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1 #undef Success
2
3 #include "mixer.h"
4
5 #include <assert.h>
6 #include <epoxy/egl.h>
7 #include <init.h>
8 #include <movit/effect_chain.h>
9 #include <movit/effect_util.h>
10 #include <movit/flat_input.h>
11 #include <movit/image_format.h>
12 #include <movit/resource_pool.h>
13 #include <movit/util.h>
14 #include <stdint.h>
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include <sys/time.h>
18 #include <time.h>
19 #include <algorithm>
20 #include <cmath>
21 #include <condition_variable>
22 #include <cstddef>
23 #include <memory>
24 #include <mutex>
25 #include <string>
26 #include <thread>
27 #include <utility>
28 #include <vector>
29
30 #include "bmusb/bmusb.h"
31 #include "context.h"
32 #include "defs.h"
33 #include "h264encode.h"
34 #include "pbo_frame_allocator.h"
35 #include "ref_counted_gl_sync.h"
36 #include "timebase.h"
37
38 class QOpenGLContext;
39
40 using namespace movit;
41 using namespace std;
42 using namespace std::placeholders;
43
44 Mixer *global_mixer = nullptr;
45
46 namespace {
47
48 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
49 {
50         for (size_t i = 0; i < num_samples; ++i) {
51                 for (size_t j = 0; j < out_channels; ++j) {
52                         uint32_t s1 = *src++;
53                         uint32_t s2 = *src++;
54                         uint32_t s3 = *src++;
55                         uint32_t s = s1 | (s1 << 8) | (s2 << 16) | (s3 << 24);
56                         dst[i * out_channels + j] = int(s) * (1.0f / 4294967296.0f);
57                 }
58                 src += 3 * (in_channels - out_channels);
59         }
60 }
61
62 void insert_new_frame(RefCountedFrame frame, unsigned field_num, bool interlaced, unsigned card_index, InputState *input_state)
63 {
64         if (interlaced) {
65                 for (unsigned frame_num = FRAME_HISTORY_LENGTH; frame_num --> 1; ) {  // :-)
66                         input_state->buffered_frames[card_index][frame_num] =
67                                 input_state->buffered_frames[card_index][frame_num - 1];
68                 }
69                 input_state->buffered_frames[card_index][0] = { frame, field_num };
70         } else {
71                 for (unsigned frame_num = 0; frame_num < FRAME_HISTORY_LENGTH; ++frame_num) {
72                         input_state->buffered_frames[card_index][frame_num] = { frame, field_num };
73                 }
74         }
75 }
76
77 }  // namespace
78
79 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
80         : httpd(LOCAL_DUMP_FILE_NAME, WIDTH, HEIGHT),
81           num_cards(num_cards),
82           mixer_surface(create_surface(format)),
83           h264_encoder_surface(create_surface(format)),
84           level_compressor(OUTPUT_FREQUENCY),
85           limiter(OUTPUT_FREQUENCY),
86           compressor(OUTPUT_FREQUENCY)
87 {
88         httpd.start(9095);
89
90         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
91         check_error();
92
93         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
94         // will be halved when sampling them, and we need to compensate here.
95         movit_texel_subpixel_precision /= 2.0;
96
97         resource_pool.reset(new ResourcePool);
98         theme.reset(new Theme("theme.lua", resource_pool.get(), num_cards));
99         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
100                 output_channel[i].parent = this;
101         }
102
103         ImageFormat inout_format;
104         inout_format.color_space = COLORSPACE_sRGB;
105         inout_format.gamma_curve = GAMMA_sRGB;
106
107         // Display chain; shows the live output produced by the main chain (its RGBA version).
108         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
109         check_error();
110         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
111         display_chain->add_input(display_input);
112         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
113         display_chain->set_dither_bits(0);  // Don't bother.
114         display_chain->finalize();
115
116         h264_encoder.reset(new H264Encoder(h264_encoder_surface, WIDTH, HEIGHT, &httpd));
117
118         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
119                 printf("Configuring card %d...\n", card_index);
120                 CaptureCard *card = &cards[card_index];
121                 card->usb = new BMUSBCapture(card_index);
122                 card->usb->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
123                 card->frame_allocator.reset(new PBOFrameAllocator(8 << 20, WIDTH, HEIGHT));  // 8 MB.
124                 card->usb->set_video_frame_allocator(card->frame_allocator.get());
125                 card->surface = create_surface(format);
126                 card->usb->set_dequeue_thread_callbacks(
127                         [card]{
128                                 eglBindAPI(EGL_OPENGL_API);
129                                 card->context = create_context(card->surface);
130                                 if (!make_current(card->context, card->surface)) {
131                                         printf("failed to create bmusb context\n");
132                                         exit(1);
133                                 }
134                         },
135                         [this]{
136                                 resource_pool->clean_context();
137                         });
138                 card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
139                 card->usb->configure_card();
140         }
141
142         BMUSBCapture::start_bm_thread();
143
144         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
145                 cards[card_index].usb->start_bm_capture();
146         }
147
148         // Set up stuff for NV12 conversion.
149
150         // Cb/Cr shader.
151         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
152         string cbcr_frag_shader =
153                 "#version 130 \n"
154                 "in vec2 tc0; \n"
155                 "uniform sampler2D cbcr_tex; \n"
156                 "void main() { \n"
157                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
158                 "} \n";
159         vector<string> frag_shader_outputs;
160         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader, frag_shader_outputs);
161
162         r128.init(2, OUTPUT_FREQUENCY);
163         r128.integr_start();
164
165         locut.init(FILTER_HPF, 2);
166
167         // hlen=16 is pretty low quality, but we use quite a bit of CPU otherwise,
168         // and there's a limit to how important the peak meter is.
169         peak_resampler.setup(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY * 4, /*num_channels=*/2, /*hlen=*/16);
170
171         alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
172 }
173
174 Mixer::~Mixer()
175 {
176         resource_pool->release_glsl_program(cbcr_program_num);
177         BMUSBCapture::stop_bm_thread();
178
179         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
180                 {
181                         unique_lock<mutex> lock(bmusb_mutex);
182                         cards[card_index].should_quit = true;  // Unblock thread.
183                         cards[card_index].new_data_ready_changed.notify_all();
184                 }
185                 cards[card_index].usb->stop_dequeue_thread();
186         }
187
188         h264_encoder.reset(nullptr);
189 }
190
191 namespace {
192
193 int unwrap_timecode(uint16_t current_wrapped, int last)
194 {
195         uint16_t last_wrapped = last & 0xffff;
196         if (current_wrapped > last_wrapped) {
197                 return (last & ~0xffff) | current_wrapped;
198         } else {
199                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
200         }
201 }
202
203 float find_peak(const float *samples, size_t num_samples)
204 {
205         float m = fabs(samples[0]);
206         for (size_t i = 1; i < num_samples; ++i) {
207                 m = std::max(m, fabs(samples[i]));
208         }
209         return m;
210 }
211
212 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
213 {
214         size_t num_samples = in.size() / 2;
215         out_l->resize(num_samples);
216         out_r->resize(num_samples);
217
218         const float *inptr = in.data();
219         float *lptr = &(*out_l)[0];
220         float *rptr = &(*out_r)[0];
221         for (size_t i = 0; i < num_samples; ++i) {
222                 *lptr++ = *inptr++;
223                 *rptr++ = *inptr++;
224         }
225 }
226
227 }  // namespace
228
229 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
230                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
231                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
232 {
233         CaptureCard *card = &cards[card_index];
234
235         unsigned width, height, second_field_start, frame_rate_nom, frame_rate_den, extra_lines_top, extra_lines_bottom;
236         bool interlaced;
237
238         decode_video_format(video_format, &width, &height, &second_field_start, &extra_lines_top, &extra_lines_bottom,
239                             &frame_rate_nom, &frame_rate_den, &interlaced);  // Ignore return value for now.
240         int64_t frame_length = TIMEBASE * frame_rate_den / frame_rate_nom;
241
242         size_t num_samples = (audio_frame.len >= audio_offset) ? (audio_frame.len - audio_offset) / 8 / 3 : 0;
243         if (num_samples > OUTPUT_FREQUENCY / 10) {
244                 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",
245                         card_index, int(audio_frame.len), int(audio_offset),
246                         timecode, int(video_frame.len), int(video_offset), video_format);
247                 if (video_frame.owner) {
248                         video_frame.owner->release_frame(video_frame);
249                 }
250                 if (audio_frame.owner) {
251                         audio_frame.owner->release_frame(audio_frame);
252                 }
253                 return;
254         }
255
256         int64_t local_pts = card->next_local_pts;
257         int dropped_frames = 0;
258         if (card->last_timecode != -1) {
259                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
260         }
261
262         // Convert the audio to stereo fp32 and add it.
263         vector<float> audio;
264         audio.resize(num_samples * 2);
265         convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, 8, num_samples);
266
267         // Add the audio.
268         {
269                 unique_lock<mutex> lock(card->audio_mutex);
270
271                 // Number of samples per frame if we need to insert silence.
272                 // (Could be nonintegral, but resampling will save us then.)
273                 int silence_samples = OUTPUT_FREQUENCY * frame_rate_den / frame_rate_nom;
274
275                 if (dropped_frames > MAX_FPS * 2) {
276                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
277                                 card_index, card->last_timecode, timecode);
278                         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
279                         dropped_frames = 0;
280                 } else if (dropped_frames > 0) {
281                         // Insert silence as needed.
282                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
283                                 card_index, dropped_frames, timecode);
284                         vector<float> silence(silence_samples * 2, 0.0f);
285                         for (int i = 0; i < dropped_frames; ++i) {
286                                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), silence.data(), silence_samples);
287                                 // Note that if the format changed in the meantime, we have
288                                 // no way of detecting that; we just have to assume the frame length
289                                 // is always the same.
290                                 local_pts += frame_length;
291                         }
292                 }
293                 if (num_samples == 0) {
294                         audio.resize(silence_samples * 2);
295                         num_samples = silence_samples;
296                 }
297                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), audio.data(), num_samples);
298                 card->next_local_pts = local_pts + frame_length;
299         }
300
301         card->last_timecode = timecode;
302
303         // Done with the audio, so release it.
304         if (audio_frame.owner) {
305                 audio_frame.owner->release_frame(audio_frame);
306         }
307
308         {
309                 // Wait until the previous frame was consumed.
310                 unique_lock<mutex> lock(bmusb_mutex);
311                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
312                 if (card->should_quit) return;
313         }
314
315         if (video_frame.len - video_offset == 0 ||
316             video_frame.len - video_offset != size_t(width * (height + extra_lines_top + extra_lines_bottom) * 2)) {
317                 if (video_frame.len != 0) {
318                         printf("Card %d: Dropping video frame with wrong length (%ld)\n",
319                                 card_index, video_frame.len - video_offset);
320                 }
321                 if (video_frame.owner) {
322                         video_frame.owner->release_frame(video_frame);
323                 }
324
325                 // Still send on the information that we _had_ a frame, even though it's corrupted,
326                 // so that pts can go up accordingly.
327                 {
328                         unique_lock<mutex> lock(bmusb_mutex);
329                         card->new_data_ready = true;
330                         card->new_frame = RefCountedFrame(FrameAllocator::Frame());
331                         card->new_frame_length = frame_length;
332                         card->new_frame_interlaced = false;
333                         card->new_data_ready_fence = nullptr;
334                         card->dropped_frames = dropped_frames;
335                         card->new_data_ready_changed.notify_all();
336                 }
337                 return;
338         }
339
340         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
341
342         unsigned num_fields = interlaced ? 2 : 1;
343         timespec frame_upload_start;
344         if (interlaced) {
345                 // NOTE: This isn't deinterlacing. This is just sending the two fields along
346                 // as separate frames without considering anything like the half-field offset.
347                 // We'll need to add a proper deinterlacer on the receiving side to get this right.
348                 assert(height % 2 == 0);
349                 height /= 2;
350                 assert(frame_length % 2 == 0);
351                 frame_length /= 2;
352                 num_fields = 2;
353                 clock_gettime(CLOCK_MONOTONIC, &frame_upload_start);
354         }
355         RefCountedFrame new_frame(video_frame);
356
357         // Upload the textures.
358         size_t cbcr_width = width / 2;
359         size_t cbcr_offset = video_offset / 2;
360         size_t y_offset = video_frame.size / 2 + video_offset / 2;
361
362         for (unsigned field = 0; field < num_fields; ++field) {
363                 unsigned field_start_line = (field == 1) ? second_field_start : extra_lines_top + field * (height + 22);
364
365                 if (userdata->tex_y[field] == 0 ||
366                     userdata->tex_cbcr[field] == 0 ||
367                     width != userdata->last_width[field] ||
368                     height != userdata->last_height[field]) {
369                         // We changed resolution since last use of this texture, so we need to create
370                         // a new object. Note that this each card has its own PBOFrameAllocator,
371                         // we don't need to worry about these flip-flopping between resolutions.
372                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
373                         check_error();
374                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
375                         check_error();
376                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
377                         check_error();
378                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
379                         check_error();
380                         userdata->last_width[field] = width;
381                         userdata->last_height[field] = height;
382                 }
383
384                 GLuint pbo = userdata->pbo;
385                 check_error();
386                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
387                 check_error();
388                 glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
389                 check_error();
390
391                 glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
392                 check_error();
393                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, cbcr_width, height, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t)));
394                 check_error();
395                 glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
396                 check_error();
397                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(y_offset + width * field_start_line));
398                 check_error();
399                 glBindTexture(GL_TEXTURE_2D, 0);
400                 check_error();
401                 GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
402                 check_error();
403                 assert(fence != nullptr);
404
405                 if (field == 1) {
406                         // Don't upload the second field as fast as we can; wait until
407                         // the field time has approximately passed. (Otherwise, we could
408                         // get timing jitter against the other sources, and possibly also
409                         // against the video display, although the latter is not as critical.)
410                         // This requires our system clock to be reasonably close to the
411                         // video clock, but that's not an unreasonable assumption.
412                         timespec second_field_start;
413                         second_field_start.tv_nsec = frame_upload_start.tv_nsec +
414                                 frame_length * 1000000000 / TIMEBASE;
415                         second_field_start.tv_sec = frame_upload_start.tv_sec +
416                                 second_field_start.tv_nsec / 1000000000;
417                         second_field_start.tv_nsec %= 1000000000;
418
419                         while (clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME,
420                                                &second_field_start, nullptr) == -1 &&
421                                errno == EINTR) ;
422                 }
423
424                 {
425                         unique_lock<mutex> lock(bmusb_mutex);
426                         card->new_data_ready = true;
427                         card->new_frame = new_frame;
428                         card->new_frame_length = frame_length;
429                         card->new_frame_field = field;
430                         card->new_frame_interlaced = interlaced;
431                         card->new_data_ready_fence = fence;
432                         card->dropped_frames = dropped_frames;
433                         card->new_data_ready_changed.notify_all();
434
435                         if (field != num_fields - 1) {
436                                 // Wait until the previous frame was consumed.
437                                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
438                                 if (card->should_quit) return;
439                         }
440                 }
441         }
442 }
443
444 void Mixer::thread_func()
445 {
446         eglBindAPI(EGL_OPENGL_API);
447         QOpenGLContext *context = create_context(mixer_surface);
448         if (!make_current(context, mixer_surface)) {
449                 printf("oops\n");
450                 exit(1);
451         }
452
453         struct timespec start, now;
454         clock_gettime(CLOCK_MONOTONIC, &start);
455
456         int frame = 0;
457         int stats_dropped_frames = 0;
458
459         while (!should_quit) {
460                 CaptureCard card_copy[MAX_CARDS];
461                 int num_samples[MAX_CARDS];
462
463                 {
464                         unique_lock<mutex> lock(bmusb_mutex);
465
466                         // The first card is the master timer, so wait for it to have a new frame.
467                         // TODO: Make configurable, and with a timeout.
468                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
469
470                         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
471                                 CaptureCard *card = &cards[card_index];
472                                 card_copy[card_index].usb = card->usb;
473                                 card_copy[card_index].new_data_ready = card->new_data_ready;
474                                 card_copy[card_index].new_frame = card->new_frame;
475                                 card_copy[card_index].new_frame_length = card->new_frame_length;
476                                 card_copy[card_index].new_frame_field = card->new_frame_field;
477                                 card_copy[card_index].new_frame_interlaced = card->new_frame_interlaced;
478                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
479                                 card_copy[card_index].dropped_frames = card->dropped_frames;
480                                 card->new_data_ready = false;
481                                 card->new_data_ready_changed.notify_all();
482
483                                 int num_samples_times_timebase = OUTPUT_FREQUENCY * card->new_frame_length + card->fractional_samples;
484                                 num_samples[card_index] = num_samples_times_timebase / TIMEBASE;
485                                 card->fractional_samples = num_samples_times_timebase % TIMEBASE;
486                                 assert(num_samples[card_index] >= 0);
487                         }
488                 }
489
490                 // Resample the audio as needed, including from previously dropped frames.
491                 for (unsigned frame_num = 0; frame_num < card_copy[0].dropped_frames + 1; ++frame_num) {
492                         {
493                                 // Signal to the audio thread to process this frame.
494                                 unique_lock<mutex> lock(audio_mutex);
495                                 audio_task_queue.push(AudioTask{pts_int, num_samples[0]});
496                                 audio_task_queue_changed.notify_one();
497                         }
498                         if (frame_num != card_copy[0].dropped_frames) {
499                                 // For dropped frames, increase the pts. Note that if the format changed
500                                 // in the meantime, we have no way of detecting that; we just have to
501                                 // assume the frame length is always the same.
502                                 ++stats_dropped_frames;
503                                 pts_int += card_copy[0].new_frame_length;
504                         }
505                 }
506
507                 if (audio_level_callback != nullptr) {
508                         unique_lock<mutex> lock(r128_mutex);
509                         double loudness_s = r128.loudness_S();
510                         double loudness_i = r128.integrated();
511                         double loudness_range_low = r128.range_min();
512                         double loudness_range_high = r128.range_max();
513
514                         audio_level_callback(loudness_s, 20.0 * log10(peak),
515                                              loudness_i, loudness_range_low, loudness_range_high,
516                                              last_gain_staging_db);
517                 }
518
519                 for (unsigned card_index = 1; card_index < num_cards; ++card_index) {
520                         if (card_copy[card_index].new_data_ready && card_copy[card_index].new_frame->len == 0) {
521                                 ++card_copy[card_index].dropped_frames;
522                         }
523                         if (card_copy[card_index].dropped_frames > 0) {
524                                 printf("Card %u dropped %d frames before this\n",
525                                         card_index, int(card_copy[card_index].dropped_frames));
526                         }
527                 }
528
529                 // If the first card is reporting a corrupted or otherwise dropped frame,
530                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
531                 if (card_copy[0].new_frame->len == 0) {
532                         ++stats_dropped_frames;
533                         pts_int += card_copy[0].new_frame_length;
534                         continue;
535                 }
536
537                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
538                         CaptureCard *card = &card_copy[card_index];
539                         if (!card->new_data_ready || card->new_frame->len == 0)
540                                 continue;
541
542                         assert(card->new_frame != nullptr);
543                         insert_new_frame(card->new_frame, card->new_frame_field, card->new_frame_interlaced, card_index, &input_state);
544                         check_error();
545
546                         // The new texture might still be uploaded,
547                         // tell the GPU to wait until it's there.
548                         if (card->new_data_ready_fence) {
549                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
550                                 check_error();
551                                 glDeleteSync(card->new_data_ready_fence);
552                                 check_error();
553                         }
554                 }
555
556                 // Get the main chain from the theme, and set its state immediately.
557                 Theme::Chain theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT, input_state);
558                 EffectChain *chain = theme_main_chain.chain;
559                 theme_main_chain.setup_chain();
560                 //theme_main_chain.chain->enable_phase_timing(true);
561
562                 GLuint y_tex, cbcr_tex;
563                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
564                 assert(got_frame);
565
566                 // Render main chain.
567                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
568                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
569                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
570                 check_error();
571                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
572                 resource_pool->release_fbo(fbo);
573
574                 subsample_chroma(cbcr_full_tex, cbcr_tex);
575                 resource_pool->release_2d_texture(cbcr_full_tex);
576
577                 // Set the right state for rgba_tex.
578                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
579                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
580                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
581                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
582                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
583
584                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
585                 check_error();
586
587                 const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampling_queue.h. TODO: Make less hard-coded.
588                 h264_encoder->end_frame(fence, pts_int + av_delay, theme_main_chain.input_frames);
589                 ++frame;
590                 pts_int += card_copy[0].new_frame_length;
591
592                 // The live frame just shows the RGBA texture we just rendered.
593                 // It owns rgba_tex now.
594                 DisplayFrame live_frame;
595                 live_frame.chain = display_chain.get();
596                 live_frame.setup_chain = [this, rgba_tex]{
597                         display_input->set_texture_num(rgba_tex);
598                 };
599                 live_frame.ready_fence = fence;
600                 live_frame.input_frames = {};
601                 live_frame.temp_textures = { rgba_tex };
602                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
603
604                 // Set up preview and any additional channels.
605                 for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
606                         DisplayFrame display_frame;
607                         Theme::Chain chain = theme->get_chain(i, pts(), WIDTH, HEIGHT, input_state);  // FIXME: dimensions
608                         display_frame.chain = chain.chain;
609                         display_frame.setup_chain = chain.setup_chain;
610                         display_frame.ready_fence = fence;
611                         display_frame.input_frames = chain.input_frames;
612                         display_frame.temp_textures = {};
613                         output_channel[i].output_frame(display_frame);
614                 }
615
616                 clock_gettime(CLOCK_MONOTONIC, &now);
617                 double elapsed = now.tv_sec - start.tv_sec +
618                         1e-9 * (now.tv_nsec - start.tv_nsec);
619                 if (frame % 100 == 0) {
620                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
621                                 frame, stats_dropped_frames, elapsed, frame / elapsed,
622                                 1e3 * elapsed / frame);
623                 //      chain->print_phase_timing();
624                 }
625
626 #if 0
627                 // Reset every 100 frames, so that local variations in frame times
628                 // (especially for the first few frames, when the shaders are
629                 // compiled etc.) don't make it hard to measure for the entire
630                 // remaining duration of the program.
631                 if (frame == 10000) {
632                         frame = 0;
633                         start = now;
634                 }
635 #endif
636                 check_error();
637         }
638
639         resource_pool->clean_context();
640 }
641
642 void Mixer::audio_thread_func()
643 {
644         while (!should_quit) {
645                 AudioTask task;
646
647                 {
648                         unique_lock<mutex> lock(audio_mutex);
649                         audio_task_queue_changed.wait(lock, [this]{ return !audio_task_queue.empty(); });
650                         task = audio_task_queue.front();
651                         audio_task_queue.pop();
652                 }
653
654                 process_audio_one_frame(task.pts_int, task.num_samples);
655         }
656 }
657
658 void Mixer::process_audio_one_frame(int64_t frame_pts_int, int num_samples)
659 {
660         vector<float> samples_card;
661         vector<float> samples_out;
662         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
663                 samples_card.resize(num_samples * 2);
664                 {
665                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
666                         if (!cards[card_index].resampling_queue->get_output_samples(double(frame_pts_int) / TIMEBASE, &samples_card[0], num_samples)) {
667                                 printf("Card %d reported previous underrun.\n", card_index);
668                         }
669                 }
670                 // TODO: Allow using audio from the other card(s) as well.
671                 if (card_index == 0) {
672                         samples_out = move(samples_card);
673                 }
674         }
675
676         // Cut away everything under 120 Hz (or whatever the cutoff is);
677         // we don't need it for voice, and it will reduce headroom
678         // and confuse the compressor. (In particular, any hums at 50 or 60 Hz
679         // should be dampened.)
680         locut.render(samples_out.data(), samples_out.size() / 2, locut_cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY, 0.5f);
681
682         // Apply a level compressor to get the general level right.
683         // Basically, if it's over about -40 dBFS, we squeeze it down to that level
684         // (or more precisely, near it, since we don't use infinite ratio),
685         // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
686         // entirely arbitrary, but from practical tests with speech, it seems to
687         // put ut around -23 LUFS, so it's a reasonable starting point for later use.
688         float ref_level_dbfs = -14.0f;
689         {
690                 float threshold = 0.01f;   // -40 dBFS.
691                 float ratio = 20.0f;
692                 float attack_time = 0.5f;
693                 float release_time = 20.0f;
694                 float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
695                 level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
696                 last_gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
697         }
698
699 #if 0
700         printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
701                 level_compressor.get_level(), 20.0 * log10(level_compressor.get_level()),
702                 level_compressor.get_attenuation(), 20.0 * log10(level_compressor.get_attenuation()),
703                 20.0 * log10(level_compressor.get_level() * level_compressor.get_attenuation() * makeup_gain));
704 #endif
705
706 //      float limiter_att, compressor_att;
707
708         // The real compressor.
709         if (compressor_enabled) {
710                 float threshold = pow(10.0f, compressor_threshold_dbfs / 20.0f);
711                 float ratio = 20.0f;
712                 float attack_time = 0.005f;
713                 float release_time = 0.040f;
714                 float makeup_gain = 2.0f;  // +6 dB.
715                 compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
716 //              compressor_att = compressor.get_attenuation();
717         }
718
719         // Finally a limiter at -4 dB (so, -10 dBFS) to take out the worst peaks only.
720         // Note that since ratio is not infinite, we could go slightly higher than this.
721         if (limiter_enabled) {
722                 float threshold = pow(10.0f, limiter_threshold_dbfs / 20.0f);
723                 float ratio = 30.0f;
724                 float attack_time = 0.0f;  // Instant.
725                 float release_time = 0.020f;
726                 float makeup_gain = 1.0f;  // 0 dB.
727                 limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
728 //              limiter_att = limiter.get_attenuation();
729         }
730
731 //      printf("limiter=%+5.1f  compressor=%+5.1f\n", 20.0*log10(limiter_att), 20.0*log10(compressor_att));
732
733         // Upsample 4x to find interpolated peak.
734         peak_resampler.inp_data = samples_out.data();
735         peak_resampler.inp_count = samples_out.size() / 2;
736
737         vector<float> interpolated_samples_out;
738         interpolated_samples_out.resize(samples_out.size());
739         while (peak_resampler.inp_count > 0) {  // About four iterations.
740                 peak_resampler.out_data = &interpolated_samples_out[0];
741                 peak_resampler.out_count = interpolated_samples_out.size() / 2;
742                 peak_resampler.process();
743                 size_t out_stereo_samples = interpolated_samples_out.size() / 2 - peak_resampler.out_count;
744                 peak = max<float>(peak, find_peak(interpolated_samples_out.data(), out_stereo_samples * 2));
745         }
746
747         // Find R128 levels.
748         vector<float> left, right;
749         deinterleave_samples(samples_out, &left, &right);
750         float *ptrs[] = { left.data(), right.data() };
751         {
752                 unique_lock<mutex> lock(r128_mutex);
753                 r128.process(left.size(), ptrs);
754         }
755
756         // Send the samples to the sound card.
757         if (alsa) {
758                 alsa->write(samples_out);
759         }
760
761         // And finally add them to the output.
762         h264_encoder->add_audio(frame_pts_int, move(samples_out));
763 }
764
765 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
766 {
767         GLuint vao;
768         glGenVertexArrays(1, &vao);
769         check_error();
770
771         float vertices[] = {
772                 0.0f, 2.0f,
773                 0.0f, 0.0f,
774                 2.0f, 0.0f
775         };
776
777         glBindVertexArray(vao);
778         check_error();
779
780         // Extract Cb/Cr.
781         GLuint fbo = resource_pool->create_fbo(dst_tex);
782         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
783         glViewport(0, 0, WIDTH/2, HEIGHT/2);
784         check_error();
785
786         glUseProgram(cbcr_program_num);
787         check_error();
788
789         glActiveTexture(GL_TEXTURE0);
790         check_error();
791         glBindTexture(GL_TEXTURE_2D, src_tex);
792         check_error();
793         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
794         check_error();
795         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
796         check_error();
797         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
798         check_error();
799
800         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
801         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
802
803         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
804         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
805
806         glDrawArrays(GL_TRIANGLES, 0, 3);
807         check_error();
808
809         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
810         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
811
812         glUseProgram(0);
813         check_error();
814
815         resource_pool->release_fbo(fbo);
816         glDeleteVertexArrays(1, &vao);
817 }
818
819 void Mixer::release_display_frame(DisplayFrame *frame)
820 {
821         for (GLuint texnum : frame->temp_textures) {
822                 resource_pool->release_2d_texture(texnum);
823         }
824         frame->temp_textures.clear();
825         frame->ready_fence.reset();
826         frame->input_frames.clear();
827 }
828
829 void Mixer::start()
830 {
831         mixer_thread = thread(&Mixer::thread_func, this);
832         audio_thread = thread(&Mixer::audio_thread_func, this);
833 }
834
835 void Mixer::quit()
836 {
837         should_quit = true;
838         mixer_thread.join();
839         audio_thread.join();
840 }
841
842 void Mixer::transition_clicked(int transition_num)
843 {
844         theme->transition_clicked(transition_num, pts());
845 }
846
847 void Mixer::channel_clicked(int preview_num)
848 {
849         theme->channel_clicked(preview_num);
850 }
851
852 void Mixer::reset_meters()
853 {
854         peak_resampler.reset();
855         peak = 0.0f;
856         r128.reset();
857         r128.integr_start();
858 }
859
860 Mixer::OutputChannel::~OutputChannel()
861 {
862         if (has_current_frame) {
863                 parent->release_display_frame(&current_frame);
864         }
865         if (has_ready_frame) {
866                 parent->release_display_frame(&ready_frame);
867         }
868 }
869
870 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
871 {
872         // Store this frame for display. Remove the ready frame if any
873         // (it was seemingly never used).
874         {
875                 unique_lock<mutex> lock(frame_mutex);
876                 if (has_ready_frame) {
877                         parent->release_display_frame(&ready_frame);
878                 }
879                 ready_frame = frame;
880                 has_ready_frame = true;
881         }
882
883         if (has_new_frame_ready_callback) {
884                 new_frame_ready_callback();
885         }
886 }
887
888 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
889 {
890         unique_lock<mutex> lock(frame_mutex);
891         if (!has_current_frame && !has_ready_frame) {
892                 return false;
893         }
894
895         if (has_current_frame && has_ready_frame) {
896                 // We have a new ready frame. Toss the current one.
897                 parent->release_display_frame(&current_frame);
898                 has_current_frame = false;
899         }
900         if (has_ready_frame) {
901                 assert(!has_current_frame);
902                 current_frame = ready_frame;
903                 ready_frame.ready_fence.reset();  // Drop the refcount.
904                 ready_frame.input_frames.clear();  // Drop the refcounts.
905                 has_current_frame = true;
906                 has_ready_frame = false;
907         }
908
909         *frame = current_frame;
910         return true;
911 }
912
913 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
914 {
915         new_frame_ready_callback = callback;
916         has_new_frame_ready_callback = true;
917 }