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