Method FFMS_VideoSource

src/core/videosource.cpp:199–440

}

FFMS_VideoSource::FFMS_VideoSource(const char *SourceFile, FFMS_Index &Index, int Track, int Threads, int SeekMode)
    : Index(Index), SeekMode(SeekMode) {

    try {
        if (Track < 0 || Track >= static_cast<int>(Index.size()))
            throw FFMS_Exception(FFMS_ERROR_INDEX, FFMS_ERROR_INVALID_ARGUMENT,
                "Out of bounds track index selected");

        if (Index[Track].TT != FFMS_TYPE_VIDEO)
            throw FFMS_Exception(FFMS_ERROR_INDEX, FFMS_ERROR_INVALID_ARGUMENT,
                "Not a video track");

        if (Index[Track].empty())
            throw FFMS_Exception(FFMS_ERROR_INDEX, FFMS_ERROR_INVALID_ARGUMENT,
                "Video track contains no frames");

        if (!Index.CompareFileSignature(SourceFile))
            throw FFMS_Exception(FFMS_ERROR_INDEX, FFMS_ERROR_FILE_MISMATCH,
                "The index does not match the source file");

        Frames = Index[Track];
        VideoTrack = Track;

        if (Threads < 1)
            DecodingThreads = (std::min)(std::thread::hardware_concurrency(), 16u);
        else
            DecodingThreads = Threads;

        DecodeFrame = av_frame_alloc();
        LastDecodedFrame = av_frame_alloc();
        StashedPacket = av_packet_alloc();

        if (!DecodeFrame || !LastDecodedFrame || !StashedPacket)
            throw FFMS_Exception(FFMS_ERROR_DECODING, FFMS_ERROR_ALLOCATION_FAILED,
                "Could not allocate dummy frame / stashed packet.");

        // Dummy allocations so the unallocated case doesn't have to be handled later
        if (av_image_alloc(SWSFrameData, SWSFrameLinesize, 16, 16, AV_PIX_FMT_GRAY8, 4) < 0)
            throw FFMS_Exception(FFMS_ERROR_DECODING, FFMS_ERROR_ALLOCATION_FAILED,
                "Could not allocate dummy frame.");

        LAVFOpenFile(SourceFile, FormatContext, VideoTrack, Index.LAVFOpts);

        auto *Codec = avcodec_find_decoder(FormatContext->streams[VideoTrack]->codecpar->codec_id);
        if (Codec == nullptr)
            throw FFMS_Exception(FFMS_ERROR_DECODING, FFMS_ERROR_CODEC,
                "Video codec not found");

        CodecContext = avcodec_alloc_context3(Codec);
        if (CodecContext == nullptr)
            throw FFMS_Exception(FFMS_ERROR_DECODING, FFMS_ERROR_ALLOCATION_FAILED,
                "Could not allocate video codec context.");
        if (avcodec_parameters_to_context(CodecContext, FormatContext->streams[VideoTrack]->codecpar) < 0)
            throw FFMS_Exception(FFMS_ERROR_DECODING, FFMS_ERROR_CODEC,
                "Could not copy video decoder parameters.");
        CodecContext->thread_count = DecodingThreads;
        CodecContext->has_b_frames = Frames.MaxBFrames;