git.sesse.net Git - nageru/blob - x264_encoder.cpp

   1 #include <string.h>
   2 #include <unistd.h>
   3
   4 #include "defs.h"
   5 #include "flags.h"
   6 #include "mux.h"
   7 #include "timebase.h"
   8 #include "x264_encoder.h"
   9
  10 extern "C" {
  11 #include <libavformat/avformat.h>
  12 }
  13
  14 using namespace std;
  15
  16 X264Encoder::X264Encoder(AVOutputFormat *oformat)
  17         : wants_global_headers(oformat->flags & AVFMT_GLOBALHEADER)
  18 {
  19         frame_pool.reset(new uint8_t[WIDTH * HEIGHT * 2 * X264_QUEUE_LENGTH]);
  20         for (unsigned i = 0; i < X264_QUEUE_LENGTH; ++i) {
  21                 free_frames.push(frame_pool.get() + i * (WIDTH * HEIGHT * 2));
  22         }
  23         encoder_thread = thread(&X264Encoder::encoder_thread_func, this);
  24 }
  25
  26 X264Encoder::~X264Encoder()
  27 {
  28         should_quit = true;
  29         queued_frames_nonempty.notify_all();
  30         encoder_thread.join();
  31 }
  32
  33 void X264Encoder::add_frame(int64_t pts, int64_t duration, const uint8_t *data)
  34 {
  35         QueuedFrame qf;
  36         qf.pts = pts;
  37         qf.duration = duration;
  38
  39         {
  40                 lock_guard<mutex> lock(mu);
  41                 if (free_frames.empty()) {
  42                         fprintf(stderr, "WARNING: x264 queue full, dropping frame with pts %ld\n", pts);
  43                         return;
  44                 }
  45
  46                 qf.data = free_frames.front();
  47                 free_frames.pop();
  48         }
  49
  50         memcpy(qf.data, data, WIDTH * HEIGHT * 2);
  51
  52         {
  53                 lock_guard<mutex> lock(mu);
  54                 queued_frames.push(qf);
  55                 queued_frames_nonempty.notify_all();
  56         }
  57 }
  58
  59 void X264Encoder::init_x264()
  60 {
  61         x264_param_t param;
  62         x264_param_default_preset(&param, global_flags.x264_preset.c_str(), global_flags.x264_tune.c_str());
  63
  64         param.i_width = WIDTH;
  65         param.i_height = HEIGHT;
  66         param.i_csp = X264_CSP_NV12;
  67         param.b_vfr_input = 1;
  68         param.i_timebase_num = 1;
  69         param.i_timebase_den = TIMEBASE;
  70         param.i_keyint_max = 50; // About one second.
  71
  72         // NOTE: These should be in sync with the ones in h264encode.cpp (sbs_rbsp()).
  73         param.vui.i_vidformat = 5;  // Unspecified.
  74         param.vui.b_fullrange = 0;
  75         param.vui.i_colorprim = 1;  // BT.709.
  76         param.vui.i_transfer = 2;  // Unspecified (since we use sRGB).
  77         param.vui.i_colmatrix = 6;  // BT.601/SMPTE 170M.
  78
  79
  80         param.rc.i_rc_method = X264_RC_ABR;
  81         param.rc.i_bitrate = global_flags.x264_vbv_max_bitrate;
  82         if (global_flags.x264_vbv_buffer_size < 0) {
  83                 param.rc.i_vbv_buffer_size = param.rc.i_bitrate;  // One-second VBV.
  84         } else {
  85                 param.rc.i_vbv_buffer_size = global_flags.x264_vbv_buffer_size;
  86         }
  87         if (global_flags.x264_vbv_max_bitrate < 0) {
  88                 param.rc.i_vbv_max_bitrate = param.rc.i_bitrate;  // CBR.
  89         } else {
  90                 param.rc.i_vbv_max_bitrate = global_flags.x264_vbv_max_bitrate;
  91         }
  92
  93         // Occasionally players have problem with extremely low quantizers;
  94         // be on the safe side. Shouldn't affect quality in any meaningful way.
  95         param.rc.i_qp_min = 5;
  96
  97         // TODO: more flags here, via x264_param_parse().
  98
  99         x264_param_apply_profile(&param, "high");
 100
 101         param.b_repeat_headers = !wants_global_headers;
 102
 103         x264 = x264_encoder_open(&param);
 104         if (x264 == nullptr) {
 105                 fprintf(stderr, "ERROR: x264 initialization failed.\n");
 106                 exit(1);
 107         }
 108
 109         if (wants_global_headers) {
 110                 x264_nal_t *nal;
 111                 int num_nal;
 112
 113                 x264_encoder_headers(x264, &nal, &num_nal);
 114
 115                 for (int i = 0; i < num_nal; ++i) {
 116                         if (nal[i].i_type == NAL_SEI) {
 117                                 // Don't put the SEI in extradata; make it part of the first frame instead.
 118                                 buffered_sei += string((const char *)nal[i].p_payload, nal[i].i_payload);
 119                         } else {
 120                                 global_headers += string((const char *)nal[i].p_payload, nal[i].i_payload);
 121                         }
 122                 }
 123         }
 124 }
 125
 126 void X264Encoder::encoder_thread_func()
 127 {
 128         nice(5);  // Note that x264 further nices some of its threads.
 129         init_x264();
 130
 131         bool frames_left;
 132
 133         do {
 134                 QueuedFrame qf;
 135
 136                 // Wait for a queued frame, then dequeue it.
 137                 {
 138                         unique_lock<mutex> lock(mu);
 139                         queued_frames_nonempty.wait(lock, [this]() { return !queued_frames.empty() || should_quit; });
 140                         if (!queued_frames.empty()) {
 141                                 qf = queued_frames.front();
 142                                 queued_frames.pop();
 143                         } else {
 144                                 qf.pts = -1;
 145                                 qf.duration = -1;
 146                                 qf.data = nullptr;
 147                         }
 148
 149                         frames_left = !queued_frames.empty();
 150                 }
 151
 152                 encode_frame(qf);
 153
 154                 {
 155                         lock_guard<mutex> lock(mu);
 156                         free_frames.push(qf.data);
 157                 }
 158
 159                 // We should quit only if the should_quit flag is set _and_ we have nothing
 160                 // in either queue.
 161         } while (!should_quit || frames_left || x264_encoder_delayed_frames(x264) > 0);
 162
 163         x264_encoder_close(x264);
 164 }
 165
 166 void X264Encoder::encode_frame(X264Encoder::QueuedFrame qf)
 167 {
 168         x264_nal_t *nal = nullptr;
 169         int num_nal = 0;
 170         x264_picture_t pic;
 171
 172         if (qf.data) {
 173                 x264_picture_init(&pic);
 174
 175                 pic.i_pts = qf.pts;
 176                 pic.img.i_csp = X264_CSP_NV12;
 177                 pic.img.i_plane = 2;
 178                 pic.img.plane[0] = qf.data;
 179                 pic.img.i_stride[0] = WIDTH;
 180                 pic.img.plane[1] = qf.data + WIDTH * HEIGHT;
 181                 pic.img.i_stride[1] = WIDTH / 2 * sizeof(uint16_t);
 182                 pic.opaque = reinterpret_cast<void *>(intptr_t(qf.duration));
 183
 184                 x264_encoder_encode(x264, &nal, &num_nal, &pic, &pic);
 185         } else {
 186                 x264_encoder_encode(x264, &nal, &num_nal, nullptr, &pic);
 187         }
 188
 189         // We really need one AVPacket for the entire frame, it seems,
 190         // so combine it all.
 191         size_t num_bytes = buffered_sei.size();
 192         for (int i = 0; i < num_nal; ++i) {
 193                 num_bytes += nal[i].i_payload;
 194         }
 195
 196         unique_ptr<uint8_t[]> data(new uint8_t[num_bytes]);
 197         uint8_t *ptr = data.get();
 198
 199         if (!buffered_sei.empty()) {
 200                 memcpy(ptr, buffered_sei.data(), buffered_sei.size());
 201                 ptr += buffered_sei.size();
 202                 buffered_sei.clear();
 203         }
 204         for (int i = 0; i < num_nal; ++i) {
 205                 memcpy(ptr, nal[i].p_payload, nal[i].i_payload);
 206                 ptr += nal[i].i_payload;
 207         }
 208
 209         AVPacket pkt;
 210         memset(&pkt, 0, sizeof(pkt));
 211         pkt.buf = nullptr;
 212         pkt.data = data.get();
 213         pkt.size = num_bytes;
 214         pkt.stream_index = 0;
 215         if (pic.b_keyframe) {
 216                 pkt.flags = AV_PKT_FLAG_KEY;
 217         } else {
 218                 pkt.flags = 0;
 219         }
 220         pkt.duration = reinterpret_cast<intptr_t>(pic.opaque);
 221
 222         mux->add_packet(pkt, pic.i_pts, pic.i_dts);
 223 }