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[nageru] / mixer.cpp
1 #define WIDTH 1280
2 #define HEIGHT 720
3 #define EXTRAHEIGHT 30
4
5 #undef Success
6
7 #include "mixer.h"
8
9 #include <assert.h>
10 #include <epoxy/egl.h>
11 #include <init.h>
12 #include <movit/effect_chain.h>
13 #include <movit/effect_util.h>
14 #include <movit/flat_input.h>
15 #include <movit/image_format.h>
16 #include <movit/resource_pool.h>
17 #include <stdint.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <sys/time.h>
21 #include <time.h>
22 #include <util.h>
23 #include <algorithm>
24 #include <cmath>
25 #include <condition_variable>
26 #include <cstddef>
27 #include <memory>
28 #include <mutex>
29 #include <string>
30 #include <thread>
31 #include <utility>
32 #include <vector>
33
34 #include "bmusb/bmusb.h"
35 #include "context.h"
36 #include "defs.h"
37 #include "h264encode.h"
38 #include "pbo_frame_allocator.h"
39 #include "ref_counted_gl_sync.h"
40 #include "timebase.h"
41
42 class QOpenGLContext;
43
44 using namespace movit;
45 using namespace std;
46 using namespace std::placeholders;
47
48 Mixer *global_mixer = nullptr;
49
50 namespace {
51
52 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
53 {
54         for (size_t i = 0; i < num_samples; ++i) {
55                 for (size_t j = 0; j < out_channels; ++j) {
56                         uint32_t s1 = *src++;
57                         uint32_t s2 = *src++;
58                         uint32_t s3 = *src++;
59                         uint32_t s = s1 | (s1 << 8) | (s2 << 16) | (s3 << 24);
60                         dst[i * out_channels + j] = int(s) * (1.0f / 4294967296.0f);
61                 }
62                 src += 3 * (in_channels - out_channels);
63         }
64 }
65
66 }  // namespace
67
68 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
69         : httpd(LOCAL_DUMP_FILE_NAME, WIDTH, HEIGHT),
70           num_cards(num_cards),
71           mixer_surface(create_surface(format)),
72           h264_encoder_surface(create_surface(format)),
73           level_compressor(OUTPUT_FREQUENCY),
74           limiter(OUTPUT_FREQUENCY),
75           compressor(OUTPUT_FREQUENCY)
76 {
77         httpd.start(9095);
78
79         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
80         check_error();
81
82         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
83         // will be halved when sampling them, and we need to compensate here.
84         movit_texel_subpixel_precision /= 2.0;
85
86         resource_pool.reset(new ResourcePool);
87         theme.reset(new Theme("theme.lua", resource_pool.get(), num_cards));
88         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
89                 output_channel[i].parent = this;
90         }
91
92         ImageFormat inout_format;
93         inout_format.color_space = COLORSPACE_sRGB;
94         inout_format.gamma_curve = GAMMA_sRGB;
95
96         // Display chain; shows the live output produced by the main chain (its RGBA version).
97         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
98         check_error();
99         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
100         display_chain->add_input(display_input);
101         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
102         display_chain->set_dither_bits(0);  // Don't bother.
103         display_chain->finalize();
104
105         h264_encoder.reset(new H264Encoder(h264_encoder_surface, WIDTH, HEIGHT, &httpd));
106
107         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
108                 printf("Configuring card %d...\n", card_index);
109                 CaptureCard *card = &cards[card_index];
110                 card->usb = new BMUSBCapture(card_index);
111                 card->usb->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
112                 card->frame_allocator.reset(new PBOFrameAllocator(WIDTH * (HEIGHT+EXTRAHEIGHT) * 2 + 44, WIDTH, HEIGHT));
113                 card->usb->set_video_frame_allocator(card->frame_allocator.get());
114                 card->surface = create_surface(format);
115                 card->usb->set_dequeue_thread_callbacks(
116                         [card]{
117                                 eglBindAPI(EGL_OPENGL_API);
118                                 card->context = create_context(card->surface);
119                                 if (!make_current(card->context, card->surface)) {
120                                         printf("failed to create bmusb context\n");
121                                         exit(1);
122                                 }
123                         },
124                         [this]{
125                                 resource_pool->clean_context();
126                         });
127                 card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
128                 card->usb->configure_card();
129         }
130
131         BMUSBCapture::start_bm_thread();
132
133         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
134                 cards[card_index].usb->start_bm_capture();
135         }
136
137         //chain->enable_phase_timing(true);
138
139         // Set up stuff for NV12 conversion.
140
141         // Cb/Cr shader.
142         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
143         string cbcr_frag_shader =
144                 "#version 130 \n"
145                 "in vec2 tc0; \n"
146                 "uniform sampler2D cbcr_tex; \n"
147                 "void main() { \n"
148                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
149                 "} \n";
150         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader);
151
152         r128.init(2, OUTPUT_FREQUENCY);
153         r128.integr_start();
154
155         locut.init(FILTER_HPF, 2);
156
157         // hlen=16 is pretty low quality, but we use quite a bit of CPU otherwise,
158         // and there's a limit to how important the peak meter is.
159         peak_resampler.setup(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY * 4, /*num_channels=*/2, /*hlen=*/16);
160
161         alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
162 }
163
164 Mixer::~Mixer()
165 {
166         resource_pool->release_glsl_program(cbcr_program_num);
167         BMUSBCapture::stop_bm_thread();
168
169         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
170                 {
171                         unique_lock<mutex> lock(bmusb_mutex);
172                         cards[card_index].should_quit = true;  // Unblock thread.
173                         cards[card_index].new_data_ready_changed.notify_all();
174                 }
175                 cards[card_index].usb->stop_dequeue_thread();
176         }
177
178         h264_encoder.reset(nullptr);
179 }
180
181 namespace {
182
183 int unwrap_timecode(uint16_t current_wrapped, int last)
184 {
185         uint16_t last_wrapped = last & 0xffff;
186         if (current_wrapped > last_wrapped) {
187                 return (last & ~0xffff) | current_wrapped;
188         } else {
189                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
190         }
191 }
192
193 float find_peak(const float *samples, size_t num_samples)
194 {
195         float m = fabs(samples[0]);
196         for (size_t i = 1; i < num_samples; ++i) {
197                 m = std::max(m, fabs(samples[i]));
198         }
199         return m;
200 }
201
202 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
203 {
204         size_t num_samples = in.size() / 2;
205         out_l->resize(num_samples);
206         out_r->resize(num_samples);
207
208         const float *inptr = in.data();
209         float *lptr = &(*out_l)[0];
210         float *rptr = &(*out_r)[0];
211         for (size_t i = 0; i < num_samples; ++i) {
212                 *lptr++ = *inptr++;
213                 *rptr++ = *inptr++;
214         }
215 }
216
217 }  // namespace
218
219 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
220                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
221                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
222 {
223         CaptureCard *card = &cards[card_index];
224
225         if (audio_frame.len - audio_offset > 30000) {
226                 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",
227                         card_index, int(audio_frame.len), int(audio_offset),
228                         timecode, int(video_frame.len), int(video_offset), video_format);
229                 if (video_frame.owner) {
230                         video_frame.owner->release_frame(video_frame);
231                 }
232                 if (audio_frame.owner) {
233                         audio_frame.owner->release_frame(audio_frame);
234                 }
235                 return;
236         }
237
238         int unwrapped_timecode = timecode;
239         int dropped_frames = 0;
240         if (card->last_timecode != -1) {
241                 unwrapped_timecode = unwrap_timecode(unwrapped_timecode, card->last_timecode);
242                 dropped_frames = unwrapped_timecode - card->last_timecode - 1;
243         }
244         card->last_timecode = unwrapped_timecode;
245
246         // Convert the audio to stereo fp32 and add it.
247         size_t num_samples = (audio_frame.len >= audio_offset) ? (audio_frame.len - audio_offset) / 8 / 3 : 0;
248         vector<float> audio;
249         audio.resize(num_samples * 2);
250         convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, 8, num_samples);
251
252         // Add the audio.
253         {
254                 unique_lock<mutex> lock(card->audio_mutex);
255
256                 int unwrapped_timecode = timecode;
257                 if (dropped_frames > FPS * 2) {
258                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around), resetting resampler\n",
259                                 card_index);
260                         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
261                 } else if (dropped_frames > 0) {
262                         // Insert silence as needed.
263                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
264                                 card_index, dropped_frames, timecode);
265                         vector<float> silence;
266                         silence.resize((OUTPUT_FREQUENCY / FPS) * 2);
267                         for (int i = 0; i < dropped_frames; ++i) {
268                                 card->resampling_queue->add_input_samples((unwrapped_timecode - dropped_frames + i) / double(FPS), silence.data(), (OUTPUT_FREQUENCY / FPS));
269                         }
270                 }
271                 card->resampling_queue->add_input_samples(unwrapped_timecode / double(FPS), audio.data(), num_samples);
272         }
273
274         // Done with the audio, so release it.
275         if (audio_frame.owner) {
276                 audio_frame.owner->release_frame(audio_frame);
277         }
278
279         {
280                 // Wait until the previous frame was consumed.
281                 unique_lock<mutex> lock(bmusb_mutex);
282                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
283                 if (card->should_quit) return;
284         }
285
286         if (video_frame.len - video_offset != WIDTH * (HEIGHT+EXTRAHEIGHT) * 2) {
287                 if (video_frame.len != 0) {
288                         printf("Card %d: Dropping video frame with wrong length (%ld)\n",
289                                 card_index, video_frame.len - video_offset);
290                 }
291                 if (video_frame.owner) {
292                         video_frame.owner->release_frame(video_frame);
293                 }
294
295                 // Still send on the information that we _had_ a frame, even though it's corrupted,
296                 // so that pts can go up accordingly.
297                 {
298                         unique_lock<mutex> lock(bmusb_mutex);
299                         card->new_data_ready = true;
300                         card->new_frame = RefCountedFrame(FrameAllocator::Frame());
301                         card->new_data_ready_fence = nullptr;
302                         card->dropped_frames = dropped_frames;
303                         card->new_data_ready_changed.notify_all();
304                 }
305                 return;
306         }
307
308         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)video_frame.userdata;
309         GLuint pbo = userdata->pbo;
310         check_error();
311         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
312         check_error();
313         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
314         check_error();
315         //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
316         //check_error();
317
318         // Upload the textures.
319         glBindTexture(GL_TEXTURE_2D, userdata->tex_y);
320         check_error();
321         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH, HEIGHT, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET((WIDTH * (HEIGHT+EXTRAHEIGHT) * 2 + 44) / 2 + WIDTH * 25 + 22));
322         check_error();
323         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr);
324         check_error();
325         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH/2, HEIGHT, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(WIDTH * 25 + 22));
326         check_error();
327         glBindTexture(GL_TEXTURE_2D, 0);
328         check_error();
329         GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);              
330         check_error();
331         assert(fence != nullptr);
332
333         {
334                 unique_lock<mutex> lock(bmusb_mutex);
335                 card->new_data_ready = true;
336                 card->new_frame = RefCountedFrame(video_frame);
337                 card->new_data_ready_fence = fence;
338                 card->dropped_frames = dropped_frames;
339                 card->new_data_ready_changed.notify_all();
340         }
341 }
342
343 void Mixer::thread_func()
344 {
345         eglBindAPI(EGL_OPENGL_API);
346         QOpenGLContext *context = create_context(mixer_surface);
347         if (!make_current(context, mixer_surface)) {
348                 printf("oops\n");
349                 exit(1);
350         }
351
352         struct timespec start, now;
353         clock_gettime(CLOCK_MONOTONIC, &start);
354
355         int frame = 0;
356         int dropped_frames = 0;
357
358         while (!should_quit) {
359                 CaptureCard card_copy[MAX_CARDS];
360
361                 {
362                         unique_lock<mutex> lock(bmusb_mutex);
363
364                         // The first card is the master timer, so wait for it to have a new frame.
365                         // TODO: Make configurable, and with a timeout.
366                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
367
368                         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
369                                 CaptureCard *card = &cards[card_index];
370                                 card_copy[card_index].usb = card->usb;
371                                 card_copy[card_index].new_data_ready = card->new_data_ready;
372                                 card_copy[card_index].new_frame = card->new_frame;
373                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
374                                 card_copy[card_index].dropped_frames = card->dropped_frames;
375                                 card->new_data_ready = false;
376                                 card->new_data_ready_changed.notify_all();
377                         }
378                 }
379
380                 // Resample the audio as needed, including from previously dropped frames.
381                 for (unsigned frame_num = 0; frame_num < card_copy[0].dropped_frames + 1; ++frame_num) {
382                         {
383                                 // Signal to the audio thread to process this frame.
384                                 unique_lock<mutex> lock(audio_mutex);
385                                 audio_pts_queue.push(pts_int);
386                                 audio_pts_queue_changed.notify_one();
387                         }
388                         if (frame_num != card_copy[0].dropped_frames) {
389                                 // For dropped frames, increase the pts.
390                                 ++dropped_frames;
391                                 pts_int += TIMEBASE / FPS;
392                         }
393                 }
394
395                 if (audio_level_callback != nullptr) {
396                         double loudness_s = r128.loudness_S();
397                         double loudness_i = r128.integrated();
398                         double loudness_range_low = r128.range_min();
399                         double loudness_range_high = r128.range_max();
400
401                         audio_level_callback(loudness_s, 20.0 * log10(peak),
402                                              loudness_i, loudness_range_low, loudness_range_high,
403                                              last_gain_staging_db);
404                 }
405
406                 for (unsigned card_index = 1; card_index < num_cards; ++card_index) {
407                         if (card_copy[card_index].new_data_ready && card_copy[card_index].new_frame->len == 0) {
408                                 ++card_copy[card_index].dropped_frames;
409                         }
410                         if (card_copy[card_index].dropped_frames > 0) {
411                                 printf("Card %u dropped %d frames before this\n",
412                                         card_index, int(card_copy[card_index].dropped_frames));
413                         }
414                 }
415
416                 // If the first card is reporting a corrupted or otherwise dropped frame,
417                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
418                 if (card_copy[0].new_frame->len == 0) {
419                         ++dropped_frames;
420                         pts_int += TIMEBASE / FPS;
421                         continue;
422                 }
423
424                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
425                         CaptureCard *card = &card_copy[card_index];
426                         if (!card->new_data_ready || card->new_frame->len == 0)
427                                 continue;
428
429                         assert(card->new_frame != nullptr);
430                         bmusb_current_rendering_frame[card_index] = card->new_frame;
431                         check_error();
432
433                         // The new texture might still be uploaded,
434                         // tell the GPU to wait until it's there.
435                         if (card->new_data_ready_fence) {
436                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
437                                 check_error();
438                                 glDeleteSync(card->new_data_ready_fence);
439                                 check_error();
440                         }
441                         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)card->new_frame->userdata;
442                         theme->set_input_textures(card_index, userdata->tex_y, userdata->tex_cbcr);
443                 }
444
445                 // Get the main chain from the theme, and set its state immediately.
446                 pair<EffectChain *, function<void()>> theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT);
447                 EffectChain *chain = theme_main_chain.first;
448                 theme_main_chain.second();
449
450                 GLuint y_tex, cbcr_tex;
451                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
452                 assert(got_frame);
453
454                 // Render main chain.
455                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
456                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
457                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
458                 check_error();
459                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
460                 resource_pool->release_fbo(fbo);
461
462                 subsample_chroma(cbcr_full_tex, cbcr_tex);
463                 resource_pool->release_2d_texture(cbcr_full_tex);
464
465                 // Set the right state for rgba_tex.
466                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
467                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
468                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
469                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
470                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
471
472                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
473                 check_error();
474
475                 // Make sure the H.264 gets a reference to all the
476                 // input frames needed, so that they are not released back
477                 // until the rendering is done.
478                 vector<RefCountedFrame> input_frames;
479                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
480                         input_frames.push_back(bmusb_current_rendering_frame[card_index]);
481                 }
482                 const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampling_queue.h. TODO: Make less hard-coded.
483                 h264_encoder->end_frame(fence, pts_int + av_delay, input_frames);
484                 ++frame;
485                 pts_int += TIMEBASE / FPS;
486
487                 // The live frame just shows the RGBA texture we just rendered.
488                 // It owns rgba_tex now.
489                 DisplayFrame live_frame;
490                 live_frame.chain = display_chain.get();
491                 live_frame.setup_chain = [this, rgba_tex]{
492                         display_input->set_texture_num(rgba_tex);
493                 };
494                 live_frame.ready_fence = fence;
495                 live_frame.input_frames = {};
496                 live_frame.temp_textures = { rgba_tex };
497                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
498
499                 // Set up preview and any additional channels.
500                 for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
501                         DisplayFrame display_frame;
502                         pair<EffectChain *, function<void()>> chain = theme->get_chain(i, pts(), WIDTH, HEIGHT);  // FIXME: dimensions
503                         display_frame.chain = chain.first;
504                         display_frame.setup_chain = chain.second;
505                         display_frame.ready_fence = fence;
506
507                         // FIXME: possible to do better?
508                         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
509                                 display_frame.input_frames.push_back(bmusb_current_rendering_frame[card_index]);
510                         }
511                         display_frame.temp_textures = {};
512                         output_channel[i].output_frame(display_frame);
513                 }
514
515                 clock_gettime(CLOCK_MONOTONIC, &now);
516                 double elapsed = now.tv_sec - start.tv_sec +
517                         1e-9 * (now.tv_nsec - start.tv_nsec);
518                 if (frame % 100 == 0) {
519                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
520                                 frame, dropped_frames, elapsed, frame / elapsed,
521                                 1e3 * elapsed / frame);
522                 //      chain->print_phase_timing();
523                 }
524
525 #if 0
526                 // Reset every 100 frames, so that local variations in frame times
527                 // (especially for the first few frames, when the shaders are
528                 // compiled etc.) don't make it hard to measure for the entire
529                 // remaining duration of the program.
530                 if (frame == 10000) {
531                         frame = 0;
532                         start = now;
533                 }
534 #endif
535                 check_error();
536         }
537
538         resource_pool->clean_context();
539 }
540
541 void Mixer::audio_thread_func()
542 {
543         while (!should_quit) {
544                 int64_t frame_pts_int;
545
546                 {
547                         unique_lock<mutex> lock(audio_mutex);
548                         audio_pts_queue_changed.wait(lock, [this]{ return !audio_pts_queue.empty(); });
549                         frame_pts_int = audio_pts_queue.front();
550                         audio_pts_queue.pop();
551                 }
552
553                 process_audio_one_frame(frame_pts_int);
554         }
555 }
556
557 void Mixer::process_audio_one_frame(int64_t frame_pts_int)
558 {
559         vector<float> samples_card;
560         vector<float> samples_out;
561         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
562                 samples_card.resize((OUTPUT_FREQUENCY / FPS) * 2);
563                 {
564                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
565                         if (!cards[card_index].resampling_queue->get_output_samples(double(frame_pts_int) / TIMEBASE, &samples_card[0], OUTPUT_FREQUENCY / FPS)) {
566                                 printf("Card %d reported previous underrun.\n", card_index);
567                         }
568                 }
569                 // TODO: Allow using audio from the other card(s) as well.
570                 if (card_index == 0) {
571                         samples_out = move(samples_card);
572                 }
573         }
574
575         // Cut away everything under 120 Hz (or whatever the cutoff is);
576         // we don't need it for voice, and it will reduce headroom
577         // and confuse the compressor. (In particular, any hums at 50 or 60 Hz
578         // should be dampened.)
579         locut.render(samples_out.data(), samples_out.size() / 2, locut_cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY, 0.5f);
580
581         // Apply a level compressor to get the general level right.
582         // Basically, if it's over about -40 dBFS, we squeeze it down to that level
583         // (or more precisely, near it, since we don't use infinite ratio),
584         // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
585         // entirely arbitrary, but from practical tests with speech, it seems to
586         // put ut around -23 LUFS, so it's a reasonable starting point for later use.
587         float ref_level_dbfs = -14.0f;
588         {
589                 float threshold = 0.01f;   // -40 dBFS.
590                 float ratio = 20.0f;
591                 float attack_time = 0.5f;
592                 float release_time = 20.0f;
593                 float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
594                 level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
595                 last_gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
596         }
597
598 #if 0
599         printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
600                 level_compressor.get_level(), 20.0 * log10(level_compressor.get_level()),
601                 level_compressor.get_attenuation(), 20.0 * log10(level_compressor.get_attenuation()),
602                 20.0 * log10(level_compressor.get_level() * level_compressor.get_attenuation() * makeup_gain));
603 #endif
604
605 //      float limiter_att, compressor_att;
606
607         // The real compressor.
608         if (compressor_enabled) {
609                 float threshold = pow(10.0f, compressor_threshold_dbfs / 20.0f);
610                 float ratio = 20.0f;
611                 float attack_time = 0.005f;
612                 float release_time = 0.040f;
613                 float makeup_gain = 2.0f;  // +6 dB.
614                 compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
615 //              compressor_att = compressor.get_attenuation();
616         }
617
618         // Finally a limiter at -4 dB (so, -10 dBFS) to take out the worst peaks only.
619         // Note that since ratio is not infinite, we could go slightly higher than this.
620         if (limiter_enabled) {
621                 float threshold = pow(10.0f, limiter_threshold_dbfs / 20.0f);
622                 float ratio = 30.0f;
623                 float attack_time = 0.0f;  // Instant.
624                 float release_time = 0.020f;
625                 float makeup_gain = 1.0f;  // 0 dB.
626                 limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
627 //              limiter_att = limiter.get_attenuation();
628         }
629
630 //      printf("limiter=%+5.1f  compressor=%+5.1f\n", 20.0*log10(limiter_att), 20.0*log10(compressor_att));
631
632         // Upsample 4x to find interpolated peak.
633         peak_resampler.inp_data = samples_out.data();
634         peak_resampler.inp_count = samples_out.size() / 2;
635
636         vector<float> interpolated_samples_out;
637         interpolated_samples_out.resize(samples_out.size());
638         while (peak_resampler.inp_count > 0) {  // About four iterations.
639                 peak_resampler.out_data = &interpolated_samples_out[0];
640                 peak_resampler.out_count = interpolated_samples_out.size() / 2;
641                 peak_resampler.process();
642                 size_t out_stereo_samples = interpolated_samples_out.size() / 2 - peak_resampler.out_count;
643                 peak = max<float>(peak, find_peak(interpolated_samples_out.data(), out_stereo_samples * 2));
644         }
645
646         // Find R128 levels.
647         vector<float> left, right;
648         deinterleave_samples(samples_out, &left, &right);
649         float *ptrs[] = { left.data(), right.data() };
650         r128.process(left.size(), ptrs);
651
652         // Send the samples to the sound card.
653         if (alsa) {
654                 alsa->write(samples_out);
655         }
656
657         // And finally add them to the output.
658         h264_encoder->add_audio(frame_pts_int, move(samples_out));
659 }
660
661 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
662 {
663         GLuint vao;
664         glGenVertexArrays(1, &vao);
665         check_error();
666
667         float vertices[] = {
668                 0.0f, 2.0f,
669                 0.0f, 0.0f,
670                 2.0f, 0.0f
671         };
672
673         glBindVertexArray(vao);
674         check_error();
675
676         // Extract Cb/Cr.
677         GLuint fbo = resource_pool->create_fbo(dst_tex);
678         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
679         glViewport(0, 0, WIDTH/2, HEIGHT/2);
680         check_error();
681
682         glUseProgram(cbcr_program_num);
683         check_error();
684
685         glActiveTexture(GL_TEXTURE0);
686         check_error();
687         glBindTexture(GL_TEXTURE_2D, src_tex);
688         check_error();
689         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
690         check_error();
691         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
692         check_error();
693         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
694         check_error();
695
696         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
697         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
698
699         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
700         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
701
702         glDrawArrays(GL_TRIANGLES, 0, 3);
703         check_error();
704
705         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
706         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
707
708         glUseProgram(0);
709         check_error();
710
711         resource_pool->release_fbo(fbo);
712         glDeleteVertexArrays(1, &vao);
713 }
714
715 void Mixer::release_display_frame(DisplayFrame *frame)
716 {
717         for (GLuint texnum : frame->temp_textures) {
718                 resource_pool->release_2d_texture(texnum);
719         }
720         frame->temp_textures.clear();
721         frame->ready_fence.reset();
722         frame->input_frames.clear();
723 }
724
725 void Mixer::start()
726 {
727         mixer_thread = thread(&Mixer::thread_func, this);
728         audio_thread = thread(&Mixer::audio_thread_func, this);
729 }
730
731 void Mixer::quit()
732 {
733         should_quit = true;
734         mixer_thread.join();
735         audio_thread.join();
736 }
737
738 void Mixer::transition_clicked(int transition_num)
739 {
740         theme->transition_clicked(transition_num, pts());
741 }
742
743 void Mixer::channel_clicked(int preview_num)
744 {
745         theme->channel_clicked(preview_num);
746 }
747
748 void Mixer::reset_meters()
749 {
750         peak_resampler.reset();
751         peak = 0.0f;
752         r128.reset();
753         r128.integr_start();
754 }
755
756 Mixer::OutputChannel::~OutputChannel()
757 {
758         if (has_current_frame) {
759                 parent->release_display_frame(&current_frame);
760         }
761         if (has_ready_frame) {
762                 parent->release_display_frame(&ready_frame);
763         }
764 }
765
766 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
767 {
768         // Store this frame for display. Remove the ready frame if any
769         // (it was seemingly never used).
770         {
771                 unique_lock<mutex> lock(frame_mutex);
772                 if (has_ready_frame) {
773                         parent->release_display_frame(&ready_frame);
774                 }
775                 ready_frame = frame;
776                 has_ready_frame = true;
777         }
778
779         if (has_new_frame_ready_callback) {
780                 new_frame_ready_callback();
781         }
782 }
783
784 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
785 {
786         unique_lock<mutex> lock(frame_mutex);
787         if (!has_current_frame && !has_ready_frame) {
788                 return false;
789         }
790
791         if (has_current_frame && has_ready_frame) {
792                 // We have a new ready frame. Toss the current one.
793                 parent->release_display_frame(&current_frame);
794                 has_current_frame = false;
795         }
796         if (has_ready_frame) {
797                 assert(!has_current_frame);
798                 current_frame = ready_frame;
799                 ready_frame.ready_fence.reset();  // Drop the refcount.
800                 ready_frame.input_frames.clear();  // Drop the refcounts.
801                 has_current_frame = true;
802                 has_ready_frame = false;
803         }
804
805         *frame = current_frame;
806         return true;
807 }
808
809 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
810 {
811         new_frame_ready_callback = callback;
812         has_new_frame_ready_callback = true;
813 }