8 #include "x264_encoder.h"
9 #include "x264_speed_control.h"
12 #include <libavformat/avformat.h>
19 void update_vbv_settings(x264_param_t *param)
21 if (global_flags.x264_vbv_buffer_size < 0) {
22 param->rc.i_vbv_buffer_size = param->rc.i_bitrate; // One-second VBV.
24 param->rc.i_vbv_buffer_size = global_flags.x264_vbv_buffer_size;
26 if (global_flags.x264_vbv_max_bitrate < 0) {
27 param->rc.i_vbv_max_bitrate = param->rc.i_bitrate; // CBR.
29 param->rc.i_vbv_max_bitrate = global_flags.x264_vbv_max_bitrate;
35 X264Encoder::X264Encoder(AVOutputFormat *oformat)
36 : wants_global_headers(oformat->flags & AVFMT_GLOBALHEADER)
38 frame_pool.reset(new uint8_t[WIDTH * HEIGHT * 2 * X264_QUEUE_LENGTH]);
39 for (unsigned i = 0; i < X264_QUEUE_LENGTH; ++i) {
40 free_frames.push(frame_pool.get() + i * (WIDTH * HEIGHT * 2));
42 encoder_thread = thread(&X264Encoder::encoder_thread_func, this);
45 X264Encoder::~X264Encoder()
48 queued_frames_nonempty.notify_all();
49 encoder_thread.join();
52 void X264Encoder::add_frame(int64_t pts, int64_t duration, const uint8_t *data)
56 qf.duration = duration;
59 lock_guard<mutex> lock(mu);
60 if (free_frames.empty()) {
61 fprintf(stderr, "WARNING: x264 queue full, dropping frame with pts %ld\n", pts);
65 qf.data = free_frames.front();
69 memcpy(qf.data, data, WIDTH * HEIGHT * 2);
72 lock_guard<mutex> lock(mu);
73 queued_frames.push(qf);
74 queued_frames_nonempty.notify_all();
78 void X264Encoder::init_x264()
81 x264_param_default_preset(¶m, global_flags.x264_preset.c_str(), global_flags.x264_tune.c_str());
83 param.i_width = WIDTH;
84 param.i_height = HEIGHT;
85 param.i_csp = X264_CSP_NV12;
86 param.b_vfr_input = 1;
87 param.i_timebase_num = 1;
88 param.i_timebase_den = TIMEBASE;
89 param.i_keyint_max = 50; // About one second.
90 if (global_flags.x264_speedcontrol) {
91 param.i_frame_reference = 16; // Because speedcontrol is never allowed to change this above what we set at start.
94 // NOTE: These should be in sync with the ones in h264encode.cpp (sbs_rbsp()).
95 param.vui.i_vidformat = 5; // Unspecified.
96 param.vui.b_fullrange = 0;
97 param.vui.i_colorprim = 1; // BT.709.
98 param.vui.i_transfer = 2; // Unspecified (since we use sRGB).
99 param.vui.i_colmatrix = 6; // BT.601/SMPTE 170M.
102 param.rc.i_rc_method = X264_RC_ABR;
103 param.rc.i_bitrate = global_flags.x264_bitrate;
104 update_vbv_settings(¶m);
105 if (param.rc.i_vbv_max_bitrate > 0) {
106 // If the user wants VBV control to cap the max rate, it is
107 // also reasonable to assume that they are fine with the stream
108 // constantly being around that rate even for very low-complexity
109 // content; the obvious and extreme example being a static
112 // One would think it's fine to have low-complexity content use
113 // less bitrate, but it seems to cause problems in practice;
114 // e.g. VLC seems to often drop the stream (similar to a buffer
115 // underrun) in such cases, but only when streaming from Nageru,
116 // not when reading a dump of the same stream from disk.
117 // I'm not 100% sure whether it's in VLC (possibly some buffering
118 // in the HTTP layer), in microhttpd or somewhere in Nageru itself,
119 // but it's a typical case of problems that can arise. Similarly,
120 // TCP's congestion control is not always fond of the rate staying
121 // low for a while and then rising quickly -- a variation on the same
124 // We solve this by simply asking x264 to fill in dummy bits
125 // in these cases, so that the bitrate stays reasonable constant.
126 // It's a waste of bandwidth, but it makes things go much more
127 // smoothly in these cases. (We don't do it if VBV control is off
128 // in general, not the least because it makes no sense and x264
129 // thus ignores the parameter.)
130 param.rc.b_filler = 1;
133 // Occasionally players have problem with extremely low quantizers;
134 // be on the safe side. Shouldn't affect quality in any meaningful way.
135 param.rc.i_qp_min = 5;
137 for (const string &str : global_flags.x264_extra_param) {
138 const size_t pos = str.find(',');
139 if (pos == string::npos) {
140 if (x264_param_parse(¶m, str.c_str(), nullptr) != 0) {
141 fprintf(stderr, "ERROR: x264 rejected parameter '%s'\n", str.c_str());
144 const string key = str.substr(0, pos);
145 const string value = str.substr(pos + 1);
146 if (x264_param_parse(¶m, key.c_str(), value.c_str()) != 0) {
147 fprintf(stderr, "ERROR: x264 rejected parameter '%s' set to '%s'\n",
148 key.c_str(), value.c_str());
153 x264_param_apply_profile(¶m, "high");
155 param.b_repeat_headers = !wants_global_headers;
157 x264 = x264_encoder_open(¶m);
158 if (x264 == nullptr) {
159 fprintf(stderr, "ERROR: x264 initialization failed.\n");
163 if (global_flags.x264_speedcontrol) {
164 speed_control.reset(new X264SpeedControl(x264, /*f_speed=*/1.0f, X264_QUEUE_LENGTH, /*f_buffer_init=*/1.0f));
167 if (wants_global_headers) {
171 x264_encoder_headers(x264, &nal, &num_nal);
173 for (int i = 0; i < num_nal; ++i) {
174 if (nal[i].i_type == NAL_SEI) {
175 // Don't put the SEI in extradata; make it part of the first frame instead.
176 buffered_sei += string((const char *)nal[i].p_payload, nal[i].i_payload);
178 global_headers += string((const char *)nal[i].p_payload, nal[i].i_payload);
184 void X264Encoder::encoder_thread_func()
186 if (nice(5) == -1) { // Note that x264 further nices some of its threads.
188 // No exit; it's not fatal.
197 // Wait for a queued frame, then dequeue it.
199 unique_lock<mutex> lock(mu);
200 queued_frames_nonempty.wait(lock, [this]() { return !queued_frames.empty() || should_quit; });
201 if (!queued_frames.empty()) {
202 qf = queued_frames.front();
210 frames_left = !queued_frames.empty();
216 lock_guard<mutex> lock(mu);
217 free_frames.push(qf.data);
220 // We should quit only if the should_quit flag is set _and_ we have nothing
222 } while (!should_quit || frames_left || x264_encoder_delayed_frames(x264) > 0);
224 x264_encoder_close(x264);
227 void X264Encoder::encode_frame(X264Encoder::QueuedFrame qf)
229 x264_nal_t *nal = nullptr;
232 x264_picture_t *input_pic = nullptr;
235 x264_picture_init(&pic);
238 pic.img.i_csp = X264_CSP_NV12;
240 pic.img.plane[0] = qf.data;
241 pic.img.i_stride[0] = WIDTH;
242 pic.img.plane[1] = qf.data + WIDTH * HEIGHT;
243 pic.img.i_stride[1] = WIDTH / 2 * sizeof(uint16_t);
244 pic.opaque = reinterpret_cast<void *>(intptr_t(qf.duration));
249 // See if we have a new bitrate to change to.
250 unsigned new_rate = new_bitrate_kbit.exchange(0); // Read and clear.
253 speed_control->set_config_override_function([new_rate](x264_param_t *param) {
254 param->rc.i_bitrate = new_rate;
255 update_vbv_settings(param);
259 x264_encoder_parameters(x264, ¶m);
260 param.rc.i_bitrate = new_rate;
261 update_vbv_settings(¶m);
262 x264_encoder_reconfig(x264, ¶m);
267 speed_control->before_frame(float(free_frames.size()) / X264_QUEUE_LENGTH, X264_QUEUE_LENGTH, 1e6 * qf.duration / TIMEBASE);
269 x264_encoder_encode(x264, &nal, &num_nal, input_pic, &pic);
271 speed_control->after_frame();
274 // We really need one AVPacket for the entire frame, it seems,
275 // so combine it all.
276 size_t num_bytes = buffered_sei.size();
277 for (int i = 0; i < num_nal; ++i) {
278 num_bytes += nal[i].i_payload;
281 unique_ptr<uint8_t[]> data(new uint8_t[num_bytes]);
282 uint8_t *ptr = data.get();
284 if (!buffered_sei.empty()) {
285 memcpy(ptr, buffered_sei.data(), buffered_sei.size());
286 ptr += buffered_sei.size();
287 buffered_sei.clear();
289 for (int i = 0; i < num_nal; ++i) {
290 memcpy(ptr, nal[i].p_payload, nal[i].i_payload);
291 ptr += nal[i].i_payload;
295 memset(&pkt, 0, sizeof(pkt));
297 pkt.data = data.get();
298 pkt.size = num_bytes;
299 pkt.stream_index = 0;
300 if (pic.b_keyframe) {
301 pkt.flags = AV_PKT_FLAG_KEY;
305 pkt.duration = reinterpret_cast<intptr_t>(pic.opaque);
307 mux->add_packet(pkt, pic.i_pts, pic.i_dts);