libopenh264

Abstract	libopenh264
Authors	Walter Fan
Status	WIP
Updated	2024-08-21

Overview 

OpenH264 is a codec library which supports H.264 encoding and decoding. It is suitable for use in real time applications such as WebRTC. See http://www.openh264.org/ for more details.

Installation 

先要安装下列工具

gcc/clang
NASM

windows 平台需要额外安装 * Visual Studio C++ 2019 * MinGW https://osdn.net/projects/mingw/releases/

执行下列步骤从源码编译安装

git clone git@github.com:cisco/openh264.git
cd openh264
make clean
make gtest-bootstrap

# architecture: arm, arm64, x86 or x86_64
make OS=linux ARCH=**ARCH**

linux

make [OS=linux] [BUILDTYPE=Release/Debug]  [ARCH=x86_64/x86] [CC=gcc] [CXX=g++] [USE_ASM=Yes/No] [ENABLEPIC=Yes]

mac

make [OS=darwin] [BUILDTYPE=Release/Debug]  [ARCH=x86_64/x86] [CC=gcc] [CXX=g++] [USE_ASM=Yes/No] [ENABLEPIC=Yes]

windows

AutoBuildForWPAndWindows.bat <Win32|Win64-Debug|Release-C|ASM>

Usage 

initialize encoder 

int initialize_encoder(ISVCEncoder*& encoder, int width, int height, int fps, int bitrate) {

    int err;
    ISVCEncoder* encoder;
    err = WelsCreateSVCEncoder(&encoder);
    if (err) { return err; }

    SEncParamBase param;
    memset(&param, 0, sizeof(SEncParamBase));
    param.iUsageType = CAMERA_VIDEO_REAL_TIME;
    param.iPicWidth = width;
    param.iPicHeight = height;
    param.iTargetBitrate = bitrate / 2;
    param.iRCMode = RC_BITRATE_MODE;
    param.fMaxFrameRate = fps;

    err = encoder->Initialize(&param);
    if (err) { return err; }

    int videoFormat = videoFormatI420;
    err = encoder->SetOption(ENCODER_OPTION_DATAFORMAT, &videoFormat);
    if (err) { return err; }

    SBitrateInfo bitrateInfo;
    bitrateInfo.iLayer = SPATIAL_LAYER_ALL;
    bitrateInfo.iBitrate = bitrate;
    err = encoder->SetOption(ENCODER_OPTION_MAX_BITRATE, &bitrateInfo);

    return err;
}

encode video frame 

int encode_frame(ISVCEncoder* encoder, unsigned char* yuv, int width, int height, long timestamp, SFrameBSInfo& enc_info;) {

    if (!encoder) { return -1; }
    int err = 0;

    memset(&enc_info, 0, sizeof(SFrameBSInfo));

    SSourcePicture frame;
    memset(&frame, 0, sizeof(SSourcePicture));
    frame.iPicWidth = width;
    frame.iPicHeight = height;
    frame.iColorFormat = videoFormatI420;
    frame.iStride[0] = width;
    frame.iStride[1] = frame.iStride[2] = width >> 1;
    frame.pData[0] = yuv;
    frame.pData[1] = frame.pData[0] + width * height;
    frame.pData[2] = frame.pData[1] + (width * height >> 2);
    frame.uiTimeStamp = timestamp;

    err = encoder->EncodeFrame(&frame, &enc_info);

    return err;
}

initialize decoder 

int initialize_decoder(ISVCDecoder*& decoder) {

    int err = WelsCreateDecoder(&decoder);
    if (err) { return err; }

    SDecodingParam param;
    memset(&param, 0, sizeof(SDecodingParam));
    param.uiTargetDqLayer = UCHAR_MAX;
    param.eEcActiveIdc = ERROR_CON_SLICE_COPY;
    param.sVideoProperty.eVideoBsType = VIDEO_BITSTREAM_DEFAULT;
    err = decoder->Initialize(&param);

    return err;
}

decode video frame 

int decode_frame(ISVCDecoder* decoder, unsigned char* data, int length, vector<uint8_t> frameData, SBufferInfo& frameInfo) {

    memset(yuv_out, 0, sizeof(yuv_out));

    memset(&info_out, 0, sizeof(SBufferInfo));

    int err = decoder->DecodeFrame2(data, length, yuv_out, &frameInfo);

    return err;
}