Method GetFrame

src/avisynth/avssources.cpp:440–539

}

PVideoFrame AvisynthVideoSource::GetFrame(int n, IScriptEnvironment *Env) {
    n = std::min(std::max(n, 0), VI.num_frames - 1);

    PVideoFrame Dst = Env->NewVideoFrame(VI);
    AVSMap *props = has_at_least_v8 ? Env->getFramePropsRW(Dst) : nullptr;

    ErrorInfo E;
    const FFMS_Frame *Frame = nullptr;

    if (FPSNum > 0 && FPSDen > 0) {
        double currentTime = FFMS_GetVideoProperties(V)->FirstTime +
            (double)(n * (int64_t)FPSDen) / FPSNum;
        Frame = FFMS_GetFrameByTime(V, currentTime, &E);
        Env->SetVar(Env->Sprintf("%s%s", this->VarPrefix, "FFVFR_TIME"), -1);
        if (has_at_least_v8) {
            Env->propSetInt(props, "_DurationNum", FPSDen, 0);
            Env->propSetInt(props, "_DurationDen", FPSNum, 0);
            Env->propSetFloat(props, "_AbsoluteTime", currentTime, 0);
        }
    } else {
        Frame = FFMS_GetFrame(V, n, &E);
        FFMS_Track *T = FFMS_GetTrackFromVideo(V);
        const FFMS_TrackTimeBase *TB = FFMS_GetTimeBase(T);
        Env->SetVar(Env->Sprintf("%s%s", this->VarPrefix, "FFVFR_TIME"), static_cast<int>(FFMS_GetFrameInfo(T, n)->PTS * static_cast<double>(TB->Num) / TB->Den));
        if (has_at_least_v8) {
            int64_t num;
            if (n + 1 < VI.num_frames)
                num = FFMS_GetFrameInfo(T, n + 1)->PTS - FFMS_GetFrameInfo(T, n)->PTS;
            else if (n > 0) // simply use the second to last frame's duration for the last one, should be good enough
                num = FFMS_GetFrameInfo(T, n)->PTS - FFMS_GetFrameInfo(T, n - 1)->PTS;
            else // just make it one timebase if it's a single frame clip
                num = 1;
            int64_t DurNum = TB->Num * num;
            int64_t DurDen = TB->Den * 1000;
            vsh::reduceRational(&DurNum, &DurDen);
            Env->propSetInt(props, "_DurationNum", DurNum, 0);
            Env->propSetInt(props, "_DurationDen", DurDen, 0);
            Env->propSetFloat(props, "_AbsoluteTime", ((static_cast<double>(TB->Num) / 1000) * FFMS_GetFrameInfo(T, n)->PTS) / TB->Den, 0);
        }
    }

    if (Frame == nullptr)
        Env->ThrowError("FFVideoSource: %s", E.Buffer);

    Env->SetVar(Env->Sprintf("%s%s", this->VarPrefix, "FFPICT_TYPE"), static_cast<int>(Frame->PictType));
    OutputFrame(Frame, Dst, Env);

    if (has_at_least_v8) {
        const FFMS_VideoProperties *VP = FFMS_GetVideoProperties(V);
        if (VP->SARNum > 0 && VP->SARDen > 0) {
            Env->propSetInt(props, "_SARNum", VP->SARNum, 0);
            Env->propSetInt(props, "_SARDen", VP->SARDen, 0);
        }

        Env->propSetInt(props, "_Matrix", Frame->ColorSpace, 0);
        Env->propSetInt(props, "_Primaries", Frame->ColorPrimaries, 0);
        Env->propSetInt(props, "_Transfer", Frame->TransferCharateristics, 0);
        if (Frame->ChromaLocation > 0)