]> git.sesse.net Git - nageru/blob - mixer.cpp
Add an option --flat-audio to start with almost all the audio processing turned off.
[nageru] / mixer.cpp
1 #undef Success
2
3 #include "mixer.h"
4
5 #include <assert.h>
6 #include <epoxy/egl.h>
7 #include <movit/effect_chain.h>
8 #include <movit/effect_util.h>
9 #include <movit/flat_input.h>
10 #include <movit/image_format.h>
11 #include <movit/init.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 #include <arpa/inet.h>
30
31 #include "bmusb/bmusb.h"
32 #include "context.h"
33 #include "decklink_capture.h"
34 #include "defs.h"
35 #include "flags.h"
36 #include "h264encode.h"
37 #include "pbo_frame_allocator.h"
38 #include "ref_counted_gl_sync.h"
39 #include "timebase.h"
40
41 class QOpenGLContext;
42
43 using namespace movit;
44 using namespace std;
45 using namespace std::placeholders;
46
47 Mixer *global_mixer = nullptr;
48
49 namespace {
50
51 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
52 {
53         assert(in_channels >= out_channels);
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 void convert_fixed32_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
67 {
68         assert(in_channels >= out_channels);
69         for (size_t i = 0; i < num_samples; ++i) {
70                 for (size_t j = 0; j < out_channels; ++j) {
71                         // Note: Assumes little-endian.
72                         int32_t s = *(int32_t *)src;
73                         dst[i * out_channels + j] = s * (1.0f / 4294967296.0f);
74                         src += 4;
75                 }
76                 src += 4 * (in_channels - out_channels);
77         }
78 }
79
80 void insert_new_frame(RefCountedFrame frame, unsigned field_num, bool interlaced, unsigned card_index, InputState *input_state)
81 {
82         if (interlaced) {
83                 for (unsigned frame_num = FRAME_HISTORY_LENGTH; frame_num --> 1; ) {  // :-)
84                         input_state->buffered_frames[card_index][frame_num] =
85                                 input_state->buffered_frames[card_index][frame_num - 1];
86                 }
87                 input_state->buffered_frames[card_index][0] = { frame, field_num };
88         } else {
89                 for (unsigned frame_num = 0; frame_num < FRAME_HISTORY_LENGTH; ++frame_num) {
90                         input_state->buffered_frames[card_index][frame_num] = { frame, field_num };
91                 }
92         }
93 }
94
95 string generate_local_dump_filename(int frame)
96 {
97         time_t now = time(NULL);
98         tm now_tm;
99         localtime_r(&now, &now_tm);
100
101         char timestamp[256];
102         strftime(timestamp, sizeof(timestamp), "%F-%T%z", &now_tm);
103
104         // Use the frame number to disambiguate between two cuts starting
105         // on the same second.
106         char filename[256];
107         snprintf(filename, sizeof(filename), "%s%s-f%02d%s",
108                 LOCAL_DUMP_PREFIX, timestamp, frame % 100, LOCAL_DUMP_SUFFIX);
109         return filename;
110 }
111
112 }  // namespace
113
114 void QueueLengthPolicy::update_policy(int queue_length)
115 {
116         if (queue_length < 0) {  // Starvation.
117                 if (been_at_safe_point_since_last_starvation && safe_queue_length < 5) {
118                         ++safe_queue_length;
119                         fprintf(stderr, "Card %u: Starvation, increasing safe limit to %u frames\n",
120                                 card_index, safe_queue_length);
121                 }
122                 frames_with_at_least_one = 0;
123                 been_at_safe_point_since_last_starvation = false;
124                 return;
125         }
126         if (queue_length > 0) {
127                 if (queue_length >= int(safe_queue_length)) {
128                         been_at_safe_point_since_last_starvation = true;
129                 }
130                 if (++frames_with_at_least_one >= 50 && safe_queue_length > 0) {
131                         --safe_queue_length;
132                         fprintf(stderr, "Card %u: Spare frames for more than 50 frames, reducing safe limit to %u frames\n",
133                                 card_index, safe_queue_length);
134                         frames_with_at_least_one = 0;
135                 }
136         } else {
137                 frames_with_at_least_one = 0;
138         }
139 }
140
141 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
142         : httpd(WIDTH, HEIGHT),
143           num_cards(num_cards),
144           mixer_surface(create_surface(format)),
145           h264_encoder_surface(create_surface(format)),
146           correlation(OUTPUT_FREQUENCY),
147           level_compressor(OUTPUT_FREQUENCY),
148           limiter(OUTPUT_FREQUENCY),
149           compressor(OUTPUT_FREQUENCY)
150 {
151         httpd.open_output_file(generate_local_dump_filename(/*frame=*/0).c_str());
152         httpd.start(9095);
153
154         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
155         check_error();
156
157         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
158         // will be halved when sampling them, and we need to compensate here.
159         movit_texel_subpixel_precision /= 2.0;
160
161         resource_pool.reset(new ResourcePool);
162         theme.reset(new Theme(global_flags.theme_filename.c_str(), resource_pool.get(), num_cards));
163         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
164                 output_channel[i].parent = this;
165         }
166
167         ImageFormat inout_format;
168         inout_format.color_space = COLORSPACE_sRGB;
169         inout_format.gamma_curve = GAMMA_sRGB;
170
171         // Display chain; shows the live output produced by the main chain (its RGBA version).
172         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
173         check_error();
174         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
175         display_chain->add_input(display_input);
176         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
177         display_chain->set_dither_bits(0);  // Don't bother.
178         display_chain->finalize();
179
180         h264_encoder.reset(new H264Encoder(h264_encoder_surface, global_flags.va_display, WIDTH, HEIGHT, &httpd));
181
182         // First try initializing the PCI devices, then USB, until we have the desired number of cards.
183         unsigned num_pci_devices = 0, num_usb_devices = 0;
184         unsigned card_index = 0;
185
186         IDeckLinkIterator *decklink_iterator = CreateDeckLinkIteratorInstance();
187         if (decklink_iterator != nullptr) {
188                 for ( ; card_index < num_cards; ++card_index) {
189                         IDeckLink *decklink;
190                         if (decklink_iterator->Next(&decklink) != S_OK) {
191                                 break;
192                         }
193
194                         configure_card(card_index, format, new DeckLinkCapture(decklink, card_index));
195                         ++num_pci_devices;
196                 }
197                 decklink_iterator->Release();
198                 fprintf(stderr, "Found %d DeckLink PCI card(s).\n", num_pci_devices);
199         } else {
200                 fprintf(stderr, "DeckLink drivers not found. Probing for USB cards only.\n");
201         }
202         for ( ; card_index < num_cards; ++card_index) {
203                 configure_card(card_index, format, new BMUSBCapture(card_index - num_pci_devices));
204                 ++num_usb_devices;
205         }
206
207         if (num_usb_devices > 0) {
208                 BMUSBCapture::start_bm_thread();
209         }
210
211         for (card_index = 0; card_index < num_cards; ++card_index) {
212                 cards[card_index].queue_length_policy.reset(card_index);
213                 cards[card_index].capture->start_bm_capture();
214         }
215
216         // Set up stuff for NV12 conversion.
217
218         // Cb/Cr shader.
219         string cbcr_vert_shader =
220                 "#version 130 \n"
221                 " \n"
222                 "in vec2 position; \n"
223                 "in vec2 texcoord; \n"
224                 "out vec2 tc0; \n"
225                 "uniform vec2 foo_chroma_offset_0; \n"
226                 " \n"
227                 "void main() \n"
228                 "{ \n"
229                 "    // The result of glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0) is: \n"
230                 "    // \n"
231                 "    //   2.000  0.000  0.000 -1.000 \n"
232                 "    //   0.000  2.000  0.000 -1.000 \n"
233                 "    //   0.000  0.000 -2.000 -1.000 \n"
234                 "    //   0.000  0.000  0.000  1.000 \n"
235                 "    gl_Position = vec4(2.0 * position.x - 1.0, 2.0 * position.y - 1.0, -1.0, 1.0); \n"
236                 "    vec2 flipped_tc = texcoord; \n"
237                 "    tc0 = flipped_tc + foo_chroma_offset_0; \n"
238                 "} \n";
239         string cbcr_frag_shader =
240                 "#version 130 \n"
241                 "in vec2 tc0; \n"
242                 "uniform sampler2D cbcr_tex; \n"
243                 "out vec4 FragColor; \n"
244                 "void main() { \n"
245                 "    FragColor = texture(cbcr_tex, tc0); \n"
246                 "} \n";
247         vector<string> frag_shader_outputs;
248         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader, frag_shader_outputs);
249
250         float vertices[] = {
251                 0.0f, 2.0f,
252                 0.0f, 0.0f,
253                 2.0f, 0.0f
254         };
255         cbcr_vbo = generate_vbo(2, GL_FLOAT, sizeof(vertices), vertices);
256         cbcr_position_attribute_index = glGetAttribLocation(cbcr_program_num, "position");
257         cbcr_texcoord_attribute_index = glGetAttribLocation(cbcr_program_num, "texcoord");
258
259         r128.init(2, OUTPUT_FREQUENCY);
260         r128.integr_start();
261
262         locut.init(FILTER_HPF, 2);
263
264         // If --flat-audio is given, turn off everything that messes with the sound,
265         // except the final makeup gain.
266         if (global_flags.flat_audio) {
267                 set_locut_enabled(false);
268                 set_limiter_enabled(false);
269                 set_compressor_enabled(false);
270         }
271
272         // hlen=16 is pretty low quality, but we use quite a bit of CPU otherwise,
273         // and there's a limit to how important the peak meter is.
274         peak_resampler.setup(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY * 4, /*num_channels=*/2, /*hlen=*/16, /*frel=*/1.0);
275
276         alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
277 }
278
279 Mixer::~Mixer()
280 {
281         resource_pool->release_glsl_program(cbcr_program_num);
282         glDeleteBuffers(1, &cbcr_vbo);
283         BMUSBCapture::stop_bm_thread();
284
285         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
286                 {
287                         unique_lock<mutex> lock(bmusb_mutex);
288                         cards[card_index].should_quit = true;  // Unblock thread.
289                         cards[card_index].new_frames_changed.notify_all();
290                 }
291                 cards[card_index].capture->stop_dequeue_thread();
292         }
293
294         h264_encoder.reset(nullptr);
295 }
296
297 void Mixer::configure_card(unsigned card_index, const QSurfaceFormat &format, CaptureInterface *capture)
298 {
299         printf("Configuring card %d...\n", card_index);
300
301         CaptureCard *card = &cards[card_index];
302         card->capture = capture;
303         card->capture->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
304         card->frame_allocator.reset(new PBOFrameAllocator(8 << 20, WIDTH, HEIGHT));  // 8 MB.
305         card->capture->set_video_frame_allocator(card->frame_allocator.get());
306         card->surface = create_surface(format);
307         card->capture->set_dequeue_thread_callbacks(
308                 [card]{
309                         eglBindAPI(EGL_OPENGL_API);
310                         card->context = create_context(card->surface);
311                         if (!make_current(card->context, card->surface)) {
312                                 printf("failed to create bmusb context\n");
313                                 exit(1);
314                         }
315                 },
316                 [this]{
317                         resource_pool->clean_context();
318                 });
319         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
320         card->capture->configure_card();
321 }
322
323
324 namespace {
325
326 int unwrap_timecode(uint16_t current_wrapped, int last)
327 {
328         uint16_t last_wrapped = last & 0xffff;
329         if (current_wrapped > last_wrapped) {
330                 return (last & ~0xffff) | current_wrapped;
331         } else {
332                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
333         }
334 }
335
336 float find_peak(const float *samples, size_t num_samples)
337 {
338         float m = fabs(samples[0]);
339         for (size_t i = 1; i < num_samples; ++i) {
340                 m = max(m, fabs(samples[i]));
341         }
342         return m;
343 }
344
345 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
346 {
347         size_t num_samples = in.size() / 2;
348         out_l->resize(num_samples);
349         out_r->resize(num_samples);
350
351         const float *inptr = in.data();
352         float *lptr = &(*out_l)[0];
353         float *rptr = &(*out_r)[0];
354         for (size_t i = 0; i < num_samples; ++i) {
355                 *lptr++ = *inptr++;
356                 *rptr++ = *inptr++;
357         }
358 }
359
360 }  // namespace
361
362 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
363                      FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
364                      FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)
365 {
366         CaptureCard *card = &cards[card_index];
367
368         if (is_mode_scanning[card_index]) {
369                 if (video_format.has_signal) {
370                         // Found a stable signal, so stop scanning.
371                         is_mode_scanning[card_index] = false;
372                 } else {
373                         static constexpr double switch_time_s = 0.5;  // Should be enough time for the signal to stabilize.
374                         timespec now;
375                         clock_gettime(CLOCK_MONOTONIC, &now);
376                         double sec_since_last_switch = (now.tv_sec - last_mode_scan_change[card_index].tv_sec) +
377                                 1e-9 * (now.tv_nsec - last_mode_scan_change[card_index].tv_nsec);
378                         if (sec_since_last_switch > switch_time_s) {
379                                 // It isn't this mode; try the next one.
380                                 mode_scanlist_index[card_index]++;
381                                 mode_scanlist_index[card_index] %= mode_scanlist[card_index].size();
382                                 cards[card_index].capture->set_video_mode(mode_scanlist[card_index][mode_scanlist_index[card_index]]);
383                                 last_mode_scan_change[card_index] = now;
384                         }
385                 }
386         }
387
388         int64_t frame_length = int64_t(TIMEBASE * video_format.frame_rate_den) / video_format.frame_rate_nom;
389
390         size_t num_samples = (audio_frame.len > audio_offset) ? (audio_frame.len - audio_offset) / audio_format.num_channels / (audio_format.bits_per_sample / 8) : 0;
391         if (num_samples > OUTPUT_FREQUENCY / 10) {
392                 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",
393                         card_index, int(audio_frame.len), int(audio_offset),
394                         timecode, int(video_frame.len), int(video_offset), video_format.id);
395                 if (video_frame.owner) {
396                         video_frame.owner->release_frame(video_frame);
397                 }
398                 if (audio_frame.owner) {
399                         audio_frame.owner->release_frame(audio_frame);
400                 }
401                 return;
402         }
403
404         int64_t local_pts = card->next_local_pts;
405         int dropped_frames = 0;
406         if (card->last_timecode != -1) {
407                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
408         }
409
410         // Convert the audio to stereo fp32 and add it.
411         vector<float> audio;
412         audio.resize(num_samples * 2);
413         switch (audio_format.bits_per_sample) {
414         case 0:
415                 assert(num_samples == 0);
416                 break;
417         case 24:
418                 convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, audio_format.num_channels, num_samples);
419                 break;
420         case 32:
421                 convert_fixed32_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, audio_format.num_channels, num_samples);
422                 break;
423         default:
424                 fprintf(stderr, "Cannot handle audio with %u bits per sample\n", audio_format.bits_per_sample);
425                 assert(false);
426         }
427
428         // Add the audio.
429         {
430                 unique_lock<mutex> lock(card->audio_mutex);
431
432                 // Number of samples per frame if we need to insert silence.
433                 // (Could be nonintegral, but resampling will save us then.)
434                 int silence_samples = OUTPUT_FREQUENCY * video_format.frame_rate_den / video_format.frame_rate_nom;
435
436                 if (dropped_frames > MAX_FPS * 2) {
437                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around; from 0x%04x to 0x%04x), resetting resampler\n",
438                                 card_index, card->last_timecode, timecode);
439                         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
440                         dropped_frames = 0;
441                 } else if (dropped_frames > 0) {
442                         // Insert silence as needed.
443                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
444                                 card_index, dropped_frames, timecode);
445                         vector<float> silence(silence_samples * 2, 0.0f);
446                         for (int i = 0; i < dropped_frames; ++i) {
447                                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), silence.data(), silence_samples);
448                                 // Note that if the format changed in the meantime, we have
449                                 // no way of detecting that; we just have to assume the frame length
450                                 // is always the same.
451                                 local_pts += frame_length;
452                         }
453                 }
454                 if (num_samples == 0) {
455                         audio.resize(silence_samples * 2);
456                         num_samples = silence_samples;
457                 }
458                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), audio.data(), num_samples);
459                 card->next_local_pts = local_pts + frame_length;
460         }
461
462         card->last_timecode = timecode;
463
464         // Done with the audio, so release it.
465         if (audio_frame.owner) {
466                 audio_frame.owner->release_frame(audio_frame);
467         }
468
469         size_t expected_length = video_format.width * (video_format.height + video_format.extra_lines_top + video_format.extra_lines_bottom) * 2;
470         if (video_frame.len - video_offset == 0 ||
471             video_frame.len - video_offset != expected_length) {
472                 if (video_frame.len != 0) {
473                         printf("Card %d: Dropping video frame with wrong length (%ld; expected %ld)\n",
474                                 card_index, video_frame.len - video_offset, expected_length);
475                 }
476                 if (video_frame.owner) {
477                         video_frame.owner->release_frame(video_frame);
478                 }
479
480                 // Still send on the information that we _had_ a frame, even though it's corrupted,
481                 // so that pts can go up accordingly.
482                 {
483                         unique_lock<mutex> lock(bmusb_mutex);
484                         CaptureCard::NewFrame new_frame;
485                         new_frame.frame = RefCountedFrame(FrameAllocator::Frame());
486                         new_frame.length = frame_length;
487                         new_frame.interlaced = false;
488                         new_frame.dropped_frames = dropped_frames;
489                         card->new_frames.push(move(new_frame));
490                         card->new_frames_changed.notify_all();
491                 }
492                 return;
493         }
494
495         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
496
497         unsigned num_fields = video_format.interlaced ? 2 : 1;
498         timespec frame_upload_start;
499         if (video_format.interlaced) {
500                 // Send the two fields along as separate frames; the other side will need to add
501                 // a deinterlacer to actually get this right.
502                 assert(video_format.height % 2 == 0);
503                 video_format.height /= 2;
504                 assert(frame_length % 2 == 0);
505                 frame_length /= 2;
506                 num_fields = 2;
507                 clock_gettime(CLOCK_MONOTONIC, &frame_upload_start);
508         }
509         userdata->last_interlaced = video_format.interlaced;
510         userdata->last_has_signal = video_format.has_signal;
511         userdata->last_frame_rate_nom = video_format.frame_rate_nom;
512         userdata->last_frame_rate_den = video_format.frame_rate_den;
513         RefCountedFrame frame(video_frame);
514
515         // Upload the textures.
516         size_t cbcr_width = video_format.width / 2;
517         size_t cbcr_offset = video_offset / 2;
518         size_t y_offset = video_frame.size / 2 + video_offset / 2;
519
520         for (unsigned field = 0; field < num_fields; ++field) {
521                 unsigned field_start_line = (field == 1) ? video_format.second_field_start : video_format.extra_lines_top + field * (video_format.height + 22);
522
523                 if (userdata->tex_y[field] == 0 ||
524                     userdata->tex_cbcr[field] == 0 ||
525                     video_format.width != userdata->last_width[field] ||
526                     video_format.height != userdata->last_height[field]) {
527                         // We changed resolution since last use of this texture, so we need to create
528                         // a new object. Note that this each card has its own PBOFrameAllocator,
529                         // we don't need to worry about these flip-flopping between resolutions.
530                         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
531                         check_error();
532                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, cbcr_width, video_format.height, 0, GL_RG, GL_UNSIGNED_BYTE, nullptr);
533                         check_error();
534                         glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
535                         check_error();
536                         glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, video_format.width, video_format.height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
537                         check_error();
538                         userdata->last_width[field] = video_format.width;
539                         userdata->last_height[field] = video_format.height;
540                 }
541
542                 GLuint pbo = userdata->pbo;
543                 check_error();
544                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo);
545                 check_error();
546                 glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
547                 check_error();
548
549                 glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
550                 check_error();
551                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, cbcr_width, video_format.height, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cbcr_offset + cbcr_width * field_start_line * sizeof(uint16_t)));
552                 check_error();
553                 glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
554                 check_error();
555                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, video_format.width, video_format.height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(y_offset + video_format.width * field_start_line));
556                 check_error();
557                 glBindTexture(GL_TEXTURE_2D, 0);
558                 check_error();
559                 glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
560                 check_error();
561                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
562                 check_error();
563                 assert(fence.get() != nullptr);
564
565                 if (field == 1) {
566                         // Don't upload the second field as fast as we can; wait until
567                         // the field time has approximately passed. (Otherwise, we could
568                         // get timing jitter against the other sources, and possibly also
569                         // against the video display, although the latter is not as critical.)
570                         // This requires our system clock to be reasonably close to the
571                         // video clock, but that's not an unreasonable assumption.
572                         timespec second_field_start;
573                         second_field_start.tv_nsec = frame_upload_start.tv_nsec +
574                                 frame_length * 1000000000 / TIMEBASE;
575                         second_field_start.tv_sec = frame_upload_start.tv_sec +
576                                 second_field_start.tv_nsec / 1000000000;
577                         second_field_start.tv_nsec %= 1000000000;
578
579                         while (clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME,
580                                                &second_field_start, nullptr) == -1 &&
581                                errno == EINTR) ;
582                 }
583
584                 {
585                         unique_lock<mutex> lock(bmusb_mutex);
586                         CaptureCard::NewFrame new_frame;
587                         new_frame.frame = frame;
588                         new_frame.length = frame_length;
589                         new_frame.field = field;
590                         new_frame.interlaced = video_format.interlaced;
591                         new_frame.ready_fence = fence;
592                         new_frame.dropped_frames = dropped_frames;
593                         card->new_frames.push(move(new_frame));
594                         card->new_frames_changed.notify_all();
595                 }
596         }
597 }
598
599 void Mixer::thread_func()
600 {
601         eglBindAPI(EGL_OPENGL_API);
602         QOpenGLContext *context = create_context(mixer_surface);
603         if (!make_current(context, mixer_surface)) {
604                 printf("oops\n");
605                 exit(1);
606         }
607
608         struct timespec start, now;
609         clock_gettime(CLOCK_MONOTONIC, &start);
610
611         int frame = 0;
612         int stats_dropped_frames = 0;
613
614         while (!should_quit) {
615                 CaptureCard::NewFrame new_frames[MAX_CARDS];
616                 bool has_new_frame[MAX_CARDS] = { false };
617                 int num_samples[MAX_CARDS] = { 0 };
618
619                 // TODO: Add a timeout.
620                 unsigned master_card_index = theme->map_signal(master_clock_channel);
621                 assert(master_card_index < num_cards);
622
623                 get_one_frame_from_each_card(master_card_index, new_frames, has_new_frame, num_samples);
624                 schedule_audio_resampling_tasks(new_frames[master_card_index].dropped_frames, num_samples[master_card_index], new_frames[master_card_index].length);
625                 stats_dropped_frames += new_frames[master_card_index].dropped_frames;
626                 send_audio_level_callback();
627
628                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
629                         if (card_index == master_card_index || !has_new_frame[card_index]) {
630                                 continue;
631                         }
632                         if (new_frames[card_index].frame->len == 0) {
633                                 ++new_frames[card_index].dropped_frames;
634                         }
635                         if (new_frames[card_index].dropped_frames > 0) {
636                                 printf("Card %u dropped %d frames before this\n",
637                                         card_index, int(new_frames[card_index].dropped_frames));
638                         }
639                 }
640
641                 // If the first card is reporting a corrupted or otherwise dropped frame,
642                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
643                 if (new_frames[master_card_index].frame->len == 0) {
644                         ++stats_dropped_frames;
645                         pts_int += new_frames[master_card_index].length;
646                         continue;
647                 }
648
649                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
650                         if (!has_new_frame[card_index] || new_frames[card_index].frame->len == 0)
651                                 continue;
652
653                         CaptureCard::NewFrame *new_frame = &new_frames[card_index];
654                         assert(new_frame->frame != nullptr);
655                         insert_new_frame(new_frame->frame, new_frame->field, new_frame->interlaced, card_index, &input_state);
656                         check_error();
657
658                         // The new texture might still be uploaded,
659                         // tell the GPU to wait until it's there.
660                         if (new_frame->ready_fence) {
661                                 glWaitSync(new_frame->ready_fence.get(), /*flags=*/0, GL_TIMEOUT_IGNORED);
662                                 check_error();
663                                 new_frame->ready_fence.reset();
664                                 check_error();
665                         }
666                 }
667
668                 render_one_frame();
669                 ++frame;
670                 pts_int += new_frames[master_card_index].length;
671
672                 clock_gettime(CLOCK_MONOTONIC, &now);
673                 double elapsed = now.tv_sec - start.tv_sec +
674                         1e-9 * (now.tv_nsec - start.tv_nsec);
675                 if (frame % 100 == 0) {
676                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
677                                 frame, stats_dropped_frames, elapsed, frame / elapsed,
678                                 1e3 * elapsed / frame);
679                 //      chain->print_phase_timing();
680                 }
681
682                 if (should_cut.exchange(false)) {  // Test and clear.
683                         string filename = generate_local_dump_filename(frame);
684                         printf("Starting new recording: %s\n", filename.c_str());
685                         h264_encoder->shutdown();
686                         httpd.close_output_file();
687                         httpd.open_output_file(filename.c_str());
688                         h264_encoder.reset(new H264Encoder(h264_encoder_surface, global_flags.va_display, WIDTH, HEIGHT, &httpd));
689                 }
690
691 #if 0
692                 // Reset every 100 frames, so that local variations in frame times
693                 // (especially for the first few frames, when the shaders are
694                 // compiled etc.) don't make it hard to measure for the entire
695                 // remaining duration of the program.
696                 if (frame == 10000) {
697                         frame = 0;
698                         start = now;
699                 }
700 #endif
701                 check_error();
702         }
703
704         resource_pool->clean_context();
705 }
706
707 void Mixer::get_one_frame_from_each_card(unsigned master_card_index, CaptureCard::NewFrame new_frames[MAX_CARDS], bool has_new_frame[MAX_CARDS], int num_samples[MAX_CARDS])
708 {
709         // The first card is the master timer, so wait for it to have a new frame.
710         unique_lock<mutex> lock(bmusb_mutex);
711         cards[master_card_index].new_frames_changed.wait(lock, [this, master_card_index]{ return !cards[master_card_index].new_frames.empty(); });
712
713         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
714                 CaptureCard *card = &cards[card_index];
715                 if (card->new_frames.empty()) {
716                         assert(card_index != master_card_index);
717                         card->queue_length_policy.update_policy(-1);
718                         continue;
719                 }
720                 new_frames[card_index] = move(card->new_frames.front());
721                 has_new_frame[card_index] = true;
722                 card->new_frames.pop();
723                 card->new_frames_changed.notify_all();
724
725                 int num_samples_times_timebase = OUTPUT_FREQUENCY * new_frames[card_index].length + card->fractional_samples;
726                 num_samples[card_index] = num_samples_times_timebase / TIMEBASE;
727                 card->fractional_samples = num_samples_times_timebase % TIMEBASE;
728                 assert(num_samples[card_index] >= 0);
729
730                 if (card_index == master_card_index) {
731                         // We don't use the queue length policy for the master card,
732                         // but we will if it stops being the master. Thus, clear out
733                         // the policy in case we switch in the future.
734                         card->queue_length_policy.reset(card_index);
735                 } else {
736                         // If we have excess frames compared to the policy for this card,
737                         // drop frames from the head.
738                         card->queue_length_policy.update_policy(card->new_frames.size());
739                         while (card->new_frames.size() > card->queue_length_policy.get_safe_queue_length()) {
740                                 card->new_frames.pop();
741                         }
742                 }
743         }
744 }
745
746 void Mixer::schedule_audio_resampling_tasks(unsigned dropped_frames, int num_samples_per_frame, int length_per_frame)
747 {
748         // Resample the audio as needed, including from previously dropped frames.
749         assert(num_cards > 0);
750         for (unsigned frame_num = 0; frame_num < dropped_frames + 1; ++frame_num) {
751                 {
752                         // Signal to the audio thread to process this frame.
753                         unique_lock<mutex> lock(audio_mutex);
754                         audio_task_queue.push(AudioTask{pts_int, num_samples_per_frame});
755                         audio_task_queue_changed.notify_one();
756                 }
757                 if (frame_num != dropped_frames) {
758                         // For dropped frames, increase the pts. Note that if the format changed
759                         // in the meantime, we have no way of detecting that; we just have to
760                         // assume the frame length is always the same.
761                         pts_int += length_per_frame;
762                 }
763         }
764 }
765
766 void Mixer::render_one_frame()
767 {
768         // Get the main chain from the theme, and set its state immediately.
769         Theme::Chain theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT, input_state);
770         EffectChain *chain = theme_main_chain.chain;
771         theme_main_chain.setup_chain();
772         //theme_main_chain.chain->enable_phase_timing(true);
773
774         GLuint y_tex, cbcr_tex;
775         bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
776         assert(got_frame);
777
778         // Render main chain.
779         GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
780         GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
781         GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
782         check_error();
783         chain->render_to_fbo(fbo, WIDTH, HEIGHT);
784         resource_pool->release_fbo(fbo);
785
786         subsample_chroma(cbcr_full_tex, cbcr_tex);
787         resource_pool->release_2d_texture(cbcr_full_tex);
788
789         // Set the right state for rgba_tex.
790         glBindFramebuffer(GL_FRAMEBUFFER, 0);
791         glBindTexture(GL_TEXTURE_2D, rgba_tex);
792         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
793         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
794         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
795
796         RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
797         check_error();
798
799         const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampling_queue.h. TODO: Make less hard-coded.
800         h264_encoder->end_frame(fence, pts_int + av_delay, theme_main_chain.input_frames);
801
802         // The live frame just shows the RGBA texture we just rendered.
803         // It owns rgba_tex now.
804         DisplayFrame live_frame;
805         live_frame.chain = display_chain.get();
806         live_frame.setup_chain = [this, rgba_tex]{
807                 display_input->set_texture_num(rgba_tex);
808         };
809         live_frame.ready_fence = fence;
810         live_frame.input_frames = {};
811         live_frame.temp_textures = { rgba_tex };
812         output_channel[OUTPUT_LIVE].output_frame(live_frame);
813
814         // Set up preview and any additional channels.
815         for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
816                 DisplayFrame display_frame;
817                 Theme::Chain chain = theme->get_chain(i, pts(), WIDTH, HEIGHT, input_state);  // FIXME: dimensions
818                 display_frame.chain = chain.chain;
819                 display_frame.setup_chain = chain.setup_chain;
820                 display_frame.ready_fence = fence;
821                 display_frame.input_frames = chain.input_frames;
822                 display_frame.temp_textures = {};
823                 output_channel[i].output_frame(display_frame);
824         }
825 }
826
827 void Mixer::send_audio_level_callback()
828 {
829         if (audio_level_callback == nullptr) {
830                 return;
831         }
832
833         unique_lock<mutex> lock(compressor_mutex);
834         double loudness_s = r128.loudness_S();
835         double loudness_i = r128.integrated();
836         double loudness_range_low = r128.range_min();
837         double loudness_range_high = r128.range_max();
838
839         audio_level_callback(loudness_s, 20.0 * log10(peak),
840                 loudness_i, loudness_range_low, loudness_range_high,
841                 gain_staging_db, 20.0 * log10(final_makeup_gain),
842                 correlation.get_correlation());
843 }
844
845 void Mixer::audio_thread_func()
846 {
847         while (!should_quit) {
848                 AudioTask task;
849
850                 {
851                         unique_lock<mutex> lock(audio_mutex);
852                         audio_task_queue_changed.wait(lock, [this]{ return !audio_task_queue.empty(); });
853                         task = audio_task_queue.front();
854                         audio_task_queue.pop();
855                 }
856
857                 process_audio_one_frame(task.pts_int, task.num_samples);
858         }
859 }
860
861 void Mixer::process_audio_one_frame(int64_t frame_pts_int, int num_samples)
862 {
863         vector<float> samples_card;
864         vector<float> samples_out;
865
866         // TODO: Allow mixing audio from several sources.
867         unsigned selected_audio_card = theme->map_signal(audio_source_channel);
868         assert(selected_audio_card < num_cards);
869
870         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
871                 samples_card.resize(num_samples * 2);
872                 {
873                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
874                         if (!cards[card_index].resampling_queue->get_output_samples(double(frame_pts_int) / TIMEBASE, &samples_card[0], num_samples)) {
875                                 printf("Card %d reported previous underrun.\n", card_index);
876                         }
877                 }
878                 if (card_index == selected_audio_card) {
879                         samples_out = move(samples_card);
880                 }
881         }
882
883         // Cut away everything under 120 Hz (or whatever the cutoff is);
884         // we don't need it for voice, and it will reduce headroom
885         // and confuse the compressor. (In particular, any hums at 50 or 60 Hz
886         // should be dampened.)
887         if (locut_enabled) {
888                 locut.render(samples_out.data(), samples_out.size() / 2, locut_cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY, 0.5f);
889         }
890
891         // Apply a level compressor to get the general level right.
892         // Basically, if it's over about -40 dBFS, we squeeze it down to that level
893         // (or more precisely, near it, since we don't use infinite ratio),
894         // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
895         // entirely arbitrary, but from practical tests with speech, it seems to
896         // put ut around -23 LUFS, so it's a reasonable starting point for later use.
897         {
898                 unique_lock<mutex> lock(compressor_mutex);
899                 if (level_compressor_enabled) {
900                         float threshold = 0.01f;   // -40 dBFS.
901                         float ratio = 20.0f;
902                         float attack_time = 0.5f;
903                         float release_time = 20.0f;
904                         float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
905                         level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
906                         gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
907                 } else {
908                         // Just apply the gain we already had.
909                         float g = pow(10.0f, gain_staging_db / 20.0f);
910                         for (size_t i = 0; i < samples_out.size(); ++i) {
911                                 samples_out[i] *= g;
912                         }
913                 }
914         }
915
916 #if 0
917         printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
918                 level_compressor.get_level(), 20.0 * log10(level_compressor.get_level()),
919                 level_compressor.get_attenuation(), 20.0 * log10(level_compressor.get_attenuation()),
920                 20.0 * log10(level_compressor.get_level() * level_compressor.get_attenuation() * makeup_gain));
921 #endif
922
923 //      float limiter_att, compressor_att;
924
925         // The real compressor.
926         if (compressor_enabled) {
927                 float threshold = pow(10.0f, compressor_threshold_dbfs / 20.0f);
928                 float ratio = 20.0f;
929                 float attack_time = 0.005f;
930                 float release_time = 0.040f;
931                 float makeup_gain = 2.0f;  // +6 dB.
932                 compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
933 //              compressor_att = compressor.get_attenuation();
934         }
935
936         // Finally a limiter at -4 dB (so, -10 dBFS) to take out the worst peaks only.
937         // Note that since ratio is not infinite, we could go slightly higher than this.
938         if (limiter_enabled) {
939                 float threshold = pow(10.0f, limiter_threshold_dbfs / 20.0f);
940                 float ratio = 30.0f;
941                 float attack_time = 0.0f;  // Instant.
942                 float release_time = 0.020f;
943                 float makeup_gain = 1.0f;  // 0 dB.
944                 limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
945 //              limiter_att = limiter.get_attenuation();
946         }
947
948 //      printf("limiter=%+5.1f  compressor=%+5.1f\n", 20.0*log10(limiter_att), 20.0*log10(compressor_att));
949
950         // Upsample 4x to find interpolated peak.
951         peak_resampler.inp_data = samples_out.data();
952         peak_resampler.inp_count = samples_out.size() / 2;
953
954         vector<float> interpolated_samples_out;
955         interpolated_samples_out.resize(samples_out.size());
956         while (peak_resampler.inp_count > 0) {  // About four iterations.
957                 peak_resampler.out_data = &interpolated_samples_out[0];
958                 peak_resampler.out_count = interpolated_samples_out.size() / 2;
959                 peak_resampler.process();
960                 size_t out_stereo_samples = interpolated_samples_out.size() / 2 - peak_resampler.out_count;
961                 peak = max<float>(peak, find_peak(interpolated_samples_out.data(), out_stereo_samples * 2));
962                 peak_resampler.out_data = nullptr;
963         }
964
965         // At this point, we are most likely close to +0 LU, but all of our
966         // measurements have been on raw sample values, not R128 values.
967         // So we have a final makeup gain to get us to +0 LU; the gain
968         // adjustments required should be relatively small, and also, the
969         // offset shouldn't change much (only if the type of audio changes
970         // significantly). Thus, we shoot for updating this value basically
971         // “whenever we process buffers”, since the R128 calculation isn't exactly
972         // something we get out per-sample.
973         //
974         // Note that there's a feedback loop here, so we choose a very slow filter
975         // (half-time of 100 seconds).
976         double target_loudness_factor, alpha;
977         {
978                 unique_lock<mutex> lock(compressor_mutex);
979                 double loudness_lu = r128.loudness_M() - ref_level_lufs;
980                 double current_makeup_lu = 20.0f * log10(final_makeup_gain);
981                 target_loudness_factor = pow(10.0f, -loudness_lu / 20.0f);
982
983                 // If we're outside +/- 5 LU uncorrected, we don't count it as
984                 // a normal signal (probably silence) and don't change the
985                 // correction factor; just apply what we already have.
986                 if (fabs(loudness_lu - current_makeup_lu) >= 5.0 || !final_makeup_gain_auto) {
987                         alpha = 0.0;
988                 } else {
989                         // Formula adapted from
990                         // https://en.wikipedia.org/wiki/Low-pass_filter#Simple_infinite_impulse_response_filter.
991                         const double half_time_s = 100.0;
992                         const double fc_mul_2pi_delta_t = 1.0 / (half_time_s * OUTPUT_FREQUENCY);
993                         alpha = fc_mul_2pi_delta_t / (fc_mul_2pi_delta_t + 1.0);
994                 }
995
996                 double m = final_makeup_gain;
997                 for (size_t i = 0; i < samples_out.size(); i += 2) {
998                         samples_out[i + 0] *= m;
999                         samples_out[i + 1] *= m;
1000                         m += (target_loudness_factor - m) * alpha;
1001                 }
1002                 final_makeup_gain = m;
1003         }
1004
1005         // Find R128 levels and L/R correlation.
1006         vector<float> left, right;
1007         deinterleave_samples(samples_out, &left, &right);
1008         float *ptrs[] = { left.data(), right.data() };
1009         {
1010                 unique_lock<mutex> lock(compressor_mutex);
1011                 r128.process(left.size(), ptrs);
1012                 correlation.process_samples(samples_out);
1013         }
1014
1015         // Send the samples to the sound card.
1016         if (alsa) {
1017                 alsa->write(samples_out);
1018         }
1019
1020         // And finally add them to the output.
1021         h264_encoder->add_audio(frame_pts_int, move(samples_out));
1022 }
1023
1024 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
1025 {
1026         GLuint vao;
1027         glGenVertexArrays(1, &vao);
1028         check_error();
1029
1030         glBindVertexArray(vao);
1031         check_error();
1032
1033         // Extract Cb/Cr.
1034         GLuint fbo = resource_pool->create_fbo(dst_tex);
1035         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1036         glViewport(0, 0, WIDTH/2, HEIGHT/2);
1037         check_error();
1038
1039         glUseProgram(cbcr_program_num);
1040         check_error();
1041
1042         glActiveTexture(GL_TEXTURE0);
1043         check_error();
1044         glBindTexture(GL_TEXTURE_2D, src_tex);
1045         check_error();
1046         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1047         check_error();
1048         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1049         check_error();
1050         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1051         check_error();
1052
1053         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
1054         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
1055
1056         glBindBuffer(GL_ARRAY_BUFFER, cbcr_vbo);
1057         check_error();
1058
1059         for (GLint attr_index : { cbcr_position_attribute_index, cbcr_texcoord_attribute_index }) {
1060                 glEnableVertexAttribArray(attr_index);
1061                 check_error();
1062                 glVertexAttribPointer(attr_index, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
1063                 check_error();
1064         }
1065
1066         glDrawArrays(GL_TRIANGLES, 0, 3);
1067         check_error();
1068
1069         for (GLint attr_index : { cbcr_position_attribute_index, cbcr_texcoord_attribute_index }) {
1070                 glDisableVertexAttribArray(attr_index);
1071                 check_error();
1072         }
1073
1074         glUseProgram(0);
1075         check_error();
1076         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1077         check_error();
1078
1079         resource_pool->release_fbo(fbo);
1080         glDeleteVertexArrays(1, &vao);
1081 }
1082
1083 void Mixer::release_display_frame(DisplayFrame *frame)
1084 {
1085         for (GLuint texnum : frame->temp_textures) {
1086                 resource_pool->release_2d_texture(texnum);
1087         }
1088         frame->temp_textures.clear();
1089         frame->ready_fence.reset();
1090         frame->input_frames.clear();
1091 }
1092
1093 void Mixer::start()
1094 {
1095         mixer_thread = thread(&Mixer::thread_func, this);
1096         audio_thread = thread(&Mixer::audio_thread_func, this);
1097 }
1098
1099 void Mixer::quit()
1100 {
1101         should_quit = true;
1102         mixer_thread.join();
1103         audio_thread.join();
1104 }
1105
1106 void Mixer::transition_clicked(int transition_num)
1107 {
1108         theme->transition_clicked(transition_num, pts());
1109 }
1110
1111 void Mixer::channel_clicked(int preview_num)
1112 {
1113         theme->channel_clicked(preview_num);
1114 }
1115
1116 void Mixer::reset_meters()
1117 {
1118         peak_resampler.reset();
1119         peak = 0.0f;
1120         r128.reset();
1121         r128.integr_start();
1122         correlation.reset();
1123 }
1124
1125 void Mixer::start_mode_scanning(unsigned card_index)
1126 {
1127         assert(card_index < num_cards);
1128         if (is_mode_scanning[card_index]) {
1129                 return;
1130         }
1131         is_mode_scanning[card_index] = true;
1132         mode_scanlist[card_index].clear();
1133         for (const auto &mode : cards[card_index].capture->get_available_video_modes()) {
1134                 mode_scanlist[card_index].push_back(mode.first);
1135         }
1136         assert(!mode_scanlist[card_index].empty());
1137         mode_scanlist_index[card_index] = 0;
1138         cards[card_index].capture->set_video_mode(mode_scanlist[card_index][0]);
1139         clock_gettime(CLOCK_MONOTONIC, &last_mode_scan_change[card_index]);
1140 }
1141
1142 Mixer::OutputChannel::~OutputChannel()
1143 {
1144         if (has_current_frame) {
1145                 parent->release_display_frame(&current_frame);
1146         }
1147         if (has_ready_frame) {
1148                 parent->release_display_frame(&ready_frame);
1149         }
1150 }
1151
1152 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
1153 {
1154         // Store this frame for display. Remove the ready frame if any
1155         // (it was seemingly never used).
1156         {
1157                 unique_lock<mutex> lock(frame_mutex);
1158                 if (has_ready_frame) {
1159                         parent->release_display_frame(&ready_frame);
1160                 }
1161                 ready_frame = frame;
1162                 has_ready_frame = true;
1163         }
1164
1165         if (has_new_frame_ready_callback) {
1166                 new_frame_ready_callback();
1167         }
1168 }
1169
1170 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
1171 {
1172         unique_lock<mutex> lock(frame_mutex);
1173         if (!has_current_frame && !has_ready_frame) {
1174                 return false;
1175         }
1176
1177         if (has_current_frame && has_ready_frame) {
1178                 // We have a new ready frame. Toss the current one.
1179                 parent->release_display_frame(&current_frame);
1180                 has_current_frame = false;
1181         }
1182         if (has_ready_frame) {
1183                 assert(!has_current_frame);
1184                 current_frame = ready_frame;
1185                 ready_frame.ready_fence.reset();  // Drop the refcount.
1186                 ready_frame.input_frames.clear();  // Drop the refcounts.
1187                 has_current_frame = true;
1188                 has_ready_frame = false;
1189         }
1190
1191         *frame = current_frame;
1192         return true;
1193 }
1194
1195 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
1196 {
1197         new_frame_ready_callback = callback;
1198         has_new_frame_ready_callback = true;
1199 }