void preroll_video_frames(unsigned int n_frames) {
IDeckLinkMutableVideoFrame *frame;
IDeckLinkVideoFrameAncillary *anc;
for (unsigned int i = 0; i < n_frames; i++) {
if (deckLinkOutput->CreateVideoFrame(norms[norm].w,
norms[norm].h, 2*norms[norm].w, bpf,
bmdFrameFlagDefault, &frame) != S_OK) {
throw std::runtime_error("Failed to create frame");
}
if (deckLinkOutput->CreateAncillaryData(bpf, &anc) != S_OK) {
throw std::runtime_error("failed to set frame ancillary data");
}
if (frame->SetAncillaryData(anc) != S_OK) {
throw std::runtime_error("failed to set frame ancillary data");
}
schedule_frame(frame);
}
}
