1 #include "x264_encoder.h"
15 #include "print_latency.h"
17 #include "x264_dynamic.h"
18 #include "x264_speed_control.h"
21 #include <libavcodec/avcodec.h>
22 #include <libavformat/avformat.h>
25 using namespace movit;
27 using namespace std::chrono;
31 void update_vbv_settings(x264_param_t *param)
33 if (global_flags.x264_vbv_buffer_size < 0) {
34 param->rc.i_vbv_buffer_size = param->rc.i_bitrate; // One-second VBV.
36 param->rc.i_vbv_buffer_size = global_flags.x264_vbv_buffer_size;
38 if (global_flags.x264_vbv_max_bitrate < 0) {
39 param->rc.i_vbv_max_bitrate = param->rc.i_bitrate; // CBR.
41 param->rc.i_vbv_max_bitrate = global_flags.x264_vbv_max_bitrate;
47 X264Encoder::X264Encoder(AVOutputFormat *oformat)
48 : wants_global_headers(oformat->flags & AVFMT_GLOBALHEADER),
49 dyn(load_x264_for_bit_depth(global_flags.x264_bit_depth))
51 size_t bytes_per_pixel = global_flags.x264_bit_depth > 8 ? 2 : 1;
52 frame_pool.reset(new uint8_t[global_flags.width * global_flags.height * 2 * bytes_per_pixel * X264_QUEUE_LENGTH]);
53 for (unsigned i = 0; i < X264_QUEUE_LENGTH; ++i) {
54 free_frames.push(frame_pool.get() + i * (global_flags.width * global_flags.height * 2 * bytes_per_pixel));
56 encoder_thread = thread(&X264Encoder::encoder_thread_func, this);
59 X264Encoder::~X264Encoder()
62 queued_frames_nonempty.notify_all();
63 encoder_thread.join();
69 void X264Encoder::add_frame(int64_t pts, int64_t duration, YCbCrLumaCoefficients ycbcr_coefficients, const uint8_t *data, const ReceivedTimestamps &received_ts)
75 qf.duration = duration;
76 qf.ycbcr_coefficients = ycbcr_coefficients;
77 qf.received_ts = received_ts;
80 lock_guard<mutex> lock(mu);
81 if (free_frames.empty()) {
82 fprintf(stderr, "WARNING: x264 queue full, dropping frame with pts %ld\n", pts);
86 qf.data = free_frames.front();
90 size_t bytes_per_pixel = global_flags.x264_bit_depth > 8 ? 2 : 1;
91 memcpy(qf.data, data, global_flags.width * global_flags.height * 2 * bytes_per_pixel);
94 lock_guard<mutex> lock(mu);
95 queued_frames.push(qf);
96 queued_frames_nonempty.notify_all();
100 void X264Encoder::init_x264()
103 dyn.x264_param_default_preset(¶m, global_flags.x264_preset.c_str(), global_flags.x264_tune.c_str());
105 param.i_width = global_flags.width;
106 param.i_height = global_flags.height;
107 param.i_csp = X264_CSP_NV12;
108 if (global_flags.x264_bit_depth > 8) {
109 param.i_csp |= X264_CSP_HIGH_DEPTH;
111 param.b_vfr_input = 1;
112 param.i_timebase_num = 1;
113 param.i_timebase_den = TIMEBASE;
114 param.i_keyint_max = 50; // About one second.
115 if (global_flags.x264_speedcontrol) {
116 param.i_frame_reference = 16; // Because speedcontrol is never allowed to change this above what we set at start.
119 // NOTE: These should be in sync with the ones in quicksync_encoder.cpp (sps_rbsp()).
120 param.vui.i_vidformat = 5; // Unspecified.
121 param.vui.b_fullrange = 0;
122 param.vui.i_colorprim = 1; // BT.709.
123 param.vui.i_transfer = 2; // Unspecified (since we use sRGB).
124 if (global_flags.ycbcr_rec709_coefficients) {
125 param.vui.i_colmatrix = 1; // BT.709.
127 param.vui.i_colmatrix = 6; // BT.601/SMPTE 170M.
130 param.rc.i_rc_method = X264_RC_ABR;
131 param.rc.i_bitrate = global_flags.x264_bitrate;
132 update_vbv_settings(¶m);
133 if (param.rc.i_vbv_max_bitrate > 0) {
134 // If the user wants VBV control to cap the max rate, it is
135 // also reasonable to assume that they are fine with the stream
136 // constantly being around that rate even for very low-complexity
137 // content; the obvious and extreme example being a static
140 // One would think it's fine to have low-complexity content use
141 // less bitrate, but it seems to cause problems in practice;
142 // e.g. VLC seems to often drop the stream (similar to a buffer
143 // underrun) in such cases, but only when streaming from Nageru,
144 // not when reading a dump of the same stream from disk.
145 // I'm not 100% sure whether it's in VLC (possibly some buffering
146 // in the HTTP layer), in microhttpd or somewhere in Nageru itself,
147 // but it's a typical case of problems that can arise. Similarly,
148 // TCP's congestion control is not always fond of the rate staying
149 // low for a while and then rising quickly -- a variation on the same
152 // We solve this by simply asking x264 to fill in dummy bits
153 // in these cases, so that the bitrate stays reasonable constant.
154 // It's a waste of bandwidth, but it makes things go much more
155 // smoothly in these cases. (We don't do it if VBV control is off
156 // in general, not the least because it makes no sense and x264
157 // thus ignores the parameter.)
158 param.rc.b_filler = 1;
161 // Occasionally players have problem with extremely low quantizers;
162 // be on the safe side. Shouldn't affect quality in any meaningful way.
163 param.rc.i_qp_min = 5;
165 for (const string &str : global_flags.x264_extra_param) {
166 const size_t pos = str.find(',');
167 if (pos == string::npos) {
168 if (dyn.x264_param_parse(¶m, str.c_str(), nullptr) != 0) {
169 fprintf(stderr, "ERROR: x264 rejected parameter '%s'\n", str.c_str());
172 const string key = str.substr(0, pos);
173 const string value = str.substr(pos + 1);
174 if (dyn.x264_param_parse(¶m, key.c_str(), value.c_str()) != 0) {
175 fprintf(stderr, "ERROR: x264 rejected parameter '%s' set to '%s'\n",
176 key.c_str(), value.c_str());
181 if (global_flags.x264_bit_depth > 8) {
182 dyn.x264_param_apply_profile(¶m, "high10");
184 dyn.x264_param_apply_profile(¶m, "high");
187 param.b_repeat_headers = !wants_global_headers;
189 x264 = dyn.x264_encoder_open(¶m);
190 if (x264 == nullptr) {
191 fprintf(stderr, "ERROR: x264 initialization failed.\n");
195 if (global_flags.x264_speedcontrol) {
196 speed_control.reset(new X264SpeedControl(x264, /*f_speed=*/1.0f, X264_QUEUE_LENGTH, /*f_buffer_init=*/1.0f));
199 if (wants_global_headers) {
203 dyn.x264_encoder_headers(x264, &nal, &num_nal);
205 for (int i = 0; i < num_nal; ++i) {
206 if (nal[i].i_type == NAL_SEI) {
207 // Don't put the SEI in extradata; make it part of the first frame instead.
208 buffered_sei += string((const char *)nal[i].p_payload, nal[i].i_payload);
210 global_headers += string((const char *)nal[i].p_payload, nal[i].i_payload);
216 void X264Encoder::encoder_thread_func()
218 if (nice(5) == -1) { // Note that x264 further nices some of its threads.
220 // No exit; it's not fatal.
223 x264_init_done = true;
230 // Wait for a queued frame, then dequeue it.
232 unique_lock<mutex> lock(mu);
233 queued_frames_nonempty.wait(lock, [this]() { return !queued_frames.empty() || should_quit; });
234 if (!queued_frames.empty()) {
235 qf = queued_frames.front();
243 frames_left = !queued_frames.empty();
249 lock_guard<mutex> lock(mu);
250 free_frames.push(qf.data);
253 // We should quit only if the should_quit flag is set _and_ we have nothing
255 } while (!should_quit || frames_left || dyn.x264_encoder_delayed_frames(x264) > 0);
257 dyn.x264_encoder_close(x264);
260 void X264Encoder::encode_frame(X264Encoder::QueuedFrame qf)
262 x264_nal_t *nal = nullptr;
265 x264_picture_t *input_pic = nullptr;
268 dyn.x264_picture_init(&pic);
271 if (global_flags.x264_bit_depth > 8) {
272 pic.img.i_csp = X264_CSP_NV12 | X264_CSP_HIGH_DEPTH;
274 pic.img.plane[0] = qf.data;
275 pic.img.i_stride[0] = global_flags.width * sizeof(uint16_t);
276 pic.img.plane[1] = qf.data + global_flags.width * global_flags.height * sizeof(uint16_t);
277 pic.img.i_stride[1] = global_flags.width / 2 * sizeof(uint32_t);
279 pic.img.i_csp = X264_CSP_NV12;
281 pic.img.plane[0] = qf.data;
282 pic.img.i_stride[0] = global_flags.width;
283 pic.img.plane[1] = qf.data + global_flags.width * global_flags.height;
284 pic.img.i_stride[1] = global_flags.width / 2 * sizeof(uint16_t);
286 pic.opaque = reinterpret_cast<void *>(intptr_t(qf.duration));
290 frames_being_encoded[qf.pts] = qf.received_ts;
293 // See if we have a new bitrate to change to.
294 unsigned new_rate = new_bitrate_kbit.exchange(0); // Read and clear.
296 bitrate_override_func = [new_rate](x264_param_t *param) {
297 param->rc.i_bitrate = new_rate;
298 update_vbv_settings(param);
302 auto ycbcr_coefficients_override_func = [qf](x264_param_t *param) {
303 if (qf.ycbcr_coefficients == YCBCR_REC_709) {
304 param->vui.i_colmatrix = 1; // BT.709.
306 assert(qf.ycbcr_coefficients == YCBCR_REC_601);
307 param->vui.i_colmatrix = 6; // BT.601/SMPTE 170M.
312 speed_control->set_config_override_function([this, ycbcr_coefficients_override_func](x264_param_t *param) {
313 if (bitrate_override_func) {
314 bitrate_override_func(param);
316 ycbcr_coefficients_override_func(param);
320 dyn.x264_encoder_parameters(x264, ¶m);
321 if (bitrate_override_func) {
322 bitrate_override_func(¶m);
324 ycbcr_coefficients_override_func(¶m);
325 dyn.x264_encoder_reconfig(x264, ¶m);
329 speed_control->before_frame(float(free_frames.size()) / X264_QUEUE_LENGTH, X264_QUEUE_LENGTH, 1e6 * qf.duration / TIMEBASE);
331 dyn.x264_encoder_encode(x264, &nal, &num_nal, input_pic, &pic);
333 speed_control->after_frame();
336 if (num_nal == 0) return;
338 if (frames_being_encoded.count(pic.i_pts)) {
339 ReceivedTimestamps received_ts = frames_being_encoded[pic.i_pts];
340 frames_being_encoded.erase(pic.i_pts);
342 static int frameno = 0;
343 print_latency("Current x264 latency (video inputs → network mux):",
344 received_ts, (pic.i_type == X264_TYPE_B || pic.i_type == X264_TYPE_BREF),
350 // We really need one AVPacket for the entire frame, it seems,
351 // so combine it all.
352 size_t num_bytes = buffered_sei.size();
353 for (int i = 0; i < num_nal; ++i) {
354 num_bytes += nal[i].i_payload;
357 unique_ptr<uint8_t[]> data(new uint8_t[num_bytes]);
358 uint8_t *ptr = data.get();
360 if (!buffered_sei.empty()) {
361 memcpy(ptr, buffered_sei.data(), buffered_sei.size());
362 ptr += buffered_sei.size();
363 buffered_sei.clear();
365 for (int i = 0; i < num_nal; ++i) {
366 memcpy(ptr, nal[i].p_payload, nal[i].i_payload);
367 ptr += nal[i].i_payload;
371 memset(&pkt, 0, sizeof(pkt));
373 pkt.data = data.get();
374 pkt.size = num_bytes;
375 pkt.stream_index = 0;
376 if (pic.b_keyframe) {
377 pkt.flags = AV_PKT_FLAG_KEY;
381 pkt.duration = reinterpret_cast<intptr_t>(pic.opaque);
383 for (Mux *mux : muxes) {
384 mux->add_packet(pkt, pic.i_pts, pic.i_dts);