1 #include "x264_encoder.h"
17 #include "shared/metrics.h"
18 #include "shared/mux.h"
19 #include "print_latency.h"
20 #include "shared/timebase.h"
21 #include "x264_dynamic.h"
22 #include "x264_speed_control.h"
25 #include <libavcodec/avcodec.h>
26 #include <libavformat/avformat.h>
29 using namespace movit;
31 using namespace std::chrono;
32 using namespace std::placeholders;
36 // X264Encoder can be restarted if --record-x264-video is set, so make these
38 atomic<int64_t> metric_x264_queued_frames{0};
39 atomic<int64_t> metric_x264_max_queued_frames{X264_QUEUE_LENGTH};
40 atomic<int64_t> metric_x264_dropped_frames{0};
41 atomic<int64_t> metric_x264_output_frames_i{0};
42 atomic<int64_t> metric_x264_output_frames_p{0};
43 atomic<int64_t> metric_x264_output_frames_b{0};
44 Histogram metric_x264_crf;
45 LatencyHistogram x264_latency_histogram;
46 once_flag x264_metrics_inited;
48 void update_vbv_settings(x264_param_t *param)
50 if (global_flags.x264_bitrate == -1) {
53 if (global_flags.x264_vbv_buffer_size < 0) {
54 param->rc.i_vbv_buffer_size = param->rc.i_bitrate; // One-second VBV.
56 param->rc.i_vbv_buffer_size = global_flags.x264_vbv_buffer_size;
58 if (global_flags.x264_vbv_max_bitrate < 0) {
59 param->rc.i_vbv_max_bitrate = param->rc.i_bitrate; // CBR.
61 param->rc.i_vbv_max_bitrate = global_flags.x264_vbv_max_bitrate;
67 X264Encoder::X264Encoder(AVOutputFormat *oformat)
68 : wants_global_headers(oformat->flags & AVFMT_GLOBALHEADER),
69 dyn(load_x264_for_bit_depth(global_flags.x264_bit_depth))
71 call_once(x264_metrics_inited, [](){
72 global_metrics.add("x264_queued_frames", &metric_x264_queued_frames, Metrics::TYPE_GAUGE);
73 global_metrics.add("x264_max_queued_frames", &metric_x264_max_queued_frames, Metrics::TYPE_GAUGE);
74 global_metrics.add("x264_dropped_frames", &metric_x264_dropped_frames);
75 global_metrics.add("x264_output_frames", {{ "type", "i" }}, &metric_x264_output_frames_i);
76 global_metrics.add("x264_output_frames", {{ "type", "p" }}, &metric_x264_output_frames_p);
77 global_metrics.add("x264_output_frames", {{ "type", "b" }}, &metric_x264_output_frames_b);
79 metric_x264_crf.init_uniform(50);
80 global_metrics.add("x264_crf", &metric_x264_crf);
81 x264_latency_histogram.init("x264");
84 size_t bytes_per_pixel = global_flags.x264_bit_depth > 8 ? 2 : 1;
85 frame_pool.reset(new uint8_t[global_flags.width * global_flags.height * 2 * bytes_per_pixel * X264_QUEUE_LENGTH]);
86 for (unsigned i = 0; i < X264_QUEUE_LENGTH; ++i) {
87 free_frames.push(frame_pool.get() + i * (global_flags.width * global_flags.height * 2 * bytes_per_pixel));
89 encoder_thread = thread(&X264Encoder::encoder_thread_func, this);
92 X264Encoder::~X264Encoder()
95 queued_frames_nonempty.notify_all();
96 encoder_thread.join();
102 void X264Encoder::add_frame(int64_t pts, int64_t duration, YCbCrLumaCoefficients ycbcr_coefficients, const uint8_t *data, const ReceivedTimestamps &received_ts)
104 assert(!should_quit);
108 qf.duration = duration;
109 qf.ycbcr_coefficients = ycbcr_coefficients;
110 qf.received_ts = received_ts;
113 lock_guard<mutex> lock(mu);
114 if (free_frames.empty()) {
115 fprintf(stderr, "WARNING: x264 queue full, dropping frame with pts %ld\n", pts);
116 ++metric_x264_dropped_frames;
120 qf.data = free_frames.front();
124 size_t bytes_per_pixel = global_flags.x264_bit_depth > 8 ? 2 : 1;
125 memcpy(qf.data, data, global_flags.width * global_flags.height * 2 * bytes_per_pixel);
128 lock_guard<mutex> lock(mu);
129 queued_frames.push(qf);
130 queued_frames_nonempty.notify_all();
131 metric_x264_queued_frames = queued_frames.size();
135 void X264Encoder::init_x264()
138 dyn.x264_param_default_preset(¶m, global_flags.x264_preset.c_str(), global_flags.x264_tune.c_str());
140 param.i_width = global_flags.width;
141 param.i_height = global_flags.height;
142 param.i_csp = X264_CSP_NV12;
143 if (global_flags.x264_bit_depth > 8) {
144 param.i_csp |= X264_CSP_HIGH_DEPTH;
146 param.b_vfr_input = 1;
147 param.i_timebase_num = 1;
148 param.i_timebase_den = TIMEBASE;
149 param.i_keyint_max = 50; // About one second.
150 if (global_flags.x264_speedcontrol) {
151 param.i_frame_reference = 16; // Because speedcontrol is never allowed to change this above what we set at start.
153 #if X264_BUILD >= 153
154 param.i_bitdepth = global_flags.x264_bit_depth;
157 // NOTE: These should be in sync with the ones in quicksync_encoder.cpp (sps_rbsp()).
158 param.vui.i_vidformat = 5; // Unspecified.
159 param.vui.b_fullrange = 0;
160 param.vui.i_colorprim = 1; // BT.709.
161 param.vui.i_transfer = 13; // sRGB.
162 if (global_flags.ycbcr_rec709_coefficients) {
163 param.vui.i_colmatrix = 1; // BT.709.
165 param.vui.i_colmatrix = 6; // BT.601/SMPTE 170M.
168 if (!isinf(global_flags.x264_crf)) {
169 param.rc.i_rc_method = X264_RC_CRF;
170 param.rc.f_rf_constant = global_flags.x264_crf;
172 param.rc.i_rc_method = X264_RC_ABR;
173 param.rc.i_bitrate = global_flags.x264_bitrate;
175 update_vbv_settings(¶m);
176 if (param.rc.i_vbv_max_bitrate > 0) {
177 // If the user wants VBV control to cap the max rate, it is
178 // also reasonable to assume that they are fine with the stream
179 // constantly being around that rate even for very low-complexity
180 // content; the obvious and extreme example being a static
183 // One would think it's fine to have low-complexity content use
184 // less bitrate, but it seems to cause problems in practice;
185 // e.g. VLC seems to often drop the stream (similar to a buffer
186 // underrun) in such cases, but only when streaming from Nageru,
187 // not when reading a dump of the same stream from disk.
188 // I'm not 100% sure whether it's in VLC (possibly some buffering
189 // in the HTTP layer), in microhttpd or somewhere in Nageru itself,
190 // but it's a typical case of problems that can arise. Similarly,
191 // TCP's congestion control is not always fond of the rate staying
192 // low for a while and then rising quickly -- a variation on the same
195 // We solve this by simply asking x264 to fill in dummy bits
196 // in these cases, so that the bitrate stays reasonable constant.
197 // It's a waste of bandwidth, but it makes things go much more
198 // smoothly in these cases. (We don't do it if VBV control is off
199 // in general, not the least because it makes no sense and x264
200 // thus ignores the parameter.)
201 param.rc.b_filler = 1;
204 // Occasionally players have problem with extremely low quantizers;
205 // be on the safe side. Shouldn't affect quality in any meaningful way.
206 param.rc.i_qp_min = 5;
208 for (const string &str : global_flags.x264_extra_param) {
209 const size_t pos = str.find(',');
210 if (pos == string::npos) {
211 if (dyn.x264_param_parse(¶m, str.c_str(), nullptr) != 0) {
212 fprintf(stderr, "ERROR: x264 rejected parameter '%s'\n", str.c_str());
215 const string key = str.substr(0, pos);
216 const string value = str.substr(pos + 1);
217 if (dyn.x264_param_parse(¶m, key.c_str(), value.c_str()) != 0) {
218 fprintf(stderr, "ERROR: x264 rejected parameter '%s' set to '%s'\n",
219 key.c_str(), value.c_str());
224 if (global_flags.x264_bit_depth > 8) {
225 dyn.x264_param_apply_profile(¶m, "high10");
227 dyn.x264_param_apply_profile(¶m, "high");
230 param.b_repeat_headers = !wants_global_headers;
232 x264 = dyn.x264_encoder_open(¶m);
233 if (x264 == nullptr) {
234 fprintf(stderr, "ERROR: x264 initialization failed.\n");
238 if (global_flags.x264_speedcontrol) {
239 speed_control.reset(new X264SpeedControl(x264, /*f_speed=*/1.0f, X264_QUEUE_LENGTH, /*f_buffer_init=*/1.0f));
242 if (wants_global_headers) {
246 dyn.x264_encoder_headers(x264, &nal, &num_nal);
248 for (int i = 0; i < num_nal; ++i) {
249 if (nal[i].i_type == NAL_SEI) {
250 // Don't put the SEI in extradata; make it part of the first frame instead.
251 buffered_sei += string((const char *)nal[i].p_payload, nal[i].i_payload);
253 global_headers += string((const char *)nal[i].p_payload, nal[i].i_payload);
259 void X264Encoder::encoder_thread_func()
261 if (nice(5) == -1) { // Note that x264 further nices some of its threads.
263 // No exit; it's not fatal.
265 pthread_setname_np(pthread_self(), "x264_encode");
267 x264_init_done = true;
274 // Wait for a queued frame, then dequeue it.
276 unique_lock<mutex> lock(mu);
277 queued_frames_nonempty.wait(lock, [this]() { return !queued_frames.empty() || should_quit; });
278 if (!queued_frames.empty()) {
279 qf = queued_frames.front();
287 metric_x264_queued_frames = queued_frames.size();
288 frames_left = !queued_frames.empty();
294 lock_guard<mutex> lock(mu);
295 free_frames.push(qf.data);
298 // We should quit only if the should_quit flag is set _and_ we have nothing
300 } while (!should_quit || frames_left || dyn.x264_encoder_delayed_frames(x264) > 0);
302 dyn.x264_encoder_close(x264);
305 void X264Encoder::encode_frame(X264Encoder::QueuedFrame qf)
307 x264_nal_t *nal = nullptr;
310 x264_picture_t *input_pic = nullptr;
313 dyn.x264_picture_init(&pic);
316 if (global_flags.x264_bit_depth > 8) {
317 pic.img.i_csp = X264_CSP_NV12 | X264_CSP_HIGH_DEPTH;
319 pic.img.plane[0] = qf.data;
320 pic.img.i_stride[0] = global_flags.width * sizeof(uint16_t);
321 pic.img.plane[1] = qf.data + global_flags.width * global_flags.height * sizeof(uint16_t);
322 pic.img.i_stride[1] = global_flags.width / 2 * sizeof(uint32_t);
324 pic.img.i_csp = X264_CSP_NV12;
326 pic.img.plane[0] = qf.data;
327 pic.img.i_stride[0] = global_flags.width;
328 pic.img.plane[1] = qf.data + global_flags.width * global_flags.height;
329 pic.img.i_stride[1] = global_flags.width / 2 * sizeof(uint16_t);
331 pic.opaque = reinterpret_cast<void *>(intptr_t(qf.duration));
335 frames_being_encoded[qf.pts] = qf.received_ts;
338 unsigned new_rate = new_bitrate_kbit.load(); // Can be 0 for no change.
340 speed_control->set_config_override_function(bind(&speed_control_override_func, new_rate, qf.ycbcr_coefficients, _1));
343 dyn.x264_encoder_parameters(x264, ¶m);
344 speed_control_override_func(new_rate, qf.ycbcr_coefficients, ¶m);
345 dyn.x264_encoder_reconfig(x264, ¶m);
349 float queue_fill_ratio;
351 lock_guard<mutex> lock(mu);
352 queue_fill_ratio = float(free_frames.size()) / X264_QUEUE_LENGTH;
354 speed_control->before_frame(queue_fill_ratio, X264_QUEUE_LENGTH, 1e6 * qf.duration / TIMEBASE);
356 dyn.x264_encoder_encode(x264, &nal, &num_nal, input_pic, &pic);
358 speed_control->after_frame();
361 if (num_nal == 0) return;
363 if (IS_X264_TYPE_I(pic.i_type)) {
364 ++metric_x264_output_frames_i;
365 } else if (IS_X264_TYPE_B(pic.i_type)) {
366 ++metric_x264_output_frames_b;
368 ++metric_x264_output_frames_p;
371 metric_x264_crf.count_event(pic.prop.f_crf_avg);
373 if (frames_being_encoded.count(pic.i_pts)) {
374 ReceivedTimestamps received_ts = frames_being_encoded[pic.i_pts];
375 frames_being_encoded.erase(pic.i_pts);
377 static int frameno = 0;
378 print_latency("Current x264 latency (video inputs → network mux):",
379 received_ts, (pic.i_type == X264_TYPE_B || pic.i_type == X264_TYPE_BREF),
380 &frameno, &x264_latency_histogram);
385 // We really need one AVPacket for the entire frame, it seems,
386 // so combine it all.
387 size_t num_bytes = buffered_sei.size();
388 for (int i = 0; i < num_nal; ++i) {
389 num_bytes += nal[i].i_payload;
392 unique_ptr<uint8_t[]> data(new uint8_t[num_bytes]);
393 uint8_t *ptr = data.get();
395 if (!buffered_sei.empty()) {
396 memcpy(ptr, buffered_sei.data(), buffered_sei.size());
397 ptr += buffered_sei.size();
398 buffered_sei.clear();
400 for (int i = 0; i < num_nal; ++i) {
401 memcpy(ptr, nal[i].p_payload, nal[i].i_payload);
402 ptr += nal[i].i_payload;
406 memset(&pkt, 0, sizeof(pkt));
408 pkt.data = data.get();
409 pkt.size = num_bytes;
410 pkt.stream_index = 0;
411 if (pic.b_keyframe) {
412 pkt.flags = AV_PKT_FLAG_KEY;
416 pkt.duration = reinterpret_cast<intptr_t>(pic.opaque);
418 for (Mux *mux : muxes) {
419 mux->add_packet(pkt, pic.i_pts, pic.i_dts);
423 void X264Encoder::speed_control_override_func(unsigned bitrate_kbit, movit::YCbCrLumaCoefficients ycbcr_coefficients, x264_param_t *param)
425 if (bitrate_kbit != 0) {
426 param->rc.i_bitrate = bitrate_kbit;
427 update_vbv_settings(param);
430 if (ycbcr_coefficients == YCBCR_REC_709) {
431 param->vui.i_colmatrix = 1; // BT.709.
433 assert(ycbcr_coefficients == YCBCR_REC_601);
434 param->vui.i_colmatrix = 6; // BT.601/SMPTE 170M.