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 class FFmpegCapture : public bmusb::CaptureInterface
39 FFmpegCapture(const std::string &filename, unsigned width, unsigned height);
42 void set_card_index(int card_index)
44 this->card_index = card_index;
47 int get_card_index() const
54 std::lock_guard<std::mutex> lock(queue_mu);
55 command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
58 void change_rate(double new_rate)
60 std::lock_guard<std::mutex> lock(queue_mu);
61 command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
65 void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
67 video_frame_allocator = allocator;
68 if (owned_video_frame_allocator.get() != allocator) {
69 owned_video_frame_allocator.reset();
73 bmusb::FrameAllocator *get_video_frame_allocator() override
75 return video_frame_allocator;
78 // Does not take ownership.
79 void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
81 audio_frame_allocator = allocator;
82 if (owned_audio_frame_allocator.get() != allocator) {
83 owned_audio_frame_allocator.reset();
87 bmusb::FrameAllocator *get_audio_frame_allocator() override
89 return audio_frame_allocator;
92 void set_frame_callback(bmusb::frame_callback_t callback) override
94 frame_callback = callback;
97 // Used to get precise information about the Y'CbCr format used
98 // for a given frame. Only valid to call during the frame callback,
99 // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
100 movit::YCbCrFormat get_current_frame_ycbcr_format() const
102 return current_frame_ycbcr_format;
105 void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
107 dequeue_init_callback = init;
108 dequeue_cleanup_callback = cleanup;
109 has_dequeue_callbacks = true;
112 std::string get_description() const override
117 void configure_card() override;
118 void start_bm_capture() override;
119 void stop_dequeue_thread() override;
120 bool get_disconnected() const override { return false; } // We never unplug.
122 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const;
123 void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
124 uint32_t get_current_video_mode() const override { return 0; }
126 std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
127 return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar };
129 void set_pixel_format(bmusb::PixelFormat pixel_format) override {
130 this->pixel_format = pixel_format;
132 bmusb::PixelFormat get_current_pixel_format() const override {
136 std::map<uint32_t, std::string> get_available_video_inputs() const override {
137 return { { 0, "Auto" } }; }
138 void set_video_input(uint32_t video_input_id) override {} // Ignore.
139 uint32_t get_current_video_input() const override { return 0; }
141 std::map<uint32_t, std::string> get_available_audio_inputs() const override {
142 return { { 0, "Embedded" } };
144 void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
145 uint32_t get_current_audio_input() const override { return 0; }
148 void producer_thread_func();
149 void send_disconnected_frame();
150 bool play_video(const std::string &pathname);
151 void internal_rewind();
153 std::string description, filename;
154 uint16_t timecode = 0;
155 unsigned width, height;
156 bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
157 movit::YCbCrFormat current_frame_ycbcr_format;
158 bool running = false;
161 bool has_dequeue_callbacks = false;
162 std::function<void()> dequeue_init_callback = nullptr;
163 std::function<void()> dequeue_cleanup_callback = nullptr;
165 bmusb::FrameAllocator *video_frame_allocator = nullptr;
166 bmusb::FrameAllocator *audio_frame_allocator = nullptr;
167 std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
168 std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
169 bmusb::frame_callback_t frame_callback = nullptr;
171 QuittableSleeper producer_thread_should_quit;
172 std::thread producer_thread;
174 int64_t pts_origin, last_pts;
175 std::chrono::steady_clock::time_point start, next_frame_start;
178 struct QueuedCommand {
179 enum Command { REWIND, CHANGE_RATE } command;
180 double new_rate; // For CHANGE_RATE.
182 std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
185 #endif // !defined(_FFMPEG_CAPTURE_H)