+// H.264 video comes out in encoding order (e.g. with two B-frames:
+// 0, 3, 1, 2, 6, 4, 5, etc.), but uncompressed video needs to
+// come in the right order. Since we do everything, including waiting
+// for the frames to come out of OpenGL, in encoding order, we need
+// a reordering buffer for uncompressed frames so that they come out
+// correctly. We go the super-lazy way of not making it understand
+// anything about the true order (which introduces some extra latency,
+// though); we know that for N B-frames we need at most (N-1) frames
+// in the reorder buffer, and can just sort on that.
+//
+// The class also deals with keeping a freelist as needed.
+class FrameReorderer {
+public:
+ FrameReorderer(unsigned queue_length, int width, int height);
+
+ // Returns the next frame to insert with its pts, if any. Otherwise -1 and nullptr.
+ // Does _not_ take ownership of data; a copy is taken if needed.
+ // The returned pointer is valid until the next call to reorder_frame, or destruction.
+ // As a special case, if queue_length == 0, will just return pts and data (no reordering needed).
+ pair<int64_t, const uint8_t *> reorder_frame(int64_t pts, const uint8_t *data);
+
+ // The same as reorder_frame, but without inserting anything. Used to empty the queue.
+ pair<int64_t, const uint8_t *> get_first_frame();
+
+ bool empty() const { return frames.empty(); }
+
+private:
+ unsigned queue_length;
+ int width, height;
+
+ priority_queue<pair<int64_t, uint8_t *>> frames;
+ stack<uint8_t *> freelist; // Includes the last value returned from reorder_frame.
+
+ // Owns all the pointers. Normally, freelist and frames could do this themselves,
+ // except priority_queue doesn't work well with movable-only types.
+ vector<unique_ptr<uint8_t[]>> owner;
+};
+
+FrameReorderer::FrameReorderer(unsigned queue_length, int width, int height)
+ : queue_length(queue_length), width(width), height(height)
+{
+ for (unsigned i = 0; i < queue_length; ++i) {
+ owner.emplace_back(new uint8_t[width * height * 2]);
+ freelist.push(owner.back().get());
+ }
+}
+
+pair<int64_t, const uint8_t *> FrameReorderer::reorder_frame(int64_t pts, const uint8_t *data)
+{
+ if (queue_length == 0) {
+ return make_pair(pts, data);
+ }
+
+ assert(!freelist.empty());
+ uint8_t *storage = freelist.top();
+ freelist.pop();
+ memcpy(storage, data, width * height * 2);
+ frames.emplace(-pts, storage); // Invert pts to get smallest first.
+
+ if (frames.size() >= queue_length) {
+ return get_first_frame();
+ } else {
+ return make_pair(-1, nullptr);
+ }
+}
+
+pair<int64_t, const uint8_t *> FrameReorderer::get_first_frame()
+{
+ assert(!frames.empty());
+ pair<int64_t, uint8_t *> storage = frames.top();
+ frames.pop();
+ int64_t pts = storage.first;
+ freelist.push(storage.second);
+ return make_pair(-pts, storage.second); // Re-invert pts (see reorder_frame()).
+}
+
+class H264EncoderImpl {
+public:
+ H264EncoderImpl(QSurface *surface, const string &va_display, int width, int height, HTTPD *httpd);
+ ~H264EncoderImpl();
+ void add_audio(int64_t pts, vector<float> audio);
+ bool begin_frame(GLuint *y_tex, GLuint *cbcr_tex);
+ void end_frame(RefCountedGLsync fence, int64_t pts, const vector<RefCountedFrame> &input_frames);
+ void shutdown();
+
+private:
+ struct storage_task {
+ unsigned long long display_order;
+ int frame_type;
+ vector<float> audio;
+ int64_t pts, dts;
+ };
+ struct PendingFrame {
+ RefCountedGLsync fence;
+ vector<RefCountedFrame> input_frames;
+ int64_t pts;
+ };
+
+ void encode_thread_func();
+ void encode_remaining_frames_as_p(int encoding_frame_num, int gop_start_display_frame_num, int64_t last_dts);
+ void add_packet_for_uncompressed_frame(int64_t pts, const uint8_t *data);
+ void encode_frame(PendingFrame frame, int encoding_frame_num, int display_frame_num, int gop_start_display_frame_num,
+ int frame_type, int64_t pts, int64_t dts);
+ void storage_task_thread();
+ void storage_task_enqueue(storage_task task);
+ void save_codeddata(storage_task task);
+ int render_packedsequence();
+ int render_packedpicture();
+ void render_packedslice();
+ int render_sequence();
+ int render_picture(int frame_type, int display_frame_num, int gop_start_display_frame_num);
+ void sps_rbsp(bitstream *bs);
+ void pps_rbsp(bitstream *bs);
+ int build_packed_pic_buffer(unsigned char **header_buffer);
+ int render_slice(int encoding_frame_num, int display_frame_num, int gop_start_display_frame_num, int frame_type);
+ void slice_header(bitstream *bs);
+ int build_packed_seq_buffer(unsigned char **header_buffer);
+ int build_packed_slice_buffer(unsigned char **header_buffer);
+ int init_va(const string &va_display);
+ int deinit_va();
+ VADisplay va_open_display(const string &va_display);
+ void va_close_display(VADisplay va_dpy);
+ int setup_encode();
+ int release_encode();
+ void update_ReferenceFrames(int frame_type);
+ int update_RefPicList(int frame_type);
+
+ bool is_shutdown = false;
+ bool use_zerocopy;
+ int drm_fd = -1;
+
+ thread encode_thread, storage_thread;
+
+ mutex storage_task_queue_mutex;
+ condition_variable storage_task_queue_changed;
+ int srcsurface_status[SURFACE_NUM]; // protected by storage_task_queue_mutex
+ queue<storage_task> storage_task_queue; // protected by storage_task_queue_mutex
+ bool storage_thread_should_quit = false; // protected by storage_task_queue_mutex
+
+ mutex frame_queue_mutex;
+ condition_variable frame_queue_nonempty;
+ bool encode_thread_should_quit = false; // under frame_queue_mutex
+
+ int current_storage_frame;
+
+ map<int, PendingFrame> pending_video_frames; // under frame_queue_mutex
+ map<int64_t, vector<float>> pending_audio_frames; // under frame_queue_mutex
+ QSurface *surface;
+
+ AVCodecContext *context_audio;
+ AVFrame *audio_frame = nullptr;
+ HTTPD *httpd;
+ unique_ptr<FrameReorderer> reorderer;
+
+ Display *x11_display = nullptr;
+
+ // Encoder parameters
+ VADisplay va_dpy;
+ VAProfile h264_profile = (VAProfile)~0;
+ VAConfigAttrib config_attrib[VAConfigAttribTypeMax];
+ int config_attrib_num = 0, enc_packed_header_idx;
+
+ struct GLSurface {
+ VASurfaceID src_surface, ref_surface;
+ VABufferID coded_buf;
+
+ VAImage surface_image;
+ GLuint y_tex, cbcr_tex;
+
+ // Only if use_zerocopy == true.
+ EGLImage y_egl_image, cbcr_egl_image;
+
+ // Only if use_zerocopy == false.
+ GLuint pbo;
+ uint8_t *y_ptr, *cbcr_ptr;
+ size_t y_offset, cbcr_offset;
+ };
+ GLSurface gl_surfaces[SURFACE_NUM];
+
+ VAConfigID config_id;
+ VAContextID context_id;
+ VAEncSequenceParameterBufferH264 seq_param;
+ VAEncPictureParameterBufferH264 pic_param;
+ VAEncSliceParameterBufferH264 slice_param;
+ VAPictureH264 CurrentCurrPic;
+ VAPictureH264 ReferenceFrames[MAX_NUM_REF1], RefPicList0_P[MAX_NUM_REF2], RefPicList0_B[MAX_NUM_REF2], RefPicList1_B[MAX_NUM_REF2];
+
+ // Static quality settings.
+ static constexpr unsigned int frame_bitrate = 15000000 / 60; // Doesn't really matter; only initial_qp does.
+ static constexpr unsigned int num_ref_frames = 2;
+ static constexpr int initial_qp = 15;
+ static constexpr int minimal_qp = 0;
+ static constexpr int intra_period = 30;
+ static constexpr int intra_idr_period = MAX_FPS; // About a second; more at lower frame rates. Not ideal.
+
+ // Quality settings that are meant to be static, but might be overridden
+ // by the profile.
+ int constraint_set_flag = 0;
+ int h264_packedheader = 0; /* support pack header? */
+ int h264_maxref = (1<<16|1);
+ int h264_entropy_mode = 1; /* cabac */
+ int ip_period = 3;
+
+ int rc_mode = -1;
+ unsigned int current_frame_num = 0;
+ unsigned int numShortTerm = 0;
+
+ int frame_width;
+ int frame_height;
+ int frame_width_mbaligned;
+ int frame_height_mbaligned;
+};
+