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 // but it would require some more plumbing, and it would also fail if the file
17 // changes parameters midway, which is allowed in some formats.
19 // There is currently no audio support.
31 #include <movit/ycbcr.h>
33 #include "bmusb/bmusb.h"
34 #include "quittable_sleeper.h"
36 struct AVFormatContext;
38 class FFmpegCapture : public bmusb::CaptureInterface
41 FFmpegCapture(const std::string &filename, unsigned width, unsigned height);
44 void set_card_index(int card_index)
46 this->card_index = card_index;
49 int get_card_index() const
56 std::lock_guard<std::mutex> lock(queue_mu);
57 command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
60 void change_rate(double new_rate)
62 std::lock_guard<std::mutex> lock(queue_mu);
63 command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
67 void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
69 video_frame_allocator = allocator;
70 if (owned_video_frame_allocator.get() != allocator) {
71 owned_video_frame_allocator.reset();
75 bmusb::FrameAllocator *get_video_frame_allocator() override
77 return video_frame_allocator;
80 // Does not take ownership.
81 void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
83 audio_frame_allocator = allocator;
84 if (owned_audio_frame_allocator.get() != allocator) {
85 owned_audio_frame_allocator.reset();
89 bmusb::FrameAllocator *get_audio_frame_allocator() override
91 return audio_frame_allocator;
94 void set_frame_callback(bmusb::frame_callback_t callback) override
96 frame_callback = callback;
99 // Used to get precise information about the Y'CbCr format used
100 // for a given frame. Only valid to call during the frame callback,
101 // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
102 movit::YCbCrFormat get_current_frame_ycbcr_format() const
104 return current_frame_ycbcr_format;
107 void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
109 dequeue_init_callback = init;
110 dequeue_cleanup_callback = cleanup;
111 has_dequeue_callbacks = true;
114 std::string get_description() const override
119 void configure_card() override;
120 void start_bm_capture() override;
121 void stop_dequeue_thread() override;
122 bool get_disconnected() const override { return false; } // We never unplug.
124 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const;
125 void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
126 uint32_t get_current_video_mode() const override { return 0; }
128 std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
129 return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar };
131 void set_pixel_format(bmusb::PixelFormat pixel_format) override {
132 this->pixel_format = pixel_format;
134 bmusb::PixelFormat get_current_pixel_format() const override {
138 std::map<uint32_t, std::string> get_available_video_inputs() const override {
139 return { { 0, "Auto" } }; }
140 void set_video_input(uint32_t video_input_id) override {} // Ignore.
141 uint32_t get_current_video_input() const override { return 0; }
143 std::map<uint32_t, std::string> get_available_audio_inputs() const override {
144 return { { 0, "Embedded" } };
146 void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
147 uint32_t get_current_audio_input() const override { return 0; }
150 void producer_thread_func();
151 void send_disconnected_frame();
152 bool play_video(const std::string &pathname);
153 void internal_rewind();
155 // Returns true if there was an error.
156 bool process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified);
158 std::string description, filename;
159 uint16_t timecode = 0;
160 unsigned width, height;
161 bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
162 movit::YCbCrFormat current_frame_ycbcr_format;
163 bool running = false;
167 bool has_dequeue_callbacks = false;
168 std::function<void()> dequeue_init_callback = nullptr;
169 std::function<void()> dequeue_cleanup_callback = nullptr;
171 bmusb::FrameAllocator *video_frame_allocator = nullptr;
172 bmusb::FrameAllocator *audio_frame_allocator = nullptr;
173 std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
174 std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
175 bmusb::frame_callback_t frame_callback = nullptr;
177 QuittableSleeper producer_thread_should_quit;
178 std::thread producer_thread;
180 int64_t pts_origin, last_pts;
181 std::chrono::steady_clock::time_point start, next_frame_start;
184 struct QueuedCommand {
185 enum Command { REWIND, CHANGE_RATE } command;
186 double new_rate; // For CHANGE_RATE.
188 std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
191 #endif // !defined(_FFMPEG_CAPTURE_H)