]> git.sesse.net Git - nageru/blob - mixer.cpp
Rework entire pts handling.
[nageru] / mixer.cpp
1 #define WIDTH 1280
2 #define HEIGHT 720
3
4 #undef Success
5
6 #include "mixer.h"
7
8 #include <assert.h>
9 #include <effect.h>
10 #include <effect_chain.h>
11 #include <effect_util.h>
12 #include <epoxy/egl.h>
13 #include <features.h>
14 #include <image_format.h>
15 #include <init.h>
16 #include <overlay_effect.h>
17 #include <padding_effect.h>
18 #include <resample_effect.h>
19 #include <resource_pool.h>
20 #include <saturation_effect.h>
21 #include <stdint.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <sys/time.h>
25 #include <time.h>
26 #include <util.h>
27 #include <white_balance_effect.h>
28 #include <ycbcr.h>
29 #include <ycbcr_input.h>
30 #include <cmath>
31 #include <condition_variable>
32 #include <cstddef>
33 #include <memory>
34 #include <mutex>
35 #include <string>
36 #include <thread>
37 #include <vector>
38
39 #include "bmusb/bmusb.h"
40 #include "context.h"
41 #include "h264encode.h"
42 #include "pbo_frame_allocator.h"
43 #include "ref_counted_gl_sync.h"
44 #include "timebase.h"
45
46 class QOpenGLContext;
47
48 using namespace movit;
49 using namespace std;
50 using namespace std::placeholders;
51
52 Mixer *global_mixer = nullptr;
53
54 namespace {
55
56 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
57 {
58         for (size_t i = 0; i < num_samples; ++i) {
59                 for (size_t j = 0; j < out_channels; ++j) {
60                         uint32_t s1 = *src++;
61                         uint32_t s2 = *src++;
62                         uint32_t s3 = *src++;
63                         uint32_t s = s1 | (s1 << 8) | (s2 << 16) | (s3 << 24);
64                         dst[i * out_channels + j] = int(s) * (1.0f / 4294967296.0f);
65                 }
66                 src += 3 * (in_channels - out_channels);
67         }
68 }
69
70 }  // namespace
71
72 Mixer::Mixer(const QSurfaceFormat &format)
73         : mixer_surface(create_surface(format)),
74           h264_encoder_surface(create_surface(format))
75 {
76         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
77         check_error();
78
79         resource_pool.reset(new ResourcePool);
80         theme.reset(new Theme("theme.lua", resource_pool.get()));
81         output_channel[OUTPUT_LIVE].parent = this;
82         output_channel[OUTPUT_PREVIEW].parent = this;
83         output_channel[OUTPUT_INPUT0].parent = this;
84         output_channel[OUTPUT_INPUT1].parent = this;
85
86         ImageFormat inout_format;
87         inout_format.color_space = COLORSPACE_sRGB;
88         inout_format.gamma_curve = GAMMA_sRGB;
89
90         // Display chain; shows the live output produced by the main chain (its RGBA version).
91         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
92         check_error();
93         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
94         display_chain->add_input(display_input);
95         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
96         display_chain->set_dither_bits(0);  // Don't bother.
97         display_chain->finalize();
98
99         h264_encoder.reset(new H264Encoder(h264_encoder_surface, WIDTH, HEIGHT, "test.mp4"));
100
101         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
102                 printf("Configuring card %d...\n", card_index);
103                 CaptureCard *card = &cards[card_index];
104                 card->usb = new BMUSBCapture(0x1edb, card_index == 0 ? 0xbd3b : 0xbd4f);
105                 card->usb->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
106                 card->frame_allocator.reset(new PBOFrameAllocator(1280 * 750 * 2 + 44, 1280, 720));
107                 card->usb->set_video_frame_allocator(card->frame_allocator.get());
108                 card->surface = create_surface(format);
109                 card->usb->set_dequeue_thread_callbacks(
110                         [card]{
111                                 eglBindAPI(EGL_OPENGL_API);
112                                 card->context = create_context();
113                                 if (!make_current(card->context, card->surface)) {
114                                         printf("failed to create bmusb context\n");
115                                         exit(1);
116                                 }
117                                 printf("inited!\n");
118                         },
119                         [this]{
120                                 resource_pool->clean_context();
121                         });
122                 card->resampler.reset(new Resampler(48000.0, 48000.0, 2));
123                 card->usb->configure_card();
124         }
125
126         BMUSBCapture::start_bm_thread();
127
128         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
129                 cards[card_index].usb->start_bm_capture();
130         }
131
132         //chain->enable_phase_timing(true);
133
134         // Set up stuff for NV12 conversion.
135
136         // Cb/Cr shader.
137         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
138         string cbcr_frag_shader =
139                 "#version 130 \n"
140                 "in vec2 tc0; \n"
141                 "uniform sampler2D cbcr_tex; \n"
142                 "void main() { \n"
143                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
144                 "} \n";
145         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader);
146 }
147
148 Mixer::~Mixer()
149 {
150         resource_pool->release_glsl_program(cbcr_program_num);
151         BMUSBCapture::stop_bm_thread();
152
153         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
154                 {
155                         unique_lock<mutex> lock(bmusb_mutex);
156                         cards[card_index].should_quit = true;  // Unblock thread.
157                         cards[card_index].new_data_ready_changed.notify_all();
158                 }
159                 cards[card_index].usb->stop_dequeue_thread();
160         }
161 }
162
163 namespace {
164
165 int unwrap_timecode(uint16_t current_wrapped, int last)
166 {
167         uint16_t last_wrapped = last & 0xffff;
168         if (current_wrapped > last_wrapped) {
169                 return (last & ~0xffff) | current_wrapped;
170         } else {
171                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
172         }
173 }
174
175 }  // namespace
176
177 void Mixer::bm_frame(int card_index, uint16_t timecode,
178                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
179                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
180 {
181         CaptureCard *card = &cards[card_index];
182
183         if (audio_frame.len - audio_offset > 30000) {
184                 printf("Card %d: Dropping frame with implausible audio length (len=%d, offset=%d) [timecode=0x%04x video_len=%d video_offset=%d video_format=%x)\n",
185                         card_index, int(audio_frame.len), int(audio_offset),
186                         timecode, int(video_frame.len), int(video_offset), video_format);
187                 if (video_frame.owner) {
188                         video_frame.owner->release_frame(video_frame);
189                 }
190                 if (audio_frame.owner) {
191                         audio_frame.owner->release_frame(audio_frame);
192                 }
193                 return;
194         }
195
196         // Convert the audio to stereo fp32 and add it.
197         size_t num_samples = (audio_frame.len - audio_offset) / 8 / 3;
198         vector<float> audio;
199         audio.resize(num_samples * 2);
200         convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, 8, num_samples);
201
202         int unwrapped_timecode = timecode;
203         int dropped_frames = 0;
204         if (card->last_timecode != -1) {
205                 unwrapped_timecode = unwrap_timecode(unwrapped_timecode, card->last_timecode);
206                 dropped_frames = unwrapped_timecode - card->last_timecode - 1;
207         }
208         card->last_timecode = unwrapped_timecode;
209
210         // Add the audio.
211         {
212                 unique_lock<mutex> lock(card->audio_mutex);
213
214                 int unwrapped_timecode = timecode;
215                 if (dropped_frames > 60 * 2) {
216                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around), resetting resampler\n",
217                                 card_index);
218                         card->resampler.reset(new Resampler(48000.0, 48000.0, 2));
219                 } else if (dropped_frames > 0) {
220                         // Insert silence as needed.
221                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
222                                 card_index, dropped_frames, timecode);
223                         vector<float> silence;
224                         silence.resize((48000 / 60) * 2);
225                         for (int i = 0; i < dropped_frames; ++i) {
226                                 card->resampler->add_input_samples((unwrapped_timecode - dropped_frames + i) / 60.0, silence.data(), (48000 / 60));
227                         }
228                 }
229                 card->resampler->add_input_samples(unwrapped_timecode / 60.0, audio.data(), num_samples);
230         }
231
232         // Done with the audio, so release it.
233         if (audio_frame.owner) {
234                 audio_frame.owner->release_frame(audio_frame);
235         }
236
237         {
238                 // Wait until the previous frame was consumed.
239                 unique_lock<mutex> lock(bmusb_mutex);
240                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
241                 if (card->should_quit) return;
242         }
243
244         if (video_frame.len - video_offset != 1280 * 750 * 2) {
245                 if (video_frame.len != 0) {
246                         printf("Card %d: Dropping video frame with wrong length (%ld)\n",
247                                 card_index, video_frame.len - video_offset);
248                 }
249                 if (video_frame.owner) {
250                         video_frame.owner->release_frame(video_frame);
251                 }
252
253                 // Still send on the information that we _had_ a frame, even though it's corrupted,
254                 // so that pts can go up accordingly.
255                 {
256                         unique_lock<mutex> lock(bmusb_mutex);
257                         card->new_data_ready = true;
258                         card->new_frame = RefCountedFrame(FrameAllocator::Frame());
259                         card->new_data_ready_fence = nullptr;
260                         card->dropped_frames = dropped_frames;
261                         card->new_data_ready_changed.notify_all();
262                 }
263                 return;
264         }
265
266         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)video_frame.userdata;
267         GLuint pbo = userdata->pbo;
268         check_error();
269         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
270         check_error();
271         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
272         check_error();
273         //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
274         //check_error();
275
276         // Upload the textures.
277         glBindTexture(GL_TEXTURE_2D, userdata->tex_y);
278         check_error();
279         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1280, 720, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET((1280 * 750 * 2 + 44) / 2 + 1280 * 25 + 22));
280         check_error();
281         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr);
282         check_error();
283         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1280/2, 720, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(1280 * 25 + 22));
284         check_error();
285         glBindTexture(GL_TEXTURE_2D, 0);
286         check_error();
287         GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);              
288         check_error();
289         assert(fence != nullptr);
290
291         {
292                 unique_lock<mutex> lock(bmusb_mutex);
293                 card->new_data_ready = true;
294                 card->new_frame = RefCountedFrame(video_frame);
295                 card->new_data_ready_fence = fence;
296                 card->dropped_frames = dropped_frames;
297                 card->new_data_ready_changed.notify_all();
298         }
299 }
300
301 void Mixer::thread_func()
302 {
303         eglBindAPI(EGL_OPENGL_API);
304         QOpenGLContext *context = create_context();
305         if (!make_current(context, mixer_surface)) {
306                 printf("oops\n");
307                 exit(1);
308         }
309
310         struct timespec start, now;
311         clock_gettime(CLOCK_MONOTONIC, &start);
312
313         int frame = 0;
314         int dropped_frames = 0;
315
316         while (!should_quit) {
317                 CaptureCard card_copy[NUM_CARDS];
318
319                 {
320                         unique_lock<mutex> lock(bmusb_mutex);
321
322                         // The first card is the master timer, so wait for it to have a new frame.
323                         // TODO: Make configurable, and with a timeout.
324                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
325
326                         for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
327                                 CaptureCard *card = &cards[card_index];
328                                 card_copy[card_index].usb = card->usb;
329                                 card_copy[card_index].new_data_ready = card->new_data_ready;
330                                 card_copy[card_index].new_frame = card->new_frame;
331                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
332                                 card_copy[card_index].new_frame_audio = move(card->new_frame_audio);
333                                 card_copy[card_index].dropped_frames = card->dropped_frames;
334                                 card->new_data_ready = false;
335                                 card->new_data_ready_changed.notify_all();
336                         }
337                 }
338
339                 // Resample the audio as needed, including from previously dropped frames.
340                 vector<float> samples_out;
341                 // TODO: Allow using audio from the other card(s) as well.
342                 for (unsigned frame_num = 0; frame_num < card_copy[0].dropped_frames + 1; ++frame_num) {
343                         for (unsigned card_index = 0; card_index < NUM_CARDS; ++card_index) {
344                                 samples_out.resize((48000 / 60) * 2);
345                                 {
346                                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
347                                         if (!cards[card_index].resampler->get_output_samples(pts(), &samples_out[0], 48000 / 60)) {
348                                                 printf("Card %d reported previous underrun.\n", card_index);
349                                         }
350                                 }
351                                 if (card_index == 0) {
352                                         h264_encoder->add_audio(pts_int, move(samples_out));
353                                 }
354                         }
355                         if (frame_num != card_copy[0].dropped_frames) {
356                                 // For dropped frames, increase the pts.
357                                 ++dropped_frames;
358                                 pts_int += TIMEBASE / 60;
359                         }
360                 }
361
362                 // If the first card is reporting a corrupted or otherwise dropped frame,
363                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
364                 if (card_copy[0].new_frame->len == 0) {
365                         ++dropped_frames;
366                         pts_int += TIMEBASE / 60;
367                         continue;
368                 }
369
370                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
371                         CaptureCard *card = &card_copy[card_index];
372                         if (!card->new_data_ready || card->new_frame->len == 0)
373                                 continue;
374
375                         assert(card->new_frame != nullptr);
376                         bmusb_current_rendering_frame[card_index] = card->new_frame;
377                         check_error();
378
379                         // The new texture might still be uploaded,
380                         // tell the GPU to wait until it's there.
381                         if (card->new_data_ready_fence) {
382                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
383                                 check_error();
384                                 glDeleteSync(card->new_data_ready_fence);
385                                 check_error();
386                         }
387                         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)card->new_frame->userdata;
388                         theme->set_input_textures(card_index, userdata->tex_y, userdata->tex_cbcr);
389                 }
390
391                 // Get the main chain from the theme, and set its state immediately.
392                 pair<EffectChain *, function<void()>> theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT);
393                 EffectChain *chain = theme_main_chain.first;
394                 theme_main_chain.second();
395
396                 GLuint y_tex, cbcr_tex;
397                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
398                 assert(got_frame);
399
400                 // Render main chain.
401                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
402                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
403                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
404                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
405                 resource_pool->release_fbo(fbo);
406
407                 subsample_chroma(cbcr_full_tex, cbcr_tex);
408                 resource_pool->release_2d_texture(cbcr_full_tex);
409
410                 // Set the right state for rgba_tex.
411                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
412                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
413                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
414                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
415                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
416
417                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
418                 check_error();
419
420                 // Make sure the H.264 gets a reference to all the
421                 // input frames needed, so that they are not released back
422                 // until the rendering is done.
423                 vector<RefCountedFrame> input_frames;
424                 for (int card_index = 0; card_index < NUM_CARDS; ++card_index) {
425                         input_frames.push_back(bmusb_current_rendering_frame[card_index]);
426                 }
427                 h264_encoder->end_frame(fence, pts_int, input_frames);
428                 ++frame;
429                 pts_int += TIMEBASE / 60;
430
431                 // The live frame just shows the RGBA texture we just rendered.
432                 // It owns rgba_tex now.
433                 DisplayFrame live_frame;
434                 live_frame.chain = display_chain.get();
435                 live_frame.setup_chain = [this, rgba_tex]{
436                         display_input->set_texture_num(rgba_tex);
437                 };
438                 live_frame.ready_fence = fence;
439                 live_frame.input_frames = {};
440                 live_frame.temp_textures = { rgba_tex };
441                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
442
443                 // Set up preview and any additional channels.
444                 for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
445                         DisplayFrame display_frame;
446                         pair<EffectChain *, function<void()>> chain = theme->get_chain(i, pts(), WIDTH, HEIGHT);  // FIXME: dimensions
447                         display_frame.chain = chain.first;
448                         display_frame.setup_chain = chain.second;
449                         display_frame.ready_fence = fence;
450                         display_frame.input_frames = { bmusb_current_rendering_frame[0], bmusb_current_rendering_frame[1] };  // FIXME: possible to do better?
451                         display_frame.temp_textures = {};
452                         output_channel[i].output_frame(display_frame);
453                 }
454
455                 clock_gettime(CLOCK_MONOTONIC, &now);
456                 double elapsed = now.tv_sec - start.tv_sec +
457                         1e-9 * (now.tv_nsec - start.tv_nsec);
458                 if (frame % 100 == 0) {
459                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
460                                 frame, dropped_frames, elapsed, frame / elapsed,
461                                 1e3 * elapsed / frame);
462                 //      chain->print_phase_timing();
463                 }
464
465 #if 0
466                 // Reset every 100 frames, so that local variations in frame times
467                 // (especially for the first few frames, when the shaders are
468                 // compiled etc.) don't make it hard to measure for the entire
469                 // remaining duration of the program.
470                 if (frame == 10000) {
471                         frame = 0;
472                         start = now;
473                 }
474 #endif
475                 check_error();
476         }
477
478         resource_pool->clean_context();
479 }
480
481 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
482 {
483         GLuint vao;
484         glGenVertexArrays(1, &vao);
485         check_error();
486
487         float vertices[] = {
488                 0.0f, 2.0f,
489                 0.0f, 0.0f,
490                 2.0f, 0.0f
491         };
492
493         glBindVertexArray(vao);
494         check_error();
495
496         // Extract Cb/Cr.
497         GLuint fbo = resource_pool->create_fbo(dst_tex);
498         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
499         glViewport(0, 0, WIDTH/2, HEIGHT/2);
500         check_error();
501
502         glUseProgram(cbcr_program_num);
503         check_error();
504
505         glActiveTexture(GL_TEXTURE0);
506         check_error();
507         glBindTexture(GL_TEXTURE_2D, src_tex);
508         check_error();
509         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
510         check_error();
511         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
512         check_error();
513         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
514         check_error();
515
516         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
517         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
518
519         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
520         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
521
522         glDrawArrays(GL_TRIANGLES, 0, 3);
523         check_error();
524
525         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
526         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
527
528         glUseProgram(0);
529         check_error();
530
531         resource_pool->release_fbo(fbo);
532         glDeleteVertexArrays(1, &vao);
533 }
534
535 void Mixer::release_display_frame(DisplayFrame *frame)
536 {
537         for (GLuint texnum : frame->temp_textures) {
538                 resource_pool->release_2d_texture(texnum);
539         }
540         frame->temp_textures.clear();
541         frame->ready_fence.reset();
542         frame->input_frames.clear();
543 }
544
545 void Mixer::start()
546 {
547         mixer_thread = thread(&Mixer::thread_func, this);
548 }
549
550 void Mixer::quit()
551 {
552         should_quit = true;
553         mixer_thread.join();
554 }
555
556 void Mixer::transition_clicked(int transition_num)
557 {
558         theme->transition_clicked(transition_num, pts());
559 }
560
561 void Mixer::channel_clicked(int preview_num)
562 {
563         theme->channel_clicked(preview_num);
564 }
565
566 Mixer::OutputChannel::~OutputChannel()
567 {
568         if (has_current_frame) {
569                 parent->release_display_frame(&current_frame);
570         }
571         if (has_ready_frame) {
572                 parent->release_display_frame(&ready_frame);
573         }
574 }
575
576 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
577 {
578         // Store this frame for display. Remove the ready frame if any
579         // (it was seemingly never used).
580         {
581                 unique_lock<mutex> lock(frame_mutex);
582                 if (has_ready_frame) {
583                         parent->release_display_frame(&ready_frame);
584                 }
585                 ready_frame = frame;
586                 has_ready_frame = true;
587         }
588
589         if (has_new_frame_ready_callback) {
590                 new_frame_ready_callback();
591         }
592 }
593
594 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
595 {
596         unique_lock<mutex> lock(frame_mutex);
597         if (!has_current_frame && !has_ready_frame) {
598                 return false;
599         }
600
601         if (has_current_frame && has_ready_frame) {
602                 // We have a new ready frame. Toss the current one.
603                 parent->release_display_frame(&current_frame);
604                 has_current_frame = false;
605         }
606         if (has_ready_frame) {
607                 assert(!has_current_frame);
608                 current_frame = ready_frame;
609                 ready_frame.ready_fence.reset();  // Drop the refcount.
610                 ready_frame.input_frames.clear();  // Drop the refcounts.
611                 has_current_frame = true;
612                 has_ready_frame = false;
613         }
614
615         *frame = current_frame;
616         return true;
617 }
618
619 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
620 {
621         new_frame_ready_callback = callback;
622         has_new_frame_ready_callback = true;
623 }