]> git.sesse.net Git - nageru/blob - mixer.cpp
Support true variable input frame rate instead of hard-coding to 60.
[nageru] / mixer.cpp
1 #define EXTRAHEIGHT 30
2
3 #undef Success
4
5 #include "mixer.h"
6
7 #include <assert.h>
8 #include <epoxy/egl.h>
9 #include <init.h>
10 #include <movit/effect_chain.h>
11 #include <movit/effect_util.h>
12 #include <movit/flat_input.h>
13 #include <movit/image_format.h>
14 #include <movit/resource_pool.h>
15 #include <stdint.h>
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <sys/time.h>
19 #include <time.h>
20 #include <util.h>
21 #include <algorithm>
22 #include <cmath>
23 #include <condition_variable>
24 #include <cstddef>
25 #include <memory>
26 #include <mutex>
27 #include <string>
28 #include <thread>
29 #include <utility>
30 #include <vector>
31
32 #include "bmusb/bmusb.h"
33 #include "context.h"
34 #include "defs.h"
35 #include "h264encode.h"
36 #include "pbo_frame_allocator.h"
37 #include "ref_counted_gl_sync.h"
38 #include "timebase.h"
39
40 class QOpenGLContext;
41
42 using namespace movit;
43 using namespace std;
44 using namespace std::placeholders;
45
46 Mixer *global_mixer = nullptr;
47
48 namespace {
49
50 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
51 {
52         for (size_t i = 0; i < num_samples; ++i) {
53                 for (size_t j = 0; j < out_channels; ++j) {
54                         uint32_t s1 = *src++;
55                         uint32_t s2 = *src++;
56                         uint32_t s3 = *src++;
57                         uint32_t s = s1 | (s1 << 8) | (s2 << 16) | (s3 << 24);
58                         dst[i * out_channels + j] = int(s) * (1.0f / 4294967296.0f);
59                 }
60                 src += 3 * (in_channels - out_channels);
61         }
62 }
63
64 }  // namespace
65
66 Mixer::Mixer(const QSurfaceFormat &format, unsigned num_cards)
67         : httpd(LOCAL_DUMP_FILE_NAME, WIDTH, HEIGHT),
68           num_cards(num_cards),
69           mixer_surface(create_surface(format)),
70           h264_encoder_surface(create_surface(format)),
71           level_compressor(OUTPUT_FREQUENCY),
72           limiter(OUTPUT_FREQUENCY),
73           compressor(OUTPUT_FREQUENCY)
74 {
75         httpd.start(9095);
76
77         CHECK(init_movit(MOVIT_SHADER_DIR, MOVIT_DEBUG_OFF));
78         check_error();
79
80         // Since we allow non-bouncing 4:2:2 YCbCrInputs, effective subpixel precision
81         // will be halved when sampling them, and we need to compensate here.
82         movit_texel_subpixel_precision /= 2.0;
83
84         resource_pool.reset(new ResourcePool);
85         theme.reset(new Theme("theme.lua", resource_pool.get(), num_cards));
86         for (unsigned i = 0; i < NUM_OUTPUTS; ++i) {
87                 output_channel[i].parent = this;
88         }
89
90         ImageFormat inout_format;
91         inout_format.color_space = COLORSPACE_sRGB;
92         inout_format.gamma_curve = GAMMA_sRGB;
93
94         // Display chain; shows the live output produced by the main chain (its RGBA version).
95         display_chain.reset(new EffectChain(WIDTH, HEIGHT, resource_pool.get()));
96         check_error();
97         display_input = new FlatInput(inout_format, FORMAT_RGB, GL_UNSIGNED_BYTE, WIDTH, HEIGHT);  // FIXME: GL_UNSIGNED_BYTE is really wrong.
98         display_chain->add_input(display_input);
99         display_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
100         display_chain->set_dither_bits(0);  // Don't bother.
101         display_chain->finalize();
102
103         h264_encoder.reset(new H264Encoder(h264_encoder_surface, WIDTH, HEIGHT, &httpd));
104
105         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
106                 printf("Configuring card %d...\n", card_index);
107                 CaptureCard *card = &cards[card_index];
108                 card->usb = new BMUSBCapture(card_index);
109                 card->usb->set_frame_callback(bind(&Mixer::bm_frame, this, card_index, _1, _2, _3, _4, _5, _6, _7));
110                 card->frame_allocator.reset(new PBOFrameAllocator(WIDTH * (HEIGHT+EXTRAHEIGHT) * 2 + 44, WIDTH, HEIGHT));
111                 card->usb->set_video_frame_allocator(card->frame_allocator.get());
112                 card->surface = create_surface(format);
113                 card->usb->set_dequeue_thread_callbacks(
114                         [card]{
115                                 eglBindAPI(EGL_OPENGL_API);
116                                 card->context = create_context(card->surface);
117                                 if (!make_current(card->context, card->surface)) {
118                                         printf("failed to create bmusb context\n");
119                                         exit(1);
120                                 }
121                         },
122                         [this]{
123                                 resource_pool->clean_context();
124                         });
125                 card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
126                 card->usb->configure_card();
127         }
128
129         BMUSBCapture::start_bm_thread();
130
131         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
132                 cards[card_index].usb->start_bm_capture();
133         }
134
135         //chain->enable_phase_timing(true);
136
137         // Set up stuff for NV12 conversion.
138
139         // Cb/Cr shader.
140         string cbcr_vert_shader = read_file("vs-cbcr.130.vert");
141         string cbcr_frag_shader =
142                 "#version 130 \n"
143                 "in vec2 tc0; \n"
144                 "uniform sampler2D cbcr_tex; \n"
145                 "void main() { \n"
146                 "    gl_FragColor = texture2D(cbcr_tex, tc0); \n"
147                 "} \n";
148         cbcr_program_num = resource_pool->compile_glsl_program(cbcr_vert_shader, cbcr_frag_shader);
149
150         r128.init(2, OUTPUT_FREQUENCY);
151         r128.integr_start();
152
153         locut.init(FILTER_HPF, 2);
154
155         // hlen=16 is pretty low quality, but we use quite a bit of CPU otherwise,
156         // and there's a limit to how important the peak meter is.
157         peak_resampler.setup(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY * 4, /*num_channels=*/2, /*hlen=*/16);
158
159         alsa.reset(new ALSAOutput(OUTPUT_FREQUENCY, /*num_channels=*/2));
160 }
161
162 Mixer::~Mixer()
163 {
164         resource_pool->release_glsl_program(cbcr_program_num);
165         BMUSBCapture::stop_bm_thread();
166
167         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
168                 {
169                         unique_lock<mutex> lock(bmusb_mutex);
170                         cards[card_index].should_quit = true;  // Unblock thread.
171                         cards[card_index].new_data_ready_changed.notify_all();
172                 }
173                 cards[card_index].usb->stop_dequeue_thread();
174         }
175
176         h264_encoder.reset(nullptr);
177 }
178
179 namespace {
180
181 int unwrap_timecode(uint16_t current_wrapped, int last)
182 {
183         uint16_t last_wrapped = last & 0xffff;
184         if (current_wrapped > last_wrapped) {
185                 return (last & ~0xffff) | current_wrapped;
186         } else {
187                 return 0x10000 + ((last & ~0xffff) | current_wrapped);
188         }
189 }
190
191 float find_peak(const float *samples, size_t num_samples)
192 {
193         float m = fabs(samples[0]);
194         for (size_t i = 1; i < num_samples; ++i) {
195                 m = std::max(m, fabs(samples[i]));
196         }
197         return m;
198 }
199
200 void deinterleave_samples(const vector<float> &in, vector<float> *out_l, vector<float> *out_r)
201 {
202         size_t num_samples = in.size() / 2;
203         out_l->resize(num_samples);
204         out_r->resize(num_samples);
205
206         const float *inptr = in.data();
207         float *lptr = &(*out_l)[0];
208         float *rptr = &(*out_r)[0];
209         for (size_t i = 0; i < num_samples; ++i) {
210                 *lptr++ = *inptr++;
211                 *rptr++ = *inptr++;
212         }
213 }
214
215 // Returns length of a frame with the given format, in TIMEBASE units.
216 int64_t find_frame_length(uint16_t video_format)
217 {
218         if (video_format == 0x0800) {
219                 // No video signal. These green pseudo-frames seem to come at about 30.13 Hz.
220                 // It's a strange thing, but what can you do.
221                 return TIMEBASE * 100 / 3013;
222         }
223         if ((video_format & 0xe800) != 0xe800) {
224                 printf("Video format 0x%04x does not appear to be a video format. Assuming 60 Hz.\n",
225                         video_format);
226                 return TIMEBASE / 60;
227         }
228
229         // 0x8 seems to be a flag about availability of deep color on the input,
230         // except when it's not (e.g. it's the only difference between NTSC 23.98
231         // and PAL). Rather confusing. But we clear it here nevertheless, because
232         // usually it doesn't mean anything.
233         //
234         // We don't really handle interlaced formats at all yet.
235         uint16_t normalized_video_format = video_format & ~0xe808;
236         if (normalized_video_format == 0x0143) {         // 720p50.
237                 return TIMEBASE / 50;
238         } else if (normalized_video_format == 0x0103) {  // 720p60.
239                 return TIMEBASE / 60;
240         } else if (normalized_video_format == 0x0121) {  // 720p59.94.
241                 return TIMEBASE * 1001 / 60000;
242         } else if (normalized_video_format == 0x01c3 ||  // 1080p30.
243                    normalized_video_format == 0x0003) {  // 1080i60.
244                 return TIMEBASE / 30;
245         } else if (normalized_video_format == 0x01e1 ||  // 1080p29.97.
246                    normalized_video_format == 0x0021 ||  // 1080i59.94.
247                    video_format == 0xe901 ||             // NTSC (480i59.94, I suppose).
248                    video_format == 0xe9c1 ||             // Ditto.
249                    video_format == 0xe801) {             // Ditto.
250                 return TIMEBASE * 1001 / 30000;
251         } else if (normalized_video_format == 0x0063 ||  // 1080p25.
252                    normalized_video_format == 0x0043 ||  // 1080i50.
253                    video_format == 0xe909) {             // PAL (576i50, I suppose).
254                 return TIMEBASE / 25;
255         } else if (normalized_video_format == 0x008e) {  // 1080p24.
256                 return TIMEBASE / 24;
257         } else if (normalized_video_format == 0x00a1) {  // 1080p23.98.
258                 return TIMEBASE * 1001 / 24000;
259                 return TIMEBASE / 25;
260         } else {
261                 printf("Unknown video format 0x%04x. Assuming 60 Hz.\n", video_format);
262                 return TIMEBASE / 60;
263         }
264 }
265
266 }  // namespace
267
268 void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
269                      FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
270                      FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)
271 {
272         CaptureCard *card = &cards[card_index];
273
274         int64_t frame_length = find_frame_length(video_format);
275
276         if (audio_frame.len - audio_offset > 30000) {
277                 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",
278                         card_index, int(audio_frame.len), int(audio_offset),
279                         timecode, int(video_frame.len), int(video_offset), video_format);
280                 if (video_frame.owner) {
281                         video_frame.owner->release_frame(video_frame);
282                 }
283                 if (audio_frame.owner) {
284                         audio_frame.owner->release_frame(audio_frame);
285                 }
286                 return;
287         }
288
289         int64_t local_pts = card->next_local_pts;
290         int dropped_frames = 0;
291         if (card->last_timecode != -1) {
292                 dropped_frames = unwrap_timecode(timecode, card->last_timecode) - card->last_timecode - 1;
293         }
294         card->last_timecode = timecode;
295
296         // Convert the audio to stereo fp32 and add it.
297         size_t num_samples = (audio_frame.len >= audio_offset) ? (audio_frame.len - audio_offset) / 8 / 3 : 0;
298         vector<float> audio;
299         audio.resize(num_samples * 2);
300         convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, 8, num_samples);
301
302         // Add the audio.
303         {
304                 unique_lock<mutex> lock(card->audio_mutex);
305
306                 if (dropped_frames > MAX_FPS * 2) {
307                         fprintf(stderr, "Card %d lost more than two seconds (or time code jumping around), resetting resampler\n",
308                                 card_index);
309                         card->resampling_queue.reset(new ResamplingQueue(OUTPUT_FREQUENCY, OUTPUT_FREQUENCY, 2));
310                 } else if (dropped_frames > 0) {
311                         // Insert silence as needed. (The number of samples could be nonintegral,
312                         // but resampling will save us then.)
313                         fprintf(stderr, "Card %d dropped %d frame(s) (before timecode 0x%04x), inserting silence.\n",
314                                 card_index, dropped_frames, timecode);
315                         vector<float> silence;
316                         silence.resize((OUTPUT_FREQUENCY * frame_length / TIMEBASE) * 2);
317                         for (int i = 0; i < dropped_frames; ++i) {
318                                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), silence.data(), silence.size() / 2);
319                                 // Note that if the format changed in the meantime, we have
320                                 // no way of detecting that; we just have to assume the frame length
321                                 // is always the same.
322                                 local_pts += frame_length;
323                         }
324                 }
325                 card->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), audio.data(), num_samples);
326                 card->next_local_pts = local_pts + frame_length;
327         }
328
329         // Done with the audio, so release it.
330         if (audio_frame.owner) {
331                 audio_frame.owner->release_frame(audio_frame);
332         }
333
334         {
335                 // Wait until the previous frame was consumed.
336                 unique_lock<mutex> lock(bmusb_mutex);
337                 card->new_data_ready_changed.wait(lock, [card]{ return !card->new_data_ready || card->should_quit; });
338                 if (card->should_quit) return;
339         }
340
341         if (video_frame.len - video_offset != WIDTH * (HEIGHT+EXTRAHEIGHT) * 2) {
342                 if (video_frame.len != 0) {
343                         printf("Card %d: Dropping video frame with wrong length (%ld)\n",
344                                 card_index, video_frame.len - video_offset);
345                 }
346                 if (video_frame.owner) {
347                         video_frame.owner->release_frame(video_frame);
348                 }
349
350                 // Still send on the information that we _had_ a frame, even though it's corrupted,
351                 // so that pts can go up accordingly.
352                 {
353                         unique_lock<mutex> lock(bmusb_mutex);
354                         card->new_data_ready = true;
355                         card->new_frame = RefCountedFrame(FrameAllocator::Frame());
356                         card->new_frame_length = frame_length;
357                         card->new_data_ready_fence = nullptr;
358                         card->dropped_frames = dropped_frames;
359                         card->new_data_ready_changed.notify_all();
360                 }
361                 return;
362         }
363
364         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)video_frame.userdata;
365         GLuint pbo = userdata->pbo;
366         check_error();
367         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, pbo);
368         check_error();
369         glFlushMappedBufferRange(GL_PIXEL_UNPACK_BUFFER, 0, video_frame.size);
370         check_error();
371         //glMemoryBarrier(GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT);
372         //check_error();
373
374         // Upload the textures.
375         glBindTexture(GL_TEXTURE_2D, userdata->tex_y);
376         check_error();
377         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH, HEIGHT, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET((WIDTH * (HEIGHT+EXTRAHEIGHT) * 2 + 44) / 2 + WIDTH * 25 + 22));
378         check_error();
379         glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr);
380         check_error();
381         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, WIDTH/2, HEIGHT, GL_RG, GL_UNSIGNED_BYTE, BUFFER_OFFSET(WIDTH * 25 + 22));
382         check_error();
383         glBindTexture(GL_TEXTURE_2D, 0);
384         check_error();
385         GLsync fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);              
386         check_error();
387         assert(fence != nullptr);
388
389         {
390                 unique_lock<mutex> lock(bmusb_mutex);
391                 card->new_data_ready = true;
392                 card->new_frame = RefCountedFrame(video_frame);
393                 card->new_frame_length = frame_length;
394                 card->new_data_ready_fence = fence;
395                 card->dropped_frames = dropped_frames;
396                 card->new_data_ready_changed.notify_all();
397         }
398 }
399
400 void Mixer::thread_func()
401 {
402         eglBindAPI(EGL_OPENGL_API);
403         QOpenGLContext *context = create_context(mixer_surface);
404         if (!make_current(context, mixer_surface)) {
405                 printf("oops\n");
406                 exit(1);
407         }
408
409         struct timespec start, now;
410         clock_gettime(CLOCK_MONOTONIC, &start);
411
412         int frame = 0;
413         int dropped_frames = 0;
414
415         while (!should_quit) {
416                 CaptureCard card_copy[MAX_CARDS];
417                 int num_samples[MAX_CARDS];
418
419                 {
420                         unique_lock<mutex> lock(bmusb_mutex);
421
422                         // The first card is the master timer, so wait for it to have a new frame.
423                         // TODO: Make configurable, and with a timeout.
424                         cards[0].new_data_ready_changed.wait(lock, [this]{ return cards[0].new_data_ready; });
425
426                         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
427                                 CaptureCard *card = &cards[card_index];
428                                 card_copy[card_index].usb = card->usb;
429                                 card_copy[card_index].new_data_ready = card->new_data_ready;
430                                 card_copy[card_index].new_frame = card->new_frame;
431                                 card_copy[card_index].new_frame_length = card->new_frame_length;
432                                 card_copy[card_index].new_data_ready_fence = card->new_data_ready_fence;
433                                 card_copy[card_index].dropped_frames = card->dropped_frames;
434                                 card->new_data_ready = false;
435                                 card->new_data_ready_changed.notify_all();
436
437                                 int num_samples_times_timebase = OUTPUT_FREQUENCY * card->new_frame_length + card->fractional_samples;
438                                 num_samples[card_index] = num_samples_times_timebase / TIMEBASE;
439                                 card->fractional_samples = num_samples_times_timebase % TIMEBASE;
440                         }
441                 }
442
443                 // Resample the audio as needed, including from previously dropped frames.
444                 for (unsigned frame_num = 0; frame_num < card_copy[0].dropped_frames + 1; ++frame_num) {
445                         {
446                                 // Signal to the audio thread to process this frame.
447                                 unique_lock<mutex> lock(audio_mutex);
448                                 audio_task_queue.push(AudioTask{pts_int, num_samples[0]});
449                                 audio_task_queue_changed.notify_one();
450                         }
451                         if (frame_num != card_copy[0].dropped_frames) {
452                                 // For dropped frames, increase the pts. Note that if the format changed
453                                 // in the meantime, we have no way of detecting that; we just have to
454                                 // assume the frame length is always the same.
455                                 ++dropped_frames;
456                                 pts_int += card_copy[0].new_frame_length;
457                         }
458                 }
459
460                 if (audio_level_callback != nullptr) {
461                         double loudness_s = r128.loudness_S();
462                         double loudness_i = r128.integrated();
463                         double loudness_range_low = r128.range_min();
464                         double loudness_range_high = r128.range_max();
465
466                         audio_level_callback(loudness_s, 20.0 * log10(peak),
467                                              loudness_i, loudness_range_low, loudness_range_high,
468                                              last_gain_staging_db);
469                 }
470
471                 for (unsigned card_index = 1; card_index < num_cards; ++card_index) {
472                         if (card_copy[card_index].new_data_ready && card_copy[card_index].new_frame->len == 0) {
473                                 ++card_copy[card_index].dropped_frames;
474                         }
475                         if (card_copy[card_index].dropped_frames > 0) {
476                                 printf("Card %u dropped %d frames before this\n",
477                                         card_index, int(card_copy[card_index].dropped_frames));
478                         }
479                 }
480
481                 // If the first card is reporting a corrupted or otherwise dropped frame,
482                 // just increase the pts (skipping over this frame) and don't try to compute anything new.
483                 if (card_copy[0].new_frame->len == 0) {
484                         ++dropped_frames;
485                         pts_int += card_copy[0].new_frame_length;
486                         continue;
487                 }
488
489                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
490                         CaptureCard *card = &card_copy[card_index];
491                         if (!card->new_data_ready || card->new_frame->len == 0)
492                                 continue;
493
494                         assert(card->new_frame != nullptr);
495                         bmusb_current_rendering_frame[card_index] = card->new_frame;
496                         check_error();
497
498                         // The new texture might still be uploaded,
499                         // tell the GPU to wait until it's there.
500                         if (card->new_data_ready_fence) {
501                                 glWaitSync(card->new_data_ready_fence, /*flags=*/0, GL_TIMEOUT_IGNORED);
502                                 check_error();
503                                 glDeleteSync(card->new_data_ready_fence);
504                                 check_error();
505                         }
506                         const PBOFrameAllocator::Userdata *userdata = (const PBOFrameAllocator::Userdata *)card->new_frame->userdata;
507                         theme->set_input_textures(card_index, userdata->tex_y, userdata->tex_cbcr);
508                 }
509
510                 // Get the main chain from the theme, and set its state immediately.
511                 pair<EffectChain *, function<void()>> theme_main_chain = theme->get_chain(0, pts(), WIDTH, HEIGHT);
512                 EffectChain *chain = theme_main_chain.first;
513                 theme_main_chain.second();
514
515                 GLuint y_tex, cbcr_tex;
516                 bool got_frame = h264_encoder->begin_frame(&y_tex, &cbcr_tex);
517                 assert(got_frame);
518
519                 // Render main chain.
520                 GLuint cbcr_full_tex = resource_pool->create_2d_texture(GL_RG8, WIDTH, HEIGHT);
521                 GLuint rgba_tex = resource_pool->create_2d_texture(GL_RGB565, WIDTH, HEIGHT);  // Saves texture bandwidth, although dithering gets messed up.
522                 GLuint fbo = resource_pool->create_fbo(y_tex, cbcr_full_tex, rgba_tex);
523                 check_error();
524                 chain->render_to_fbo(fbo, WIDTH, HEIGHT);
525                 resource_pool->release_fbo(fbo);
526
527                 subsample_chroma(cbcr_full_tex, cbcr_tex);
528                 resource_pool->release_2d_texture(cbcr_full_tex);
529
530                 // Set the right state for rgba_tex.
531                 glBindFramebuffer(GL_FRAMEBUFFER, 0);
532                 glBindTexture(GL_TEXTURE_2D, rgba_tex);
533                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
534                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
535                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
536
537                 RefCountedGLsync fence(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
538                 check_error();
539
540                 // Make sure the H.264 gets a reference to all the
541                 // input frames needed, so that they are not released back
542                 // until the rendering is done.
543                 vector<RefCountedFrame> input_frames;
544                 for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
545                         input_frames.push_back(bmusb_current_rendering_frame[card_index]);
546                 }
547                 const int64_t av_delay = TIMEBASE / 10;  // Corresponds to the fixed delay in resampling_queue.h. TODO: Make less hard-coded.
548                 h264_encoder->end_frame(fence, pts_int + av_delay, input_frames);
549                 ++frame;
550                 pts_int += card_copy[0].new_frame_length;
551
552                 // The live frame just shows the RGBA texture we just rendered.
553                 // It owns rgba_tex now.
554                 DisplayFrame live_frame;
555                 live_frame.chain = display_chain.get();
556                 live_frame.setup_chain = [this, rgba_tex]{
557                         display_input->set_texture_num(rgba_tex);
558                 };
559                 live_frame.ready_fence = fence;
560                 live_frame.input_frames = {};
561                 live_frame.temp_textures = { rgba_tex };
562                 output_channel[OUTPUT_LIVE].output_frame(live_frame);
563
564                 // Set up preview and any additional channels.
565                 for (int i = 1; i < theme->get_num_channels() + 2; ++i) {
566                         DisplayFrame display_frame;
567                         pair<EffectChain *, function<void()>> chain = theme->get_chain(i, pts(), WIDTH, HEIGHT);  // FIXME: dimensions
568                         display_frame.chain = chain.first;
569                         display_frame.setup_chain = chain.second;
570                         display_frame.ready_fence = fence;
571
572                         // FIXME: possible to do better?
573                         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
574                                 display_frame.input_frames.push_back(bmusb_current_rendering_frame[card_index]);
575                         }
576                         display_frame.temp_textures = {};
577                         output_channel[i].output_frame(display_frame);
578                 }
579
580                 clock_gettime(CLOCK_MONOTONIC, &now);
581                 double elapsed = now.tv_sec - start.tv_sec +
582                         1e-9 * (now.tv_nsec - start.tv_nsec);
583                 if (frame % 100 == 0) {
584                         printf("%d frames (%d dropped) in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
585                                 frame, dropped_frames, elapsed, frame / elapsed,
586                                 1e3 * elapsed / frame);
587                 //      chain->print_phase_timing();
588                 }
589
590 #if 0
591                 // Reset every 100 frames, so that local variations in frame times
592                 // (especially for the first few frames, when the shaders are
593                 // compiled etc.) don't make it hard to measure for the entire
594                 // remaining duration of the program.
595                 if (frame == 10000) {
596                         frame = 0;
597                         start = now;
598                 }
599 #endif
600                 check_error();
601         }
602
603         resource_pool->clean_context();
604 }
605
606 void Mixer::audio_thread_func()
607 {
608         while (!should_quit) {
609                 AudioTask task;
610
611                 {
612                         unique_lock<mutex> lock(audio_mutex);
613                         audio_task_queue_changed.wait(lock, [this]{ return !audio_task_queue.empty(); });
614                         task = audio_task_queue.front();
615                         audio_task_queue.pop();
616                 }
617
618                 process_audio_one_frame(task.pts_int, task.num_samples);
619         }
620 }
621
622 void Mixer::process_audio_one_frame(int64_t frame_pts_int, int num_samples)
623 {
624         vector<float> samples_card;
625         vector<float> samples_out;
626         for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
627                 samples_card.resize(num_samples * 2);
628                 {
629                         unique_lock<mutex> lock(cards[card_index].audio_mutex);
630                         if (!cards[card_index].resampling_queue->get_output_samples(double(frame_pts_int) / TIMEBASE, &samples_card[0], num_samples)) {
631                                 printf("Card %d reported previous underrun.\n", card_index);
632                         }
633                 }
634                 // TODO: Allow using audio from the other card(s) as well.
635                 if (card_index == 0) {
636                         samples_out = move(samples_card);
637                 }
638         }
639
640         // Cut away everything under 120 Hz (or whatever the cutoff is);
641         // we don't need it for voice, and it will reduce headroom
642         // and confuse the compressor. (In particular, any hums at 50 or 60 Hz
643         // should be dampened.)
644         locut.render(samples_out.data(), samples_out.size() / 2, locut_cutoff_hz * 2.0 * M_PI / OUTPUT_FREQUENCY, 0.5f);
645
646         // Apply a level compressor to get the general level right.
647         // Basically, if it's over about -40 dBFS, we squeeze it down to that level
648         // (or more precisely, near it, since we don't use infinite ratio),
649         // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
650         // entirely arbitrary, but from practical tests with speech, it seems to
651         // put ut around -23 LUFS, so it's a reasonable starting point for later use.
652         float ref_level_dbfs = -14.0f;
653         {
654                 float threshold = 0.01f;   // -40 dBFS.
655                 float ratio = 20.0f;
656                 float attack_time = 0.5f;
657                 float release_time = 20.0f;
658                 float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
659                 level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
660                 last_gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
661         }
662
663 #if 0
664         printf("level=%f (%+5.2f dBFS) attenuation=%f (%+5.2f dB) end_result=%+5.2f dB\n",
665                 level_compressor.get_level(), 20.0 * log10(level_compressor.get_level()),
666                 level_compressor.get_attenuation(), 20.0 * log10(level_compressor.get_attenuation()),
667                 20.0 * log10(level_compressor.get_level() * level_compressor.get_attenuation() * makeup_gain));
668 #endif
669
670 //      float limiter_att, compressor_att;
671
672         // The real compressor.
673         if (compressor_enabled) {
674                 float threshold = pow(10.0f, compressor_threshold_dbfs / 20.0f);
675                 float ratio = 20.0f;
676                 float attack_time = 0.005f;
677                 float release_time = 0.040f;
678                 float makeup_gain = 2.0f;  // +6 dB.
679                 compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
680 //              compressor_att = compressor.get_attenuation();
681         }
682
683         // Finally a limiter at -4 dB (so, -10 dBFS) to take out the worst peaks only.
684         // Note that since ratio is not infinite, we could go slightly higher than this.
685         if (limiter_enabled) {
686                 float threshold = pow(10.0f, limiter_threshold_dbfs / 20.0f);
687                 float ratio = 30.0f;
688                 float attack_time = 0.0f;  // Instant.
689                 float release_time = 0.020f;
690                 float makeup_gain = 1.0f;  // 0 dB.
691                 limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
692 //              limiter_att = limiter.get_attenuation();
693         }
694
695 //      printf("limiter=%+5.1f  compressor=%+5.1f\n", 20.0*log10(limiter_att), 20.0*log10(compressor_att));
696
697         // Upsample 4x to find interpolated peak.
698         peak_resampler.inp_data = samples_out.data();
699         peak_resampler.inp_count = samples_out.size() / 2;
700
701         vector<float> interpolated_samples_out;
702         interpolated_samples_out.resize(samples_out.size());
703         while (peak_resampler.inp_count > 0) {  // About four iterations.
704                 peak_resampler.out_data = &interpolated_samples_out[0];
705                 peak_resampler.out_count = interpolated_samples_out.size() / 2;
706                 peak_resampler.process();
707                 size_t out_stereo_samples = interpolated_samples_out.size() / 2 - peak_resampler.out_count;
708                 peak = max<float>(peak, find_peak(interpolated_samples_out.data(), out_stereo_samples * 2));
709         }
710
711         // Find R128 levels.
712         vector<float> left, right;
713         deinterleave_samples(samples_out, &left, &right);
714         float *ptrs[] = { left.data(), right.data() };
715         r128.process(left.size(), ptrs);
716
717         // Send the samples to the sound card.
718         if (alsa) {
719                 alsa->write(samples_out);
720         }
721
722         // And finally add them to the output.
723         h264_encoder->add_audio(frame_pts_int, move(samples_out));
724 }
725
726 void Mixer::subsample_chroma(GLuint src_tex, GLuint dst_tex)
727 {
728         GLuint vao;
729         glGenVertexArrays(1, &vao);
730         check_error();
731
732         float vertices[] = {
733                 0.0f, 2.0f,
734                 0.0f, 0.0f,
735                 2.0f, 0.0f
736         };
737
738         glBindVertexArray(vao);
739         check_error();
740
741         // Extract Cb/Cr.
742         GLuint fbo = resource_pool->create_fbo(dst_tex);
743         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
744         glViewport(0, 0, WIDTH/2, HEIGHT/2);
745         check_error();
746
747         glUseProgram(cbcr_program_num);
748         check_error();
749
750         glActiveTexture(GL_TEXTURE0);
751         check_error();
752         glBindTexture(GL_TEXTURE_2D, src_tex);
753         check_error();
754         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
755         check_error();
756         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
757         check_error();
758         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
759         check_error();
760
761         float chroma_offset_0[] = { -0.5f / WIDTH, 0.0f };
762         set_uniform_vec2(cbcr_program_num, "foo", "chroma_offset_0", chroma_offset_0);
763
764         GLuint position_vbo = fill_vertex_attribute(cbcr_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
765         GLuint texcoord_vbo = fill_vertex_attribute(cbcr_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
766
767         glDrawArrays(GL_TRIANGLES, 0, 3);
768         check_error();
769
770         cleanup_vertex_attribute(cbcr_program_num, "position", position_vbo);
771         cleanup_vertex_attribute(cbcr_program_num, "texcoord", texcoord_vbo);
772
773         glUseProgram(0);
774         check_error();
775
776         resource_pool->release_fbo(fbo);
777         glDeleteVertexArrays(1, &vao);
778 }
779
780 void Mixer::release_display_frame(DisplayFrame *frame)
781 {
782         for (GLuint texnum : frame->temp_textures) {
783                 resource_pool->release_2d_texture(texnum);
784         }
785         frame->temp_textures.clear();
786         frame->ready_fence.reset();
787         frame->input_frames.clear();
788 }
789
790 void Mixer::start()
791 {
792         mixer_thread = thread(&Mixer::thread_func, this);
793         audio_thread = thread(&Mixer::audio_thread_func, this);
794 }
795
796 void Mixer::quit()
797 {
798         should_quit = true;
799         mixer_thread.join();
800         audio_thread.join();
801 }
802
803 void Mixer::transition_clicked(int transition_num)
804 {
805         theme->transition_clicked(transition_num, pts());
806 }
807
808 void Mixer::channel_clicked(int preview_num)
809 {
810         theme->channel_clicked(preview_num);
811 }
812
813 void Mixer::reset_meters()
814 {
815         peak_resampler.reset();
816         peak = 0.0f;
817         r128.reset();
818         r128.integr_start();
819 }
820
821 Mixer::OutputChannel::~OutputChannel()
822 {
823         if (has_current_frame) {
824                 parent->release_display_frame(&current_frame);
825         }
826         if (has_ready_frame) {
827                 parent->release_display_frame(&ready_frame);
828         }
829 }
830
831 void Mixer::OutputChannel::output_frame(DisplayFrame frame)
832 {
833         // Store this frame for display. Remove the ready frame if any
834         // (it was seemingly never used).
835         {
836                 unique_lock<mutex> lock(frame_mutex);
837                 if (has_ready_frame) {
838                         parent->release_display_frame(&ready_frame);
839                 }
840                 ready_frame = frame;
841                 has_ready_frame = true;
842         }
843
844         if (has_new_frame_ready_callback) {
845                 new_frame_ready_callback();
846         }
847 }
848
849 bool Mixer::OutputChannel::get_display_frame(DisplayFrame *frame)
850 {
851         unique_lock<mutex> lock(frame_mutex);
852         if (!has_current_frame && !has_ready_frame) {
853                 return false;
854         }
855
856         if (has_current_frame && has_ready_frame) {
857                 // We have a new ready frame. Toss the current one.
858                 parent->release_display_frame(&current_frame);
859                 has_current_frame = false;
860         }
861         if (has_ready_frame) {
862                 assert(!has_current_frame);
863                 current_frame = ready_frame;
864                 ready_frame.ready_fence.reset();  // Drop the refcount.
865                 ready_frame.input_frames.clear();  // Drop the refcounts.
866                 has_current_frame = true;
867                 has_ready_frame = false;
868         }
869
870         *frame = current_frame;
871         return true;
872 }
873
874 void Mixer::OutputChannel::set_frame_ready_callback(Mixer::new_frame_ready_callback_t callback)
875 {
876         new_frame_ready_callback = callback;
877         has_new_frame_ready_callback = true;
878 }