Set iUsageType = SCREEN_CONTENT_REAL_TIME for low-motion UI overlays (health bars, maps). Use constant bitrate to avoid network spikes. 5. Common Pitfalls & Fixes | Problem | Solution | |---------|----------| | High CPU usage | Reduce resolution or use iRCMode = RC_QUALITY_MODE | | Color shift | Ensure correct RGB↔YUV matrix (BT.709 for HDTV) | | Dropped frames | Increase iMaxNalSz and use EncodeParameterSets() before first frame | | Audio sync | Store PTS (presentation timestamps) separately — H.264 stream has no audio | 6. Legal & Licensing Note OpenH264 is BSD 2-Clause — free for commercial use. However, it uses patents from MPEG LA, but Cisco provides a patent license when using the binary form from their official distribution.
encoder->Initialize(¶m); OpenH264 expects YUV 4:2:0. Convert your frame buffer:
ISVCDecoder* decoder = nullptr; WelsCreateDecoder(&decoder); SDecodingParam decParam; decParam.uiTargetDqLayer = UCHAR_MAX; decParam.eEcActiveIdc = ERROR_CON_SLICE_COPY; decoder->Initialize(&decParam); the killer's game openh264
// Assuming game gives you RGB24 void RGB24toYUV420(uint8_t* rgb, uint8_t* yuv, int width, int height) // Standard conversion matrix (BT.601) for (int i = 0; i < width * height; i++) int r = rgb[3*i]; int g = rgb[3*i+1]; int b = rgb[3*i+2]; yuv[i] = (66*r + 129*g + 25*b + 128)>>8 + 16; // Y // ... U/V planes
SEncParamExt param; encoder->GetDefaultParams(¶m); param.iUsageType = CAMERA_VIDEO_REAL_TIME; // Low latency param.iPicWidth = 1280; param.iPicHeight = 720; param.fMaxFrameRate = 30.0f; param.iTargetBitrate = 2000000; // 2 Mbps param.iRCMode = RC_BITRATE_MODE; Common Pitfalls & Fixes | Problem | Solution
SSourcePicture pic; pic.iPicWidth = width; pic.iPicHeight = height; pic.iColorFormat = videoFormatI420; pic.pData[0] = y_plane; pic.pData[1] = u_plane; pic.pData[2] = v_plane; SFrameBSInfo info; encoder->EncodeFrame(&pic, &info);
std::deque<std::vector<uint8_t>> replay_buffer; // On kill: std::ofstream replay("killcam_replay.h264", std::ios::binary); for (auto& nal : replay_buffer) replay.write((char*)nal.data(), nal.size()); encoder->Initialize(¶m); OpenH264 expects YUV 4:2:0
uint8_t* h264_stream = ...; // read from file uint8_t* yuv_out = new uint8_t[width height 3/2]; decoder->DecodeFrameNoDelay(h264_stream, stream_len, yuv_out);