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

   1 #include <algorithm>
   2 #include <chrono>
   3 #include <condition_variable>
   4 #include <mutex>
   5 #include <thread>
   6 #include <vector>
   7
   8 #include <stdio.h>
   9
  10 #include <movit/util.h>
  11
  12 #include "clip_list.h"
  13 #include "context.h"
  14 #include "defs.h"
  15 #include "ffmpeg_raii.h"
  16 #include "httpd.h"
  17 #include "jpeg_frame_view.h"
  18 #include "mux.h"
  19 #include "player.h"
  20 #include "timebase.h"
  21 #include "video_stream.h"
  22
  23 using namespace std;
  24 using namespace std::chrono;
  25
  26 extern mutex frame_mu;
  27 extern vector<int64_t> frames[MAX_STREAMS];
  28 extern HTTPD *global_httpd;
  29
  30 void Player::thread_func(bool also_output_to_stream)
  31 {
  32         pthread_setname_np(pthread_self(), "Player");
  33
  34         QSurface *surface = create_surface();
  35         QOpenGLContext *context = create_context(surface);
  36         if (!make_current(context, surface)) {
  37                 printf("oops\n");
  38                 exit(1);
  39         }
  40
  41         check_error();
  42
  43         // Create the VideoStream object, now that we have an OpenGL context.
  44         if (also_output_to_stream) {
  45                 video_stream.reset(new VideoStream);
  46                 video_stream->start();
  47         }
  48
  49         check_error();
  50
  51         constexpr double output_framerate = 60000.0 / 1001.0;  // FIXME: make configurable
  52         int64_t pts = 0;
  53
  54         for ( ;; ) {
  55                 // Wait until we're supposed to play something.
  56                 {
  57                         unique_lock<mutex> lock(queue_state_mu);
  58                         new_clip_changed.wait(lock, [this]{
  59                                 return new_clip_ready && current_clip.pts_in != -1;
  60                         });
  61                         new_clip_ready = false;
  62                         playing = true;
  63                 }
  64
  65                 Clip clip;
  66                 unsigned stream_idx;
  67                 {
  68                         lock_guard<mutex> lock(mu);
  69                         clip = current_clip;
  70                         stream_idx = current_stream_idx;
  71                 }
  72                 steady_clock::time_point origin = steady_clock::now();
  73                 int64_t in_pts_origin = clip.pts_in;
  74                 int64_t out_pts_origin = pts;
  75
  76                 // Start playing exactly at a frame.
  77                 {
  78                         lock_guard<mutex> lock(frame_mu);
  79
  80                         // Find the first frame such that frame.pts <= in_pts.
  81                         auto it = lower_bound(frames[stream_idx].begin(),
  82                                 frames[stream_idx].end(),
  83                                 in_pts_origin);
  84                         if (it != frames[stream_idx].end()) {
  85                                 in_pts_origin = *it;
  86                         }
  87                 }
  88
  89                 // TODO: Lock to a rational multiple of the frame rate if possible.
  90                 double speed = 0.5;
  91
  92                 for (int frameno = 0; ; ++frameno) {  // Ends when the clip ends.
  93                         double out_pts = out_pts_origin + TIMEBASE * frameno / output_framerate;
  94                         steady_clock::time_point next_frame_start =
  95                                 origin + microseconds(lrint((out_pts - out_pts_origin) * 1e6 / TIMEBASE));
  96                         int64_t in_pts = lrint(in_pts_origin + TIMEBASE * frameno * speed / output_framerate);
  97                         pts = lrint(out_pts);
  98
  99                         steady_clock::duration time_behind = steady_clock::now() - next_frame_start;
 100                         if (time_behind >= milliseconds(200)) {
 101                                 fprintf(stderr, "WARNING: %ld ms behind, dropping a frame (no matter the type).\n",
 102                                         lrint(1e3 * duration<double>(time_behind).count()));
 103                                 continue;
 104                         }
 105
 106                         int64_t in_pts_lower, in_pts_upper;
 107                         bool ok = find_surrounding_frames(in_pts, stream_idx, &in_pts_lower, &in_pts_upper);
 108                         if (!ok || in_pts_upper >= clip.pts_out) {
 109                                 break;
 110                         }
 111
 112                         // Sleep until the next frame start, or until there's a new clip we're supposed to play.
 113                         {
 114                                 unique_lock<mutex> lock(queue_state_mu);
 115                                 new_clip_changed.wait_until(lock, next_frame_start, [this]{
 116                                         return new_clip_ready || override_stream_idx != -1;
 117                                 });
 118                                 if (new_clip_ready) break;
 119                                 if (override_stream_idx != -1) {
 120                                         stream_idx = override_stream_idx;
 121                                         override_stream_idx = -1;
 122                                         continue;
 123                                 }
 124                         }
 125
 126                         if (progress_callback != nullptr) {
 127                                 // NOTE: None of this will take into account any snapping done below.
 128                                 double played_this_clip = double(in_pts - clip.pts_in) / TIMEBASE / speed;
 129                                 double total_length = double(clip.pts_out - clip.pts_in) / TIMEBASE / speed;
 130                                 progress_callback(played_this_clip, total_length);
 131                         }
 132
 133                         if (in_pts_lower == in_pts_upper) {
 134                                 destination->setFrame(stream_idx, in_pts_lower, /*interpolated=*/false);
 135                                 if (video_stream != nullptr) {
 136                                         video_stream->schedule_original_frame(pts, stream_idx, in_pts_lower);
 137                                 }
 138                                 continue;
 139                         }
 140
 141                         // Snap to input frame: If we can do so with less than 1% jitter
 142                         // (ie., move less than 1% of an _output_ frame), do so.
 143                         bool snapped = false;
 144                         for (int64_t snap_pts : { in_pts_lower, in_pts_upper }) {
 145                                 double snap_pts_as_frameno = (snap_pts - in_pts_origin) * output_framerate / TIMEBASE / speed;
 146                                 if (fabs(snap_pts_as_frameno - frameno) < 0.01) {
 147                                         destination->setFrame(stream_idx, snap_pts, /*interpolated=*/false);
 148                                         if (video_stream != nullptr) {
 149                                                 video_stream->schedule_original_frame(pts, stream_idx, snap_pts);
 150                                         }
 151                                         in_pts_origin += snap_pts - in_pts;
 152                                         snapped = true;
 153                                         break;
 154                                 }
 155                         }
 156                         if (snapped) {
 157                                 continue;
 158                         }
 159
 160                         if (time_behind >= milliseconds(100)) {
 161                                 fprintf(stderr, "WARNING: %ld ms behind, dropping an interpolated frame.\n",
 162                                         lrint(1e3 * duration<double>(time_behind).count()));
 163                                 continue;
 164                         }
 165
 166                         double alpha = double(in_pts - in_pts_lower) / (in_pts_upper - in_pts_lower);
 167
 168                         if (video_stream == nullptr) {
 169                                 // Previews don't do any interpolation.
 170                                 destination->setFrame(stream_idx, in_pts_lower, /*interpolated=*/false);
 171                         } else {
 172                                 // Calculate the interpolated frame. When it's done, the destination
 173                                 // will be unblocked.
 174                                 destination->setFrame(stream_idx, pts, /*interpolated=*/true);
 175                                 video_stream->schedule_interpolated_frame(pts, stream_idx, in_pts_lower, in_pts_upper, alpha);
 176                         }
 177                 }
 178
 179                 {
 180                         unique_lock<mutex> lock(queue_state_mu);
 181                         playing = false;
 182                 }
 183                 if (done_callback != nullptr) {
 184                         done_callback();
 185                 }
 186         }
 187 }
 188
 189 // Find the frame immediately before and after this point.
 190 bool Player::find_surrounding_frames(int64_t pts, int stream_idx, int64_t *pts_lower, int64_t *pts_upper)
 191 {
 192         lock_guard<mutex> lock(frame_mu);
 193
 194         // Find the first frame such that frame.pts >= pts.
 195         auto it = lower_bound(frames[stream_idx].begin(),
 196                 frames[stream_idx].end(),
 197                 pts);
 198         if (it == frames[stream_idx].end()) {
 199                 return false;
 200         }
 201         *pts_upper = *it;
 202
 203         // Find the last frame such that in_pts <= frame.pts (if any).
 204         if (it == frames[stream_idx].begin()) {
 205                 *pts_lower = *it;
 206         } else {
 207                 *pts_lower = *(it - 1);
 208         }
 209         assert(pts >= *pts_lower);
 210         assert(pts <= *pts_upper);
 211         return true;
 212 }
 213
 214 Player::Player(JPEGFrameView *destination, bool also_output_to_stream)
 215         : destination(destination)
 216 {
 217         thread(&Player::thread_func, this, also_output_to_stream).detach();
 218 }
 219
 220 void Player::play_clip(const Clip &clip, unsigned stream_idx)
 221 {
 222         {
 223                 lock_guard<mutex> lock(mu);
 224                 current_clip = clip;
 225                 current_stream_idx = stream_idx;
 226         }
 227
 228         {
 229                 lock_guard<mutex> lock(queue_state_mu);
 230                 new_clip_ready = true;
 231                 override_stream_idx = -1;
 232                 new_clip_changed.notify_all();
 233         }
 234 }
 235
 236 void Player::override_angle(unsigned stream_idx)
 237 {
 238         // Corner case: If a new clip is waiting to be played, change its stream and then we're done.
 239         {
 240                 unique_lock<mutex> lock(queue_state_mu);
 241                 if (new_clip_ready) {
 242                         lock_guard<mutex> lock2(mu);
 243                         current_stream_idx = stream_idx;
 244                         return;
 245                 }
 246         }
 247
 248         // If we are playing a clip, set override_stream_idx, and the player thread will
 249         // pick it up and change its internal index.
 250         {
 251                 unique_lock<mutex> lock(queue_state_mu);
 252                 if (playing) {
 253                         override_stream_idx = stream_idx;
 254                         new_clip_changed.notify_all();
 255                 }
 256         }
 257
 258         // OK, so we're standing still, presumably at the end of a clip.
 259         // Look at the current pts_out (if it exists), and show the closest
 260         // thing we've got.
 261         int64_t pts_out;
 262         {
 263                 lock_guard<mutex> lock(mu);
 264                 if (current_clip.pts_out < 0) {
 265                         return;
 266                 }
 267                 pts_out = current_clip.pts_out;
 268         }
 269
 270         lock_guard<mutex> lock(frame_mu);
 271         auto it = upper_bound(frames[stream_idx].begin(), frames[stream_idx].end(), pts_out);
 272         if (it == frames[stream_idx].end()) {
 273                 return;
 274         }
 275         destination->setFrame(stream_idx, *it, /*interpolated=*/false);
 276 }