git.sesse.net Git - nageru/blob - nageru/mjpeg_encoder.cpp

   1 #include "mjpeg_encoder.h"
   2
   3 #include <assert.h>
   4 #include <jpeglib.h>
   5 #include <unistd.h>
   6 #if __SSE2__
   7 #include <immintrin.h>
   8 #endif
   9 #include <list>
  10
  11 extern "C" {
  12 #include <libavformat/avformat.h>
  13 }
  14
  15 #include "defs.h"
  16 #include "shared/ffmpeg_raii.h"
  17 #include "flags.h"
  18 #include "shared/httpd.h"
  19 #include "shared/memcpy_interleaved.h"
  20 #include "shared/metrics.h"
  21 #include "pbo_frame_allocator.h"
  22 #include "shared/timebase.h"
  23 #include "va_display_with_cleanup.h"
  24
  25 #include <movit/colorspace_conversion_effect.h>
  26
  27 #include <va/va.h>
  28 #include <va/va_drm.h>
  29 #include <va/va_x11.h>
  30
  31 using namespace Eigen;
  32 using namespace bmusb;
  33 using namespace movit;
  34 using namespace std;
  35
  36 static VAImageFormat uyvy_format;
  37
  38 extern void memcpy_with_pitch(uint8_t *dst, const uint8_t *src, size_t src_width, size_t dst_pitch, size_t height);
  39
  40 // From libjpeg (although it's of course identical between implementations).
  41 static const int jpeg_natural_order[DCTSIZE2] = {
  42          0,  1,  8, 16,  9,  2,  3, 10,
  43         17, 24, 32, 25, 18, 11,  4,  5,
  44         12, 19, 26, 33, 40, 48, 41, 34,
  45         27, 20, 13,  6,  7, 14, 21, 28,
  46         35, 42, 49, 56, 57, 50, 43, 36,
  47         29, 22, 15, 23, 30, 37, 44, 51,
  48         58, 59, 52, 45, 38, 31, 39, 46,
  49         53, 60, 61, 54, 47, 55, 62, 63,
  50 };
  51
  52 struct VectorDestinationManager {
  53         jpeg_destination_mgr pub;
  54         std::vector<uint8_t> dest;
  55
  56         VectorDestinationManager()
  57         {
  58                 pub.init_destination = init_destination_thunk;
  59                 pub.empty_output_buffer = empty_output_buffer_thunk;
  60                 pub.term_destination = term_destination_thunk;
  61         }
  62
  63         static void init_destination_thunk(j_compress_ptr ptr)
  64         {
  65                 ((VectorDestinationManager *)(ptr->dest))->init_destination();
  66         }
  67
  68         inline void init_destination()
  69         {
  70                 make_room(0);
  71         }
  72
  73         static boolean empty_output_buffer_thunk(j_compress_ptr ptr)
  74         {
  75                 return ((VectorDestinationManager *)(ptr->dest))->empty_output_buffer();
  76         }
  77
  78         inline bool empty_output_buffer()
  79         {
  80                 make_room(dest.size());  // Should ignore pub.free_in_buffer!
  81                 return true;
  82         }
  83
  84         inline void make_room(size_t bytes_used)
  85         {
  86                 dest.resize(bytes_used + 4096);
  87                 dest.resize(dest.capacity());
  88                 pub.next_output_byte = dest.data() + bytes_used;
  89                 pub.free_in_buffer = dest.size() - bytes_used;
  90         }
  91
  92         static void term_destination_thunk(j_compress_ptr ptr)
  93         {
  94                 ((VectorDestinationManager *)(ptr->dest))->term_destination();
  95         }
  96
  97         inline void term_destination()
  98         {
  99                 dest.resize(dest.size() - pub.free_in_buffer);
 100         }
 101 };
 102 static_assert(std::is_standard_layout<VectorDestinationManager>::value, "");
 103
 104 int MJPEGEncoder::write_packet2_thunk(void *opaque, uint8_t *buf, int buf_size, AVIODataMarkerType type, int64_t time)
 105 {
 106         WritePacket2Context *ctx = (WritePacket2Context *)opaque;
 107         return ctx->mjpeg_encoder->write_packet2(ctx->stream_id, buf, buf_size, type, time);
 108 }
 109
 110 int MJPEGEncoder::write_packet2(HTTPD::StreamID stream_id, uint8_t *buf, int buf_size, AVIODataMarkerType type, int64_t time)
 111 {
 112         string *mux_header = &streams[stream_id].mux_header;
 113         if (type == AVIO_DATA_MARKER_HEADER) {
 114                 mux_header->append((char *)buf, buf_size);
 115                 httpd->set_header(stream_id, *mux_header);
 116         } else {
 117                 httpd->add_data(stream_id, (char *)buf, buf_size, /*keyframe=*/true, AV_NOPTS_VALUE, AVRational{ AV_TIME_BASE, 1 });
 118         }
 119         return buf_size;
 120 }
 121
 122 namespace {
 123
 124 void add_video_stream(AVFormatContext *avctx)
 125 {
 126         AVStream *stream = avformat_new_stream(avctx, nullptr);
 127         if (stream == nullptr) {
 128                 fprintf(stderr, "avformat_new_stream() failed\n");
 129                 abort();
 130         }
 131
 132         // FFmpeg is very picky about having audio at 1/48000 timebase,
 133         // no matter what we write. Even though we'd prefer our usual 1/120000,
 134         // put the video on the same one, so that we can have locked audio.
 135         stream->time_base = AVRational{ 1, OUTPUT_FREQUENCY };
 136         stream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 137         stream->codecpar->codec_id = AV_CODEC_ID_MJPEG;
 138
 139         // Used for aspect ratio only. Can change without notice (the mux won't care).
 140         stream->codecpar->width = global_flags.width;
 141         stream->codecpar->height = global_flags.height;
 142
 143         // TODO: We could perhaps use the interpretation for each card here
 144         // (or at least the command-line flags) instead of the defaults,
 145         // but what would we do when they change?
 146         stream->codecpar->color_primaries = AVCOL_PRI_BT709;
 147         stream->codecpar->color_trc = AVCOL_TRC_IEC61966_2_1;
 148         stream->codecpar->color_space = AVCOL_SPC_BT709;
 149         stream->codecpar->color_range = AVCOL_RANGE_MPEG;
 150         stream->codecpar->chroma_location = AVCHROMA_LOC_LEFT;
 151         stream->codecpar->field_order = AV_FIELD_PROGRESSIVE;
 152 }
 153
 154 void add_audio_stream(AVFormatContext *avctx)
 155 {
 156         AVStream *stream = avformat_new_stream(avctx, nullptr);
 157         if (stream == nullptr) {
 158                 fprintf(stderr, "avformat_new_stream() failed\n");
 159                 abort();
 160         }
 161         stream->time_base = AVRational{ 1, OUTPUT_FREQUENCY };
 162         stream->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
 163         stream->codecpar->codec_id = AV_CODEC_ID_PCM_S32LE;
 164         stream->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
 165         stream->codecpar->channels = 2;
 166         stream->codecpar->sample_rate = OUTPUT_FREQUENCY;
 167 }
 168
 169 void finalize_mux(AVFormatContext *avctx)
 170 {
 171         AVDictionary *options = NULL;
 172         vector<pair<string, string>> opts = MUX_OPTS;
 173         for (pair<string, string> opt : opts) {
 174                 av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
 175         }
 176         if (avformat_write_header(avctx, &options) < 0) {
 177                 fprintf(stderr, "avformat_write_header() failed\n");
 178                 abort();
 179         }
 180 }
 181
 182 }  // namespace
 183
 184 MJPEGEncoder::MJPEGEncoder(HTTPD *httpd, const string &va_display)
 185         : httpd(httpd)
 186 {
 187         create_ffmpeg_context(HTTPD::StreamID{ HTTPD::MULTICAM_STREAM, 0 });
 188         for (unsigned stream_idx = 0; stream_idx < MAX_VIDEO_CARDS; ++stream_idx) {
 189                 create_ffmpeg_context(HTTPD::StreamID{ HTTPD::SIPHON_STREAM, stream_idx });
 190         }
 191
 192         add_stream(HTTPD::StreamID{ HTTPD::MULTICAM_STREAM, 0 });
 193
 194         // Initialize VA-API.
 195         string error;
 196         va_dpy = try_open_va(va_display, &error, &config_id);
 197         if (va_dpy == nullptr) {
 198                 fprintf(stderr, "Could not initialize VA-API for MJPEG encoding: %s. JPEGs will be encoded in software if needed.\n", error.c_str());
 199         }
 200
 201         encoder_thread = thread(&MJPEGEncoder::encoder_thread_func, this);
 202         if (va_dpy != nullptr) {
 203                 va_receiver_thread = thread(&MJPEGEncoder::va_receiver_thread_func, this);
 204         }
 205
 206         global_metrics.add("mjpeg_frames", {{ "status", "dropped" }, { "reason", "zero_size" }}, &metric_mjpeg_frames_zero_size_dropped);
 207         global_metrics.add("mjpeg_frames", {{ "status", "dropped" }, { "reason", "interlaced" }}, &metric_mjpeg_frames_interlaced_dropped);
 208         global_metrics.add("mjpeg_frames", {{ "status", "dropped" }, { "reason", "unsupported_pixel_format" }}, &metric_mjpeg_frames_unsupported_pixel_format_dropped);
 209         global_metrics.add("mjpeg_frames", {{ "status", "dropped" }, { "reason", "oversized" }}, &metric_mjpeg_frames_oversized_dropped);
 210         global_metrics.add("mjpeg_frames", {{ "status", "dropped" }, { "reason", "overrun" }}, &metric_mjpeg_overrun_dropped);
 211         global_metrics.add("mjpeg_frames", {{ "status", "submitted" }}, &metric_mjpeg_overrun_submitted);
 212
 213         running = true;
 214 }
 215
 216 MJPEGEncoder::~MJPEGEncoder()
 217 {
 218         for (auto &id_and_stream : streams) {
 219                 av_free(id_and_stream.second.avctx->pb->buffer);
 220         }
 221
 222         global_metrics.remove("mjpeg_frames", {{ "status", "dropped" }, { "reason", "zero_size" }});
 223         global_metrics.remove("mjpeg_frames", {{ "status", "dropped" }, { "reason", "interlaced" }});
 224         global_metrics.remove("mjpeg_frames", {{ "status", "dropped" }, { "reason", "unsupported_pixel_format" }});
 225         global_metrics.remove("mjpeg_frames", {{ "status", "dropped" }, { "reason", "oversized" }});
 226         global_metrics.remove("mjpeg_frames", {{ "status", "dropped" }, { "reason", "overrun" }});
 227         global_metrics.remove("mjpeg_frames", {{ "status", "submitted" }});
 228 }
 229
 230 void MJPEGEncoder::stop()
 231 {
 232         if (!running) {
 233                 return;
 234         }
 235         running = false;
 236         should_quit = true;
 237         any_frames_to_be_encoded.notify_all();
 238         any_frames_encoding.notify_all();
 239         encoder_thread.join();
 240         if (va_dpy != nullptr) {
 241                 va_receiver_thread.join();
 242         }
 243 }
 244
 245 unique_ptr<VADisplayWithCleanup> MJPEGEncoder::try_open_va(const string &va_display, string *error, VAConfigID *config_id)
 246 {
 247         unique_ptr<VADisplayWithCleanup> va_dpy = va_open_display(va_display);
 248         if (va_dpy == nullptr) {
 249                 if (error) *error = "Opening VA display failed";
 250                 return nullptr;
 251         }
 252         int major_ver, minor_ver;
 253         VAStatus va_status = vaInitialize(va_dpy->va_dpy, &major_ver, &minor_ver);
 254         if (va_status != VA_STATUS_SUCCESS) {
 255                 char buf[256];
 256                 snprintf(buf, sizeof(buf), "vaInitialize() failed with status %d\n", va_status);
 257                 if (error != nullptr) *error = buf;
 258                 return nullptr;
 259         }
 260
 261         VAConfigAttrib attr = { VAConfigAttribRTFormat, VA_RT_FORMAT_YUV422 };
 262         va_status = vaCreateConfig(va_dpy->va_dpy, VAProfileJPEGBaseline, VAEntrypointEncPicture,
 263                 &attr, 1, config_id);
 264         if (va_status == VA_STATUS_ERROR_UNSUPPORTED_ENTRYPOINT) {
 265                 if (error != nullptr) *error = "No hardware support";
 266                 return nullptr;
 267         } else if (va_status != VA_STATUS_SUCCESS) {
 268                 char buf[256];
 269                 snprintf(buf, sizeof(buf), "vaCreateConfig() failed with status %d\n", va_status);
 270                 if (error != nullptr) *error = buf;
 271                 return nullptr;
 272         }
 273
 274         // TODO: Unify with the code in Futatabi.
 275         int num_formats = vaMaxNumImageFormats(va_dpy->va_dpy);
 276         assert(num_formats > 0);
 277
 278         unique_ptr<VAImageFormat[]> formats(new VAImageFormat[num_formats]);
 279         va_status = vaQueryImageFormats(va_dpy->va_dpy, formats.get(), &num_formats);
 280         if (va_status != VA_STATUS_SUCCESS) {
 281                 char buf[256];
 282                 snprintf(buf, sizeof(buf), "vaQueryImageFormats() failed with status %d\n", va_status);
 283                 if (error != nullptr) *error = buf;
 284                 return nullptr;
 285         }
 286
 287         bool found = false;
 288         for (int i = 0; i < num_formats; ++i) {
 289                 if (formats[i].fourcc == VA_FOURCC_UYVY) {
 290                         memcpy(&uyvy_format, &formats[i], sizeof(VAImageFormat));
 291                         found = true;
 292                         break;
 293                 }
 294         }
 295         if (!found) {
 296                 if (error != nullptr) *error = "UYVY format not found";
 297                 return nullptr;
 298         }
 299
 300         return va_dpy;
 301 }
 302
 303 void MJPEGEncoder::upload_frame(int64_t pts, unsigned card_index, RefCountedFrame frame, const bmusb::VideoFormat &video_format, size_t y_offset, size_t cbcr_offset, vector<int32_t> audio, const RGBTriplet &white_balance)
 304 {
 305         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)frame->userdata;
 306         if (video_format.width == 0 || video_format.height == 0) {
 307                 ++metric_mjpeg_frames_zero_size_dropped;
 308                 return;
 309         }
 310         if (video_format.interlaced) {
 311                 fprintf(stderr, "Card %u: Ignoring JPEG encoding for interlaced frame\n", card_index);
 312                 ++metric_mjpeg_frames_interlaced_dropped;
 313                 return;
 314         }
 315         if (userdata->pixel_format != PixelFormat_8BitYCbCr ||
 316             !frame->interleaved) {
 317                 fprintf(stderr, "Card %u: Ignoring JPEG encoding for unsupported pixel format\n", card_index);
 318                 ++metric_mjpeg_frames_unsupported_pixel_format_dropped;
 319                 return;
 320         }
 321         if (video_format.width > 4096 || video_format.height > 4096) {
 322                 fprintf(stderr, "Card %u: Ignoring JPEG encoding for oversized frame\n", card_index);
 323                 ++metric_mjpeg_frames_oversized_dropped;
 324                 return;
 325         }
 326
 327         lock_guard<mutex> lock(mu);
 328         if (frames_to_be_encoded.size() + frames_encoding.size() > 50) {
 329                 fprintf(stderr, "WARNING: MJPEG encoding doesn't keep up, discarding frame.\n");
 330                 ++metric_mjpeg_overrun_dropped;
 331                 return;
 332         }
 333         ++metric_mjpeg_overrun_submitted;
 334         frames_to_be_encoded.push(QueuedFrame{ pts, card_index, frame, video_format, y_offset, cbcr_offset, move(audio), white_balance });
 335         any_frames_to_be_encoded.notify_all();
 336 }
 337
 338 bool MJPEGEncoder::should_encode_mjpeg_for_card(unsigned card_index)
 339 {
 340         // Only bother doing MJPEG encoding if there are any connected clients
 341         // that want the stream.
 342         if (httpd->get_num_connected_multicam_clients() == 0 &&
 343             httpd->get_num_connected_siphon_clients(card_index) == 0) {
 344                 return false;
 345         }
 346
 347         auto it = global_flags.card_to_mjpeg_stream_export.find(card_index);
 348         return (it != global_flags.card_to_mjpeg_stream_export.end());
 349 }
 350
 351 void MJPEGEncoder::encoder_thread_func()
 352 {
 353         pthread_setname_np(pthread_self(), "MJPEG_Encode");
 354         posix_memalign((void **)&tmp_y, 4096, 4096 * 8);
 355         posix_memalign((void **)&tmp_cbcr, 4096, 4096 * 8);
 356         posix_memalign((void **)&tmp_cb, 4096, 4096 * 8);
 357         posix_memalign((void **)&tmp_cr, 4096, 4096 * 8);
 358
 359         for (;;) {
 360                 QueuedFrame qf;
 361                 {
 362                         unique_lock<mutex> lock(mu);
 363                         any_frames_to_be_encoded.wait(lock, [this] { return !frames_to_be_encoded.empty() || should_quit; });
 364                         if (should_quit) break;
 365                         qf = move(frames_to_be_encoded.front());
 366                         frames_to_be_encoded.pop();
 367                 }
 368
 369                 assert(global_flags.card_to_mjpeg_stream_export.count(qf.card_index));  // Or should_encode_mjpeg_for_card() would have returned false.
 370                 int stream_index = global_flags.card_to_mjpeg_stream_export[qf.card_index];
 371
 372                 if (va_dpy != nullptr) {
 373                         // Will call back in the receiver thread.
 374                         encode_jpeg_va(move(qf));
 375                 } else {
 376                         update_siphon_streams();
 377
 378                         HTTPD::StreamID multicam_id{ HTTPD::MULTICAM_STREAM, 0 };
 379                         HTTPD::StreamID siphon_id{ HTTPD::SIPHON_STREAM, qf.card_index };
 380                         assert(streams.count(multicam_id));
 381
 382                         // Write audio before video, since Futatabi expects it.
 383                         if (qf.audio.size() > 0) {
 384                                 write_audio_packet(streams[multicam_id].avctx.get(), qf.pts, stream_index + global_flags.card_to_mjpeg_stream_export.size(), qf.audio);
 385                                 if (streams.count(siphon_id)) {
 386                                         write_audio_packet(streams[siphon_id].avctx.get(), qf.pts, /*stream_index=*/1, qf.audio);
 387                                 }
 388                         }
 389
 390                         // Encode synchronously, in the same thread.
 391                         vector<uint8_t> jpeg = encode_jpeg_libjpeg(qf);
 392                         write_mjpeg_packet(streams[multicam_id].avctx.get(), qf.pts, stream_index, jpeg.data(), jpeg.size());
 393                         if (streams.count(siphon_id)) {
 394                                 write_mjpeg_packet(streams[siphon_id].avctx.get(), qf.pts, /*stream_index=*/0, jpeg.data(), jpeg.size());
 395                         }
 396                 }
 397         }
 398
 399         free(tmp_y);
 400         free(tmp_cbcr);
 401         free(tmp_cb);
 402         free(tmp_cr);
 403 }
 404
 405 void MJPEGEncoder::write_mjpeg_packet(AVFormatContext *avctx, int64_t pts, unsigned stream_index, const uint8_t *jpeg, size_t jpeg_size)
 406 {
 407         AVPacket pkt;
 408         memset(&pkt, 0, sizeof(pkt));
 409         pkt.buf = nullptr;
 410         pkt.data = const_cast<uint8_t *>(jpeg);
 411         pkt.size = jpeg_size;
 412         pkt.stream_index = stream_index;
 413         pkt.flags = AV_PKT_FLAG_KEY;
 414         AVRational time_base = avctx->streams[pkt.stream_index]->time_base;
 415         pkt.pts = pkt.dts = av_rescale_q(pts, AVRational{ 1, TIMEBASE }, time_base);
 416         pkt.duration = 0;
 417
 418         if (av_write_frame(avctx, &pkt) < 0) {
 419                 fprintf(stderr, "av_write_frame() failed\n");
 420                 abort();
 421         }
 422 }
 423
 424 void MJPEGEncoder::write_audio_packet(AVFormatContext *avctx, int64_t pts, unsigned stream_index, const vector<int32_t> &audio)
 425 {
 426         AVPacket pkt;
 427         memset(&pkt, 0, sizeof(pkt));
 428         pkt.buf = nullptr;
 429         pkt.data = reinterpret_cast<uint8_t *>(const_cast<int32_t *>(&audio[0]));
 430         pkt.size = audio.size() * sizeof(audio[0]);
 431         pkt.stream_index = stream_index;
 432         pkt.flags = AV_PKT_FLAG_KEY;
 433         AVRational time_base = avctx->streams[pkt.stream_index]->time_base;
 434         pkt.pts = pkt.dts = av_rescale_q(pts, AVRational{ 1, TIMEBASE }, time_base);
 435         size_t num_stereo_samples = audio.size() / 2;
 436         pkt.duration = av_rescale_q(num_stereo_samples, AVRational{ 1, OUTPUT_FREQUENCY }, time_base);
 437
 438         if (av_write_frame(avctx, &pkt) < 0) {
 439                 fprintf(stderr, "av_write_frame() failed\n");
 440                 abort();
 441         }
 442 }
 443
 444 class VABufferDestroyer {
 445 public:
 446         VABufferDestroyer(VADisplay dpy, VABufferID buf)
 447                 : dpy(dpy), buf(buf) {}
 448
 449         ~VABufferDestroyer() {
 450                 VAStatus va_status = vaDestroyBuffer(dpy, buf);
 451                 CHECK_VASTATUS(va_status, "vaDestroyBuffer");
 452         }
 453
 454 private:
 455         VADisplay dpy;
 456         VABufferID buf;
 457 };
 458
 459 MJPEGEncoder::VAResources MJPEGEncoder::get_va_resources(unsigned width, unsigned height)
 460 {
 461         {
 462                 lock_guard<mutex> lock(va_resources_mutex);
 463                 for (auto it = va_resources_freelist.begin(); it != va_resources_freelist.end(); ++it) {
 464                         if (it->width == width && it->height == height) {
 465                                 VAResources ret = *it;
 466                                 va_resources_freelist.erase(it);
 467                                 return ret;
 468                         }
 469                 }
 470         }
 471
 472         VAResources ret;
 473
 474         ret.width = width;
 475         ret.height = height;
 476
 477         VASurfaceAttrib attrib;
 478         attrib.flags = VA_SURFACE_ATTRIB_SETTABLE;
 479         attrib.type = VASurfaceAttribPixelFormat;
 480         attrib.value.type = VAGenericValueTypeInteger;
 481         attrib.value.value.i = VA_FOURCC_UYVY;
 482
 483         VAStatus va_status = vaCreateSurfaces(va_dpy->va_dpy, VA_RT_FORMAT_YUV422,
 484                 width, height,
 485                 &ret.surface, 1, &attrib, 1);
 486         CHECK_VASTATUS(va_status, "vaCreateSurfaces");
 487
 488         va_status = vaCreateContext(va_dpy->va_dpy, config_id, width, height, 0, &ret.surface, 1, &ret.context);
 489         CHECK_VASTATUS(va_status, "vaCreateContext");
 490
 491         va_status = vaCreateBuffer(va_dpy->va_dpy, ret.context, VAEncCodedBufferType, width * height * 3 + 8192, 1, nullptr, &ret.data_buffer);
 492         CHECK_VASTATUS(va_status, "vaCreateBuffer");
 493
 494         va_status = vaCreateImage(va_dpy->va_dpy, &uyvy_format, width, height, &ret.image);
 495         CHECK_VASTATUS(va_status, "vaCreateImage");
 496
 497         return ret;
 498 }
 499
 500 void MJPEGEncoder::release_va_resources(MJPEGEncoder::VAResources resources)
 501 {
 502         lock_guard<mutex> lock(va_resources_mutex);
 503         if (va_resources_freelist.size() > 50) {
 504                 auto it = va_resources_freelist.end();
 505                 --it;
 506
 507                 VAStatus va_status = vaDestroyBuffer(va_dpy->va_dpy, it->data_buffer);
 508                 CHECK_VASTATUS(va_status, "vaDestroyBuffer");
 509
 510                 va_status = vaDestroyContext(va_dpy->va_dpy, it->context);
 511                 CHECK_VASTATUS(va_status, "vaDestroyContext");
 512
 513                 va_status = vaDestroySurfaces(va_dpy->va_dpy, &it->surface, 1);
 514                 CHECK_VASTATUS(va_status, "vaDestroySurfaces");
 515
 516                 va_status = vaDestroyImage(va_dpy->va_dpy, it->image.image_id);
 517                 CHECK_VASTATUS(va_status, "vaDestroyImage");
 518
 519                 va_resources_freelist.erase(it);
 520         }
 521
 522         va_resources_freelist.push_front(resources);
 523 }
 524
 525 namespace {
 526
 527 void push16(uint16_t val, string *str)
 528 {
 529         str->push_back(val >> 8);
 530         str->push_back(val & 0xff);
 531 }
 532
 533 void push32(uint32_t val, string *str)
 534 {
 535         str->push_back(val >> 24);
 536         str->push_back((val >> 16) & 0xff);
 537         str->push_back((val >> 8) & 0xff);
 538         str->push_back(val & 0xff);
 539 }
 540
 541 }  // namespace
 542
 543 void MJPEGEncoder::init_jpeg_422(unsigned width, unsigned height, const RGBTriplet &white_balance, VectorDestinationManager *dest, jpeg_compress_struct *cinfo)
 544 {
 545         jpeg_error_mgr jerr;
 546         cinfo->err = jpeg_std_error(&jerr);
 547         jpeg_create_compress(cinfo);
 548
 549         cinfo->dest = (jpeg_destination_mgr *)dest;
 550
 551         cinfo->input_components = 3;
 552         jpeg_set_defaults(cinfo);
 553         jpeg_set_quality(cinfo, quality, /*force_baseline=*/false);
 554
 555         cinfo->image_width = width;
 556         cinfo->image_height = height;
 557         cinfo->raw_data_in = true;
 558         jpeg_set_colorspace(cinfo, JCS_YCbCr);
 559         cinfo->comp_info[0].h_samp_factor = 2;
 560         cinfo->comp_info[0].v_samp_factor = 1;
 561         cinfo->comp_info[1].h_samp_factor = 1;
 562         cinfo->comp_info[1].v_samp_factor = 1;
 563         cinfo->comp_info[2].h_samp_factor = 1;
 564         cinfo->comp_info[2].v_samp_factor = 1;
 565         cinfo->CCIR601_sampling = true;  // Seems to be mostly ignored by libjpeg, though.
 566         jpeg_start_compress(cinfo, true);
 567
 568         if (fabs(white_balance.r - 1.0f) > 1e-3 ||
 569             fabs(white_balance.g - 1.0f) > 1e-3 ||
 570             fabs(white_balance.b - 1.0f) > 1e-3) {
 571                 // Convert from (linear) RGB to XYZ.
 572                 Matrix3d rgb_to_xyz_matrix = movit::ColorspaceConversionEffect::get_xyz_matrix(COLORSPACE_sRGB);
 573                 Vector3d xyz = rgb_to_xyz_matrix * Vector3d(white_balance.r, white_balance.g, white_balance.b);
 574
 575                 // Convert from XYZ to xyz by normalizing.
 576                 xyz /= (xyz[0] + xyz[1] + xyz[2]);
 577
 578                 // Create a very rudimentary EXIF header to hold our white point.
 579                 string exif;
 580
 581                 // Exif header, followed by some padding.
 582                 exif = "Exif";
 583                 push16(0, &exif);
 584
 585                 // TIFF header first:
 586                 exif += "MM";  // Big endian.
 587
 588                 // Magic number.
 589                 push16(42, &exif);
 590
 591                 // Offset of first IFD (relative to the MM, immediately after the header).
 592                 push32(exif.size() - 6 + 4, &exif);
 593
 594                 // Now the actual IFD.
 595
 596                 // One entry.
 597                 push16(1, &exif);
 598
 599                 // WhitePoint tag ID.
 600                 push16(0x13e, &exif);
 601
 602                 // Rational type.
 603                 push16(5, &exif);
 604
 605                 // Two values (x and y; z is implicit due to normalization).
 606                 push32(2, &exif);
 607
 608                 // Offset (relative to the MM, immediately after the last IFD).
 609                 push32(exif.size() - 6 + 8, &exif);
 610
 611                 // No more IFDs.
 612                 push32(0, &exif);
 613
 614                 // The actual values.
 615                 push32(lrintf(xyz[0] * 10000.0f), &exif);
 616                 push32(10000, &exif);
 617                 push32(lrintf(xyz[1] * 10000.0f), &exif);
 618                 push32(10000, &exif);
 619
 620                 jpeg_write_marker(cinfo, JPEG_APP0 + 1, (const JOCTET *)exif.data(), exif.size());
 621         }
 622
 623         // This comment marker is private to FFmpeg. It signals limited Y'CbCr range
 624         // (and nothing else).
 625         jpeg_write_marker(cinfo, JPEG_COM, (const JOCTET *)"CS=ITU601", strlen("CS=ITU601"));
 626 }
 627
 628 vector<uint8_t> MJPEGEncoder::get_jpeg_header(unsigned width, unsigned height, const RGBTriplet &white_balance, jpeg_compress_struct *cinfo)
 629 {
 630         VectorDestinationManager dest;
 631         init_jpeg_422(width, height, white_balance, &dest, cinfo);
 632
 633         // Make a dummy black image; there's seemingly no other easy way of
 634         // making libjpeg outputting all of its headers.
 635         JSAMPROW yptr[8], cbptr[8], crptr[8];
 636         JSAMPARRAY data[3] = { yptr, cbptr, crptr };
 637         memset(tmp_y, 0, 4096);
 638         memset(tmp_cb, 0, 4096);
 639         memset(tmp_cr, 0, 4096);
 640         for (unsigned yy = 0; yy < 8; ++yy) {
 641                 yptr[yy] = tmp_y;
 642                 cbptr[yy] = tmp_cb;
 643                 crptr[yy] = tmp_cr;
 644         }
 645         for (unsigned y = 0; y < height; y += 8) {
 646                 jpeg_write_raw_data(cinfo, data, /*num_lines=*/8);
 647         }
 648         jpeg_finish_compress(cinfo);
 649
 650         // We're only interested in the header, not the data after it.
 651         dest.term_destination();
 652         for (size_t i = 0; i < dest.dest.size() - 1; ++i) {
 653                 if (dest.dest[i] == 0xff && dest.dest[i + 1] == 0xda) {  // Start of scan (SOS).
 654                         unsigned len = dest.dest[i + 2] * 256 + dest.dest[i + 3];
 655                         dest.dest.resize(i + len + 2);
 656                         break;
 657                 }
 658         }
 659
 660         return dest.dest;
 661 }
 662
 663 MJPEGEncoder::VAData MJPEGEncoder::get_va_data_for_parameters(unsigned width, unsigned height, const RGBTriplet &white_balance)
 664 {
 665         VAKey key{width, height, white_balance};
 666         if (va_data_for_parameters.count(key)) {
 667                 return va_data_for_parameters[key];
 668         }
 669
 670         // Use libjpeg to generate a header and set sane defaults for e.g.
 671         // quantization tables. Then do the actual encode with VA-API.
 672         jpeg_compress_struct cinfo;
 673         vector<uint8_t> jpeg_header = get_jpeg_header(width, height, white_balance, &cinfo);
 674
 675         // Picture parameters.
 676         VAEncPictureParameterBufferJPEG pic_param;
 677         memset(&pic_param, 0, sizeof(pic_param));
 678         pic_param.reconstructed_picture = VA_INVALID_ID;
 679         pic_param.picture_width = cinfo.image_width;
 680         pic_param.picture_height = cinfo.image_height;
 681         for (int component_idx = 0; component_idx < cinfo.num_components; ++component_idx) {
 682                 const jpeg_component_info *comp = &cinfo.comp_info[component_idx];
 683                 pic_param.component_id[component_idx] = comp->component_id;
 684                 pic_param.quantiser_table_selector[component_idx] = comp->quant_tbl_no;
 685         }
 686         pic_param.num_components = cinfo.num_components;
 687         pic_param.num_scan = 1;
 688         pic_param.sample_bit_depth = 8;
 689         pic_param.coded_buf = VA_INVALID_ID;  // To be filled out by caller.
 690         pic_param.pic_flags.bits.huffman = 1;
 691         pic_param.quality = 50;  // Don't scale the given quantization matrices. (See gen8_mfc_jpeg_fqm_state)
 692
 693         // Quantization matrices.
 694         VAQMatrixBufferJPEG q;
 695         memset(&q, 0, sizeof(q));
 696
 697         q.load_lum_quantiser_matrix = true;
 698         q.load_chroma_quantiser_matrix = true;
 699         for (int quant_tbl_idx = 0; quant_tbl_idx < min(4, NUM_QUANT_TBLS); ++quant_tbl_idx) {
 700                 const JQUANT_TBL *qtbl = cinfo.quant_tbl_ptrs[quant_tbl_idx];
 701                 assert((qtbl == nullptr) == (quant_tbl_idx >= 2));
 702                 if (qtbl == nullptr) continue;
 703
 704                 uint8_t *qmatrix = (quant_tbl_idx == 0) ? q.lum_quantiser_matrix : q.chroma_quantiser_matrix;
 705                 for (int i = 0; i < 64; ++i) {
 706                         if (qtbl->quantval[i] > 255) {
 707                                 fprintf(stderr, "Baseline JPEG only!\n");
 708                                 abort();
 709                         }
 710                         qmatrix[i] = qtbl->quantval[jpeg_natural_order[i]];
 711                 }
 712         }
 713
 714         // Huffman tables (arithmetic is not supported).
 715         VAHuffmanTableBufferJPEGBaseline huff;
 716         memset(&huff, 0, sizeof(huff));
 717
 718         for (int huff_tbl_idx = 0; huff_tbl_idx < min(2, NUM_HUFF_TBLS); ++huff_tbl_idx) {
 719                 const JHUFF_TBL *ac_hufftbl = cinfo.ac_huff_tbl_ptrs[huff_tbl_idx];
 720                 const JHUFF_TBL *dc_hufftbl = cinfo.dc_huff_tbl_ptrs[huff_tbl_idx];
 721                 if (ac_hufftbl == nullptr) {
 722                         assert(dc_hufftbl == nullptr);
 723                         huff.load_huffman_table[huff_tbl_idx] = 0;
 724                 } else {
 725                         assert(dc_hufftbl != nullptr);
 726                         huff.load_huffman_table[huff_tbl_idx] = 1;
 727
 728                         for (int i = 0; i < 16; ++i) {
 729                                 huff.huffman_table[huff_tbl_idx].num_dc_codes[i] = dc_hufftbl->bits[i + 1];
 730                         }
 731                         for (int i = 0; i < 12; ++i) {
 732                                 huff.huffman_table[huff_tbl_idx].dc_values[i] = dc_hufftbl->huffval[i];
 733                         }
 734                         for (int i = 0; i < 16; ++i) {
 735                                 huff.huffman_table[huff_tbl_idx].num_ac_codes[i] = ac_hufftbl->bits[i + 1];
 736                         }
 737                         for (int i = 0; i < 162; ++i) {
 738                                 huff.huffman_table[huff_tbl_idx].ac_values[i] = ac_hufftbl->huffval[i];
 739                         }
 740                 }
 741         }
 742
 743         // Slice parameters (metadata about the slice).
 744         VAEncSliceParameterBufferJPEG parms;
 745         memset(&parms, 0, sizeof(parms));
 746         for (int component_idx = 0; component_idx < cinfo.num_components; ++component_idx) {
 747                 const jpeg_component_info *comp = &cinfo.comp_info[component_idx];
 748                 parms.components[component_idx].component_selector = comp->component_id;
 749                 parms.components[component_idx].dc_table_selector = comp->dc_tbl_no;
 750                 parms.components[component_idx].ac_table_selector = comp->ac_tbl_no;
 751                 if (parms.components[component_idx].dc_table_selector > 1 ||
 752                     parms.components[component_idx].ac_table_selector > 1) {
 753                         fprintf(stderr, "Uses too many Huffman tables\n");
 754                         abort();
 755                 }
 756         }
 757         parms.num_components = cinfo.num_components;
 758         parms.restart_interval = cinfo.restart_interval;
 759
 760         jpeg_destroy_compress(&cinfo);
 761
 762         VAData ret;
 763         ret.jpeg_header = move(jpeg_header);
 764         ret.pic_param = pic_param;
 765         ret.q = q;
 766         ret.huff = huff;
 767         ret.parms = parms;
 768         va_data_for_parameters[key] = ret;
 769         return ret;
 770 }
 771
 772 void MJPEGEncoder::encode_jpeg_va(QueuedFrame &&qf)
 773 {
 774         PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)qf.frame->userdata;
 775         unsigned width = qf.video_format.width;
 776         unsigned height = qf.video_format.height;
 777
 778         VAResources resources;
 779         ReleaseVAResources release;
 780         if (userdata->data_copy_current_src == PBOFrameAllocator::Userdata::FROM_VA_API) {
 781                 resources = move(userdata->va_resources);
 782                 release = move(userdata->va_resources_release);
 783         } else {
 784                 assert(userdata->data_copy_current_src == PBOFrameAllocator::Userdata::FROM_MALLOC);
 785                 resources = get_va_resources(width, height);
 786                 release = ReleaseVAResources(this, resources);
 787         }
 788
 789         VAData va_data = get_va_data_for_parameters(width, height, qf.white_balance);
 790         va_data.pic_param.coded_buf = resources.data_buffer;
 791
 792         VABufferID pic_param_buffer;
 793         VAStatus va_status = vaCreateBuffer(va_dpy->va_dpy, resources.context, VAEncPictureParameterBufferType, sizeof(va_data.pic_param), 1, &va_data.pic_param, &pic_param_buffer);
 794         CHECK_VASTATUS(va_status, "vaCreateBuffer");
 795         VABufferDestroyer destroy_pic_param(va_dpy->va_dpy, pic_param_buffer);
 796
 797         VABufferID q_buffer;
 798         va_status = vaCreateBuffer(va_dpy->va_dpy, resources.context, VAQMatrixBufferType, sizeof(va_data.q), 1, &va_data.q, &q_buffer);
 799         CHECK_VASTATUS(va_status, "vaCreateBuffer");
 800         VABufferDestroyer destroy_iq(va_dpy->va_dpy, q_buffer);
 801
 802         VABufferID huff_buffer;
 803         va_status = vaCreateBuffer(va_dpy->va_dpy, resources.context, VAHuffmanTableBufferType, sizeof(va_data.huff), 1, &va_data.huff, &huff_buffer);
 804         CHECK_VASTATUS(va_status, "vaCreateBuffer");
 805         VABufferDestroyer destroy_huff(va_dpy->va_dpy, huff_buffer);
 806
 807         VABufferID slice_param_buffer;
 808         va_status = vaCreateBuffer(va_dpy->va_dpy, resources.context, VAEncSliceParameterBufferType, sizeof(va_data.parms), 1, &va_data.parms, &slice_param_buffer);
 809         CHECK_VASTATUS(va_status, "vaCreateBuffer");
 810         VABufferDestroyer destroy_slice_param(va_dpy->va_dpy, slice_param_buffer);
 811
 812         if (userdata->data_copy_current_src == PBOFrameAllocator::Userdata::FROM_VA_API) {
 813                 // The pixel data is already put into the image by the caller.
 814                 va_status = vaUnmapBuffer(va_dpy->va_dpy, resources.image.buf);
 815                 CHECK_VASTATUS(va_status, "vaUnmapBuffer");
 816         } else {
 817                 assert(userdata->data_copy_current_src == PBOFrameAllocator::Userdata::FROM_MALLOC);
 818
 819                 // Upload the pixel data.
 820                 uint8_t *surface_p = nullptr;
 821                 vaMapBuffer(va_dpy->va_dpy, resources.image.buf, (void **)&surface_p);
 822
 823                 size_t field_start_line = qf.video_format.extra_lines_top;  // No interlacing support.
 824                 size_t field_start = qf.cbcr_offset * 2 + qf.video_format.width * field_start_line * 2;
 825
 826                 {
 827                         const uint8_t *src = qf.frame->data_copy + field_start;
 828                         uint8_t *dst = (unsigned char *)surface_p + resources.image.offsets[0];
 829                         memcpy_with_pitch(dst, src, qf.video_format.width * 2, resources.image.pitches[0], qf.video_format.height);
 830                 }
 831
 832                 va_status = vaUnmapBuffer(va_dpy->va_dpy, resources.image.buf);
 833                 CHECK_VASTATUS(va_status, "vaUnmapBuffer");
 834         }
 835
 836         qf.frame->data_copy = nullptr;
 837
 838         // Seemingly vaPutImage() (which triggers a GPU copy) is much nicer to the
 839         // CPU than vaDeriveImage() and copying directly into the GPU's buffers.
 840         // Exactly why is unclear, but it seems to involve L3 cache usage when there
 841         // are many high-res (1080p+) images in play.
 842         va_status = vaPutImage(va_dpy->va_dpy, resources.surface, resources.image.image_id, 0, 0, width, height, 0, 0, width, height);
 843         CHECK_VASTATUS(va_status, "vaPutImage");
 844
 845         // Finally, stick in the JPEG header.
 846         VAEncPackedHeaderParameterBuffer header_parm;
 847         header_parm.type = VAEncPackedHeaderRawData;
 848         header_parm.bit_length = 8 * va_data.jpeg_header.size();
 849
 850         VABufferID header_parm_buffer;
 851         va_status = vaCreateBuffer(va_dpy->va_dpy, resources.context, VAEncPackedHeaderParameterBufferType, sizeof(header_parm), 1, &header_parm, &header_parm_buffer);
 852         CHECK_VASTATUS(va_status, "vaCreateBuffer");
 853         VABufferDestroyer destroy_header(va_dpy->va_dpy, header_parm_buffer);
 854
 855         VABufferID header_data_buffer;
 856         va_status = vaCreateBuffer(va_dpy->va_dpy, resources.context, VAEncPackedHeaderDataBufferType, va_data.jpeg_header.size(), 1, va_data.jpeg_header.data(), &header_data_buffer);
 857         CHECK_VASTATUS(va_status, "vaCreateBuffer");
 858         VABufferDestroyer destroy_header_data(va_dpy->va_dpy, header_data_buffer);
 859
 860         va_status = vaBeginPicture(va_dpy->va_dpy, resources.context, resources.surface);
 861         CHECK_VASTATUS(va_status, "vaBeginPicture");
 862         va_status = vaRenderPicture(va_dpy->va_dpy, resources.context, &pic_param_buffer, 1);
 863         CHECK_VASTATUS(va_status, "vaRenderPicture(pic_param)");
 864         va_status = vaRenderPicture(va_dpy->va_dpy, resources.context, &q_buffer, 1);
 865         CHECK_VASTATUS(va_status, "vaRenderPicture(q)");
 866         va_status = vaRenderPicture(va_dpy->va_dpy, resources.context, &huff_buffer, 1);
 867         CHECK_VASTATUS(va_status, "vaRenderPicture(huff)");
 868         va_status = vaRenderPicture(va_dpy->va_dpy, resources.context, &slice_param_buffer, 1);
 869         CHECK_VASTATUS(va_status, "vaRenderPicture(slice_param)");
 870         va_status = vaRenderPicture(va_dpy->va_dpy, resources.context, &header_parm_buffer, 1);
 871         CHECK_VASTATUS(va_status, "vaRenderPicture(header_parm)");
 872         va_status = vaRenderPicture(va_dpy->va_dpy, resources.context, &header_data_buffer, 1);
 873         CHECK_VASTATUS(va_status, "vaRenderPicture(header_data)");
 874         va_status = vaEndPicture(va_dpy->va_dpy, resources.context);
 875         CHECK_VASTATUS(va_status, "vaEndPicture");
 876
 877         qf.resources = move(resources);
 878         qf.resource_releaser = move(release);
 879
 880         lock_guard<mutex> lock(mu);
 881         frames_encoding.push(move(qf));
 882         any_frames_encoding.notify_all();
 883 }
 884
 885 void MJPEGEncoder::va_receiver_thread_func()
 886 {
 887         pthread_setname_np(pthread_self(), "MJPEG_Receive");
 888         for (;;) {
 889                 QueuedFrame qf;
 890                 {
 891                         unique_lock<mutex> lock(mu);
 892                         any_frames_encoding.wait(lock, [this] { return !frames_encoding.empty() || should_quit; });
 893                         if (should_quit) return;
 894                         qf = move(frames_encoding.front());
 895                         frames_encoding.pop();
 896                 }
 897
 898                 update_siphon_streams();
 899
 900                 assert(global_flags.card_to_mjpeg_stream_export.count(qf.card_index));  // Or should_encode_mjpeg_for_card() would have returned false.
 901                 int stream_index = global_flags.card_to_mjpeg_stream_export[qf.card_index];
 902
 903                 HTTPD::StreamID multicam_id{ HTTPD::MULTICAM_STREAM, 0 };
 904                 HTTPD::StreamID siphon_id{ HTTPD::SIPHON_STREAM, qf.card_index };
 905                 assert(streams.count(multicam_id));
 906                 assert(streams[multicam_id].avctx != nullptr);
 907
 908                 // Write audio before video, since Futatabi expects it.
 909                 if (qf.audio.size() > 0) {
 910                         write_audio_packet(streams[multicam_id].avctx.get(), qf.pts, stream_index + global_flags.card_to_mjpeg_stream_export.size(), qf.audio);
 911                         if (streams.count(siphon_id)) {
 912                                 write_audio_packet(streams[siphon_id].avctx.get(), qf.pts, /*stream_index=*/1, qf.audio);
 913                         }
 914                 }
 915
 916                 VAStatus va_status = vaSyncSurface(va_dpy->va_dpy, qf.resources.surface);
 917                 CHECK_VASTATUS(va_status, "vaSyncSurface");
 918
 919                 VACodedBufferSegment *segment;
 920                 va_status = vaMapBuffer(va_dpy->va_dpy, qf.resources.data_buffer, (void **)&segment);
 921                 CHECK_VASTATUS(va_status, "vaMapBuffer");
 922
 923                 const uint8_t *coded_buf = reinterpret_cast<uint8_t *>(segment->buf);
 924                 write_mjpeg_packet(streams[multicam_id].avctx.get(), qf.pts, stream_index, coded_buf, segment->size);
 925                 if (streams.count(siphon_id)) {
 926                         write_mjpeg_packet(streams[siphon_id].avctx.get(), qf.pts, /*stream_index=*/0, coded_buf, segment->size);
 927                 }
 928
 929                 va_status = vaUnmapBuffer(va_dpy->va_dpy, qf.resources.data_buffer);
 930                 CHECK_VASTATUS(va_status, "vaUnmapBuffer");
 931         }
 932 }
 933
 934 vector<uint8_t> MJPEGEncoder::encode_jpeg_libjpeg(const QueuedFrame &qf)
 935 {
 936         unsigned width = qf.video_format.width;
 937         unsigned height = qf.video_format.height;
 938
 939         VectorDestinationManager dest;
 940         jpeg_compress_struct cinfo;
 941         init_jpeg_422(width, height, qf.white_balance, &dest, &cinfo);
 942
 943         size_t field_start_line = qf.video_format.extra_lines_top;  // No interlacing support.
 944         size_t field_start = qf.cbcr_offset * 2 + qf.video_format.width * field_start_line * 2;
 945
 946         JSAMPROW yptr[8], cbptr[8], crptr[8];
 947         JSAMPARRAY data[3] = { yptr, cbptr, crptr };
 948         for (unsigned y = 0; y < qf.video_format.height; y += 8) {
 949                 const uint8_t *src = qf.frame->data_copy + field_start + y * qf.video_format.width * 2;
 950
 951                 memcpy_interleaved(tmp_cbcr, tmp_y, src, qf.video_format.width * 8 * 2);
 952                 memcpy_interleaved(tmp_cb, tmp_cr, tmp_cbcr, qf.video_format.width * 8);
 953                 for (unsigned yy = 0; yy < 8; ++yy) {
 954                         yptr[yy] = tmp_y + yy * width;
 955                         cbptr[yy] = tmp_cb + yy * width / 2;
 956                         crptr[yy] = tmp_cr + yy * width / 2;
 957                 }
 958                 jpeg_write_raw_data(&cinfo, data, /*num_lines=*/8);
 959         }
 960         jpeg_finish_compress(&cinfo);
 961
 962         return dest.dest;
 963 }
 964
 965 void MJPEGEncoder::add_stream(HTTPD::StreamID stream_id)
 966 {
 967         AVFormatContextWithCloser avctx;
 968
 969         // Set up the mux. We don't use the Mux wrapper, because it's geared towards
 970         // a situation with only one video stream (and possibly one audio stream)
 971         // with known width/height, and we don't need the extra functionality it provides.
 972         avctx.reset(avformat_alloc_context());
 973         avctx->oformat = av_guess_format("nut", nullptr, nullptr);
 974
 975         uint8_t *buf = (uint8_t *)av_malloc(MUX_BUFFER_SIZE);
 976         avctx->pb = avio_alloc_context(buf, MUX_BUFFER_SIZE, 1, &ffmpeg_contexts[stream_id], nullptr, nullptr, nullptr);
 977         avctx->pb->write_data_type = &MJPEGEncoder::write_packet2_thunk;
 978         avctx->flags = AVFMT_FLAG_CUSTOM_IO;
 979
 980         if (stream_id.type == HTTPD::MULTICAM_STREAM) {
 981                 for (unsigned card_idx = 0; card_idx < global_flags.card_to_mjpeg_stream_export.size(); ++card_idx) {
 982                         add_video_stream(avctx.get());
 983                 }
 984                 for (unsigned card_idx = 0; card_idx < global_flags.card_to_mjpeg_stream_export.size(); ++card_idx) {
 985                         add_audio_stream(avctx.get());
 986                 }
 987         } else {
 988                 assert(stream_id.type == HTTPD::SIPHON_STREAM);
 989                 add_video_stream(avctx.get());
 990                 add_audio_stream(avctx.get());
 991         }
 992         finalize_mux(avctx.get());
 993
 994         Stream s;
 995         s.avctx = move(avctx);
 996         streams[stream_id] = move(s);
 997 }
 998
 999 void MJPEGEncoder::update_siphon_streams()
1000 {
1001         // Bring the list of streams into sync with what the clients need.
1002         for (auto it = streams.begin(); it != streams.end(); ) {
1003                 if (it->first.type != HTTPD::SIPHON_STREAM) {
1004                         ++it;
1005                         continue;
1006                 }
1007                 if (httpd->get_num_connected_siphon_clients(it->first.index) == 0) {
1008                         av_free(it->second.avctx->pb->buffer);
1009                         streams.erase(it++);
1010                 } else {
1011                         ++it;
1012                 }
1013         }
1014         for (unsigned stream_idx = 0; stream_idx < MAX_VIDEO_CARDS; ++stream_idx) {
1015                 HTTPD::StreamID stream_id{ HTTPD::SIPHON_STREAM, stream_idx };
1016                 if (streams.count(stream_id) == 0 && httpd->get_num_connected_siphon_clients(stream_idx) > 0) {
1017                         add_stream(stream_id);
1018                 }
1019         }
1020 }
1021
1022 void MJPEGEncoder::create_ffmpeg_context(HTTPD::StreamID stream_id)
1023 {
1024         ffmpeg_contexts.emplace(stream_id, WritePacket2Context{ this, stream_id });
1025 }