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 "ffmpeg_raii.h"
35 #include "quittable_sleeper.h"
37 struct AVFormatContext;
39 class FFmpegCapture : public bmusb::CaptureInterface
42 FFmpegCapture(const std::string &filename, unsigned width, unsigned height);
45 void set_card_index(int card_index)
47 this->card_index = card_index;
50 int get_card_index() const
57 std::lock_guard<std::mutex> lock(queue_mu);
58 command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
61 void change_rate(double new_rate)
63 std::lock_guard<std::mutex> lock(queue_mu);
64 command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
68 void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
70 video_frame_allocator = allocator;
71 if (owned_video_frame_allocator.get() != allocator) {
72 owned_video_frame_allocator.reset();
76 bmusb::FrameAllocator *get_video_frame_allocator() override
78 return video_frame_allocator;
81 // Does not take ownership.
82 void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
84 audio_frame_allocator = allocator;
85 if (owned_audio_frame_allocator.get() != allocator) {
86 owned_audio_frame_allocator.reset();
90 bmusb::FrameAllocator *get_audio_frame_allocator() override
92 return audio_frame_allocator;
95 void set_frame_callback(bmusb::frame_callback_t callback) override
97 frame_callback = callback;
100 // Used to get precise information about the Y'CbCr format used
101 // for a given frame. Only valid to call during the frame callback,
102 // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
103 movit::YCbCrFormat get_current_frame_ycbcr_format() const
105 return current_frame_ycbcr_format;
108 void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
110 dequeue_init_callback = init;
111 dequeue_cleanup_callback = cleanup;
112 has_dequeue_callbacks = true;
115 std::string get_description() const override
120 void configure_card() override;
121 void start_bm_capture() override;
122 void stop_dequeue_thread() override;
123 bool get_disconnected() const override { return false; } // We never unplug.
125 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const;
126 void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
127 uint32_t get_current_video_mode() const override { return 0; }
129 std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
130 return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar };
132 void set_pixel_format(bmusb::PixelFormat pixel_format) override {
133 this->pixel_format = pixel_format;
135 bmusb::PixelFormat get_current_pixel_format() const override {
139 std::map<uint32_t, std::string> get_available_video_inputs() const override {
140 return { { 0, "Auto" } }; }
141 void set_video_input(uint32_t video_input_id) override {} // Ignore.
142 uint32_t get_current_video_input() const override { return 0; }
144 std::map<uint32_t, std::string> get_available_audio_inputs() const override {
145 return { { 0, "Embedded" } };
147 void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
148 uint32_t get_current_audio_input() const override { return 0; }
151 void producer_thread_func();
152 void send_disconnected_frame();
153 bool play_video(const std::string &pathname);
154 void internal_rewind();
156 // Returns true if there was an error.
157 bool process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified);
159 // Returns nullptr if no frame was decoded (e.g. EOF).
160 AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *codec_ctx, const std::string &pathname, int video_stream_index, bool *error);
162 std::string description, filename;
163 uint16_t timecode = 0;
164 unsigned width, height;
165 bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
166 movit::YCbCrFormat current_frame_ycbcr_format;
167 bool running = false;
171 bool has_dequeue_callbacks = false;
172 std::function<void()> dequeue_init_callback = nullptr;
173 std::function<void()> dequeue_cleanup_callback = nullptr;
175 bmusb::FrameAllocator *video_frame_allocator = nullptr;
176 bmusb::FrameAllocator *audio_frame_allocator = nullptr;
177 std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
178 std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
179 bmusb::frame_callback_t frame_callback = nullptr;
181 QuittableSleeper producer_thread_should_quit;
182 std::thread producer_thread;
184 int64_t pts_origin, last_pts;
185 std::chrono::steady_clock::time_point start, next_frame_start;
188 struct QueuedCommand {
189 enum Command { REWIND, CHANGE_RATE } command;
190 double new_rate; // For CHANGE_RATE.
192 std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
195 #endif // !defined(_FFMPEG_CAPTURE_H)