bool
HardwareAccel::extractData(VideoFrame& input)
{
try {
auto inFrame = input.pointer();
if (inFrame->format != format_) {
std::stringstream buf;
buf << "Frame format mismatch: expected " << av_get_pix_fmt_name(format_);
buf << ", got " << av_get_pix_fmt_name((AVPixelFormat)inFrame->format);
throw std::runtime_error(buf.str());
}
// FFmpeg requires a second frame in which to transfer the data
// from the GPU buffer to the main memory
auto output = std::unique_ptr<VideoFrame>(new VideoFrame());
auto outFrame = output->pointer();
outFrame->format = AV_PIX_FMT_YUV420P;
extractData(input, *output);
// move outFrame into inFrame so the caller receives extracted image data
// but we have to delete inFrame first
av_frame_unref(inFrame);
av_frame_move_ref(inFrame, outFrame);
} catch (const std::runtime_error& e) {
fail(false);
RING_ERR("%s", e.what());
return false;
}
succeed();
return true;
}
MediaDecoder::Status
MediaDecoder::flush(VideoFrame& result)
{
AVPacket inpacket;
av_init_packet(&inpacket);
int frameFinished = 0;
auto len = avcodec_decode_video2(decoderCtx_, result.pointer(),
&frameFinished, &inpacket);
av_packet_unref(&inpacket);
if (len <= 0)
return Status::DecodeError;
if (frameFinished) {
#ifdef RING_ACCEL
// flush is called when closing the stream
// so don't restart the media decoder
if (accel_ && !accel_->hasFailed())
accel_->extractData(result);
#endif // RING_ACCEL
return Status::FrameFinished;
}
return Status::Success;
}
MediaDecoder::Status
MediaDecoder::decode(VideoFrame& result)
{
AVPacket inpacket;
av_init_packet(&inpacket);
int ret = av_read_frame(inputCtx_, &inpacket);
if (ret == AVERROR(EAGAIN)) {
return Status::Success;
} else if (ret == AVERROR_EOF) {
return Status::EOFError;
} else if (ret < 0) {
char errbuf[64];
av_strerror(ret, errbuf, sizeof(errbuf));
RING_ERR("Couldn't read frame: %s\n", errbuf);
return Status::ReadError;
}
// is this a packet from the video stream?
if (inpacket.stream_index != streamIndex_) {
av_packet_unref(&inpacket);
return Status::Success;
}
auto frame = result.pointer();
int frameFinished = 0;
int len = avcodec_decode_video2(decoderCtx_, frame,
&frameFinished, &inpacket);
av_packet_unref(&inpacket);
if (len <= 0)
return Status::DecodeError;
if (frameFinished) {
frame->format = (AVPixelFormat) correctPixFmt(frame->format);
#ifdef RING_ACCEL
if (accel_) {
if (!accel_->hasFailed())
accel_->extractData(result);
else
return Status::RestartRequired;
}
#endif // RING_ACCEL
if (emulateRate_ and frame->pkt_pts != AV_NOPTS_VALUE) {
auto frame_time = getTimeBase()*(frame->pkt_pts - avStream_->start_time);
auto target = startTime_ + static_cast<std::int64_t>(frame_time.real() * 1e6);
auto now = av_gettime();
if (target > now) {
std::this_thread::sleep_for(std::chrono::microseconds(target - now));
}
}
return Status::FrameFinished;
}
return Status::Success;
}
void
VideoMixer::render_frame(VideoFrame& output, const VideoFrame& input, int index)
{
if (!width_ or !height_ or !input.pointer())
return;
const int n = sources_.size();
const int zoom = ceil(sqrt(n));
int cell_width = width_ / zoom;
int cell_height = height_ / zoom;
int xoff = (index % zoom) * cell_width;
int yoff = (index / zoom) * cell_height;
scaler_.scale_and_pad(input, output, xoff, yoff, cell_width, cell_height, true);
}
