--- /dev/null
+#ifndef _FFMPEG_CAPTURE_H
+#define _FFMPEG_CAPTURE_H 1
+
+// FFmpegCapture looks much like a capture card, but the frames it spits out
+// come from a video in real time, looping. Because it decodes the video using
+// FFmpeg (thus the name), this means it can handle a very wide array of video
+// formats, and also things like network streaming and V4L capture, but it is
+// also significantly less integrated and optimized than the regular capture
+// cards. In particular, the frames are always scaled and converted to 8-bit
+// RGBA on the CPU before being sent on to the GPU.
+//
+// Since we don't really know much about the video when building the chains,
+// there are some limitations. In particular, frames are always assumed to be
+// sRGB even if the video container says something else. We could probably
+// try to load the video on startup and pick out the parameters at that point,
+// but it would require some more plumbing, and it would also fail if the file
+// changes parameters midway, which is allowed in some formats.
+//
+// You can get out the audio either as decoded or in raw form (Kaeru uses this).
+
+#include <assert.h>
+#include <stdint.h>
+#include <functional>
+#include <map>
+#include <memory>
+#include <mutex>
+#include <set>
+#include <string>
+#include <thread>
+
+#include <movit/ycbcr.h>
+
+extern "C" {
+#include <libavresample/avresample.h>
+#include <libavutil/pixfmt.h>
+#include <libavutil/rational.h>
+#include <libavutil/samplefmt.h>
+}
+
+#include "bmusb/bmusb.h"
+#include "ffmpeg_raii.h"
+#include "ref_counted_frame.h"
+#include "quittable_sleeper.h"
+
+struct AVFormatContext;
+struct AVFrame;
+struct AVRational;
+struct AVPacket;
+
+class FFmpegCapture : public bmusb::CaptureInterface
+{
+public:
+ FFmpegCapture(const std::string &filename, unsigned width, unsigned height);
+ ~FFmpegCapture();
+
+ void set_card_index(int card_index)
+ {
+ this->card_index = card_index;
+ }
+
+ int get_card_index() const
+ {
+ return card_index;
+ }
+
+ void rewind()
+ {
+ std::lock_guard<std::mutex> lock(queue_mu);
+ command_queue.push_back(QueuedCommand { QueuedCommand::REWIND });
+ producer_thread_should_quit.wakeup();
+ }
+
+ void change_rate(double new_rate)
+ {
+ std::lock_guard<std::mutex> lock(queue_mu);
+ command_queue.push_back(QueuedCommand { QueuedCommand::CHANGE_RATE, new_rate });
+ producer_thread_should_quit.wakeup();
+ }
+
+ std::string get_filename() const
+ {
+ std::lock_guard<std::mutex> lock(filename_mu);
+ return filename;
+ }
+
+ void change_filename(const std::string &new_filename)
+ {
+ std::lock_guard<std::mutex> lock(filename_mu);
+ filename = new_filename;
+ should_interrupt = true;
+ }
+
+ // Will stop the stream even if it's hung on blocking I/O.
+ void disconnect()
+ {
+ should_interrupt = true;
+ }
+
+ // CaptureInterface.
+ void set_video_frame_allocator(bmusb::FrameAllocator *allocator) override
+ {
+ video_frame_allocator = allocator;
+ if (owned_video_frame_allocator.get() != allocator) {
+ owned_video_frame_allocator.reset();
+ }
+ }
+
+ bmusb::FrameAllocator *get_video_frame_allocator() override
+ {
+ return video_frame_allocator;
+ }
+
+ // Does not take ownership.
+ void set_audio_frame_allocator(bmusb::FrameAllocator *allocator) override
+ {
+ audio_frame_allocator = allocator;
+ if (owned_audio_frame_allocator.get() != allocator) {
+ owned_audio_frame_allocator.reset();
+ }
+ }
+
+ bmusb::FrameAllocator *get_audio_frame_allocator() override
+ {
+ return audio_frame_allocator;
+ }
+
+ // FFmpegCapture-specific overload of set_frame_callback that also gives
+ // the raw original pts from the video. Negative pts means a dummy frame.
+ typedef std::function<void(int64_t video_pts, AVRational video_timebase, int64_t audio_pts, AVRational audio_timebase,
+ uint16_t timecode,
+ bmusb::FrameAllocator::Frame video_frame, size_t video_offset, bmusb::VideoFormat video_format,
+ bmusb::FrameAllocator::Frame audio_frame, size_t audio_offset, bmusb::AudioFormat audio_format)>
+ frame_callback_t;
+ void set_frame_callback(frame_callback_t callback)
+ {
+ frame_callback = callback;
+ }
+
+ void set_frame_callback(bmusb::frame_callback_t callback) override
+ {
+ frame_callback = std::bind(
+ callback,
+ std::placeholders::_5,
+ std::placeholders::_6,
+ std::placeholders::_7,
+ std::placeholders::_8,
+ std::placeholders::_9,
+ std::placeholders::_10,
+ std::placeholders::_11);
+ }
+
+ // FFmpegCapture-specific callback that gives the raw audio.
+ typedef std::function<void(const AVPacket *pkt, const AVRational timebase)> audio_callback_t;
+ void set_audio_callback(audio_callback_t callback)
+ {
+ audio_callback = callback;
+ }
+
+ // Used to get precise information about the Y'CbCr format used
+ // for a given frame. Only valid to call during the frame callback,
+ // and only when receiving a frame with pixel format PixelFormat_8BitYCbCrPlanar.
+ movit::YCbCrFormat get_current_frame_ycbcr_format() const
+ {
+ return current_frame_ycbcr_format;
+ }
+
+ void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
+ {
+ dequeue_init_callback = init;
+ dequeue_cleanup_callback = cleanup;
+ has_dequeue_callbacks = true;
+ }
+
+ std::string get_description() const override
+ {
+ return description;
+ }
+
+ void configure_card() override;
+ void start_bm_capture() override;
+ void stop_dequeue_thread() override;
+ bool get_disconnected() const override { return false; } // We never unplug.
+
+ std::map<uint32_t, bmusb::VideoMode> get_available_video_modes() const override;
+ void set_video_mode(uint32_t video_mode_id) override {} // Ignore.
+ uint32_t get_current_video_mode() const override { return 0; }
+
+ static constexpr bmusb::PixelFormat PixelFormat_NV12 = static_cast<bmusb::PixelFormat>(100); // In the private range.
+ std::set<bmusb::PixelFormat> get_available_pixel_formats() const override {
+ return std::set<bmusb::PixelFormat>{ bmusb::PixelFormat_8BitBGRA, bmusb::PixelFormat_8BitYCbCrPlanar, PixelFormat_NV12 };
+ }
+ void set_pixel_format(bmusb::PixelFormat pixel_format) override {
+ this->pixel_format = pixel_format;
+ }
+ bmusb::PixelFormat get_current_pixel_format() const override {
+ return pixel_format;
+ }
+
+ std::map<uint32_t, std::string> get_available_video_inputs() const override {
+ return { { 0, "Auto" } }; }
+ void set_video_input(uint32_t video_input_id) override {} // Ignore.
+ uint32_t get_current_video_input() const override { return 0; }
+
+ std::map<uint32_t, std::string> get_available_audio_inputs() const override {
+ return { { 0, "Embedded" } };
+ }
+ void set_audio_input(uint32_t audio_input_id) override {} // Ignore.
+ uint32_t get_current_audio_input() const override { return 0; }
+
+private:
+ void producer_thread_func();
+ void send_disconnected_frame();
+ bool play_video(const std::string &pathname);
+ void internal_rewind();
+
+ // Returns true if there was an error.
+ bool process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound);
+
+ // Returns nullptr if no frame was decoded (e.g. EOF).
+ AVFrameWithDeleter decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, AVCodecContext *audio_codec_ctx,
+ const std::string &pathname, int video_stream_index, int audio_stream_index,
+ bmusb::FrameAllocator::Frame *audio_frame, bmusb::AudioFormat *audio_format, int64_t *audio_pts, bool *error);
+ void convert_audio(const AVFrame *audio_avframe, bmusb::FrameAllocator::Frame *audio_frame, bmusb::AudioFormat *audio_format);
+
+ bmusb::VideoFormat construct_video_format(const AVFrame *frame, AVRational video_timebase);
+ UniqueFrame make_video_frame(const AVFrame *frame, const std::string &pathname, bool *error);
+
+ static int interrupt_cb_thunk(void *unique);
+ int interrupt_cb();
+
+ mutable std::mutex filename_mu;
+ std::string description, filename;
+ uint16_t timecode = 0;
+ unsigned width, height;
+ bmusb::PixelFormat pixel_format = bmusb::PixelFormat_8BitBGRA;
+ movit::YCbCrFormat current_frame_ycbcr_format;
+ bool running = false;
+ int card_index = -1;
+ double rate = 1.0;
+ std::atomic<bool> should_interrupt{false};
+ bool last_frame_was_connected = true;
+
+ bool has_dequeue_callbacks = false;
+ std::function<void()> dequeue_init_callback = nullptr;
+ std::function<void()> dequeue_cleanup_callback = nullptr;
+
+ bmusb::FrameAllocator *video_frame_allocator = nullptr;
+ bmusb::FrameAllocator *audio_frame_allocator = nullptr;
+ std::unique_ptr<bmusb::FrameAllocator> owned_video_frame_allocator;
+ std::unique_ptr<bmusb::FrameAllocator> owned_audio_frame_allocator;
+ frame_callback_t frame_callback = nullptr;
+ audio_callback_t audio_callback = nullptr;
+
+ SwsContextWithDeleter sws_ctx;
+ int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
+ AVPixelFormat sws_dst_format = AVPixelFormat(-1); // In practice, always initialized.
+ AVRational video_timebase, audio_timebase;
+
+ QuittableSleeper producer_thread_should_quit;
+ std::thread producer_thread;
+
+ int64_t pts_origin, last_pts;
+ std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
+
+ std::mutex queue_mu;
+ struct QueuedCommand {
+ enum Command { REWIND, CHANGE_RATE } command;
+ double new_rate; // For CHANGE_RATE.
+ };
+ std::vector<QueuedCommand> command_queue; // Protected by <queue_mu>.
+
+ // Audio resampler.
+ AVAudioResampleContext *resampler = nullptr;
+ AVSampleFormat last_src_format, last_dst_format;
+ int64_t last_channel_layout;
+ int last_sample_rate;
+
+};
+
+#endif // !defined(_FFMPEG_CAPTURE_H)
projects / nageru / blobdiff