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.
36 #include <movit/ycbcr.h>
39 #include <libswresample/swresample.h>
40 #include <libavutil/pixfmt.h>
41 #include <libavutil/rational.h>
42 #include <libavutil/samplefmt.h>
45 #include "bmusb/bmusb.h"
46 #include "shared/ffmpeg_raii.h"
47 #include "ref_counted_frame.h"
48 #include "quittable_sleeper.h"
50 struct AVFormatContext;
55 class FFmpegCapture : public bmusb::CaptureInterface
58 FFmpegCapture(const std::string &filename, unsigned width, unsigned height);
61 void set_card_index(int card_index)
63 this->card_index = card_index;
66 int get_card_index() const
73 std::lock_guard<std::mutex> lock(queue_mu);
74 command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
75 producer_thread_should_quit.wakeup();
78 void change_rate(double new_rate)
80 std::lock_guard<std::mutex> lock(queue_mu);
81 command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
82 producer_thread_should_quit.wakeup();
85 std::string get_filename() const
87 std::lock_guard<std::mutex> lock(filename_mu);
91 void change_filename(const std::string &new_filename)
93 std::lock_guard<std::mutex> lock(filename_mu);
94 filename = new_filename;
95 should_interrupt = true;
98 // Will stop the stream even if it's hung on blocking I/O.
101 should_interrupt = true;
105 void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
107 video_frame_allocator = allocator;
108 if (owned_video_frame_allocator.get() != allocator) {
109 owned_video_frame_allocator.reset();
113 bmusb::FrameAllocator *get_video_frame_allocator() override
115 return video_frame_allocator;
118 // Does not take ownership.
119 void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
121 audio_frame_allocator = allocator;
122 if (owned_audio_frame_allocator.get() != allocator) {
123 owned_audio_frame_allocator.reset();
127 bmusb::FrameAllocator *get_audio_frame_allocator() override
129 return audio_frame_allocator;
132 // FFmpegCapture-specific overload of set_frame_callback that also gives
133 // the raw original pts from the video. Negative pts means a dummy frame.
134 typedef std::function<void(int64_t video_pts, AVRational video_timebase, int64_t audio_pts, AVRational audio_timebase,
136 bmusb::FrameAllocator::Frame video_frame, size_t video_offset, bmusb::VideoFormat video_format,
137 bmusb::FrameAllocator::Frame audio_frame, size_t audio_offset, bmusb::AudioFormat audio_format)>
139 void set_frame_callback(frame_callback_t callback)
141 frame_callback = callback;
144 void set_frame_callback(bmusb::frame_callback_t callback) override
146 frame_callback = std::bind(
148 std::placeholders::_5,
149 std::placeholders::_6,
150 std::placeholders::_7,
151 std::placeholders::_8,
152 std::placeholders::_9,
153 std::placeholders::_10,
154 std::placeholders::_11);
157 // FFmpegCapture-specific callback that gives the raw audio.
158 typedef std::function<void(const AVPacket *pkt, const AVRational timebase)> audio_callback_t;
159 void set_audio_callback(audio_callback_t callback)
161 audio_callback = callback;
164 // Used to get precise information about the Y'CbCr format used
165 // for a given frame. Only valid to call during the frame callback,
166 // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
167 movit::YCbCrFormat get_current_frame_ycbcr_format() const
169 return current_frame_ycbcr_format;
172 // Only valid to call during the frame callback.
173 std::string get_last_subtitle() const
175 return last_subtitle;
179 bool get_has_last_subtitle() const
181 return has_last_subtitle;
184 void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
186 dequeue_init_callback = init;
187 dequeue_cleanup_callback = cleanup;
188 has_dequeue_callbacks = true;
191 std::string get_description() const override
196 void configure_card() override;
197 void start_bm_capture() override;
198 void stop_dequeue_thread() override;
199 bool get_disconnected() const override { return false; } // We never unplug.
201 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const override;
202 void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
203 uint32_t get_current_video_mode() const override { return 0; }
205 static constexpr bmusb::PixelFormat PixelFormat_NV12 = static_cast<bmusb::PixelFormat>(100); // In the private range.
206 std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
207 return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar, PixelFormat_NV12 };
209 void set_pixel_format(bmusb::PixelFormat pixel_format) override {
210 this->pixel_format = pixel_format;
212 bmusb::PixelFormat get_current_pixel_format() const override {
216 std::map<uint32_t, std::string> get_available_video_inputs() const override {
217 return { { 0, "Auto" } }; }
218 void set_video_input(uint32_t video_input_id) override {} // Ignore.
219 uint32_t get_current_video_input() const override { return 0; }
221 std::map<uint32_t, std::string> get_available_audio_inputs() const override {
222 return { { 0, "Embedded" } };
224 void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
225 uint32_t get_current_audio_input() const override { return 0; }
228 void producer_thread_func();
229 void send_disconnected_frame();
230 bool play_video(const std::string &pathname);
231 void internal_rewind();
233 // Returns true if there was an error.
234 bool process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound);
236 // Returns nullptr if no frame was decoded (e.g. EOF).
237 AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, AVCodecContext *audio_codec_ctx,
238 const std::string &pathname, int video_stream_index, int audio_stream_index, int subtitle_stream_index,
239 bmusb::FrameAllocator::Frame *audio_frame, bmusb::AudioFormat *audio_format, int64_t *audio_pts, bool *error);
240 void convert_audio(const AVFrame *audio_avframe, bmusb::FrameAllocator::Frame *audio_frame, bmusb::AudioFormat *audio_format);
242 bmusb::VideoFormat construct_video_format(const AVFrame *frame, AVRational video_timebase);
243 UniqueFrame make_video_frame(const AVFrame *frame, const std::string &pathname, bool *error);
245 static int interrupt_cb_thunk(void *unique);
248 mutable std::mutex filename_mu;
249 std::string description, filename;
250 uint16_t timecode = 0;
251 unsigned width, height;
252 bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
253 movit::YCbCrFormat current_frame_ycbcr_format;
254 bool running = false;
257 std::atomic<bool> should_interrupt{false};
258 bool last_frame_was_connected = true;
260 bool has_dequeue_callbacks = false;
261 std::function<void()> dequeue_init_callback = nullptr;
262 std::function<void()> dequeue_cleanup_callback = nullptr;
264 bmusb::FrameAllocator *video_frame_allocator = nullptr;
265 bmusb::FrameAllocator *audio_frame_allocator = nullptr;
266 std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
267 std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
268 frame_callback_t frame_callback = nullptr;
269 audio_callback_t audio_callback = nullptr;
271 SwsContextWithDeleter sws_ctx;
272 int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
273 AVPixelFormat sws_dst_format = AVPixelFormat(-1); // In practice, always initialized.
274 AVRational video_timebase, audio_timebase;
275 bool is_mjpeg = false;
277 QuittableSleeper producer_thread_should_quit;
278 std::thread producer_thread;
280 int64_t pts_origin, last_pts;
281 std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
284 struct QueuedCommand {
285 enum Command { REWIND, CHANGE_RATE } command;
286 double new_rate; // For CHANGE_RATE.
288 std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
291 SwrContext *resampler = nullptr;
292 AVSampleFormat last_src_format, last_dst_format;
293 int64_t last_channel_layout;
294 int last_sample_rate;
296 // Subtitles (no decoding done, really).
297 bool has_last_subtitle = false;
298 std::string last_subtitle;
301 #endif // !defined(_FFMPEG_CAPTURE_H)