1 #include "x264_speed_control.h"
11 #include <type_traits>
16 using namespace std::chrono;
18 X264SpeedControl::X264SpeedControl(x264_t *x264, float f_speed, int i_buffer_size, float f_buffer_init)
19 : dyn(load_x264_for_bit_depth(global_flags.x264_bit_depth)),
20 x264(x264), f_speed(f_speed)
23 dyn.x264_encoder_parameters(x264, ¶m);
25 float fps = (float)param.i_fps_num / param.i_fps_den;
27 set_buffer_size(i_buffer_size);
28 buffer_fill = buffer_size * f_buffer_init;
29 buffer_fill = max<int64_t>(buffer_fill, uspf);
30 buffer_fill = min(buffer_fill, buffer_size);
31 timestamp = steady_clock::now();
33 cplx_num = 3e3; //FIXME estimate initial complexity
35 stat.min_buffer = buffer_size;
37 stat.avg_preset = 0.0;
41 X264SpeedControl::~X264SpeedControl()
43 fprintf(stderr, "speedcontrol: avg preset=%.3f buffer min=%.3f max=%.3f\n",
44 stat.avg_preset / stat.den,
45 (float)stat.min_buffer / buffer_size,
46 (float)stat.max_buffer / buffer_size );
47 // x264_log( x264, X264_LOG_INFO, "speedcontrol: avg cplx=%.5f\n", cplx_num / cplx_den );
55 float time; // relative encoding time, compared to the other presets
68 // The actual presets, including the equivalent commandline options. Note that
69 // all presets are benchmarked with --weightp 1 --mbtree --rc-lookahead 20
70 // on top of the given settings (equivalent settings to the "faster" preset).
71 // Timings and SSIM measurements were done on a quadcore Haswell i5 3.2 GHz
72 // on the first 1000 frames of "Tears of Steel" in 1080p.
74 // Note that the two first and the two last are also used for extrapolation
75 // should the desired time be outside the range. Thus, it is disadvantageous if
76 // they are chosen so that the timings are too close to each other.
78 static const sc_preset_t presets[SC_PRESETS] = {
79 #define I4 X264_ANALYSE_I4x4
80 #define I8 X264_ANALYSE_I8x8
81 #define P4 X264_ANALYSE_PSUB8x8
82 #define P8 X264_ANALYSE_PSUB16x16
83 #define B8 X264_ANALYSE_BSUB16x16
84 // Preset 0: 14.179db, --preset superfast --b-adapt 0 --bframes 0
85 { .time= 1.000, .subme=1, .me=X264_ME_DIA, .refs=1, .mix=0, .trellis=0, .partitions=I8|I4, .badapt=0, .bframes=0, .direct=0, .merange=16 },
87 // Preset 1: 14.459db, --preset superfast
88 { .time= 1.283, .subme=1, .me=X264_ME_DIA, .refs=1, .mix=0, .trellis=0, .partitions=I8|I4, .badapt=1, .bframes=3, .direct=1, .merange=16 },
90 // Preset 2: 14.761db, --preset superfast --subme 2
91 { .time= 1.603, .subme=2, .me=X264_ME_DIA, .refs=1, .mix=0, .trellis=0, .partitions=I8|I4, .badapt=1, .bframes=3, .direct=1, .merange=16 },
93 // Preset 3: 15.543db, --preset veryfast
94 { .time= 1.843, .subme=2, .me=X264_ME_HEX, .refs=1, .mix=0, .trellis=0, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
96 // Preset 4: 15.716db, --preset veryfast --subme 3
97 { .time= 2.452, .subme=3, .me=X264_ME_HEX, .refs=1, .mix=0, .trellis=0, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
99 // Preset 5: 15.786db, --preset veryfast --subme 3 --ref 2
100 { .time= 2.733, .subme=3, .me=X264_ME_HEX, .refs=2, .mix=0, .trellis=0, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
102 // Preset 6: 15.813db, --preset veryfast --subme 4 --ref 2
103 { .time= 3.085, .subme=4, .me=X264_ME_HEX, .refs=2, .mix=0, .trellis=0, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
105 // Preset 7: 15.849db, --preset faster
106 { .time= 3.101, .subme=4, .me=X264_ME_HEX, .refs=2, .mix=0, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
108 // Preset 8: 15.857db, --preset faster --mixed-refs
109 { .time= 3.284, .subme=4, .me=X264_ME_HEX, .refs=2, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
111 // Preset 9: 15.869db, --preset faster --mixed-refs --subme 5
112 { .time= 3.587, .subme=5, .me=X264_ME_HEX, .refs=2, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
114 // Preset 10: 16.051db, --preset fast
115 { .time= 3.947, .subme=6, .me=X264_ME_HEX, .refs=2, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
117 // Preset 11: 16.356db, --preset fast --subme 7
118 { .time= 4.041, .subme=7, .me=X264_ME_HEX, .refs=2, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
120 // Preset 12: 16.418db, --preset fast --subme 7 --ref 3
121 { .time= 4.406, .subme=7, .me=X264_ME_HEX, .refs=3, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
123 // Preset 13: 16.460db, --preset medium
124 { .time= 4.707, .subme=7, .me=X264_ME_HEX, .refs=3, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
126 // Preset 14: 16.517db, --preset medium --subme 8
127 { .time= 5.133, .subme=8, .me=X264_ME_HEX, .refs=3, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
129 // Preset 15: 16.523db, --preset medium --subme 8 --me umh
130 { .time= 6.050, .subme=8, .me=X264_ME_UMH, .refs=3, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=1, .bframes=3, .direct=1, .merange=16 },
132 // Preset 16: 16.543db, --preset medium --subme 8 --me umh --direct auto --b-adapt 2
133 { .time= 6.849, .subme=8, .me=X264_ME_UMH, .refs=3, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=2, .bframes=3, .direct=3, .merange=16 },
135 // Preset 17: 16.613db, --preset slow
136 { .time= 8.042, .subme=8, .me=X264_ME_UMH, .refs=5, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=2, .bframes=3, .direct=3, .merange=16 },
138 // Preset 18: 16.641db, --preset slow --subme 9
139 { .time= 8.972, .subme=9, .me=X264_ME_UMH, .refs=5, .mix=1, .trellis=1, .partitions=I8|I4|P8|B8, .badapt=2, .bframes=3, .direct=3, .merange=16 },
141 // Preset 19: 16.895db, --preset slow --subme 9 --trellis 2
142 { .time=10.073, .subme=9, .me=X264_ME_UMH, .refs=5, .mix=1, .trellis=2, .partitions=I8|I4|P8|B8, .badapt=2, .bframes=3, .direct=3, .merange=16 },
144 // Preset 20: 16.918db, --preset slow --subme 9 --trellis 2 --ref 6
145 { .time=11.147, .subme=9, .me=X264_ME_UMH, .refs=6, .mix=1, .trellis=2, .partitions=I8|I4|P8|B8, .badapt=2, .bframes=3, .direct=3, .merange=16 },
147 // Preset 21: 16.934db, --preset slow --subme 9 --trellis 2 --ref 7
148 { .time=12.267, .subme=9, .me=X264_ME_UMH, .refs=7, .mix=1, .trellis=2, .partitions=I8|I4|P8|B8, .badapt=2, .bframes=3, .direct=3, .merange=16 },
150 // Preset 22: 16.948db, --preset slower
151 { .time=13.829, .subme=9, .me=X264_ME_UMH, .refs=8, .mix=1, .trellis=2, .partitions=I8|I4|P8|B8|P4, .badapt=2, .bframes=3, .direct=3, .merange=16 },
153 // Preset 23: 17.058db, --preset slower --subme 10
154 { .time=14.831, .subme=10, .me=X264_ME_UMH, .refs=8, .mix=1, .trellis=2, .partitions=I8|I4|P8|B8|P4, .badapt=2, .bframes=3, .direct=3, .merange=16 },
156 // Preset 24: 17.268db, --preset slower --subme 10 --bframes 8
157 { .time=18.705, .subme=10, .me=X264_ME_UMH, .refs=8, .mix=1, .trellis=2, .partitions=I8|I4|P8|B8|P4, .badapt=2, .bframes=8, .direct=3, .merange=16 },
159 // Preset 25: 17.297db, --preset veryslow
160 { .time=31.419, .subme=10, .me=X264_ME_UMH, .refs=16, .mix=1, .trellis=2, .partitions=I8|I4|P8|B8|P4, .badapt=2, .bframes=8, .direct=3, .merange=24 },
168 void X264SpeedControl::before_frame(float new_buffer_fill, int new_buffer_size, float new_uspf)
170 if (new_uspf > 0.0) {
173 if (new_buffer_size) {
174 set_buffer_size(new_buffer_size);
176 buffer_fill = buffer_size * new_buffer_fill;
178 steady_clock::time_point t;
180 // update buffer state after encoding and outputting the previous frame(s)
182 t = timestamp = steady_clock::now();
185 t = steady_clock::now();
188 auto delta_t = t - timestamp;
191 // update the time predictor
193 int cpu_time = duration_cast<microseconds>(cpu_time_last_frame).count();
194 cplx_num *= cplx_decay;
195 cplx_den *= cplx_decay;
196 cplx_num += cpu_time / presets[preset].time;
199 stat.avg_preset += preset;
203 stat.min_buffer = min(buffer_fill, stat.min_buffer);
204 stat.max_buffer = max(buffer_fill, stat.max_buffer);
206 if (buffer_fill >= buffer_size) { // oops, cpu was idle
207 // not really an error, but we'll warn for debugging purposes
208 static int64_t idle_t = 0;
209 static steady_clock::time_point print_interval;
210 static bool first = false;
211 idle_t += buffer_fill - buffer_size;
212 if (first || duration<double>(t - print_interval).count() > 0.1) {
213 //fprintf(stderr, "speedcontrol idle (%.6f sec)\n", idle_t/1e6);
218 buffer_fill = buffer_size;
219 } else if (buffer_fill <= 0) { // oops, we're late
220 // fprintf(stderr, "speedcontrol underflow (%.6f sec)\n", buffer_fill/1e6);
224 // Pick the preset that should return the buffer to 3/4-full within a time
225 // specified by compensation_period.
227 // NOTE: This doesn't actually do that, at least assuming the same target is
228 // chosen for every frame; exactly what it does is unclear to me. It seems
229 // to consistently undershoot a bit, so it needs to be saved by the second
230 // predictor below. However, fixing the formula seems to yield somewhat less
231 // stable results in practice; in particular, once the buffer is half-full
232 // or so, it would give us a negative target. Perhaps increasing
233 // compensation_period would be a good idea, but initial (very brief) tests
234 // did not yield good results.
235 float target = uspf / f_speed
236 * (buffer_fill + compensation_period)
237 / (buffer_size*3/4 + compensation_period);
238 float cplx = cplx_num / cplx_den;
240 float filled = (float) buffer_fill / buffer_size;
242 t0 = presets[0].time * cplx;
244 t1 = presets[i].time * cplx;
245 if (t1 >= target || i == SC_PRESETS - 1)
249 // exponential interpolation between states
250 set = i-1 + (log(target) - log(t0)) / (log(t1) - log(t0));
251 set = max<float>(set, -5);
252 set = min<float>(set, (SC_PRESETS-1) + 5);
253 // Even if our time estimations in the SC_PRESETS array are off
254 // this will push us towards our target fullness
256 set += (40 * (filled-0.75));
257 float s2 = (40 * (filled-0.75));
258 set = min<float>(max<float>(set, 0), SC_PRESETS - 1);
259 apply_preset(dither_preset(set));
261 if (global_flags.x264_speedcontrol_verbose) {
262 static float cpu, wall, tgt, den;
263 const float decay = 1-1/100.;
264 cpu = cpu*decay + duration_cast<microseconds>(cpu_time_last_frame).count();
265 wall = wall*decay + duration_cast<microseconds>(delta_t).count();
266 tgt = tgt*decay + target;
268 fprintf(stderr, "speed: %.2f+%.2f %d[%.5f] (t/c/w: %6.0f/%6.0f/%6.0f = %.4f) fps=%.2f\r",
269 s1, s2, preset, (float)buffer_fill / buffer_size,
270 tgt/den, cpu/den, wall/den, cpu/wall, 1e6*den/wall );
276 void X264SpeedControl::after_frame()
278 cpu_time_last_frame = steady_clock::now() - timestamp;
281 void X264SpeedControl::set_buffer_size(int new_buffer_size)
283 new_buffer_size = max(3, new_buffer_size);
284 buffer_size = new_buffer_size * uspf;
285 cplx_decay = 1 - 1./new_buffer_size;
286 compensation_period = buffer_size/4;
289 int X264SpeedControl::dither_preset(float f)
303 void X264SpeedControl::apply_preset(int new_preset)
305 new_preset = max(new_preset, 0);
306 new_preset = min(new_preset, SC_PRESETS - 1);
308 const sc_preset_t *s = &presets[new_preset];
310 dyn.x264_encoder_parameters(x264, &p);
312 p.i_frame_reference = s->refs;
313 p.i_bframe_adaptive = s->badapt;
314 p.i_bframe = s->bframes;
315 p.analyse.inter = s->partitions;
316 p.analyse.i_subpel_refine = s->subme;
317 p.analyse.i_me_method = s->me;
318 p.analyse.i_trellis = s->trellis;
319 p.analyse.b_mixed_references = s->mix;
320 p.analyse.i_direct_mv_pred = s->direct;
321 p.analyse.i_me_range = s->merange;
325 dyn.x264_encoder_reconfig(x264, &p);