
encodeConfig.b_quant_factor = DEFAULT_B_QFACTOR;
encodeConfig.i_quant_offset = DEFAULT_I_QOFFSET;
encodeConfig.b_quant_offset = DEFAULT_B_QOFFSET;
encodeConfig.presetGUID = NV_ENC_PRESET_DEFAULT_GUID;
encodeConfig.pictureStruct = NV_ENC_PIC_STRUCT_FRAME; NVENCSTATUS nvStatus = CNvHWEncoder::ParseArguments(&encodeConfig, argc, argv);
if (nvStatus != NV_ENC_SUCCESS)
{
PrintHelp();
return ;
} if (!encodeConfig.inputFileName || !encodeConfig.outputFileName)
{
PrintHelp();
return ;
} encodeConfig.fOutput = fopen(encodeConfig.outputFileName, "wb");
if (encodeConfig.fOutput == NULL)
{
PRINTERR("Failed to create \"%s\"\n", encodeConfig.outputFileName);
return ;
} //init cuda
CUcontext cudaCtx;
CUdevice device;
__cu(cuDeviceGet(&device, encodeConfig.deviceID));
__cu(cuCtxCreate(&cudaCtx, CU_CTX_SCHED_AUTO, device)); CUcontext curCtx;
CUvideoctxlock ctxLock;
__cu(cuCtxPopCurrent(&curCtx));
__cu(cuvidCtxLockCreate(&ctxLock, curCtx)); CudaDecoder* pDecoder = new CudaDecoder;
FrameQueue* pFrameQueue = new CUVIDFrameQueue(ctxLock);
pDecoder->InitVideoDecoder(encodeConfig.inputFileName, ctxLock, pFrameQueue, encodeConfig.width, encodeConfig.height); int decodedW, decodedH, decodedFRN, decodedFRD, isProgressive;
pDecoder->GetCodecParam(&decodedW, &decodedH, &decodedFRN, &decodedFRD, &isProgressive);
if (decodedFRN <= || decodedFRD <= ) {
decodedFRN = ;
decodedFRD = ;
} if(encodeConfig.width <= || encodeConfig.height <= ) {
encodeConfig.width = decodedW;
encodeConfig.height = decodedH;
} float fpsRatio = .f;
if (encodeConfig.fps <= ) {
encodeConfig.fps = decodedFRN / decodedFRD;
}
else {
fpsRatio = (float)encodeConfig.fps * decodedFRD / decodedFRN;
} encodeConfig.pictureStruct = (isProgressive ? NV_ENC_PIC_STRUCT_FRAME : );
pFrameQueue->init(encodeConfig.width, encodeConfig.height); VideoEncoder* pEncoder = new VideoEncoder(ctxLock);
assert(pEncoder->GetHWEncoder()); nvStatus = pEncoder->GetHWEncoder()->Initialize(cudaCtx, NV_ENC_DEVICE_TYPE_CUDA);
if (nvStatus != NV_ENC_SUCCESS)
return ; encodeConfig.presetGUID = pEncoder->GetHWEncoder()->GetPresetGUID(encodeConfig.encoderPreset, encodeConfig.codec); printf("Encoding input : \"%s\"\n", encodeConfig.inputFileName);
printf(" output : \"%s\"\n", encodeConfig.outputFileName);
printf(" codec : \"%s\"\n", encodeConfig.codec == NV_ENC_HEVC ? "HEVC" : "H264");
printf(" size : %dx%d\n", encodeConfig.width, encodeConfig.height);
printf(" bitrate : %d bits/sec\n", encodeConfig.bitrate);
printf(" vbvMaxBitrate : %d bits/sec\n", encodeConfig.vbvMaxBitrate);
printf(" vbvSize : %d bits\n", encodeConfig.vbvSize);
printf(" fps : %d frames/sec\n", encodeConfig.fps);
printf(" rcMode : %s\n", encodeConfig.rcMode == NV_ENC_PARAMS_RC_CONSTQP ? "CONSTQP" :
encodeConfig.rcMode == NV_ENC_PARAMS_RC_VBR ? "VBR" :
encodeConfig.rcMode == NV_ENC_PARAMS_RC_CBR ? "CBR" :
encodeConfig.rcMode == NV_ENC_PARAMS_RC_VBR_MINQP ? "VBR MINQP (deprecated)" :
encodeConfig.rcMode == NV_ENC_PARAMS_RC_CBR_LOWDELAY_HQ ? "CBR_LOWDELAY_HQ" :
encodeConfig.rcMode == NV_ENC_PARAMS_RC_CBR_HQ ? "CBR_HQ" :
encodeConfig.rcMode == NV_ENC_PARAMS_RC_VBR_HQ ? "VBR_HQ" : "UNKNOWN");
if (encodeConfig.gopLength == NVENC_INFINITE_GOPLENGTH)
printf(" goplength : INFINITE GOP \n");
else
printf(" goplength : %d \n", encodeConfig.gopLength);
printf(" B frames : %d \n", encodeConfig.numB);
printf(" QP : %d \n", encodeConfig.qp);
printf(" preset : %s\n", (encodeConfig.presetGUID == NV_ENC_PRESET_LOW_LATENCY_HQ_GUID) ? "LOW_LATENCY_HQ" :
(encodeConfig.presetGUID == NV_ENC_PRESET_LOW_LATENCY_HP_GUID) ? "LOW_LATENCY_HP" :
(encodeConfig.presetGUID == NV_ENC_PRESET_HQ_GUID) ? "HQ_PRESET" :
(encodeConfig.presetGUID == NV_ENC_PRESET_HP_GUID) ? "HP_PRESET" :
(encodeConfig.presetGUID == NV_ENC_PRESET_LOSSLESS_HP_GUID) ? "LOSSLESS_HP" : "LOW_LATENCY_DEFAULT");
printf("\n"); nvStatus = pEncoder->GetHWEncoder()->CreateEncoder(&encodeConfig);
if (nvStatus != NV_ENC_SUCCESS)
return ; nvStatus = pEncoder->AllocateIOBuffers(&encodeConfig);
if (nvStatus != NV_ENC_SUCCESS)
return ; unsigned long long lStart, lEnd, lFreq;
NvQueryPerformanceCounter(&lStart); //start decoding thread
#ifdef _WIN32
HANDLE decodeThread = CreateThread(NULL, , DecodeProc, (LPVOID)pDecoder, , NULL);
#else
pthread_t pid;
pthread_create(&pid, NULL, DecodeProc, (void*)pDecoder);
#endif //start encoding thread
int frmProcessed = ;
int frmActual = ;
while(!(pFrameQueue->isEndOfDecode() && pFrameQueue->isEmpty()) ) { CUVIDPARSERDISPINFO pInfo;
if(pFrameQueue->dequeue(&pInfo)) {
CUdeviceptr dMappedFrame = ;
unsigned int pitch;
CUVIDPROCPARAMS oVPP = { };
oVPP.progressive_frame = pInfo.progressive_frame;
oVPP.second_field = ;
oVPP.top_field_first = pInfo.top_field_first;
oVPP.unpaired_field = (pInfo.progressive_frame == || pInfo.repeat_first_field <= ); cuvidMapVideoFrame(pDecoder->GetDecoder(), pInfo.picture_index, &dMappedFrame, &pitch, &oVPP); EncodeFrameConfig stEncodeConfig = { };
NV_ENC_PIC_STRUCT picType = (pInfo.progressive_frame || pInfo.repeat_first_field >= ? NV_ENC_PIC_STRUCT_FRAME :
(pInfo.top_field_first ? NV_ENC_PIC_STRUCT_FIELD_TOP_BOTTOM : NV_ENC_PIC_STRUCT_FIELD_BOTTOM_TOP)); stEncodeConfig.dptr = dMappedFrame;
stEncodeConfig.pitch = pitch;
stEncodeConfig.width = encodeConfig.width;
stEncodeConfig.height = encodeConfig.height; int dropOrDuplicate = MatchFPS(fpsRatio, frmProcessed, frmActual);
for (int i = ; i <= dropOrDuplicate; i++) {
pEncoder->EncodeFrame(&stEncodeConfig, picType);
frmActual++;
}
frmProcessed++; cuvidUnmapVideoFrame(pDecoder->GetDecoder(), dMappedFrame);
pFrameQueue->releaseFrame(&pInfo);
}
} pEncoder->EncodeFrame(NULL, NV_ENC_PIC_STRUCT_FRAME, true); #ifdef _WIN32
WaitForSingleObject(decodeThread, INFINITE);
#else
pthread_join(pid, NULL);
#endif if (pEncoder->GetEncodedFrames() > )
{
NvQueryPerformanceCounter(&lEnd);
NvQueryPerformanceFrequency(&lFreq);
double elapsedTime = (double)(lEnd - lStart)/(double)lFreq;
printf("Total time: %fms, Decoded Frames: %d, Encoded Frames: %d, Average FPS: %f\n",
elapsedTime * ,
pDecoder->m_decodedFrames,
pEncoder->GetEncodedFrames(),
(float)pEncoder->GetEncodedFrames() / elapsedTime);
} pEncoder->Deinitialize();
delete pDecoder;
delete pEncoder;
delete pFrameQueue; cuvidCtxLockDestroy(ctxLock);
__cu(cuCtxDestroy(cudaCtx)); return ;
}
下面这个是我的主要流程精简版
int main(int argc, char* argv[])
{
#if defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
typedef HMODULE CUDADRIVER;
#else
typedef void *CUDADRIVER;
#endif
CUDADRIVER hHandleDriver = ; __cu(cuInit(, __CUDA_API_VERSION, hHandleDriver));//初始化cuda环境,必须的
__cu(cuvidInit()); //初始化解码器 //init cuda
CUcontext cudaCtx;
CUdevice device;
__cu(cuDeviceGet(&device, deviceID)); //得到显卡操作对象，deviceID是显卡的id，一般说来如果一张显卡，id就是0，两张就是0,1
__cu(cuCtxCreate(&cudaCtx, CU_CTX_SCHED_AUTO, device)); //创建对应显卡的运行环境 CUcontext curCtx;
CUvideoctxlock ctxLock;
__cu(cuCtxPopCurrent(&curCtx));//弹出当前CPU线程的里面的可用的cuda环境，也就是上面创建的环境
__cu(cuvidCtxLockCreate(&ctxLock, curCtx));//为gpu上锁
CudaDecoder* pDecoder = new CudaDecoder;//创建cuda解码对象（重点查看）
FrameQueue* pFrameQueue = new CUVIDFrameQueue(ctxLock);//创建解码输出队列
pDecoder->InitVideoDecoder(encodeConfig.inputFileName, ctxLock, pFrameQueue, encodeConfig.width, encodeConfig.height);//初始化解码器（重点查看） pFrameQueue->init(encodeConfig.width, encodeConfig.height);//初始化解码输出队列 //启动解码线程
#ifdef _WIN32
HANDLE decodeThread = CreateThread(NULL, , DecodeProc, (LPVOID)pDecoder, , NULL);
#else
pthread_t pid;
pthread_create(&pid, NULL, DecodeProc, (void*)pDecoder);
#endif //start encoding thread
int frmProcessed = ;
int frmActual = ;
//从解码输出队列里面拉取解出来的数据
while(!(pFrameQueue->isEndOfDecode() && pFrameQueue->isEmpty()) ) { CUVIDPARSERDISPINFO pInfo;
if(pFrameQueue->dequeue(&pInfo)) {
CUdeviceptr dMappedFrame = ;
unsigned int pitch;
CUVIDPROCPARAMS oVPP = { };
oVPP.progressive_frame = pInfo.progressive_frame;
oVPP.second_field = ;
oVPP.top_field_first = pInfo.top_field_first;
oVPP.unpaired_field = (pInfo.progressive_frame == || pInfo.repeat_first_field <= );
//获取数据在GPU中的地址dMappedFrame，大小为pitch个
cuvidMapVideoFrame(pDecoder->GetDecoder(), pInfo.picture_index, &dMappedFrame, &pitch, &oVPP);
//因为解码后的数据地址还是在GPU中，所有需要找到
unsigned int nv12_size = pitch * (pDecoder->iHeight + pDecoder->iHeight/); // 12bpp
//从GPU内存拷贝到pa->pFrameBuffer（CPU的内存地址）
oResult = cuMemcpyDtoH(pa->pFrameBuffer, dMappedFrame, nv12_size); //释放GPU中的内存
cuvidUnmapVideoFrame(pDecoder->GetDecoder(), dMappedFrame);
pFrameQueue->releaseFrame(&pInfo);
}
} #ifdef _WIN32
WaitForSingleObject(decodeThread, INFINITE);
#else
pthread_join(pid, NULL);
#endif
delete pDecoder;
delete pFrameQueue; cuvidCtxLockDestroy(ctxLock);
__cu(cuCtxDestroy(cudaCtx)); return ;
}
其中的解码器的流程调用是重点关注的
new解码器
CudaDecoder::CudaDecoder() : m_videoSource(NULL), m_videoParser(NULL), m_videoDecoder(NULL),
m_ctxLock(NULL), m_decodedFrames(), m_bFinish(false)
{
}
初始化解码器，这里创建了三个对象，一个是源，一个是解码器，一个是解析器，
//初始化Gpu解码器
void CudaDecoder::InitVideoDecoder(const char* videoPath, CUvideoctxlock ctxLock, FrameQueue* pFrameQueue,
int targetWidth, int targetHeight)
{
assert(videoPath);//数据流地址
assert(ctxLock);
assert(pFrameQueue); m_pFrameQueue = pFrameQueue; CUresult oResult;
m_ctxLock = ctxLock; //init video source
CUVIDSOURCEPARAMS oVideoSourceParameters;
memset(&oVideoSourceParameters, , sizeof(CUVIDSOURCEPARAMS));
oVideoSourceParameters.pUserData = this;
oVideoSourceParameters.pfnVideoDataHandler = HandleVideoData;
oVideoSourceParameters.pfnAudioDataHandler = NULL; oResult = cuvidCreateVideoSource(&m_videoSource, videoPath, &oVideoSourceParameters);//创建数据源对象，目的是在回调里面得到数据包，然后在回调里面可以用m_videoParser处理，只支持文件
if (oResult != CUDA_SUCCESS) {
fprintf(stderr, "cuvidCreateVideoSource failed\n");
fprintf(stderr, "Please check if the path exists, or the video is a valid H264 file\n");
exit(-);
} //init video decoder
CUVIDEOFORMAT oFormat;
cuvidGetSourceVideoFormat(m_videoSource, &oFormat, ); if (oFormat.codec != cudaVideoCodec_H264 && oFormat.codec != cudaVideoCodec_HEVC) {
fprintf(stderr, "The sample only supports H264/HEVC input video!\n");
exit(-);
} if (oFormat.chroma_format != cudaVideoChromaFormat_420) {
fprintf(stderr, "The sample only supports 4:2:0 chroma!\n");
exit(-);
} CUVIDDECODECREATEINFO oVideoDecodeCreateInfo;
memset(&oVideoDecodeCreateInfo, , sizeof(CUVIDDECODECREATEINFO));
oVideoDecodeCreateInfo.CodecType = oFormat.codec;
oVideoDecodeCreateInfo.ulWidth = oFormat.coded_width;
oVideoDecodeCreateInfo.ulHeight = oFormat.coded_height;
oVideoDecodeCreateInfo.ulNumDecodeSurfaces = ;
if ((oVideoDecodeCreateInfo.CodecType == cudaVideoCodec_H264) ||
(oVideoDecodeCreateInfo.CodecType == cudaVideoCodec_H264_SVC) ||
(oVideoDecodeCreateInfo.CodecType == cudaVideoCodec_H264_MVC))
{
// assume worst-case of 20 decode surfaces for H264
oVideoDecodeCreateInfo.ulNumDecodeSurfaces = ;
}
if (oVideoDecodeCreateInfo.CodecType == cudaVideoCodec_VP9)
oVideoDecodeCreateInfo.ulNumDecodeSurfaces = ;
if (oVideoDecodeCreateInfo.CodecType == cudaVideoCodec_HEVC)
{
// ref HEVC spec: A.4.1 General tier and level limits
int MaxLumaPS = ; // currently assuming level 6.2, 8Kx4K
int MaxDpbPicBuf = ;
int PicSizeInSamplesY = oVideoDecodeCreateInfo.ulWidth * oVideoDecodeCreateInfo.ulHeight;
int MaxDpbSize;
if (PicSizeInSamplesY <= (MaxLumaPS>>))
MaxDpbSize = MaxDpbPicBuf * ;
else if (PicSizeInSamplesY <= (MaxLumaPS>>))
MaxDpbSize = MaxDpbPicBuf * ;
else if (PicSizeInSamplesY <= ((*MaxLumaPS)>>))
MaxDpbSize = (MaxDpbPicBuf * ) / ;
else
MaxDpbSize = MaxDpbPicBuf;
MaxDpbSize = MaxDpbSize < ? MaxDpbSize : ;
oVideoDecodeCreateInfo.ulNumDecodeSurfaces = MaxDpbSize + ;
}
oVideoDecodeCreateInfo.ChromaFormat = oFormat.chroma_format;
oVideoDecodeCreateInfo.OutputFormat = cudaVideoSurfaceFormat_NV12;//设置输出格式为NV12
oVideoDecodeCreateInfo.DeinterlaceMode = cudaVideoDeinterlaceMode_Weave; if (targetWidth <= || targetHeight <= ) {
oVideoDecodeCreateInfo.ulTargetWidth = oFormat.display_area.right - oFormat.display_area.left;
oVideoDecodeCreateInfo.ulTargetHeight = oFormat.display_area.bottom - oFormat.display_area.top;
}
else {
oVideoDecodeCreateInfo.ulTargetWidth = targetWidth;//输出长宽
oVideoDecodeCreateInfo.ulTargetHeight = targetHeight;
}
oVideoDecodeCreateInfo.display_area.left = ;
oVideoDecodeCreateInfo.display_area.right = (short)oVideoDecodeCreateInfo.ulTargetWidth;
oVideoDecodeCreateInfo.display_area.top = ;
oVideoDecodeCreateInfo.display_area.bottom = (short)oVideoDecodeCreateInfo.ulTargetHeight; oVideoDecodeCreateInfo.ulNumOutputSurfaces = ;
oVideoDecodeCreateInfo.ulCreationFlags = cudaVideoCreate_PreferCUVID;
oVideoDecodeCreateInfo.vidLock = m_ctxLock; oResult = cuvidCreateDecoder(&m_videoDecoder, &oVideoDecodeCreateInfo);//创建解码器
if (oResult != CUDA_SUCCESS) {
fprintf(stderr, "cuvidCreateDecoder() failed, error code: %d\n", oResult);
exit(-);
} m_oVideoDecodeCreateInfo = oVideoDecodeCreateInfo; //init video parser
CUVIDPARSERPARAMS oVideoParserParameters;
memset(&oVideoParserParameters, , sizeof(CUVIDPARSERPARAMS));
oVideoParserParameters.CodecType = oVideoDecodeCreateInfo.CodecType;
oVideoParserParameters.ulMaxNumDecodeSurfaces = oVideoDecodeCreateInfo.ulNumDecodeSurfaces;
oVideoParserParameters.ulMaxDisplayDelay = ;
oVideoParserParameters.pUserData = this;
oVideoParserParameters.pfnSequenceCallback = HandleVideoSequence;//数据源拉取出来的回调
oVideoParserParameters.pfnDecodePicture = HandlePictureDecode;
oVideoParserParameters.pfnDisplayPicture = HandlePictureDisplay;//解码后的数据回调 oResult = cuvidCreateVideoParser(&m_videoParser, &oVideoParserParameters);//创建解析器 目的是协助解析包，可以回调得到每帧的格式，回调得到预解码的数据，回调得到最后图片数据
if (oResult != CUDA_SUCCESS) {
fprintf(stderr, "cuvidCreateVideoParser failed, error code: %d\n", oResult);
exit(-);
}
}
源对象加载数据后会回调，里面有CUVIDSOURCEDATAPACKET格式的数据包，数据包会给解析器，解析器回传数据给解码器，解码器把数据回传给队列，发往主线程
static int CUDAAPI HandleVideoData(void* pUserData, CUVIDSOURCEDATAPACKET* pPacket)
{
assert(pUserData);
CudaDecoder* pDecoder = (CudaDecoder*)pUserData; CUresult oResult = cuvidParseVideoData(pDecoder->m_videoParser, pPacket);
if(oResult != CUDA_SUCCESS) {
printf("error!\n");
} return ;
} static int CUDAAPI HandleVideoSequence(void* pUserData, CUVIDEOFORMAT* pFormat)
{
assert(pUserData);
CudaDecoder* pDecoder = (CudaDecoder*)pUserData; if ((pFormat->codec != pDecoder->m_oVideoDecodeCreateInfo.CodecType) || // codec-type
(pFormat->coded_width != pDecoder->m_oVideoDecodeCreateInfo.ulWidth) ||
(pFormat->coded_height != pDecoder->m_oVideoDecodeCreateInfo.ulHeight) ||
(pFormat->chroma_format != pDecoder->m_oVideoDecodeCreateInfo.ChromaFormat))
{
fprintf(stderr, "NvTranscoder doesn't deal with dynamic video format changing\n");
return ;
} return ;
} static int CUDAAPI HandlePictureDecode(void* pUserData, CUVIDPICPARAMS* pPicParams)
{
assert(pUserData);
CudaDecoder* pDecoder = (CudaDecoder*)pUserData;
pDecoder->m_pFrameQueue->waitUntilFrameAvailable(pPicParams->CurrPicIdx);
assert(CUDA_SUCCESS == cuvidDecodePicture(pDecoder->m_videoDecoder, pPicParams));
return ;
} static int CUDAAPI HandlePictureDisplay(void* pUserData, CUVIDPARSERDISPINFO* pPicParams)
{
assert(pUserData);
CudaDecoder* pDecoder = (CudaDecoder*)pUserData;
pDecoder->m_pFrameQueue->enqueue(pPicParams);
pDecoder->m_decodedFrames++; return ;
}
看了以上流程，估计有一个大概的流程在心里了，
必要的gpu初始化------》初始化解码器，解析器，源解释器------》运行-----》处理输出数据
2.自己解码器的调用对接
现在轮到我们自己的需求，我的需求就是实现那个ffmpeg的解码GPU化，先看看官方文档
首先用这个必须有一些要求
NVIDIA Video Codec SDK 8.0 System Requirements * NVIDIA Kepler/Maxwell/Pascal GPU with hardware video accelerators - Refer to the NVIDIA Video SDK developer zone web page (https://developer.nvidia.com/nvidia-video-codec-sdk) for GPUs which
support encoding and decoding acceleration.
* Windows: Driver version 378.66 or higher
* Linux: Driver version 378.13 or higher
* CUDA 7.5 Toolkit (optional) [Windows Configuration Requirements]
- DirectX SDK is needed. You can download the latest SDK from Microsoft's DirectX website
- The CUDA 7.5 Toolkit is optional to install (see below on how to get it)
- CUDA toolkit is used for building CUDA kernels that can interop with NVENC. The following environment variables need to be set to build the sample applications included with the SDK
* For Windows
- DXSDK_DIR: pointing to the DirectX SDK root directory [Linux Configuration Requirements]
* For Linux
- X11 and OpenGL, GLUT, GLEW libraries for video playback and display
- The CUDA 7.5 Toolkit is optional to install (see below on how to get it)
- CUDA toolkit is used for building CUDA kernels that can interop with NVENC.
我看下了我的linux基本满足条件
验证可行性
再看Using_FFmpeg_with_NVIDIA_GPU_Hardware_Acceleration.pdf里面的提示可以直接编译ffmpeg，使用它自带的cuda解码器来测试解码，不过也是有要求的
对号入座，我用的是8.0，所以使用ffmpeg3.4
编译
./configure --enable-shared -–enable-cuda --enable-cuvid --enable-nvenc --enable-nonfree -–enable-libnpp --extra-cflags=-I/usr/local/cuda/include --extra-ldflags=-L/usr/local/cuda/lib64 --prefix=/home/user/mjl/algo/ffmpeg/build make -j (建议用四线程，八线程可能出现找不到的错误)
验证
ffmpeg -y -hwaccel cuvid -c:v h264_cuvid -vsync -i input.mp4 -vf scale_npp=: -vcodec h264_nvenc output0. -vf scale_npp=: -vcodec h264_nvenc output1.
报错：Unknown decoder 'h264_cuvid'
注意一定要在超级管理员权限下面运行，应为只有超级管理员才能访问gpu
正常输出了文件，证明可行
关于它自带的解码器，我一直不是很了解，ffmpeg在初始化的时候统一注册了各种编解码器，但是如何在上层简单的调用，一直不明白，这点可以大家交流
我这里是自己直接对接，也便于控制数据
avformat_network_init();
av_register_all();//1.注册各种编码解码模块，如果3.3及以上版本，里面包含GPU解码模块 std::string tempfile = “xxxx”;//视频流地址 avformat_find_stream_info(format_context_, nullptr）//2.拉取一小段数据流分析，便于得到数据的基本格式
if (AVMEDIA_TYPE_VIDEO == enc->codec_type && video_stream_index_ < )//3.筛选出视频流
codec_ = avcodec_find_decoder(enc->codec_id);//4.找到对应的解码器
codec_context_ = avcodec_alloc_context3(codec_);//5.创建解码器对应的结构体 av_read_frame(format_context_, &packet_); //6.读取数据包 avcodec_send_packet(codec_context_, &packet_) //7.发出解码
avcodec_receive_frame(codec_context_, yuv_frame_) //8.接收解码 sws_scale(y2r_sws_context_, yuv_frame_->data, yuv_frame_->linesize, , codec_context_->height, rgb_data_, rgb_line_size_) //9.数据格式转换
在第一节中说过，4，7，8，9步骤需要修改
数据还是由ffmpeg拉取，也就是说不需要cuda自带的源获取器，只需要对接解码器和解析器（如果拉取数据也可以用GPU会更好）
而在ffmpeg中出来的数据格式是AVPacket，而cuda解码器需要的格式是CUVIDSOURCEDATAPACKET，所以涉及到格式的转换
开始的时候我在网上资料发现一个 https://www.cnblogs.com/dwdxdy/archive/2013/08/07/3244723.html 这位兄弟的格式转换部分是这样实现的
我试过，不行的，没有任何解码输出！
https://www.cnblogs.com/betterwgo/p/6613641.html 这位兄弟比较全面，但是其中的
void VideoSource::play_thread(LPVOID lpParam)
{
AVPacket *avpkt;
avpkt = (AVPacket *)av_malloc(sizeof(AVPacket));
CUVIDSOURCEDATAPACKET cupkt;
int iPkt = ;
CUresult oResult;
while (av_read_frame(pFormatCtx, avpkt) >= ){
if (bThreadExit){
break;
}
bStarted = true;
if (avpkt->stream_index == videoindex){ cuCtxPushCurrent(g_oContext); if (avpkt && avpkt->size) {
if (h264bsfc)
{
av_bitstream_filter_filter(h264bsfc, pFormatCtx->streams[videoindex]->codec, NULL, &avpkt->data, &avpkt->size, avpkt->data, avpkt->size, );
} cupkt.payload_size = (unsigned long)avpkt->size;
cupkt.payload = (const unsigned char*)avpkt->data; if (avpkt->pts != AV_NOPTS_VALUE) {
cupkt.flags = CUVID_PKT_TIMESTAMP;
if (pCodecCtx->pkt_timebase.num && pCodecCtx->pkt_timebase.den){
AVRational tb;
tb.num = ;
tb.den = AV_TIME_BASE;
cupkt.timestamp = av_rescale_q(avpkt->pts, pCodecCtx->pkt_timebase, tb);
}
else
cupkt.timestamp = avpkt->pts;
}
}
else {
cupkt.flags = CUVID_PKT_ENDOFSTREAM;
} oResult = cuvidParseVideoData(oSourceData_.hVideoParser, &cupkt);
if ((cupkt.flags & CUVID_PKT_ENDOFSTREAM) || (oResult != CUDA_SUCCESS)){
break;
}
iPkt++;
//printf("Succeed to read avpkt %d !\n", iPkt);
checkCudaErrors(cuCtxPopCurrent(NULL));
}
av_free_packet(avpkt);
} oSourceData_.pFrameQueue->endDecode();
bStarted = false;
}
这部分代码比较陈旧，还是没能正常运行，起来，不过很敬佩这兄弟，能分享到这一步，已经很不错了！
这是我在他的基础上修改的代码，没有用他的下面这种方式
//h264bsfc = av_bitstream_filter_init("h264_mp4toannexb");
//av_bsf_alloc(av_bsf_get_by_name("h264_mp4toannexb"), &bsf);
改用了av_bsf_send_packet和av_bsf_receive_packet方式，下面的我的代码
if ((&fsc->packet_) && fsc->packet_.size) {
if (fsc->bsf) {
//av_bitstream_filter_filter(h264bsfc, codec_context_, NULL, &packet_.data, &packet_.size, packet_.data, packet_.size, 0);
//av_bitstream_filter_filter(h264bsfc, video_st->codec, NULL, &packet_.data, &packet_.size, packet_.data, packet_.size, 0);
AVPacket filter_packet = { };
AVPacket filtered_packet = { };
int ret;
if (&fsc->packet_ && fsc->packet_.size) {
if ((ret = av_packet_ref(&filter_packet, &fsc->packet_)) < ) {
//av_log(avctx, AV_LOG_ERROR, "av_packet_ref failed\n");
printf("av_packet_ref failed \n");
//return ret;
}
if ((ret = av_bsf_send_packet(fsc->bsf, &filter_packet)) < ) {
//av_log(avctx, AV_LOG_ERROR, "av_bsf_send_packet failed\n");
printf("av_bsf_send_packet failed \n");
av_packet_unref(&filter_packet);
//return ret;
}
if ((ret = av_bsf_receive_packet(fsc->bsf, &filtered_packet)) < ) {
//av_log(avctx, AV_LOG_ERROR, "av_bsf_receive_packet failed\n");
printf("av_bsf_receive_packet failed \n");
//return ret;
}
memcpy(&fsc->packet_, &filtered_packet, sizeof(AVPacket));
//&packet_ = &filtered_packet;
}
}
//if (fsc->h264bsfc){
// //av_bitstream_filter_filter(fsc->h264bsfc, fsc->codec_context_, NULL, &fsc->packet_.data, &fsc->packet_.size, fsc->packet_.data, fsc->packet_.size, 0);
// av_bitstream_filter_filter(fsc->h264bsfc, fsc->video_st->codec, NULL, &fsc->packet_.data, &fsc->packet_.size, fsc->packet_.data, fsc->packet_.size, 0);
//}
pPacket.payload_size = (unsigned long)fsc->packet_.size;
pPacket.payload = (const unsigned char*)fsc->packet_.data;
if (fsc->packet_.pts != AV_NOPTS_VALUE) {
//fprintf(stderr, "fsc->packet_.pts != AV_NOPTS_VALUE \n");
pPacket.flags = CUVID_PKT_TIMESTAMP;
if (fsc->codec_context_->pkt_timebase.num && fsc->codec_context_->pkt_timebase.den) {
//fprintf(stderr, "pkt_timebase.num ok \n");
AVRational tb;
tb.num = ;
tb.den = AV_TIME_BASE;
//pPacket.timestamp = av_rescale_q(fsc->packet_.pts, fsc->codec_context_->pkt_timebase, tb);
pPacket.timestamp = av_rescale_q(fsc->packet_.pts, fsc->codec_context_->pkt_timebase, (AVRational) { , });
}
else {
//fprintf(stderr, "pkt_timebase.num null \n");
pPacket.timestamp = fsc->packet_.pts;
}
}
}
else {
pPacket.flags = CUVID_PKT_ENDOFSTREAM;
//fprintf(stderr, "fsc->packet_.pts == AV_NOPTS_VALUE \n");
}
fsc->pDecoder->HandleVideoData(&pPacket);
于是，解码部分就已经实现，有空在贴出全部源码。
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