1 #ifndef _FFMPEG_CAPTURE_H
2 #define _FFMPEG_CAPTURE_H 1
4 // FFmpegCapture looks much like a capture card, but the frames it spits out
5 // come from a video in real time, looping. Because it decodes the video using
6 // FFmpeg (thus the name), this means it can handle a very wide array of video
7 // formats, and also things like network streaming and V4L capture, but it is
8 // also significantly less integrated and optimized than the regular capture
9 // cards. In particular, the frames are always scaled and converted to 8-bit
10 // RGBA on the CPU before being sent on to the GPU.
12 // Since we don't really know much about the video when building the chains,
13 // there are some limitations. In particular, frames are always assumed to be
14 // sRGB even if the video container says something else. We could probably
15 // try to load the video on startup and pick out the parameters at that point
16 // (which would probably also allow us to send Y'CbCr video through without
17 // CPU conversion), but it would require some more plumbing, and it would also
18 // fail if the file changes parameters midway, which is allowed in some formats.
20 // There is currently no audio support.
32 #include <movit/ycbcr.h>
34 #include "bmusb/bmusb.h"
35 #include "quittable_sleeper.h"
37 class FFmpegCapture : public bmusb::CaptureInterface
40 FFmpegCapture(const std::string &filename, unsigned width, unsigned height);
43 void set_card_index(int card_index)
45 this->card_index = card_index;
48 int get_card_index() const
55 std::lock_guard<std::mutex> lock(queue_mu);
56 command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
59 void change_rate(double new_rate)
61 std::lock_guard<std::mutex> lock(queue_mu);
62 command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
66 void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
68 video_frame_allocator = allocator;
69 if (owned_video_frame_allocator.get() != allocator) {
70 owned_video_frame_allocator.reset();
74 bmusb::FrameAllocator *get_video_frame_allocator() override
76 return video_frame_allocator;
79 // Does not take ownership.
80 void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
82 audio_frame_allocator = allocator;
83 if (owned_audio_frame_allocator.get() != allocator) {
84 owned_audio_frame_allocator.reset();
88 bmusb::FrameAllocator *get_audio_frame_allocator() override
90 return audio_frame_allocator;
93 void set_frame_callback(bmusb::frame_callback_t callback) override
95 frame_callback = callback;
98 // Used to get precise information about the Y'CbCr format used
99 // for a given frame. Only valid to call during the frame callback,
100 // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
101 movit::YCbCrFormat get_current_frame_ycbcr_format() const
103 return current_frame_ycbcr_format;
106 void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
108 dequeue_init_callback = init;
109 dequeue_cleanup_callback = cleanup;
110 has_dequeue_callbacks = true;
113 std::string get_description() const override
118 void configure_card() override;
119 void start_bm_capture() override;
120 void stop_dequeue_thread() override;
121 bool get_disconnected() const override { return false; } // We never unplug.
123 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const;
124 void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
125 uint32_t get_current_video_mode() const override { return 0; }
127 std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
128 return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar };
130 void set_pixel_format(bmusb::PixelFormat pixel_format) override {
131 this->pixel_format = pixel_format;
133 bmusb::PixelFormat get_current_pixel_format() const override {
137 std::map<uint32_t, std::string> get_available_video_inputs() const override {
138 return { { 0, "Auto" } }; }
139 void set_video_input(uint32_t video_input_id) override {} // Ignore.
140 uint32_t get_current_video_input() const override { return 0; }
142 std::map<uint32_t, std::string> get_available_audio_inputs() const override {
143 return { { 0, "Embedded" } };
145 void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
146 uint32_t get_current_audio_input() const override { return 0; }
149 void producer_thread_func();
150 void send_disconnected_frame();
151 bool play_video(const std::string &pathname);
152 void internal_rewind();
154 std::string description, filename;
155 uint16_t timecode = 0;
156 unsigned width, height;
157 bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
158 movit::YCbCrFormat current_frame_ycbcr_format;
159 bool running = false;
162 bool has_dequeue_callbacks = false;
163 std::function<void()> dequeue_init_callback = nullptr;
164 std::function<void()> dequeue_cleanup_callback = nullptr;
166 bmusb::FrameAllocator *video_frame_allocator = nullptr;
167 bmusb::FrameAllocator *audio_frame_allocator = nullptr;
168 std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
169 std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
170 bmusb::frame_callback_t frame_callback = nullptr;
172 QuittableSleeper producer_thread_should_quit;
173 std::thread producer_thread;
175 int64_t pts_origin, last_pts;
176 std::chrono::steady_clock::time_point start, next_frame_start;
179 struct QueuedCommand {
180 enum Command { REWIND, CHANGE_RATE } command;
181 double new_rate; // For CHANGE_RATE.
183 std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
186 #endif // !defined(_FFMPEG_CAPTURE_H)