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 // You can get out the audio either as decoded or in raw form (Kaeru uses this).
21 // If there's a subtitle track, you can also get out the last subtitle at the
22 // point of the frame. Note that once we get a video frame, we don't look for
23 // subtitle, so if subtitles and a frame comes at the same time, you might not
24 // see the subtitle until the next frame.
42 #include <movit/effect.h>
43 #include <movit/ycbcr.h>
46 #include <libavutil/frame.h>
47 #include <libswresample/swresample.h>
48 #include <libavutil/channel_layout.h>
49 #include <libavutil/pixfmt.h>
50 #include <libavutil/rational.h>
51 #include <libavutil/samplefmt.h>
54 #include "bmusb/bmusb.h"
55 #include "shared/ffmpeg_raii.h"
56 #include "ref_counted_frame.h"
57 #include "quittable_sleeper.h"
59 struct AVFormatContext;
65 class FFmpegCapture : public bmusb::CaptureInterface
68 FFmpegCapture(const std::string &filename, unsigned width, unsigned height, QSurface *surface);
70 // Takes ownership of the SRT client socket.
71 FFmpegCapture(int srt_sock, const std::string &stream_id, QSurface *surface);
75 void set_card_index(int card_index)
77 this->card_index = card_index;
80 int get_card_index() const
87 std::lock_guard<std::mutex> lock(queue_mu);
88 command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
89 producer_thread_should_quit.wakeup();
92 void change_rate(double new_rate)
94 std::lock_guard<std::mutex> lock(queue_mu);
95 command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
96 producer_thread_should_quit.wakeup();
99 std::string get_filename() const
101 std::lock_guard<std::mutex> lock(filename_mu);
105 void change_filename(const std::string &new_filename)
107 std::lock_guard<std::mutex> lock(filename_mu);
108 filename = new_filename;
109 should_interrupt = true;
112 // Will stop the stream even if it's hung on blocking I/O.
115 should_interrupt = true;
119 void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
121 video_frame_allocator = allocator;
122 if (owned_video_frame_allocator.get() != allocator) {
123 owned_video_frame_allocator.reset();
127 bmusb::FrameAllocator *get_video_frame_allocator() override
129 return video_frame_allocator;
132 // Does not take ownership.
133 void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
135 audio_frame_allocator = allocator;
136 if (owned_audio_frame_allocator.get() != allocator) {
137 owned_audio_frame_allocator.reset();
141 bmusb::FrameAllocator *get_audio_frame_allocator() override
143 return audio_frame_allocator;
146 // FFmpegCapture-specific overload of set_frame_callback that also gives
147 // the raw original pts from the video. Negative pts means a dummy frame.
148 typedef std::function<void(int64_t video_pts, AVRational video_timebase, int64_t audio_pts, AVRational audio_timebase,
150 bmusb::FrameAllocator::Frame video_frame, size_t video_offset, bmusb::VideoFormat video_format,
151 bmusb::FrameAllocator::Frame audio_frame, size_t audio_offset, bmusb::AudioFormat audio_format)>
153 void set_frame_callback(frame_callback_t callback)
155 frame_callback = callback;
158 void set_frame_callback(bmusb::frame_callback_t callback) override
160 frame_callback = std::bind(
162 std::placeholders::_5,
163 std::placeholders::_6,
164 std::placeholders::_7,
165 std::placeholders::_8,
166 std::placeholders::_9,
167 std::placeholders::_10,
168 std::placeholders::_11);
171 // FFmpegCapture-specific callback that gives the raw audio/video.
172 typedef std::function<void(const AVPacket *pkt, const AVRational timebase)> packet_callback_t;
173 void set_video_callback(packet_callback_t callback)
175 video_callback = callback;
177 void set_audio_callback(packet_callback_t callback)
179 audio_callback = callback;
182 // Used to get precise information about the Y'CbCr format used
183 // for a given frame. Only valid to call during the frame callback,
184 // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
185 movit::YCbCrFormat get_current_frame_ycbcr_format() const
187 return current_frame_ycbcr_format;
190 // Only valid to call during the frame callback.
191 std::string get_last_subtitle() const
193 return last_subtitle;
197 bool get_has_last_subtitle() const
199 return has_last_subtitle;
203 movit::RGBTriplet get_last_neutral_color() const
205 return last_neutral_color;
208 void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
210 dequeue_init_callback = init;
211 dequeue_cleanup_callback = cleanup;
212 has_dequeue_callbacks = true;
215 void set_card_disconnected_callback(bmusb::card_disconnected_callback_t callback)
217 card_disconnected_callback = callback;
220 std::string get_description() const override
225 void configure_card() override;
226 void start_bm_capture() override;
227 void stop_dequeue_thread() override;
228 bool get_disconnected() const override { return disconnected; } // Only if play_once == true.
229 int get_srt_sock() const { return srt_sock; }
231 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const override;
232 void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
233 uint32_t get_current_video_mode() const override { return 0; }
235 static constexpr bmusb::PixelFormat PixelFormat_NV12 = static_cast<bmusb::PixelFormat>(100); // In the private range.
236 std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
237 return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar, PixelFormat_NV12 };
239 void set_pixel_format(bmusb::PixelFormat pixel_format) override {
240 this->pixel_format = pixel_format;
242 bmusb::PixelFormat get_current_pixel_format() const override {
246 std::map<uint32_t, std::string> get_available_video_inputs() const override {
247 return { { 0, "Auto" } }; }
248 void set_video_input(uint32_t video_input_id) override {} // Ignore.
249 uint32_t get_current_video_input() const override { return 0; }
251 std::map<uint32_t, std::string> get_available_audio_inputs() const override {
252 return { { 0, "Embedded" } };
254 void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
255 uint32_t get_current_audio_input() const override { return 0; }
258 void producer_thread_func();
259 void send_disconnected_frame();
260 bool play_video(const std::string &pathname);
261 void internal_rewind();
263 // Returns true if there was an error.
264 bool process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound);
266 // Returns nullptr if no frame was decoded (e.g. EOF).
267 AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, AVCodecContext *audio_codec_ctx,
268 const std::string &pathname, int video_stream_index, int audio_stream_index, int subtitle_stream_index,
269 bmusb::FrameAllocator::Frame *audio_frame, bmusb::AudioFormat *audio_format, int64_t *audio_pts, bool *error);
270 void convert_audio(const AVFrame *audio_avframe, bmusb::FrameAllocator::Frame *audio_frame, bmusb::AudioFormat *audio_format);
272 bmusb::VideoFormat construct_video_format(const AVFrame *frame, AVRational video_timebase);
273 UniqueFrame make_video_frame(const AVFrame *frame, const std::string &pathname, bool *error);
275 static int interrupt_cb_thunk(void *opaque);
279 static int read_srt_thunk(void *opaque, uint8_t *buf, int buf_size);
280 int read_srt(uint8_t *buf, int buf_size);
283 inline unsigned frame_width(const AVFrame *frame) const;
284 inline unsigned frame_height(const AVFrame *frame) const;
286 mutable std::mutex filename_mu;
287 std::string description, filename;
289 uint16_t timecode = 0;
290 unsigned width, height; // 0 means keep input size.
291 bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
292 movit::YCbCrFormat current_frame_ycbcr_format;
293 bool running = false;
296 bool play_as_fast_as_possible = false; // Activated iff rate >= 10.0.
297 std::atomic<bool> should_interrupt{false};
298 bool last_frame_was_connected = true;
300 // TODO: Replace with std::optional if we go C++17.
301 bool frame_timeout_valid = false; // If true, will time out any reads after ten seconds.
302 std::chrono::steady_clock::time_point frame_timeout_started; // Only relevant if frame_timeout_valid == true.
304 bool has_dequeue_callbacks = false;
305 std::function<void()> dequeue_init_callback = nullptr;
306 std::function<void()> dequeue_cleanup_callback = nullptr;
308 bmusb::card_disconnected_callback_t card_disconnected_callback = nullptr;
309 bool play_once = false; // End thread after playing. Only for SRT, since the socket is ephemeral.
310 std::atomic<bool> disconnected{false};
312 bmusb::FrameAllocator *video_frame_allocator = nullptr;
313 bmusb::FrameAllocator *audio_frame_allocator = nullptr;
314 std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
315 std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
316 frame_callback_t frame_callback = nullptr;
317 packet_callback_t video_callback = nullptr;
318 packet_callback_t audio_callback = nullptr;
320 SwsContextWithDeleter sws_ctx;
321 int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
322 AVPixelFormat sws_dst_format = AVPixelFormat(-1); // In practice, always initialized.
323 AVRational video_timebase, audio_timebase;
324 bool is_mjpeg = false;
326 QuittableSleeper producer_thread_should_quit;
327 std::thread producer_thread;
329 int64_t pts_origin, last_pts;
330 std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
333 struct QueuedCommand {
334 enum Command { REWIND, CHANGE_RATE } command;
335 double new_rate; // For CHANGE_RATE.
337 std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
340 SwrContext *resampler = nullptr;
341 AVSampleFormat last_src_format, last_dst_format;
342 AVChannelLayout last_channel_layout;
343 int last_sample_rate;
345 // Subtitles (no decoding done, really).
346 bool has_last_subtitle = false;
347 std::string last_subtitle;
349 movit::RGBTriplet last_neutral_color{1.0f, 1.0f, 1.0f};
351 // Used for suppressing repeated warnings. Reset when a video starts playing.
352 // -1 is strictly speaking outside the range of the enum, but hopefully, it will be alright.
353 AVColorSpace last_colorspace = static_cast<AVColorSpace>(-1);
354 AVChromaLocation last_chroma_location = static_cast<AVChromaLocation>(-1);
355 QSurface *const surface;
358 #endif // !defined(_FFMPEG_CAPTURE_H)