1 #include "x264_encoder.h"
18 #include "print_latency.h"
20 #include "x264_dynamic.h"
21 #include "x264_speed_control.h"
24 #include <libavcodec/avcodec.h>
25 #include <libavformat/avformat.h>
28 using namespace movit;
30 using namespace std::chrono;
34 // X264Encoder can be restarted if --record-x264-video is set, so make these
36 atomic<int64_t> metric_x264_queued_frames{0};
37 atomic<int64_t> metric_x264_max_queued_frames{X264_QUEUE_LENGTH};
38 atomic<int64_t> metric_x264_dropped_frames{0};
39 atomic<int64_t> metric_x264_output_frames_i{0};
40 atomic<int64_t> metric_x264_output_frames_p{0};
41 atomic<int64_t> metric_x264_output_frames_b{0};
42 Histogram metric_x264_crf;
43 LatencyHistogram x264_latency_histogram;
44 once_flag x264_metrics_inited;
46 void update_vbv_settings(x264_param_t *param)
48 if (global_flags.x264_bitrate == -1) {
51 if (global_flags.x264_vbv_buffer_size < 0) {
52 param->rc.i_vbv_buffer_size = param->rc.i_bitrate; // One-second VBV.
54 param->rc.i_vbv_buffer_size = global_flags.x264_vbv_buffer_size;
56 if (global_flags.x264_vbv_max_bitrate < 0) {
57 param->rc.i_vbv_max_bitrate = param->rc.i_bitrate; // CBR.
59 param->rc.i_vbv_max_bitrate = global_flags.x264_vbv_max_bitrate;
65 X264Encoder::X264Encoder(AVOutputFormat *oformat)
66 : wants_global_headers(oformat->flags & AVFMT_GLOBALHEADER),
67 dyn(load_x264_for_bit_depth(global_flags.x264_bit_depth))
69 call_once(x264_metrics_inited, [](){
70 global_metrics.add("x264_queued_frames", &metric_x264_queued_frames, Metrics::TYPE_GAUGE);
71 global_metrics.add("x264_max_queued_frames", &metric_x264_max_queued_frames, Metrics::TYPE_GAUGE);
72 global_metrics.add("x264_dropped_frames", &metric_x264_dropped_frames);
73 global_metrics.add("x264_output_frames", {{ "type", "i" }}, &metric_x264_output_frames_i);
74 global_metrics.add("x264_output_frames", {{ "type", "p" }}, &metric_x264_output_frames_p);
75 global_metrics.add("x264_output_frames", {{ "type", "b" }}, &metric_x264_output_frames_b);
77 metric_x264_crf.init_uniform(50);
78 global_metrics.add("x264_crf", &metric_x264_crf);
79 x264_latency_histogram.init("x264");
82 size_t bytes_per_pixel = global_flags.x264_bit_depth > 8 ? 2 : 1;
83 frame_pool.reset(new uint8_t[global_flags.width * global_flags.height * 2 * bytes_per_pixel * X264_QUEUE_LENGTH]);
84 for (unsigned i = 0; i < X264_QUEUE_LENGTH; ++i) {
85 free_frames.push(frame_pool.get() + i * (global_flags.width * global_flags.height * 2 * bytes_per_pixel));
87 encoder_thread = thread(&X264Encoder::encoder_thread_func, this);
90 X264Encoder::~X264Encoder()
93 queued_frames_nonempty.notify_all();
94 encoder_thread.join();
100 void X264Encoder::add_frame(int64_t pts, int64_t duration, YCbCrLumaCoefficients ycbcr_coefficients, const uint8_t *data, const ReceivedTimestamps &received_ts)
102 assert(!should_quit);
106 qf.duration = duration;
107 qf.ycbcr_coefficients = ycbcr_coefficients;
108 qf.received_ts = received_ts;
111 lock_guard<mutex> lock(mu);
112 if (free_frames.empty()) {
113 fprintf(stderr, "WARNING: x264 queue full, dropping frame with pts %ld\n", pts);
114 ++metric_x264_dropped_frames;
118 qf.data = free_frames.front();
122 size_t bytes_per_pixel = global_flags.x264_bit_depth > 8 ? 2 : 1;
123 memcpy(qf.data, data, global_flags.width * global_flags.height * 2 * bytes_per_pixel);
126 lock_guard<mutex> lock(mu);
127 queued_frames.push(qf);
128 queued_frames_nonempty.notify_all();
129 metric_x264_queued_frames = queued_frames.size();
133 void X264Encoder::init_x264()
136 dyn.x264_param_default_preset(¶m, global_flags.x264_preset.c_str(), global_flags.x264_tune.c_str());
138 param.i_width = global_flags.width;
139 param.i_height = global_flags.height;
140 param.i_csp = X264_CSP_NV12;
141 if (global_flags.x264_bit_depth > 8) {
142 param.i_csp |= X264_CSP_HIGH_DEPTH;
144 param.b_vfr_input = 1;
145 param.i_timebase_num = 1;
146 param.i_timebase_den = TIMEBASE;
147 param.i_keyint_max = 50; // About one second.
148 if (global_flags.x264_speedcontrol) {
149 param.i_frame_reference = 16; // Because speedcontrol is never allowed to change this above what we set at start.
152 // NOTE: These should be in sync with the ones in quicksync_encoder.cpp (sps_rbsp()).
153 param.vui.i_vidformat = 5; // Unspecified.
154 param.vui.b_fullrange = 0;
155 param.vui.i_colorprim = 1; // BT.709.
156 param.vui.i_transfer = 13; // sRGB.
157 if (global_flags.ycbcr_rec709_coefficients) {
158 param.vui.i_colmatrix = 1; // BT.709.
160 param.vui.i_colmatrix = 6; // BT.601/SMPTE 170M.
163 if (!isinf(global_flags.x264_crf)) {
164 param.rc.i_rc_method = X264_RC_CRF;
165 param.rc.f_rf_constant = global_flags.x264_crf;
167 param.rc.i_rc_method = X264_RC_ABR;
168 param.rc.i_bitrate = global_flags.x264_bitrate;
170 update_vbv_settings(¶m);
171 if (param.rc.i_vbv_max_bitrate > 0) {
172 // If the user wants VBV control to cap the max rate, it is
173 // also reasonable to assume that they are fine with the stream
174 // constantly being around that rate even for very low-complexity
175 // content; the obvious and extreme example being a static
178 // One would think it's fine to have low-complexity content use
179 // less bitrate, but it seems to cause problems in practice;
180 // e.g. VLC seems to often drop the stream (similar to a buffer
181 // underrun) in such cases, but only when streaming from Nageru,
182 // not when reading a dump of the same stream from disk.
183 // I'm not 100% sure whether it's in VLC (possibly some buffering
184 // in the HTTP layer), in microhttpd or somewhere in Nageru itself,
185 // but it's a typical case of problems that can arise. Similarly,
186 // TCP's congestion control is not always fond of the rate staying
187 // low for a while and then rising quickly -- a variation on the same
190 // We solve this by simply asking x264 to fill in dummy bits
191 // in these cases, so that the bitrate stays reasonable constant.
192 // It's a waste of bandwidth, but it makes things go much more
193 // smoothly in these cases. (We don't do it if VBV control is off
194 // in general, not the least because it makes no sense and x264
195 // thus ignores the parameter.)
196 param.rc.b_filler = 1;
199 // Occasionally players have problem with extremely low quantizers;
200 // be on the safe side. Shouldn't affect quality in any meaningful way.
201 param.rc.i_qp_min = 5;
203 for (const string &str : global_flags.x264_extra_param) {
204 const size_t pos = str.find(',');
205 if (pos == string::npos) {
206 if (dyn.x264_param_parse(¶m, str.c_str(), nullptr) != 0) {
207 fprintf(stderr, "ERROR: x264 rejected parameter '%s'\n", str.c_str());
210 const string key = str.substr(0, pos);
211 const string value = str.substr(pos + 1);
212 if (dyn.x264_param_parse(¶m, key.c_str(), value.c_str()) != 0) {
213 fprintf(stderr, "ERROR: x264 rejected parameter '%s' set to '%s'\n",
214 key.c_str(), value.c_str());
219 if (global_flags.x264_bit_depth > 8) {
220 dyn.x264_param_apply_profile(¶m, "high10");
222 dyn.x264_param_apply_profile(¶m, "high");
225 param.b_repeat_headers = !wants_global_headers;
227 x264 = dyn.x264_encoder_open(¶m);
228 if (x264 == nullptr) {
229 fprintf(stderr, "ERROR: x264 initialization failed.\n");
233 if (global_flags.x264_speedcontrol) {
234 speed_control.reset(new X264SpeedControl(x264, /*f_speed=*/1.0f, X264_QUEUE_LENGTH, /*f_buffer_init=*/1.0f));
237 if (wants_global_headers) {
241 dyn.x264_encoder_headers(x264, &nal, &num_nal);
243 for (int i = 0; i < num_nal; ++i) {
244 if (nal[i].i_type == NAL_SEI) {
245 // Don't put the SEI in extradata; make it part of the first frame instead.
246 buffered_sei += string((const char *)nal[i].p_payload, nal[i].i_payload);
248 global_headers += string((const char *)nal[i].p_payload, nal[i].i_payload);
254 void X264Encoder::encoder_thread_func()
256 if (nice(5) == -1) { // Note that x264 further nices some of its threads.
258 // No exit; it's not fatal.
260 pthread_setname_np(pthread_self(), "x264_encode");
262 x264_init_done = true;
269 // Wait for a queued frame, then dequeue it.
271 unique_lock<mutex> lock(mu);
272 queued_frames_nonempty.wait(lock, [this]() { return !queued_frames.empty() || should_quit; });
273 if (!queued_frames.empty()) {
274 qf = queued_frames.front();
282 metric_x264_queued_frames = queued_frames.size();
283 frames_left = !queued_frames.empty();
289 lock_guard<mutex> lock(mu);
290 free_frames.push(qf.data);
293 // We should quit only if the should_quit flag is set _and_ we have nothing
295 } while (!should_quit || frames_left || dyn.x264_encoder_delayed_frames(x264) > 0);
297 dyn.x264_encoder_close(x264);
300 void X264Encoder::encode_frame(X264Encoder::QueuedFrame qf)
302 x264_nal_t *nal = nullptr;
305 x264_picture_t *input_pic = nullptr;
308 dyn.x264_picture_init(&pic);
311 if (global_flags.x264_bit_depth > 8) {
312 pic.img.i_csp = X264_CSP_NV12 | X264_CSP_HIGH_DEPTH;
314 pic.img.plane[0] = qf.data;
315 pic.img.i_stride[0] = global_flags.width * sizeof(uint16_t);
316 pic.img.plane[1] = qf.data + global_flags.width * global_flags.height * sizeof(uint16_t);
317 pic.img.i_stride[1] = global_flags.width / 2 * sizeof(uint32_t);
319 pic.img.i_csp = X264_CSP_NV12;
321 pic.img.plane[0] = qf.data;
322 pic.img.i_stride[0] = global_flags.width;
323 pic.img.plane[1] = qf.data + global_flags.width * global_flags.height;
324 pic.img.i_stride[1] = global_flags.width / 2 * sizeof(uint16_t);
326 pic.opaque = reinterpret_cast<void *>(intptr_t(qf.duration));
330 frames_being_encoded[qf.pts] = qf.received_ts;
333 // See if we have a new bitrate to change to.
334 unsigned new_rate = new_bitrate_kbit.exchange(0); // Read and clear.
336 bitrate_override_func = [new_rate](x264_param_t *param) {
337 param->rc.i_bitrate = new_rate;
338 update_vbv_settings(param);
342 auto ycbcr_coefficients_override_func = [qf](x264_param_t *param) {
343 if (qf.ycbcr_coefficients == YCBCR_REC_709) {
344 param->vui.i_colmatrix = 1; // BT.709.
346 assert(qf.ycbcr_coefficients == YCBCR_REC_601);
347 param->vui.i_colmatrix = 6; // BT.601/SMPTE 170M.
352 speed_control->set_config_override_function([this, ycbcr_coefficients_override_func](x264_param_t *param) {
353 if (bitrate_override_func) {
354 bitrate_override_func(param);
356 ycbcr_coefficients_override_func(param);
360 dyn.x264_encoder_parameters(x264, ¶m);
361 if (bitrate_override_func) {
362 bitrate_override_func(¶m);
364 ycbcr_coefficients_override_func(¶m);
365 dyn.x264_encoder_reconfig(x264, ¶m);
369 speed_control->before_frame(float(free_frames.size()) / X264_QUEUE_LENGTH, X264_QUEUE_LENGTH, 1e6 * qf.duration / TIMEBASE);
371 dyn.x264_encoder_encode(x264, &nal, &num_nal, input_pic, &pic);
373 speed_control->after_frame();
376 if (num_nal == 0) return;
378 if (IS_X264_TYPE_I(pic.i_type)) {
379 ++metric_x264_output_frames_i;
380 } else if (IS_X264_TYPE_B(pic.i_type)) {
381 ++metric_x264_output_frames_b;
383 ++metric_x264_output_frames_p;
386 metric_x264_crf.count_event(pic.prop.f_crf_avg);
388 if (frames_being_encoded.count(pic.i_pts)) {
389 ReceivedTimestamps received_ts = frames_being_encoded[pic.i_pts];
390 frames_being_encoded.erase(pic.i_pts);
392 static int frameno = 0;
393 print_latency("Current x264 latency (video inputs → network mux):",
394 received_ts, (pic.i_type == X264_TYPE_B || pic.i_type == X264_TYPE_BREF),
395 &frameno, &x264_latency_histogram);
400 // We really need one AVPacket for the entire frame, it seems,
401 // so combine it all.
402 size_t num_bytes = buffered_sei.size();
403 for (int i = 0; i < num_nal; ++i) {
404 num_bytes += nal[i].i_payload;
407 unique_ptr<uint8_t[]> data(new uint8_t[num_bytes]);
408 uint8_t *ptr = data.get();
410 if (!buffered_sei.empty()) {
411 memcpy(ptr, buffered_sei.data(), buffered_sei.size());
412 ptr += buffered_sei.size();
413 buffered_sei.clear();
415 for (int i = 0; i < num_nal; ++i) {
416 memcpy(ptr, nal[i].p_payload, nal[i].i_payload);
417 ptr += nal[i].i_payload;
421 memset(&pkt, 0, sizeof(pkt));
423 pkt.data = data.get();
424 pkt.size = num_bytes;
425 pkt.stream_index = 0;
426 if (pic.b_keyframe) {
427 pkt.flags = AV_PKT_FLAG_KEY;
431 pkt.duration = reinterpret_cast<intptr_t>(pic.opaque);
433 for (Mux *mux : muxes) {
434 mux->add_packet(pkt, pic.i_pts, pic.i_dts);