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