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).
20 // However, the rest of Nageru can't really use the audio for anything yet.
32 #include <movit/ycbcr.h>
35 #include <libavresample/avresample.h>
36 #include <libavutil/pixfmt.h>
37 #include <libavutil/rational.h>
40 #include "bmusb/bmusb.h"
41 #include "ffmpeg_raii.h"
42 #include "ref_counted_frame.h"
43 #include "quittable_sleeper.h"
45 struct AVFormatContext;
50 class FFmpegCapture : public bmusb::CaptureInterface
53 FFmpegCapture(const std::string &filename, unsigned width, unsigned height);
56 void set_card_index(int card_index)
58 this->card_index = card_index;
61 int get_card_index() const
68 std::lock_guard<std::mutex> lock(queue_mu);
69 command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
70 producer_thread_should_quit.wakeup();
73 void change_rate(double new_rate)
75 std::lock_guard<std::mutex> lock(queue_mu);
76 command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
77 producer_thread_should_quit.wakeup();
81 void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
83 video_frame_allocator = allocator;
84 if (owned_video_frame_allocator.get() != allocator) {
85 owned_video_frame_allocator.reset();
89 bmusb::FrameAllocator *get_video_frame_allocator() override
91 return video_frame_allocator;
94 // Does not take ownership.
95 void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
97 audio_frame_allocator = allocator;
98 if (owned_audio_frame_allocator.get() != allocator) {
99 owned_audio_frame_allocator.reset();
103 bmusb::FrameAllocator *get_audio_frame_allocator() override
105 return audio_frame_allocator;
108 // FFmpegCapture-specific overload of set_frame_callback that also gives
109 // the raw original pts from the video. Negative pts means a dummy frame.
110 typedef std::function<void(int64_t video_pts, AVRational video_timebase, int64_t audio_pts, AVRational audio_timebase,
112 bmusb::FrameAllocator::Frame video_frame, size_t video_offset, bmusb::VideoFormat video_format,
113 bmusb::FrameAllocator::Frame audio_frame, size_t audio_offset, bmusb::AudioFormat audio_format)>
115 void set_frame_callback(frame_callback_t callback)
117 frame_callback = callback;
120 void set_frame_callback(bmusb::frame_callback_t callback) override
122 frame_callback = std::bind(
124 std::placeholders::_5,
125 std::placeholders::_6,
126 std::placeholders::_7,
127 std::placeholders::_8,
128 std::placeholders::_9,
129 std::placeholders::_10,
130 std::placeholders::_11);
133 // FFmpegCapture-specific callback that gives the raw audio.
134 typedef std::function<void(const AVPacket *pkt, const AVRational timebase)> audio_callback_t;
135 void set_audio_callback(audio_callback_t callback)
137 audio_callback = callback;
140 // Used to get precise information about the Y'CbCr format used
141 // for a given frame. Only valid to call during the frame callback,
142 // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
143 movit::YCbCrFormat get_current_frame_ycbcr_format() const
145 return current_frame_ycbcr_format;
148 void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
150 dequeue_init_callback = init;
151 dequeue_cleanup_callback = cleanup;
152 has_dequeue_callbacks = true;
155 std::string get_description() const override
160 void configure_card() override;
161 void start_bm_capture() override;
162 void stop_dequeue_thread() override;
163 bool get_disconnected() const override { return false; } // We never unplug.
165 std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const override;
166 void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
167 uint32_t get_current_video_mode() const override { return 0; }
169 static constexpr bmusb::PixelFormat PixelFormat_NV12 = static_cast<bmusb::PixelFormat>(100); // In the private range.
170 std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
171 return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar, PixelFormat_NV12 };
173 void set_pixel_format(bmusb::PixelFormat pixel_format) override {
174 this->pixel_format = pixel_format;
176 bmusb::PixelFormat get_current_pixel_format() const override {
180 std::map<uint32_t, std::string> get_available_video_inputs() const override {
181 return { { 0, "Auto" } }; }
182 void set_video_input(uint32_t video_input_id) override {} // Ignore.
183 uint32_t get_current_video_input() const override { return 0; }
185 std::map<uint32_t, std::string> get_available_audio_inputs() const override {
186 return { { 0, "Embedded" } };
188 void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
189 uint32_t get_current_audio_input() const override { return 0; }
192 void producer_thread_func();
193 void send_disconnected_frame();
194 bool play_video(const std::string &pathname);
195 void internal_rewind();
197 // Returns true if there was an error.
198 bool process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound);
200 // Returns nullptr if no frame was decoded (e.g. EOF).
201 AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, AVCodecContext *audio_codec_ctx,
202 const std::string &pathname, int video_stream_index, int audio_stream_index,
203 bmusb::FrameAllocator::Frame *audio_frame, bmusb::AudioFormat *audio_format, int64_t *audio_pts, bool *error);
204 void convert_audio(const AVFrame *audio_avframe, bmusb::FrameAllocator::Frame *audio_frame, bmusb::AudioFormat *audio_format);
206 bmusb::VideoFormat construct_video_format(const AVFrame *frame, AVRational video_timebase);
207 UniqueFrame make_video_frame(const AVFrame *frame, const std::string &pathname, bool *error);
209 std::string description, filename;
210 uint16_t timecode = 0;
211 unsigned width, height;
212 bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
213 movit::YCbCrFormat current_frame_ycbcr_format;
214 bool running = false;
218 bool has_dequeue_callbacks = false;
219 std::function<void()> dequeue_init_callback = nullptr;
220 std::function<void()> dequeue_cleanup_callback = nullptr;
222 bmusb::FrameAllocator *video_frame_allocator = nullptr;
223 bmusb::FrameAllocator *audio_frame_allocator = nullptr;
224 std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
225 std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
226 frame_callback_t frame_callback = nullptr;
227 audio_callback_t audio_callback = nullptr;
229 SwsContextWithDeleter sws_ctx;
230 int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
231 AVPixelFormat sws_dst_format = AVPixelFormat(-1); // In practice, always initialized.
232 AVRational video_timebase, audio_timebase;
234 QuittableSleeper producer_thread_should_quit;
235 std::thread producer_thread;
237 int64_t pts_origin, last_pts;
238 std::chrono::steady_clock::time_point start, next_frame_start;
241 struct QueuedCommand {
242 enum Command { REWIND, CHANGE_RATE } command;
243 double new_rate; // For CHANGE_RATE.
245 std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
248 AVAudioResampleContext *resampler = nullptr;
249 AVSampleFormat last_src_format, last_dst_format;
250 int64_t last_channel_layout;
251 int last_sample_rate;
255 #endif // !defined(_FFMPEG_CAPTURE_H)