1 #include "x264_speed_control.h"
11 X264SpeedControl::X264SpeedControl(x264_t *x264, float f_speed, int i_buffer_size, float f_buffer_init)
12 : x264(x264), f_speed(f_speed)
15 x264_encoder_parameters(x264, ¶m);
17 float fps = (float)param.i_fps_num / param.i_fps_den;
19 set_buffer_size(i_buffer_size);
20 buffer_fill = buffer_size * f_buffer_init;
21 buffer_fill = max<int64_t>(buffer_fill, uspf);
22 buffer_fill = min(buffer_fill, buffer_size);
25 cplx_num = 3e3; //FIXME estimate initial complexity
27 stat.min_buffer = buffer_size;
31 X264SpeedControl::~X264SpeedControl()
33 fprintf(stderr, "speedcontrol: avg preset=%.3f buffer min=%.3f max=%.3f\n",
34 stat.avg_preset / stat.den,
35 (float)stat.min_buffer / buffer_size,
36 (float)stat.max_buffer / buffer_size );
37 // x264_log( x264, X264_LOG_INFO, "speedcontrol: avg cplx=%.5f\n", cplx_num / cplx_den );
42 float time; // relative encoding time, compared to the other presets
55 // The actual presets, including the equivalent commandline options. Note that
56 // all presets are benchmarked with --weightp 1 --mbtree --rc-lookahead 20
57 // on top of the given settings (equivalent settings to the "faster" preset).
58 // Timings and SSIM measurements were done on a quadcore Haswell i5 3.2 GHz
59 // on the first 1000 frames of "Tears of Steel" in 1080p.
61 // Note that the two first and the two last are also used for extrapolation
62 // should the desired time be outside the range. Thus, it is disadvantageous if
63 // they are chosen so that the timings are too close to each other.
65 static const sc_preset_t presets[SC_PRESETS] = {
66 #define I4 X264_ANALYSE_I4x4
67 #define I8 X264_ANALYSE_I8x8
68 #define P4 X264_ANALYSE_PSUB8x8
69 #define P8 X264_ANALYSE_PSUB16x16
70 #define B8 X264_ANALYSE_BSUB16x16
71 // Preset 0: 14.179db, --preset superfast --b-adapt 0 --bframes 0
72 { .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 },
74 // Preset 1: 14.459db, --preset superfast
75 { .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 },
77 // Preset 2: 14.761db, --preset superfast --subme 2
78 { .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 },
80 // Preset 3: 15.543db, --preset veryfast
81 { .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 },
83 // Preset 4: 15.716db, --preset veryfast --subme 3
84 { .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 },
86 // Preset 5: 15.786db, --preset veryfast --subme 3 --ref 2
87 { .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 },
89 // Preset 6: 15.813db, --preset veryfast --subme 4 --ref 2
90 { .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 },
92 // Preset 7: 15.849db, --preset faster
93 { .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 },
95 // Preset 8: 15.857db, --preset faster --mixed-refs
96 { .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 },
98 // Preset 9: 15.869db, --preset faster --mixed-refs --subme 5
99 { .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 },
101 // Preset 10: 16.051db, --preset fast
102 { .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 },
104 // Preset 11: 16.356db, --preset fast --subme 7
105 { .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 },
107 // Preset 12: 16.418db, --preset fast --subme 7 --ref 3
108 { .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 },
110 // Preset 13: 16.460db, --preset medium
111 { .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 },
113 // Preset 14: 16.517db, --preset medium --subme 8
114 { .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 },
116 // Preset 15: 16.523db, --preset medium --subme 8 --me umh
117 { .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 },
119 // Preset 16: 16.543db, --preset medium --subme 8 --me umh --direct auto --b-adapt 2
120 { .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 },
122 // Preset 17: 16.613db, --preset slow
123 { .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 },
125 // Preset 18: 16.641db, --preset slow --subme 9
126 { .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 },
128 // Preset 19: 16.895db, --preset slow --subme 9 --trellis 2
129 { .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 },
131 // Preset 20: 16.918db, --preset slow --subme 9 --trellis 2 --ref 6
132 { .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 },
134 // Preset 21: 16.934db, --preset slow --subme 9 --trellis 2 --ref 7
135 { .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 },
137 // Preset 22: 16.948db, --preset slower
138 { .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 },
140 // Preset 23: 17.058db, --preset slower --subme 10
141 { .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 },
143 // Preset 24: 17.268db, --preset slower --subme 10 --bframes 8
144 { .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 },
146 // Preset 25: 17.297db, --preset veryslow
147 { .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 },
155 void X264SpeedControl::before_frame(float new_buffer_fill, int new_buffer_size, float new_uspf)
157 if (new_uspf > 0.0) {
160 if (new_buffer_size) {
161 set_buffer_size(new_buffer_size);
163 buffer_fill = buffer_size * new_buffer_fill;
167 // update buffer state after encoding and outputting the previous frame(s)
169 t = timestamp = mdate();
175 delta_t = t - timestamp;
178 // update the time predictor
180 int cpu_time = cpu_time_last_frame;
181 cplx_num *= cplx_decay;
182 cplx_den *= cplx_decay;
183 cplx_num += cpu_time / presets[preset].time;
186 stat.avg_preset += preset;
190 stat.min_buffer = min(buffer_fill, stat.min_buffer);
191 stat.max_buffer = max(buffer_fill, stat.max_buffer);
193 if (buffer_fill >= buffer_size) { // oops, cpu was idle
194 // not really an error, but we'll warn for debugging purposes
195 static int64_t idle_t = 0, print_interval = 0;
196 idle_t += buffer_fill - buffer_size;
197 if (t - print_interval > 1e6) {
198 //fprintf(stderr, "speedcontrol idle (%.6f sec)\n", idle_t/1e6);
202 buffer_fill = buffer_size;
203 } else if (buffer_fill <= 0) { // oops, we're late
204 // fprintf(stderr, "speedcontrol underflow (%.6f sec)\n", buffer_fill/1e6);
208 // Pick the preset that should return the buffer to 3/4-full within a time
209 // specified by compensation_period.
211 // NOTE: This doesn't actually do that, at least assuming the same target is
212 // chosen for every frame; exactly what it does is unclear to me. It seems
213 // to consistently undershoot a bit, so it needs to be saved by the second
214 // predictor below. However, fixing the formula seems to yield somewhat less
215 // stable results in practice; in particular, once the buffer is half-full
216 // or so, it would give us a negative target. Perhaps increasing
217 // compensation_period would be a good idea, but initial (very brief) tests
218 // did not yield good results.
219 float target = uspf / f_speed
220 * (buffer_fill + compensation_period)
221 / (buffer_size*3/4 + compensation_period);
222 float cplx = cplx_num / cplx_den;
224 float filled = (float) buffer_fill / buffer_size;
226 t0 = presets[0].time * cplx;
228 t1 = presets[i].time * cplx;
229 if (t1 >= target || i == SC_PRESETS - 1)
233 // exponential interpolation between states
234 set = i-1 + (log(target) - log(t0)) / (log(t1) - log(t0));
235 set = max<float>(set, -5);
236 set = min<float>(set, (SC_PRESETS-1) + 5);
237 // Even if our time estimations in the SC_PRESETS array are off
238 // this will push us towards our target fullness
240 set += (40 * (filled-0.75));
241 float s2 = (40 * (filled-0.75));
242 set = min<float>(max<float>(set, 0), SC_PRESETS - 1);
243 apply_preset(dither_preset(set));
245 if (global_flags.x264_speedcontrol_verbose) {
246 static float cpu, wall, tgt, den;
247 const float decay = 1-1/100.;
248 cpu = cpu*decay + cpu_time_last_frame;
249 wall = wall*decay + delta_t;
250 tgt = tgt*decay + target;
252 fprintf(stderr, "speed: %.2f+%.2f %d[%.5f] (t/c/w: %6.0f/%6.0f/%6.0f = %.4f) fps=%.2f\r",
253 s1, s2, preset, (float)buffer_fill / buffer_size,
254 tgt/den, cpu/den, wall/den, cpu/wall, 1e6*den/wall );
260 void X264SpeedControl::after_frame()
262 cpu_time_last_frame = mdate() - timestamp;
265 void X264SpeedControl::set_buffer_size(int new_buffer_size)
267 new_buffer_size = max(3, new_buffer_size);
268 buffer_size = new_buffer_size * uspf;
269 cplx_decay = 1 - 1./new_buffer_size;
270 compensation_period = buffer_size/4;
273 int X264SpeedControl::dither_preset(float f)
287 void X264SpeedControl::apply_preset(int new_preset)
289 new_preset = max(new_preset, 0);
290 new_preset = min(new_preset, SC_PRESETS - 1);
292 const sc_preset_t *s = &presets[new_preset];
294 x264_encoder_parameters(x264, &p);
296 p.i_frame_reference = s->refs;
297 p.i_bframe_adaptive = s->badapt;
298 p.i_bframe = s->bframes;
299 p.analyse.inter = s->partitions;
300 p.analyse.i_subpel_refine = s->subme;
301 p.analyse.i_me_method = s->me;
302 p.analyse.i_trellis = s->trellis;
303 p.analyse.b_mixed_references = s->mix;
304 p.analyse.i_direct_mv_pred = s->direct;
305 p.analyse.i_me_range = s->merange;
306 x264_encoder_reconfig(x264, &p);
310 int64_t X264SpeedControl::mdate()
313 clock_gettime(CLOCK_MONOTONIC, &now);
314 return now.tv_sec * 1000000 + now.tv_nsec / 1000;