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>
34 #include <libavutil/pixfmt.h>
35 #include <libavutil/rational.h>
38 #include "bmusb/bmusb.h"
39 #include "ffmpeg_raii.h"
40 #include "quittable_sleeper.h"
42 struct AVFormatContext;
46 class FFmpegCapture : public bmusb::CaptureInterface
49 FFmpegCapture(const std::string &filename, unsigned width, unsigned height);
52 void set_card_index(int card_index)
54 this->card_index = card_index;
57 int get_card_index() const
64 std::lock_guard<std::mutex> lock(queue_mu);
65 command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
66 producer_thread_should_quit.wakeup();
69 void change_rate(double new_rate)
71 std::lock_guard<std::mutex> lock(queue_mu);
72 command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
73 producer_thread_should_quit.wakeup();
77 void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
79 video_frame_allocator = allocator;
80 if (owned_video_frame_allocator.get() != allocator) {
81 owned_video_frame_allocator.reset();
85 bmusb::FrameAllocator *get_video_frame_allocator() override
87 return video_frame_allocator;
90 // Does not take ownership.
91 void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
93 audio_frame_allocator = allocator;
94 if (owned_audio_frame_allocator.get() != allocator) {
95 owned_audio_frame_allocator.reset();
99 bmusb::FrameAllocator *get_audio_frame_allocator() override
101 return audio_frame_allocator;
104 void set_frame_callback(bmusb::frame_callback_t callback) override
106 frame_callback = callback;
109 // Used to get precise information about the Y'CbCr format used
110 // for a given frame. Only valid to call during the frame callback,
111 // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
112 movit::YCbCrFormat get_current_frame_ycbcr_format() const
114 return current_frame_ycbcr_format;
117 void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
119 dequeue_init_callback = init;
120 dequeue_cleanup_callback = cleanup;
121 has_dequeue_callbacks = true;
124 std::string get_description() const override
129 void configure_card() override;
130 void start_bm_capture() override;
131 void stop_dequeue_thread() override;
132 bool get_disconnected() const override { return false; } // We never unplug.
134 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const;
135 void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
136 uint32_t get_current_video_mode() const override { return 0; }
138 std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
139 return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar };
141 void set_pixel_format(bmusb::PixelFormat pixel_format) override {
142 this->pixel_format = pixel_format;
144 bmusb::PixelFormat get_current_pixel_format() const override {
148 std::map<uint32_t, std::string> get_available_video_inputs() const override {
149 return { { 0, "Auto" } }; }
150 void set_video_input(uint32_t video_input_id) override {} // Ignore.
151 uint32_t get_current_video_input() const override { return 0; }
153 std::map<uint32_t, std::string> get_available_audio_inputs() const override {
154 return { { 0, "Embedded" } };
156 void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
157 uint32_t get_current_audio_input() const override { return 0; }
160 void producer_thread_func();
161 void send_disconnected_frame();
162 bool play_video(const std::string &pathname);
163 void internal_rewind();
165 // Returns true if there was an error.
166 bool process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound);
168 // Returns nullptr if no frame was decoded (e.g. EOF).
169 AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *codec_ctx, const std::string &pathname, int video_stream_index, bool *error);
171 bmusb::VideoFormat construct_video_format(const AVFrame *frame, AVRational video_timebase);
172 bmusb::FrameAllocator::Frame make_video_frame(const AVFrame *frame, const std::string &pathname, bool *error);
174 std::string description, filename;
175 uint16_t timecode = 0;
176 unsigned width, height;
177 bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
178 movit::YCbCrFormat current_frame_ycbcr_format;
179 bool running = false;
183 bool has_dequeue_callbacks = false;
184 std::function<void()> dequeue_init_callback = nullptr;
185 std::function<void()> dequeue_cleanup_callback = nullptr;
187 bmusb::FrameAllocator *video_frame_allocator = nullptr;
188 bmusb::FrameAllocator *audio_frame_allocator = nullptr;
189 std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
190 std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
191 bmusb::frame_callback_t frame_callback = nullptr;
193 SwsContextWithDeleter sws_ctx;
194 int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
195 AVPixelFormat sws_dst_format = AVPixelFormat(-1); // In practice, always initialized.
196 AVRational video_timebase;
198 QuittableSleeper producer_thread_should_quit;
199 std::thread producer_thread;
201 int64_t pts_origin, last_pts;
202 std::chrono::steady_clock::time_point start, next_frame_start;
205 struct QueuedCommand {
206 enum Command { REWIND, CHANGE_RATE } command;
207 double new_rate; // For CHANGE_RATE.
209 std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
212 #endif // !defined(_FFMPEG_CAPTURE_H)