1 #include "x264_encoder.h"
14 #include "x264_speed_control.h"
17 #include <libavcodec/avcodec.h>
18 #include <libavformat/avformat.h>
25 void update_vbv_settings(x264_param_t *param)
27 if (global_flags.x264_vbv_buffer_size < 0) {
28 param->rc.i_vbv_buffer_size = param->rc.i_bitrate; // One-second VBV.
30 param->rc.i_vbv_buffer_size = global_flags.x264_vbv_buffer_size;
32 if (global_flags.x264_vbv_max_bitrate < 0) {
33 param->rc.i_vbv_max_bitrate = param->rc.i_bitrate; // CBR.
35 param->rc.i_vbv_max_bitrate = global_flags.x264_vbv_max_bitrate;
41 X264Encoder::X264Encoder(AVOutputFormat *oformat)
42 : wants_global_headers(oformat->flags & AVFMT_GLOBALHEADER)
44 frame_pool.reset(new uint8_t[WIDTH * HEIGHT * 2 * X264_QUEUE_LENGTH]);
45 for (unsigned i = 0; i < X264_QUEUE_LENGTH; ++i) {
46 free_frames.push(frame_pool.get() + i * (WIDTH * HEIGHT * 2));
48 encoder_thread = thread(&X264Encoder::encoder_thread_func, this);
51 X264Encoder::~X264Encoder()
54 queued_frames_nonempty.notify_all();
55 encoder_thread.join();
58 void X264Encoder::add_frame(int64_t pts, int64_t duration, const uint8_t *data)
62 qf.duration = duration;
65 lock_guard<mutex> lock(mu);
66 if (free_frames.empty()) {
67 fprintf(stderr, "WARNING: x264 queue full, dropping frame with pts %ld\n", pts);
71 qf.data = free_frames.front();
75 memcpy(qf.data, data, WIDTH * HEIGHT * 2);
78 lock_guard<mutex> lock(mu);
79 queued_frames.push(qf);
80 queued_frames_nonempty.notify_all();
84 void X264Encoder::init_x264()
87 x264_param_default_preset(¶m, global_flags.x264_preset.c_str(), global_flags.x264_tune.c_str());
89 param.i_width = WIDTH;
90 param.i_height = HEIGHT;
91 param.i_csp = X264_CSP_NV12;
92 param.b_vfr_input = 1;
93 param.i_timebase_num = 1;
94 param.i_timebase_den = TIMEBASE;
95 param.i_keyint_max = 50; // About one second.
96 if (global_flags.x264_speedcontrol) {
97 param.i_frame_reference = 16; // Because speedcontrol is never allowed to change this above what we set at start.
100 // NOTE: These should be in sync with the ones in h264encode.cpp (sbs_rbsp()).
101 param.vui.i_vidformat = 5; // Unspecified.
102 param.vui.b_fullrange = 0;
103 param.vui.i_colorprim = 1; // BT.709.
104 param.vui.i_transfer = 2; // Unspecified (since we use sRGB).
105 param.vui.i_colmatrix = 6; // BT.601/SMPTE 170M.
108 param.rc.i_rc_method = X264_RC_ABR;
109 param.rc.i_bitrate = global_flags.x264_bitrate;
110 update_vbv_settings(¶m);
111 if (param.rc.i_vbv_max_bitrate > 0) {
112 // If the user wants VBV control to cap the max rate, it is
113 // also reasonable to assume that they are fine with the stream
114 // constantly being around that rate even for very low-complexity
115 // content; the obvious and extreme example being a static
118 // One would think it's fine to have low-complexity content use
119 // less bitrate, but it seems to cause problems in practice;
120 // e.g. VLC seems to often drop the stream (similar to a buffer
121 // underrun) in such cases, but only when streaming from Nageru,
122 // not when reading a dump of the same stream from disk.
123 // I'm not 100% sure whether it's in VLC (possibly some buffering
124 // in the HTTP layer), in microhttpd or somewhere in Nageru itself,
125 // but it's a typical case of problems that can arise. Similarly,
126 // TCP's congestion control is not always fond of the rate staying
127 // low for a while and then rising quickly -- a variation on the same
130 // We solve this by simply asking x264 to fill in dummy bits
131 // in these cases, so that the bitrate stays reasonable constant.
132 // It's a waste of bandwidth, but it makes things go much more
133 // smoothly in these cases. (We don't do it if VBV control is off
134 // in general, not the least because it makes no sense and x264
135 // thus ignores the parameter.)
136 param.rc.b_filler = 1;
139 // Occasionally players have problem with extremely low quantizers;
140 // be on the safe side. Shouldn't affect quality in any meaningful way.
141 param.rc.i_qp_min = 5;
143 for (const string &str : global_flags.x264_extra_param) {
144 const size_t pos = str.find(',');
145 if (pos == string::npos) {
146 if (x264_param_parse(¶m, str.c_str(), nullptr) != 0) {
147 fprintf(stderr, "ERROR: x264 rejected parameter '%s'\n", str.c_str());
150 const string key = str.substr(0, pos);
151 const string value = str.substr(pos + 1);
152 if (x264_param_parse(¶m, key.c_str(), value.c_str()) != 0) {
153 fprintf(stderr, "ERROR: x264 rejected parameter '%s' set to '%s'\n",
154 key.c_str(), value.c_str());
159 x264_param_apply_profile(¶m, "high");
161 param.b_repeat_headers = !wants_global_headers;
163 x264 = x264_encoder_open(¶m);
164 if (x264 == nullptr) {
165 fprintf(stderr, "ERROR: x264 initialization failed.\n");
169 if (global_flags.x264_speedcontrol) {
170 speed_control.reset(new X264SpeedControl(x264, /*f_speed=*/1.0f, X264_QUEUE_LENGTH, /*f_buffer_init=*/1.0f));
173 if (wants_global_headers) {
177 x264_encoder_headers(x264, &nal, &num_nal);
179 for (int i = 0; i < num_nal; ++i) {
180 if (nal[i].i_type == NAL_SEI) {
181 // Don't put the SEI in extradata; make it part of the first frame instead.
182 buffered_sei += string((const char *)nal[i].p_payload, nal[i].i_payload);
184 global_headers += string((const char *)nal[i].p_payload, nal[i].i_payload);
190 void X264Encoder::encoder_thread_func()
192 if (nice(5) == -1) { // Note that x264 further nices some of its threads.
194 // No exit; it's not fatal.
203 // Wait for a queued frame, then dequeue it.
205 unique_lock<mutex> lock(mu);
206 queued_frames_nonempty.wait(lock, [this]() { return !queued_frames.empty() || should_quit; });
207 if (!queued_frames.empty()) {
208 qf = queued_frames.front();
216 frames_left = !queued_frames.empty();
222 lock_guard<mutex> lock(mu);
223 free_frames.push(qf.data);
226 // We should quit only if the should_quit flag is set _and_ we have nothing
228 } while (!should_quit || frames_left || x264_encoder_delayed_frames(x264) > 0);
230 x264_encoder_close(x264);
233 void X264Encoder::encode_frame(X264Encoder::QueuedFrame qf)
235 x264_nal_t *nal = nullptr;
238 x264_picture_t *input_pic = nullptr;
241 x264_picture_init(&pic);
244 pic.img.i_csp = X264_CSP_NV12;
246 pic.img.plane[0] = qf.data;
247 pic.img.i_stride[0] = WIDTH;
248 pic.img.plane[1] = qf.data + WIDTH * HEIGHT;
249 pic.img.i_stride[1] = WIDTH / 2 * sizeof(uint16_t);
250 pic.opaque = reinterpret_cast<void *>(intptr_t(qf.duration));
255 // See if we have a new bitrate to change to.
256 unsigned new_rate = new_bitrate_kbit.exchange(0); // Read and clear.
259 speed_control->set_config_override_function([new_rate](x264_param_t *param) {
260 param->rc.i_bitrate = new_rate;
261 update_vbv_settings(param);
265 x264_encoder_parameters(x264, ¶m);
266 param.rc.i_bitrate = new_rate;
267 update_vbv_settings(¶m);
268 x264_encoder_reconfig(x264, ¶m);
273 speed_control->before_frame(float(free_frames.size()) / X264_QUEUE_LENGTH, X264_QUEUE_LENGTH, 1e6 * qf.duration / TIMEBASE);
275 x264_encoder_encode(x264, &nal, &num_nal, input_pic, &pic);
277 speed_control->after_frame();
280 // We really need one AVPacket for the entire frame, it seems,
281 // so combine it all.
282 size_t num_bytes = buffered_sei.size();
283 for (int i = 0; i < num_nal; ++i) {
284 num_bytes += nal[i].i_payload;
287 unique_ptr<uint8_t[]> data(new uint8_t[num_bytes]);
288 uint8_t *ptr = data.get();
290 if (!buffered_sei.empty()) {
291 memcpy(ptr, buffered_sei.data(), buffered_sei.size());
292 ptr += buffered_sei.size();
293 buffered_sei.clear();
295 for (int i = 0; i < num_nal; ++i) {
296 memcpy(ptr, nal[i].p_payload, nal[i].i_payload);
297 ptr += nal[i].i_payload;
301 memset(&pkt, 0, sizeof(pkt));
303 pkt.data = data.get();
304 pkt.size = num_bytes;
305 pkt.stream_index = 0;
306 if (pic.b_keyframe) {
307 pkt.flags = AV_PKT_FLAG_KEY;
311 pkt.duration = reinterpret_cast<intptr_t>(pic.opaque);
313 mux->add_packet(pkt, pic.i_pts, pic.i_dts);