} // namespace
FFmpegCapture::FFmpegCapture(const string &filename, unsigned width, unsigned height)
- : filename(filename), width(width), height(height)
+ : filename(filename), width(width), height(height), video_timebase{1, 1}
{
// Not really used for anything.
description = "Video: " + filename;
}
const AVCodecParameters *codecpar = format_ctx->streams[video_stream_index]->codecpar;
- AVRational video_timebase = format_ctx->streams[video_stream_index]->time_base;
+ video_timebase = format_ctx->streams[video_stream_index]->time_base;
AVCodecContextWithDeleter codec_ctx = avcodec_alloc_context3_unique(nullptr);
if (avcodec_parameters_to_context(codec_ctx.get(), codecpar) < 0) {
fprintf(stderr, "%s: Cannot fill codec parameters\n", pathname.c_str());
// Main loop.
while (!producer_thread_should_quit.should_quit()) {
- if (process_queued_commands(format_ctx.get(), pathname, last_modified)) {
+ if (process_queued_commands(format_ctx.get(), pathname, last_modified, /*rewound=*/nullptr)) {
return true;
}
internal_rewind();
continue;
}
- last_pts = frame->pts;
VideoFormat video_format = construct_video_format(frame.get(), video_timebase);
FrameAllocator::Frame video_frame = make_video_frame(frame.get(), pathname, &error);
audio_format.bits_per_sample = 32;
audio_format.num_channels = 8;
- next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
- video_frame.received_timestamp = next_frame_start;
- producer_thread_should_quit.sleep_until(next_frame_start);
- frame_callback(timecode++,
- video_frame, 0, video_format,
- audio_frame, 0, audio_format);
+ for ( ;; ) {
+ next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
+ video_frame.received_timestamp = next_frame_start;
+ bool finished_wakeup = producer_thread_should_quit.sleep_until(next_frame_start);
+ if (finished_wakeup) {
+ frame_callback(timecode++,
+ video_frame, 0, video_format,
+ audio_frame, 0, audio_format);
+ break;
+ } else {
+ if (producer_thread_should_quit.should_quit()) break;
+
+ bool rewound = false;
+ if (process_queued_commands(format_ctx.get(), pathname, last_modified, &rewound)) {
+ return true;
+ }
+ // If we just rewound, drop this frame on the floor and be done.
+ if (rewound) {
+ video_frame_allocator->release_frame(video_frame);
+ break;
+ }
+ // OK, we didn't, so probably a rate change. Recalculate next_frame_start,
+ // but if it's now in the past, we'll reset the origin, so that we don't
+ // generate a huge backlog of frames that we need to run through quickly.
+ next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
+ steady_clock::time_point now = steady_clock::now();
+ if (next_frame_start < now) {
+ pts_origin = frame->pts;
+ start = next_frame_start = now;
+ }
+ }
+ }
+ last_pts = frame->pts;
}
return true;
}
start = next_frame_start = steady_clock::now();
}
-bool FFmpegCapture::process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified)
+bool FFmpegCapture::process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound)
{
// Process any queued commands from other threads.
vector<QueuedCommand> commands;
return true;
}
internal_rewind();
+ if (rewound != nullptr) {
+ *rewound = true;
+ }
break;
case QueuedCommand::CHANGE_RATE:
- start = next_frame_start;
+ // Change the origin to the last played frame.
+ start = compute_frame_start(last_pts, pts_origin, video_timebase, start, rate);
pts_origin = last_pts;
rate = cmd.new_rate;
break;