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         QSurface *surface = create_surface();
  33         QOpenGLContext *context = create_context(surface);
  34         if (!make_current(context, surface)) {
  35                 printf("oops\n");
  36                 exit(1);
  37         }
  38
  39         check_error();
  40
  41         // Create the VideoStream object, now that we have an OpenGL context.
  42         if (also_output_to_stream) {
  43                 video_stream.reset(new VideoStream);
  44                 video_stream->start();
  45         }
  46
  47         check_error();
  48
  49         constexpr double output_framerate = 60000.0 / 1001.0;  // FIXME: make configurable
  50         int64_t pts = 0;
  51
  52         for ( ;; ) {
  53                 // Wait until we're supposed to play something.
  54                 {
  55                         unique_lock<mutex> lock(queue_state_mu);
  56                         new_clip_changed.wait(lock, [this]{
  57                                 return new_clip_ready && current_clip.pts_in != -1;
  58                         });
  59                         new_clip_ready = false;
  60                         playing = true;
  61                 }
  62
  63                 Clip clip;
  64                 unsigned stream_idx;
  65                 {
  66                         lock_guard<mutex> lock(mu);
  67                         clip = current_clip;
  68                         stream_idx = current_stream_idx;
  69                 }
  70                 steady_clock::time_point origin = steady_clock::now();
  71                 int64_t in_pts_origin = clip.pts_in;
  72                 int64_t out_pts_origin = pts;
  73
  74                 // Start playing exactly at a frame.
  75                 {
  76                         lock_guard<mutex> lock(frame_mu);
  77
  78                         // Find the first frame such that frame.pts <= in_pts.
  79                         auto it = lower_bound(frames[stream_idx].begin(),
  80                                 frames[stream_idx].end(),
  81                                 in_pts_origin);
  82                         if (it != frames[stream_idx].end()) {
  83                                 in_pts_origin = *it;
  84                         }
  85                 }
  86
  87                 // TODO: Lock to a rational multiple of the frame rate if possible.
  88                 double speed = 0.5;
  89
  90                 bool aborted = false;
  91                 for (int frameno = 0; ; ++frameno) {  // Ends when the clip ends.
  92                         double out_pts = out_pts_origin + TIMEBASE * frameno / output_framerate;
  93                         steady_clock::time_point next_frame_start =
  94                                 origin + microseconds(lrint((out_pts - out_pts_origin) * 1e6 / TIMEBASE));
  95                         int64_t in_pts = lrint(in_pts_origin + TIMEBASE * frameno * speed / output_framerate);
  96                         pts = lrint(out_pts);
  97
  98                         int64_t in_pts_lower, in_pts_upper;
  99
 100                         // Find the frame immediately before and after this point.
 101                         {
 102                                 lock_guard<mutex> lock(frame_mu);
 103
 104                                 // Find the first frame such that in_pts >= frame.pts.
 105                                 auto it = lower_bound(frames[stream_idx].begin(),
 106                                         frames[stream_idx].end(),
 107                                         in_pts);
 108                                 if (it == frames[stream_idx].end() || *it >= clip.pts_out) {
 109                                         break;
 110                                 }
 111                                 in_pts_upper = *it;
 112
 113                                 // Find the last frame such that in_pts <= frame.pts (if any).
 114                                 if (it == frames[stream_idx].begin()) {
 115                                         in_pts_lower = *it;
 116                                 } else {
 117                                         in_pts_lower = *(it - 1);
 118                                 }
 119                         }
 120                         assert(in_pts >= in_pts_lower);
 121                         assert(in_pts <= in_pts_upper);
 122
 123                         // Sleep until the next frame start, or until there's a new clip we're supposed to play.
 124                         {
 125                                 unique_lock<mutex> lock(queue_state_mu);
 126                                 new_clip_changed.wait_until(lock, next_frame_start, [this]{
 127                                         return new_clip_ready || override_stream_idx != -1;
 128                                 });
 129                                 if (new_clip_ready) break;
 130                                 if (override_stream_idx != -1) {
 131                                         stream_idx = override_stream_idx;
 132                                         override_stream_idx = -1;
 133                                         continue;
 134                                 }
 135                         }
 136
 137                         if (in_pts_lower == in_pts_upper) {
 138                                 destination->setFrame(stream_idx, in_pts_lower);
 139                                 if (video_stream != nullptr) {
 140                                         video_stream->schedule_original_frame(lrint(out_pts), stream_idx, in_pts_lower);
 141                                 }
 142                                 continue;
 143                         }
 144
 145                         // Snap to input frame: If we can do so with less than 1% jitter
 146                         // (ie., move less than 1% of an _output_ frame), do so.
 147                         double in_pts_lower_as_frameno = (in_pts_lower - in_pts_origin) * output_framerate / TIMEBASE / speed;
 148                         double in_pts_upper_as_frameno = (in_pts_upper - in_pts_origin) * output_framerate / TIMEBASE / speed;
 149                         if (fabs(in_pts_lower_as_frameno - frameno) < 0.01) {
 150                                 destination->setFrame(stream_idx, in_pts_lower);
 151                                 if (video_stream != nullptr) {
 152                                         video_stream->schedule_original_frame(lrint(out_pts), stream_idx, in_pts_lower);
 153                                 }
 154                                 in_pts_origin += in_pts_lower - in_pts;
 155                                 continue;
 156                         } else if (fabs(in_pts_upper_as_frameno - frameno) < 0.01) {
 157                                 destination->setFrame(stream_idx, in_pts_upper);
 158                                 if (video_stream != nullptr) {
 159                                         video_stream->schedule_original_frame(lrint(out_pts), stream_idx, in_pts_upper);
 160                                 }
 161                                 in_pts_origin += in_pts_upper - in_pts;
 162                                 continue;
 163                         }
 164
 165                         double alpha = double(in_pts - in_pts_lower) / (in_pts_upper - in_pts_lower);
 166                         destination->setFrame(stream_idx, in_pts_lower);  // FIXME
 167
 168                         if (video_stream != nullptr) {
 169                                 // Send the frame to the stream.
 170                                 video_stream->schedule_interpolated_frame(lrint(out_pts), stream_idx, in_pts_lower, in_pts_upper, alpha);
 171                         }
 172                 }
 173
 174                 {
 175                         unique_lock<mutex> lock(queue_state_mu);
 176                         playing = false;
 177                 }
 178                 if (done_callback != nullptr && !aborted) {
 179                         done_callback();
 180                 }
 181         }
 182 }
 183
 184 Player::Player(JPEGFrameView *destination, bool also_output_to_stream)
 185         : destination(destination)
 186 {
 187         thread(&Player::thread_func, this, also_output_to_stream).detach();
 188 }
 189
 190 void Player::play_clip(const Clip &clip, unsigned stream_idx)
 191 {
 192         {
 193                 lock_guard<mutex> lock(mu);
 194                 current_clip = clip;
 195                 current_stream_idx = stream_idx;
 196         }
 197
 198         {
 199                 lock_guard<mutex> lock(queue_state_mu);
 200                 new_clip_ready = true;
 201                 override_stream_idx = -1;
 202                 new_clip_changed.notify_all();
 203         }
 204 }
 205
 206 void Player::override_angle(unsigned stream_idx)
 207 {
 208         // Corner case: If a new clip is waiting to be played, change its stream and then we're done.
 209         {
 210                 unique_lock<mutex> lock(queue_state_mu);
 211                 if (new_clip_ready) {
 212                         lock_guard<mutex> lock2(mu);
 213                         current_stream_idx = stream_idx;
 214                         return;
 215                 }
 216         }
 217
 218         // If we are playing a clip, set override_stream_idx, and the player thread will
 219         // pick it up and change its internal index.
 220         {
 221                 unique_lock<mutex> lock(queue_state_mu);
 222                 if (playing) {
 223                         override_stream_idx = stream_idx;
 224                         new_clip_changed.notify_all();
 225                 }
 226         }
 227
 228         // OK, so we're standing still, presumably at the end of a clip.
 229         // Look at the current pts_out (if it exists), and show the closest
 230         // thing we've got.
 231         int64_t pts_out;
 232         {
 233                 lock_guard<mutex> lock(mu);
 234                 if (current_clip.pts_out < 0) {
 235                         return;
 236                 }
 237                 pts_out = current_clip.pts_out;
 238         }
 239
 240         lock_guard<mutex> lock(frame_mu);
 241         auto it = upper_bound(frames[stream_idx].begin(), frames[stream_idx].end(), pts_out);
 242         if (it == frames[stream_idx].end()) {
 243                 return;
 244         }
 245         destination->setFrame(stream_idx, *it);
 246 }