使用ffmpeg将多张图片生成H264裸流并获取帧图片

#include "EncoderH264.h" #include "opencv2/core/core.hpp" #include "opencv2/highgui/highgui.hpp" #include "opencv2/imgcodecs.hpp" #include "ShareHeader.h" CEnCoderH264::CEnCoderH264(const char *_fpath) : m_pts(0) , m_pCodecCtx(0) , m_pSwsContext(0) , m_pFrame(0) , m_pPacket(0) , m_src_pix_fmt(AV_PIX_FMT_BGR24) { m_filePath = _fpath; m_OutFile.close(); m_OutFile.clear(); m_OutFile.open(_fpath, std::ios::out | std::ios::trunc | std::ios::binary); } CEnCoderH264::~CEnCoderH264() { uninit(); } void CEnCoderH264::init(const ENCODEINFO *_p) { const ENCODEINFO *_info = (_p == 0) ? &ENCODEINFO() : _p; //find h264 encoder. AVCodec *pEnCode = avcodec_find_encoder(AV_CODEC_ID_H264); RETURN_H264(pEnCode == 0, "Encoder initialize fail.\n"); //get a AVCodecContext. m_pCodecCtx = avcodec_alloc_context3(pEnCode); RETURN_H264(m_pCodecCtx == 0, "alloc AVCodecContext fail.\n"); m_pCodecCtx->bit_rate = _info->bitRate; m_pCodecCtx->width = _info->width; m_pCodecCtx->height = _info->height; m_pCodecCtx->time_base.den = 25;//fps. m_pCodecCtx->time_base.num = 1; m_pCodecCtx->framerate.den = 1; m_pCodecCtx->framerate.num = 25; //The fewer I frames are inserted into every 25 frames, the smaller the video is. m_pCodecCtx->gop_size = 25; /** * How many B frames are allowed between two non-B frames. * 0 indicates that B frame is not applicable. * B the more frames, the smaller the picture. * note: * It'seems that B frame is not suitable for live broadcast. */ m_pCodecCtx->max_b_frames = 0; m_pCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P; //Set Option[just for AV_CODEC_ID_H264]. //Set encoder to non-delay format. //av_opt_set(pCodecCtx->priv_data, "preset", "slow", 0); //Set the encoder delay to solve the previous dozens of frames without data. av_opt_set(m_pCodecCtx->priv_data, "tune", "zerolatency", 0); //open encoder. RETURN_H264(avcodec_open2(m_pCodecCtx, pEnCode, NULL) < 0, "open encoder fail.\n"); //get a swscontext according to the image format. switch (_info->format) { case ENCODEINFO::FMT_BGR24: m_src_pix_fmt = AV_PIX_FMT_BGR24; break; case ENCODEINFO::FMT_RGB24: m_src_pix_fmt = AV_PIX_FMT_RGB24; break; //case ENCODEINFO::FMT_RGBA: m_src_pix_fmt = AV_PIX_FMT_RGBA; break; default:break; } m_pSwsContext = sws_getContext( m_pCodecCtx->width, m_pCodecCtx->height, m_src_pix_fmt, m_pCodecCtx->width, m_pCodecCtx->height, AV_PIX_FMT_YUV420P, SWS_POINT, NULL, NULL, NULL); RETURN_H264(m_pSwsContext == 0, "create swscontext fail.\n"); //alloc a frame to deal with data. m_pFrame = av_frame_alloc(); RETURN_H264(m_pFrame == 0, "alloc a frame fail.\n"); m_pFrame->format = m_pCodecCtx->pix_fmt; m_pFrame->width = m_pCodecCtx->width; m_pFrame->height = m_pCodecCtx->height; RETURN_H264(av_frame_get_buffer(m_pFrame, /*32*/0) !=0, "frame get buffer fail.\n"); //alloc a packet to deal with data. m_pPacket = av_packet_alloc(); m_pts = 0; } void CEnCoderH264::addPicture(uint8_t *_data, uint32_t _linestride) { RETURN_H264(m_pFrame == 0 || m_pSwsContext == 0 || _data == 0 || _linestride <= 0 || m_pCodecCtx == 0, "paramter is unvalid.\n"); //make sure the frame data is writable. RETURN_H264(av_frame_make_writable(m_pFrame)<0, "is not writable"); int _StrideLen = _linestride; sws_scale(m_pSwsContext, &_data, &_StrideLen, 0, m_pCodecCtx->height, m_pFrame->data, m_pFrame->linesize); m_pFrame->pts = m_pts++; //encode the image. Encode(); } void CEnCoderH264::addPicture(const char *_fpath) { RETURN_H264(m_src_pix_fmt != AV_PIX_FMT_BGR24, "format of picture data is not meet the requirements.\n"); //read file data with opencv. RETURN_H264(_access(_fpath, 0) == -1, "file does not exist.\n"); cv::Mat _img = cv::imread(_fpath); //to encode. size_t _imgstep = _img.step; size_t _imgsize = _img.rows*_img.step; uint8_t *_imgdata = (uint8_t *)malloc(sizeof(uint8_t) * _imgsize); memcpy(_imgdata, _img.data, _imgsize); addPicture(_imgdata, (uint32_t)_imgstep); //release. _img.release(); free(_imgdata); } void CEnCoderH264::Encode() { RETURN_H264(m_pCodecCtx == 0 || m_pPacket == 0, "Encode fail,paramters is null.\n"); RETURN_H264(avcodec_send_frame(m_pCodecCtx, m_pFrame) < 0, "send frame fail.\n"); //frame to packet is encode. int _ret = avcodec_receive_packet(m_pCodecCtx, m_pPacket); RETURN_H264(_ret == AVERROR(EAGAIN) || _ret == AVERROR_EOF || _ret < 0, "receive packet fail.\n"); fflush(stdout); //write to h264 file. if (m_OutFile.is_open()) { m_OutFile.write((char *)m_pPacket->data, m_pPacket->size); } av_packet_unref(m_pPacket); } void CEnCoderH264::uninit() { //flush the encoder. av_frame_free(&m_pFrame); m_pFrame = 0; Encode(); //add sequence end code to have a real MPEG file. if (m_OutFile.is_open()) { uint8_t endcode[] = { 0, 0, 1, 0xb7 }; m_OutFile.write((char *)endcode, sizeof(endcode)); m_OutFile.close(); } avcodec_free_context(&m_pCodecCtx); av_packet_free(&m_pPacket); }