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

   1 #include "ffmpeg_capture.h"
   2
   3 #include <assert.h>
   4 #include <pthread.h>
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <sys/stat.h>
  10 #include <unistd.h>
  11
  12 extern "C" {
  13 #include <libavcodec/avcodec.h>
  14 #include <libavformat/avformat.h>
  15 #include <libavutil/avutil.h>
  16 #include <libavutil/error.h>
  17 #include <libavutil/frame.h>
  18 #include <libavutil/imgutils.h>
  19 #include <libavutil/mem.h>
  20 #include <libavutil/pixfmt.h>
  21 #include <libswscale/swscale.h>
  22 }
  23
  24 #include <chrono>
  25 #include <cstdint>
  26 #include <utility>
  27 #include <vector>
  28
  29 #include "bmusb/bmusb.h"
  30 #include "ffmpeg_raii.h"
  31 #include "flags.h"
  32 #include "image_input.h"
  33
  34 #define FRAME_SIZE (8 << 20)  // 8 MB.
  35
  36 using namespace std;
  37 using namespace std::chrono;
  38 using namespace bmusb;
  39
  40 namespace {
  41
  42 steady_clock::time_point compute_frame_start(int64_t frame_pts, int64_t pts_origin, const AVRational &video_timebase, const steady_clock::time_point &origin, double rate)
  43 {
  44         const duration<double> pts((frame_pts - pts_origin) * double(video_timebase.num) / double(video_timebase.den));
  45         return origin + duration_cast<steady_clock::duration>(pts / rate);
  46 }
  47
  48 bool changed_since(const std::string &pathname, const timespec &ts)
  49 {
  50         if (ts.tv_sec < 0) {
  51                 return false;
  52         }
  53         struct stat buf;
  54         if (stat(pathname.c_str(), &buf) != 0) {
  55                 fprintf(stderr, "%s: Couldn't check for new version, leaving the old in place.\n", pathname.c_str());
  56                 return false;
  57         }
  58         return (buf.st_mtim.tv_sec != ts.tv_sec || buf.st_mtim.tv_nsec != ts.tv_nsec);
  59 }
  60
  61 }  // namespace
  62
  63 FFmpegCapture::FFmpegCapture(const string &filename, unsigned width, unsigned height)
  64         : filename(filename), width(width), height(height)
  65 {
  66         // Not really used for anything.
  67         description = "Video: " + filename;
  68 }
  69
  70 FFmpegCapture::~FFmpegCapture()
  71 {
  72         if (has_dequeue_callbacks) {
  73                 dequeue_cleanup_callback();
  74         }
  75 }
  76
  77 void FFmpegCapture::configure_card()
  78 {
  79         if (video_frame_allocator == nullptr) {
  80                 owned_video_frame_allocator.reset(new MallocFrameAllocator(FRAME_SIZE, NUM_QUEUED_VIDEO_FRAMES));
  81                 set_video_frame_allocator(owned_video_frame_allocator.get());
  82         }
  83         if (audio_frame_allocator == nullptr) {
  84                 owned_audio_frame_allocator.reset(new MallocFrameAllocator(65536, NUM_QUEUED_AUDIO_FRAMES));
  85                 set_audio_frame_allocator(owned_audio_frame_allocator.get());
  86         }
  87 }
  88
  89 void FFmpegCapture::start_bm_capture()
  90 {
  91         if (running) {
  92                 return;
  93         }
  94         running = true;
  95         producer_thread_should_quit.unquit();
  96         producer_thread = thread(&FFmpegCapture::producer_thread_func, this);
  97 }
  98
  99 void FFmpegCapture::stop_dequeue_thread()
 100 {
 101         if (!running) {
 102                 return;
 103         }
 104         running = false;
 105         producer_thread_should_quit.quit();
 106         producer_thread.join();
 107 }
 108
 109 std::map<uint32_t, VideoMode> FFmpegCapture::get_available_video_modes() const
 110 {
 111         // Note: This will never really be shown in the UI.
 112         VideoMode mode;
 113
 114         char buf[256];
 115         snprintf(buf, sizeof(buf), "%ux%u", width, height);
 116         mode.name = buf;
 117
 118         mode.autodetect = false;
 119         mode.width = width;
 120         mode.height = height;
 121         mode.frame_rate_num = 60;
 122         mode.frame_rate_den = 1;
 123         mode.interlaced = false;
 124
 125         return {{ 0, mode }};
 126 }
 127
 128 void FFmpegCapture::producer_thread_func()
 129 {
 130         char thread_name[16];
 131         snprintf(thread_name, sizeof(thread_name), "FFmpeg_C_%d", card_index);
 132         pthread_setname_np(pthread_self(), thread_name);
 133
 134         while (!producer_thread_should_quit.should_quit()) {
 135                 string pathname = search_for_file(filename);
 136                 if (filename.empty()) {
 137                         fprintf(stderr, "%s not found, sleeping one second and trying again...\n", filename.c_str());
 138                         producer_thread_should_quit.sleep_for(seconds(1));
 139                         continue;
 140                 }
 141                 if (!play_video(pathname)) {
 142                         // Error.
 143                         fprintf(stderr, "Error when playing %s, sleeping one second and trying again...\n", pathname.c_str());
 144                         producer_thread_should_quit.sleep_for(seconds(1));
 145                         continue;
 146                 }
 147
 148                 // Probably just EOF, will exit the loop above on next test.
 149         }
 150
 151         if (has_dequeue_callbacks) {
 152                 dequeue_cleanup_callback();
 153                 has_dequeue_callbacks = false;
 154         }
 155 }
 156
 157 bool FFmpegCapture::play_video(const string &pathname)
 158 {
 159         // Note: Call before open, not after; otherwise, there's a race.
 160         // (There is now, too, but it tips the correct way. We could use fstat()
 161         // if we had the file descriptor.)
 162         timespec last_modified;
 163         struct stat buf;
 164         if (stat(pathname.c_str(), &buf) != 0) {
 165                 // Probably some sort of protocol, so can't stat.
 166                 last_modified.tv_sec = -1;
 167         } else {
 168                 last_modified = buf.st_mtim;
 169         }
 170
 171         auto format_ctx = avformat_open_input_unique(pathname.c_str(), nullptr, nullptr);
 172         if (format_ctx == nullptr) {
 173                 fprintf(stderr, "%s: Error opening file\n", pathname.c_str());
 174                 return false;
 175         }
 176
 177         if (avformat_find_stream_info(format_ctx.get(), nullptr) < 0) {
 178                 fprintf(stderr, "%s: Error finding stream info\n", pathname.c_str());
 179                 return false;
 180         }
 181
 182         int video_stream_index = -1, audio_stream_index = -1;
 183         AVRational video_timebase{ 1, 1 };
 184         for (unsigned i = 0; i < format_ctx->nb_streams; ++i) {
 185                 if (format_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
 186                     video_stream_index == -1) {
 187                         video_stream_index = i;
 188                         video_timebase = format_ctx->streams[i]->time_base;
 189                 }
 190                 if (format_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
 191                     audio_stream_index == -1) {
 192                         audio_stream_index = i;
 193                 }
 194         }
 195         if (video_stream_index == -1) {
 196                 fprintf(stderr, "%s: No video stream found\n", pathname.c_str());
 197                 return false;
 198         }
 199
 200         const AVCodecParameters *codecpar = format_ctx->streams[video_stream_index]->codecpar;
 201         AVCodecContextWithDeleter codec_ctx = avcodec_alloc_context3_unique(nullptr);
 202         if (avcodec_parameters_to_context(codec_ctx.get(), codecpar) < 0) {
 203                 fprintf(stderr, "%s: Cannot fill codec parameters\n", pathname.c_str());
 204                 return false;
 205         }
 206         AVCodec *codec = avcodec_find_decoder(codecpar->codec_id);
 207         if (codec == nullptr) {
 208                 fprintf(stderr, "%s: Cannot find decoder\n", pathname.c_str());
 209                 return false;
 210         }
 211         if (avcodec_open2(codec_ctx.get(), codec, nullptr) < 0) {
 212                 fprintf(stderr, "%s: Cannot open decoder\n", pathname.c_str());
 213                 return false;
 214         }
 215         unique_ptr<AVCodecContext, decltype(avcodec_close)*> codec_ctx_cleanup(
 216                 codec_ctx.get(), avcodec_close);
 217
 218         internal_rewind();
 219         double rate = 1.0;
 220
 221         unique_ptr<SwsContext, decltype(sws_freeContext)*> sws_ctx(nullptr, sws_freeContext);
 222         int sws_last_width = -1, sws_last_height = -1;
 223
 224         // Main loop.
 225         while (!producer_thread_should_quit.should_quit()) {
 226                 // Process any queued commands from other threads.
 227                 vector<QueuedCommand> commands;
 228                 {
 229                         lock_guard<mutex> lock(queue_mu);
 230                         swap(commands, command_queue);
 231                 }
 232                 for (const QueuedCommand &cmd : commands) {
 233                         switch (cmd.command) {
 234                         case QueuedCommand::REWIND:
 235                                 if (av_seek_frame(format_ctx.get(), /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) {
 236                                         fprintf(stderr, "%s: Rewind failed, stopping play.\n", pathname.c_str());
 237                                 }
 238                                 // If the file has changed since last time, return to get it reloaded.
 239                                 // Note that depending on how you move the file into place, you might
 240                                 // end up corrupting the one you're already playing, so this path
 241                                 // might not trigger.
 242                                 if (changed_since(pathname, last_modified)) {
 243                                         return true;
 244                                 }
 245                                 internal_rewind();
 246                                 break;
 247
 248                         case QueuedCommand::CHANGE_RATE:
 249                                 start = next_frame_start;
 250                                 pts_origin = last_pts;
 251                                 rate = cmd.new_rate;
 252                                 break;
 253                         }
 254                 }
 255
 256                 // Read packets until we have a frame or there are none left.
 257                 int frame_finished = 0;
 258                 AVFrameWithDeleter frame = av_frame_alloc_unique();
 259                 bool eof = false;
 260                 do {
 261                         AVPacket pkt;
 262                         unique_ptr<AVPacket, decltype(av_packet_unref)*> pkt_cleanup(
 263                                 &pkt, av_packet_unref);
 264                         av_init_packet(&pkt);
 265                         pkt.data = nullptr;
 266                         pkt.size = 0;
 267                         if (av_read_frame(format_ctx.get(), &pkt) == 0) {
 268                                 if (pkt.stream_index != video_stream_index) {
 269                                         // Ignore audio for now.
 270                                         continue;
 271                                 }
 272                                 if (avcodec_send_packet(codec_ctx.get(), &pkt) < 0) {
 273                                         fprintf(stderr, "%s: Cannot send packet to codec.\n", pathname.c_str());
 274                                         return false;
 275                                 }
 276                         } else {
 277                                 eof = true;  // Or error, but ignore that for the time being.
 278                         }
 279
 280                         int err = avcodec_receive_frame(codec_ctx.get(), frame.get());
 281                         if (err == 0) {
 282                                 frame_finished = true;
 283                                 break;
 284                         } else if (err != AVERROR(EAGAIN)) {
 285                                 fprintf(stderr, "%s: Cannot receive frame from codec.\n", pathname.c_str());
 286                                 return false;
 287                         }
 288                 } while (!eof);
 289
 290                 if (!frame_finished) {
 291                         // EOF. Loop back to the start if we can.
 292                         if (av_seek_frame(format_ctx.get(), /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) {
 293                                 fprintf(stderr, "%s: Rewind failed, not looping.\n", pathname.c_str());
 294                                 return true;
 295                         }
 296                         // If the file has changed since last time, return to get it reloaded.
 297                         // Note that depending on how you move the file into place, you might
 298                         // end up corrupting the one you're already playing, so this path
 299                         // might not trigger.
 300                         if (changed_since(pathname, last_modified)) {
 301                                 return true;
 302                         }
 303                         internal_rewind();
 304                         continue;
 305                 }
 306
 307                 if (sws_ctx == nullptr || sws_last_width != frame->width || sws_last_height != frame->height) {
 308                         sws_ctx.reset(
 309                                 sws_getContext(frame->width, frame->height, (AVPixelFormat)frame->format,
 310                                         width, height, AV_PIX_FMT_RGBA,
 311                                         SWS_BICUBIC, nullptr, nullptr, nullptr));
 312                         sws_last_width = frame->width;
 313                         sws_last_height = frame->height;
 314                 }
 315                 if (sws_ctx == nullptr) {
 316                         fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str());
 317                         return false;
 318                 }
 319
 320                 VideoFormat video_format;
 321                 video_format.width = width;
 322                 video_format.height = height;
 323                 video_format.stride = width * 4;
 324                 video_format.frame_rate_nom = video_timebase.den;
 325                 video_format.frame_rate_den = av_frame_get_pkt_duration(frame.get()) * video_timebase.num;
 326                 video_format.has_signal = true;
 327                 video_format.is_connected = true;
 328
 329                 next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
 330                 last_pts = frame->pts;
 331
 332                 FrameAllocator::Frame video_frame = video_frame_allocator->alloc_frame();
 333                 if (video_frame.data != nullptr) {
 334                         uint8_t *pic_data[4] = { video_frame.data, nullptr, nullptr, nullptr };
 335                         int linesizes[4] = { int(video_format.stride), 0, 0, 0 };
 336                         sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
 337                         video_frame.len = video_format.stride * height;
 338                         video_frame.received_timestamp = next_frame_start;
 339                 }
 340
 341                 FrameAllocator::Frame audio_frame;
 342                 AudioFormat audio_format;
 343                 audio_format.bits_per_sample = 32;
 344                 audio_format.num_channels = 8;
 345
 346                 producer_thread_should_quit.sleep_until(next_frame_start);
 347                 frame_callback(timecode++,
 348                         video_frame, 0, video_format,
 349                         audio_frame, 0, audio_format);
 350         }
 351         return true;
 352 }
 353
 354 void FFmpegCapture::internal_rewind()
 355 {
 356         pts_origin = last_pts = 0;
 357         start = next_frame_start = steady_clock::now();
 358 }