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1 | /* |
2 | * AAC encoder psychoacoustic model | |
3 | * Copyright (C) 2008 Konstantin Shishkov | |
4 | * | |
5 | * This file is part of FFmpeg. | |
6 | * | |
7 | * FFmpeg is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; either | |
10 | * version 2.1 of the License, or (at your option) any later version. | |
11 | * | |
12 | * FFmpeg is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with FFmpeg; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | /** | |
23 | * @file | |
24 | * AAC encoder psychoacoustic model | |
25 | */ | |
26 | ||
27 | #include "libavutil/attributes.h" | |
28 | #include "libavutil/libm.h" | |
29 | ||
30 | #include "avcodec.h" | |
31 | #include "aactab.h" | |
32 | #include "psymodel.h" | |
33 | ||
34 | /*********************************** | |
35 | * TODOs: | |
36 | * try other bitrate controlling mechanism (maybe use ratecontrol.c?) | |
37 | * control quality for quality-based output | |
38 | **********************************/ | |
39 | ||
40 | /** | |
41 | * constants for 3GPP AAC psychoacoustic model | |
42 | * @{ | |
43 | */ | |
44 | #define PSY_3GPP_THR_SPREAD_HI 1.5f // spreading factor for low-to-hi threshold spreading (15 dB/Bark) | |
45 | #define PSY_3GPP_THR_SPREAD_LOW 3.0f // spreading factor for hi-to-low threshold spreading (30 dB/Bark) | |
46 | /* spreading factor for low-to-hi energy spreading, long block, > 22kbps/channel (20dB/Bark) */ | |
47 | #define PSY_3GPP_EN_SPREAD_HI_L1 2.0f | |
48 | /* spreading factor for low-to-hi energy spreading, long block, <= 22kbps/channel (15dB/Bark) */ | |
49 | #define PSY_3GPP_EN_SPREAD_HI_L2 1.5f | |
50 | /* spreading factor for low-to-hi energy spreading, short block (15 dB/Bark) */ | |
51 | #define PSY_3GPP_EN_SPREAD_HI_S 1.5f | |
52 | /* spreading factor for hi-to-low energy spreading, long block (30dB/Bark) */ | |
53 | #define PSY_3GPP_EN_SPREAD_LOW_L 3.0f | |
54 | /* spreading factor for hi-to-low energy spreading, short block (20dB/Bark) */ | |
55 | #define PSY_3GPP_EN_SPREAD_LOW_S 2.0f | |
56 | ||
57 | #define PSY_3GPP_RPEMIN 0.01f | |
58 | #define PSY_3GPP_RPELEV 2.0f | |
59 | ||
60 | #define PSY_3GPP_C1 3.0f /* log2(8) */ | |
61 | #define PSY_3GPP_C2 1.3219281f /* log2(2.5) */ | |
62 | #define PSY_3GPP_C3 0.55935729f /* 1 - C2 / C1 */ | |
63 | ||
64 | #define PSY_SNR_1DB 7.9432821e-1f /* -1dB */ | |
65 | #define PSY_SNR_25DB 3.1622776e-3f /* -25dB */ | |
66 | ||
67 | #define PSY_3GPP_SAVE_SLOPE_L -0.46666667f | |
68 | #define PSY_3GPP_SAVE_SLOPE_S -0.36363637f | |
69 | #define PSY_3GPP_SAVE_ADD_L -0.84285712f | |
70 | #define PSY_3GPP_SAVE_ADD_S -0.75f | |
71 | #define PSY_3GPP_SPEND_SLOPE_L 0.66666669f | |
72 | #define PSY_3GPP_SPEND_SLOPE_S 0.81818181f | |
73 | #define PSY_3GPP_SPEND_ADD_L -0.35f | |
74 | #define PSY_3GPP_SPEND_ADD_S -0.26111111f | |
75 | #define PSY_3GPP_CLIP_LO_L 0.2f | |
76 | #define PSY_3GPP_CLIP_LO_S 0.2f | |
77 | #define PSY_3GPP_CLIP_HI_L 0.95f | |
78 | #define PSY_3GPP_CLIP_HI_S 0.75f | |
79 | ||
80 | #define PSY_3GPP_AH_THR_LONG 0.5f | |
81 | #define PSY_3GPP_AH_THR_SHORT 0.63f | |
82 | ||
83 | enum { | |
84 | PSY_3GPP_AH_NONE, | |
85 | PSY_3GPP_AH_INACTIVE, | |
86 | PSY_3GPP_AH_ACTIVE | |
87 | }; | |
88 | ||
89 | #define PSY_3GPP_BITS_TO_PE(bits) ((bits) * 1.18f) | |
90 | ||
91 | /* LAME psy model constants */ | |
92 | #define PSY_LAME_FIR_LEN 21 ///< LAME psy model FIR order | |
93 | #define AAC_BLOCK_SIZE_LONG 1024 ///< long block size | |
94 | #define AAC_BLOCK_SIZE_SHORT 128 ///< short block size | |
95 | #define AAC_NUM_BLOCKS_SHORT 8 ///< number of blocks in a short sequence | |
96 | #define PSY_LAME_NUM_SUBBLOCKS 3 ///< Number of sub-blocks in each short block | |
97 | ||
98 | /** | |
99 | * @} | |
100 | */ | |
101 | ||
102 | /** | |
103 | * information for single band used by 3GPP TS26.403-inspired psychoacoustic model | |
104 | */ | |
105 | typedef struct AacPsyBand{ | |
106 | float energy; ///< band energy | |
107 | float thr; ///< energy threshold | |
108 | float thr_quiet; ///< threshold in quiet | |
109 | float nz_lines; ///< number of non-zero spectral lines | |
110 | float active_lines; ///< number of active spectral lines | |
111 | float pe; ///< perceptual entropy | |
112 | float pe_const; ///< constant part of the PE calculation | |
113 | float norm_fac; ///< normalization factor for linearization | |
114 | int avoid_holes; ///< hole avoidance flag | |
115 | }AacPsyBand; | |
116 | ||
117 | /** | |
118 | * single/pair channel context for psychoacoustic model | |
119 | */ | |
120 | typedef struct AacPsyChannel{ | |
121 | AacPsyBand band[128]; ///< bands information | |
122 | AacPsyBand prev_band[128]; ///< bands information from the previous frame | |
123 | ||
124 | float win_energy; ///< sliding average of channel energy | |
125 | float iir_state[2]; ///< hi-pass IIR filter state | |
126 | uint8_t next_grouping; ///< stored grouping scheme for the next frame (in case of 8 short window sequence) | |
127 | enum WindowSequence next_window_seq; ///< window sequence to be used in the next frame | |
128 | /* LAME psy model specific members */ | |
129 | float attack_threshold; ///< attack threshold for this channel | |
130 | float prev_energy_subshort[AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS]; | |
131 | int prev_attack; ///< attack value for the last short block in the previous sequence | |
132 | }AacPsyChannel; | |
133 | ||
134 | /** | |
135 | * psychoacoustic model frame type-dependent coefficients | |
136 | */ | |
137 | typedef struct AacPsyCoeffs{ | |
138 | float ath; ///< absolute threshold of hearing per bands | |
139 | float barks; ///< Bark value for each spectral band in long frame | |
140 | float spread_low[2]; ///< spreading factor for low-to-high threshold spreading in long frame | |
141 | float spread_hi [2]; ///< spreading factor for high-to-low threshold spreading in long frame | |
142 | float min_snr; ///< minimal SNR | |
143 | }AacPsyCoeffs; | |
144 | ||
145 | /** | |
146 | * 3GPP TS26.403-inspired psychoacoustic model specific data | |
147 | */ | |
148 | typedef struct AacPsyContext{ | |
149 | int chan_bitrate; ///< bitrate per channel | |
150 | int frame_bits; ///< average bits per frame | |
151 | int fill_level; ///< bit reservoir fill level | |
152 | struct { | |
153 | float min; ///< minimum allowed PE for bit factor calculation | |
154 | float max; ///< maximum allowed PE for bit factor calculation | |
155 | float previous; ///< allowed PE of the previous frame | |
156 | float correction; ///< PE correction factor | |
157 | } pe; | |
158 | AacPsyCoeffs psy_coef[2][64]; | |
159 | AacPsyChannel *ch; | |
160 | }AacPsyContext; | |
161 | ||
162 | /** | |
163 | * LAME psy model preset struct | |
164 | */ | |
165 | typedef struct { | |
166 | int quality; ///< Quality to map the rest of the vaules to. | |
167 | /* This is overloaded to be both kbps per channel in ABR mode, and | |
168 | * requested quality in constant quality mode. | |
169 | */ | |
170 | float st_lrm; ///< short threshold for L, R, and M channels | |
171 | } PsyLamePreset; | |
172 | ||
173 | /** | |
174 | * LAME psy model preset table for ABR | |
175 | */ | |
176 | static const PsyLamePreset psy_abr_map[] = { | |
177 | /* TODO: Tuning. These were taken from LAME. */ | |
178 | /* kbps/ch st_lrm */ | |
179 | { 8, 6.60}, | |
180 | { 16, 6.60}, | |
181 | { 24, 6.60}, | |
182 | { 32, 6.60}, | |
183 | { 40, 6.60}, | |
184 | { 48, 6.60}, | |
185 | { 56, 6.60}, | |
186 | { 64, 6.40}, | |
187 | { 80, 6.00}, | |
188 | { 96, 5.60}, | |
189 | {112, 5.20}, | |
190 | {128, 5.20}, | |
191 | {160, 5.20} | |
192 | }; | |
193 | ||
194 | /** | |
195 | * LAME psy model preset table for constant quality | |
196 | */ | |
197 | static const PsyLamePreset psy_vbr_map[] = { | |
198 | /* vbr_q st_lrm */ | |
199 | { 0, 4.20}, | |
200 | { 1, 4.20}, | |
201 | { 2, 4.20}, | |
202 | { 3, 4.20}, | |
203 | { 4, 4.20}, | |
204 | { 5, 4.20}, | |
205 | { 6, 4.20}, | |
206 | { 7, 4.20}, | |
207 | { 8, 4.20}, | |
208 | { 9, 4.20}, | |
209 | {10, 4.20} | |
210 | }; | |
211 | ||
212 | /** | |
213 | * LAME psy model FIR coefficient table | |
214 | */ | |
215 | static const float psy_fir_coeffs[] = { | |
216 | -8.65163e-18 * 2, -0.00851586 * 2, -6.74764e-18 * 2, 0.0209036 * 2, | |
217 | -3.36639e-17 * 2, -0.0438162 * 2, -1.54175e-17 * 2, 0.0931738 * 2, | |
218 | -5.52212e-17 * 2, -0.313819 * 2 | |
219 | }; | |
220 | ||
221 | #if ARCH_MIPS | |
222 | # include "mips/aacpsy_mips.h" | |
223 | #endif /* ARCH_MIPS */ | |
224 | ||
225 | /** | |
226 | * Calculate the ABR attack threshold from the above LAME psymodel table. | |
227 | */ | |
228 | static float lame_calc_attack_threshold(int bitrate) | |
229 | { | |
230 | /* Assume max bitrate to start with */ | |
231 | int lower_range = 12, upper_range = 12; | |
232 | int lower_range_kbps = psy_abr_map[12].quality; | |
233 | int upper_range_kbps = psy_abr_map[12].quality; | |
234 | int i; | |
235 | ||
236 | /* Determine which bitrates the value specified falls between. | |
237 | * If the loop ends without breaking our above assumption of 320kbps was correct. | |
238 | */ | |
239 | for (i = 1; i < 13; i++) { | |
240 | if (FFMAX(bitrate, psy_abr_map[i].quality) != bitrate) { | |
241 | upper_range = i; | |
242 | upper_range_kbps = psy_abr_map[i ].quality; | |
243 | lower_range = i - 1; | |
244 | lower_range_kbps = psy_abr_map[i - 1].quality; | |
245 | break; /* Upper range found */ | |
246 | } | |
247 | } | |
248 | ||
249 | /* Determine which range the value specified is closer to */ | |
250 | if ((upper_range_kbps - bitrate) > (bitrate - lower_range_kbps)) | |
251 | return psy_abr_map[lower_range].st_lrm; | |
252 | return psy_abr_map[upper_range].st_lrm; | |
253 | } | |
254 | ||
255 | /** | |
256 | * LAME psy model specific initialization | |
257 | */ | |
258 | static av_cold void lame_window_init(AacPsyContext *ctx, AVCodecContext *avctx) | |
259 | { | |
260 | int i, j; | |
261 | ||
262 | for (i = 0; i < avctx->channels; i++) { | |
263 | AacPsyChannel *pch = &ctx->ch[i]; | |
264 | ||
265 | if (avctx->flags & CODEC_FLAG_QSCALE) | |
266 | pch->attack_threshold = psy_vbr_map[avctx->global_quality / FF_QP2LAMBDA].st_lrm; | |
267 | else | |
268 | pch->attack_threshold = lame_calc_attack_threshold(avctx->bit_rate / avctx->channels / 1000); | |
269 | ||
270 | for (j = 0; j < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; j++) | |
271 | pch->prev_energy_subshort[j] = 10.0f; | |
272 | } | |
273 | } | |
274 | ||
275 | /** | |
276 | * Calculate Bark value for given line. | |
277 | */ | |
278 | static av_cold float calc_bark(float f) | |
279 | { | |
280 | return 13.3f * atanf(0.00076f * f) + 3.5f * atanf((f / 7500.0f) * (f / 7500.0f)); | |
281 | } | |
282 | ||
283 | #define ATH_ADD 4 | |
284 | /** | |
285 | * Calculate ATH value for given frequency. | |
286 | * Borrowed from Lame. | |
287 | */ | |
288 | static av_cold float ath(float f, float add) | |
289 | { | |
290 | f /= 1000.0f; | |
291 | return 3.64 * pow(f, -0.8) | |
292 | - 6.8 * exp(-0.6 * (f - 3.4) * (f - 3.4)) | |
293 | + 6.0 * exp(-0.15 * (f - 8.7) * (f - 8.7)) | |
294 | + (0.6 + 0.04 * add) * 0.001 * f * f * f * f; | |
295 | } | |
296 | ||
297 | static av_cold int psy_3gpp_init(FFPsyContext *ctx) { | |
298 | AacPsyContext *pctx; | |
299 | float bark; | |
300 | int i, j, g, start; | |
301 | float prev, minscale, minath, minsnr, pe_min; | |
302 | const int chan_bitrate = ctx->avctx->bit_rate / ctx->avctx->channels; | |
303 | const int bandwidth = ctx->avctx->cutoff ? ctx->avctx->cutoff : AAC_CUTOFF(ctx->avctx); | |
304 | const float num_bark = calc_bark((float)bandwidth); | |
305 | ||
306 | ctx->model_priv_data = av_mallocz(sizeof(AacPsyContext)); | |
307 | pctx = (AacPsyContext*) ctx->model_priv_data; | |
308 | ||
309 | pctx->chan_bitrate = chan_bitrate; | |
310 | pctx->frame_bits = chan_bitrate * AAC_BLOCK_SIZE_LONG / ctx->avctx->sample_rate; | |
311 | pctx->pe.min = 8.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f); | |
312 | pctx->pe.max = 12.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f); | |
313 | ctx->bitres.size = 6144 - pctx->frame_bits; | |
314 | ctx->bitres.size -= ctx->bitres.size % 8; | |
315 | pctx->fill_level = ctx->bitres.size; | |
316 | minath = ath(3410, ATH_ADD); | |
317 | for (j = 0; j < 2; j++) { | |
318 | AacPsyCoeffs *coeffs = pctx->psy_coef[j]; | |
319 | const uint8_t *band_sizes = ctx->bands[j]; | |
320 | float line_to_frequency = ctx->avctx->sample_rate / (j ? 256.f : 2048.0f); | |
321 | float avg_chan_bits = chan_bitrate * (j ? 128.0f : 1024.0f) / ctx->avctx->sample_rate; | |
322 | /* reference encoder uses 2.4% here instead of 60% like the spec says */ | |
323 | float bark_pe = 0.024f * PSY_3GPP_BITS_TO_PE(avg_chan_bits) / num_bark; | |
324 | float en_spread_low = j ? PSY_3GPP_EN_SPREAD_LOW_S : PSY_3GPP_EN_SPREAD_LOW_L; | |
325 | /* High energy spreading for long blocks <= 22kbps/channel and short blocks are the same. */ | |
326 | float en_spread_hi = (j || (chan_bitrate <= 22.0f)) ? PSY_3GPP_EN_SPREAD_HI_S : PSY_3GPP_EN_SPREAD_HI_L1; | |
327 | ||
328 | i = 0; | |
329 | prev = 0.0; | |
330 | for (g = 0; g < ctx->num_bands[j]; g++) { | |
331 | i += band_sizes[g]; | |
332 | bark = calc_bark((i-1) * line_to_frequency); | |
333 | coeffs[g].barks = (bark + prev) / 2.0; | |
334 | prev = bark; | |
335 | } | |
336 | for (g = 0; g < ctx->num_bands[j] - 1; g++) { | |
337 | AacPsyCoeffs *coeff = &coeffs[g]; | |
338 | float bark_width = coeffs[g+1].barks - coeffs->barks; | |
339 | coeff->spread_low[0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_LOW); | |
340 | coeff->spread_hi [0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_HI); | |
341 | coeff->spread_low[1] = pow(10.0, -bark_width * en_spread_low); | |
342 | coeff->spread_hi [1] = pow(10.0, -bark_width * en_spread_hi); | |
343 | pe_min = bark_pe * bark_width; | |
344 | minsnr = exp2(pe_min / band_sizes[g]) - 1.5f; | |
345 | coeff->min_snr = av_clipf(1.0f / minsnr, PSY_SNR_25DB, PSY_SNR_1DB); | |
346 | } | |
347 | start = 0; | |
348 | for (g = 0; g < ctx->num_bands[j]; g++) { | |
349 | minscale = ath(start * line_to_frequency, ATH_ADD); | |
350 | for (i = 1; i < band_sizes[g]; i++) | |
351 | minscale = FFMIN(minscale, ath((start + i) * line_to_frequency, ATH_ADD)); | |
352 | coeffs[g].ath = minscale - minath; | |
353 | start += band_sizes[g]; | |
354 | } | |
355 | } | |
356 | ||
357 | pctx->ch = av_mallocz_array(ctx->avctx->channels, sizeof(AacPsyChannel)); | |
358 | ||
359 | lame_window_init(pctx, ctx->avctx); | |
360 | ||
361 | return 0; | |
362 | } | |
363 | ||
364 | /** | |
365 | * IIR filter used in block switching decision | |
366 | */ | |
367 | static float iir_filter(int in, float state[2]) | |
368 | { | |
369 | float ret; | |
370 | ||
371 | ret = 0.7548f * (in - state[0]) + 0.5095f * state[1]; | |
372 | state[0] = in; | |
373 | state[1] = ret; | |
374 | return ret; | |
375 | } | |
376 | ||
377 | /** | |
378 | * window grouping information stored as bits (0 - new group, 1 - group continues) | |
379 | */ | |
380 | static const uint8_t window_grouping[9] = { | |
381 | 0xB6, 0x6C, 0xD8, 0xB2, 0x66, 0xC6, 0x96, 0x36, 0x36 | |
382 | }; | |
383 | ||
384 | /** | |
385 | * Tell encoder which window types to use. | |
386 | * @see 3GPP TS26.403 5.4.1 "Blockswitching" | |
387 | */ | |
388 | static av_unused FFPsyWindowInfo psy_3gpp_window(FFPsyContext *ctx, | |
389 | const int16_t *audio, | |
390 | const int16_t *la, | |
391 | int channel, int prev_type) | |
392 | { | |
393 | int i, j; | |
394 | int br = ctx->avctx->bit_rate / ctx->avctx->channels; | |
395 | int attack_ratio = br <= 16000 ? 18 : 10; | |
396 | AacPsyContext *pctx = (AacPsyContext*) ctx->model_priv_data; | |
397 | AacPsyChannel *pch = &pctx->ch[channel]; | |
398 | uint8_t grouping = 0; | |
399 | int next_type = pch->next_window_seq; | |
400 | FFPsyWindowInfo wi = { { 0 } }; | |
401 | ||
402 | if (la) { | |
403 | float s[8], v; | |
404 | int switch_to_eight = 0; | |
405 | float sum = 0.0, sum2 = 0.0; | |
406 | int attack_n = 0; | |
407 | int stay_short = 0; | |
408 | for (i = 0; i < 8; i++) { | |
409 | for (j = 0; j < 128; j++) { | |
410 | v = iir_filter(la[i*128+j], pch->iir_state); | |
411 | sum += v*v; | |
412 | } | |
413 | s[i] = sum; | |
414 | sum2 += sum; | |
415 | } | |
416 | for (i = 0; i < 8; i++) { | |
417 | if (s[i] > pch->win_energy * attack_ratio) { | |
418 | attack_n = i + 1; | |
419 | switch_to_eight = 1; | |
420 | break; | |
421 | } | |
422 | } | |
423 | pch->win_energy = pch->win_energy*7/8 + sum2/64; | |
424 | ||
425 | wi.window_type[1] = prev_type; | |
426 | switch (prev_type) { | |
427 | case ONLY_LONG_SEQUENCE: | |
428 | wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE; | |
429 | next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE; | |
430 | break; | |
431 | case LONG_START_SEQUENCE: | |
432 | wi.window_type[0] = EIGHT_SHORT_SEQUENCE; | |
433 | grouping = pch->next_grouping; | |
434 | next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE; | |
435 | break; | |
436 | case LONG_STOP_SEQUENCE: | |
437 | wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE; | |
438 | next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE; | |
439 | break; | |
440 | case EIGHT_SHORT_SEQUENCE: | |
441 | stay_short = next_type == EIGHT_SHORT_SEQUENCE || switch_to_eight; | |
442 | wi.window_type[0] = stay_short ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE; | |
443 | grouping = next_type == EIGHT_SHORT_SEQUENCE ? pch->next_grouping : 0; | |
444 | next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE; | |
445 | break; | |
446 | } | |
447 | ||
448 | pch->next_grouping = window_grouping[attack_n]; | |
449 | pch->next_window_seq = next_type; | |
450 | } else { | |
451 | for (i = 0; i < 3; i++) | |
452 | wi.window_type[i] = prev_type; | |
453 | grouping = (prev_type == EIGHT_SHORT_SEQUENCE) ? window_grouping[0] : 0; | |
454 | } | |
455 | ||
456 | wi.window_shape = 1; | |
457 | if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) { | |
458 | wi.num_windows = 1; | |
459 | wi.grouping[0] = 1; | |
460 | } else { | |
461 | int lastgrp = 0; | |
462 | wi.num_windows = 8; | |
463 | for (i = 0; i < 8; i++) { | |
464 | if (!((grouping >> i) & 1)) | |
465 | lastgrp = i; | |
466 | wi.grouping[lastgrp]++; | |
467 | } | |
468 | } | |
469 | ||
470 | return wi; | |
471 | } | |
472 | ||
473 | /* 5.6.1.2 "Calculation of Bit Demand" */ | |
474 | static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size, | |
475 | int short_window) | |
476 | { | |
477 | const float bitsave_slope = short_window ? PSY_3GPP_SAVE_SLOPE_S : PSY_3GPP_SAVE_SLOPE_L; | |
478 | const float bitsave_add = short_window ? PSY_3GPP_SAVE_ADD_S : PSY_3GPP_SAVE_ADD_L; | |
479 | const float bitspend_slope = short_window ? PSY_3GPP_SPEND_SLOPE_S : PSY_3GPP_SPEND_SLOPE_L; | |
480 | const float bitspend_add = short_window ? PSY_3GPP_SPEND_ADD_S : PSY_3GPP_SPEND_ADD_L; | |
481 | const float clip_low = short_window ? PSY_3GPP_CLIP_LO_S : PSY_3GPP_CLIP_LO_L; | |
482 | const float clip_high = short_window ? PSY_3GPP_CLIP_HI_S : PSY_3GPP_CLIP_HI_L; | |
483 | float clipped_pe, bit_save, bit_spend, bit_factor, fill_level; | |
484 | ||
485 | ctx->fill_level += ctx->frame_bits - bits; | |
486 | ctx->fill_level = av_clip(ctx->fill_level, 0, size); | |
487 | fill_level = av_clipf((float)ctx->fill_level / size, clip_low, clip_high); | |
488 | clipped_pe = av_clipf(pe, ctx->pe.min, ctx->pe.max); | |
489 | bit_save = (fill_level + bitsave_add) * bitsave_slope; | |
490 | assert(bit_save <= 0.3f && bit_save >= -0.05000001f); | |
491 | bit_spend = (fill_level + bitspend_add) * bitspend_slope; | |
492 | assert(bit_spend <= 0.5f && bit_spend >= -0.1f); | |
493 | /* The bit factor graph in the spec is obviously incorrect. | |
494 | * bit_spend + ((bit_spend - bit_spend))... | |
495 | * The reference encoder subtracts everything from 1, but also seems incorrect. | |
496 | * 1 - bit_save + ((bit_spend + bit_save))... | |
497 | * Hopefully below is correct. | |
498 | */ | |
499 | bit_factor = 1.0f - bit_save + ((bit_spend - bit_save) / (ctx->pe.max - ctx->pe.min)) * (clipped_pe - ctx->pe.min); | |
500 | /* NOTE: The reference encoder attempts to center pe max/min around the current pe. */ | |
501 | ctx->pe.max = FFMAX(pe, ctx->pe.max); | |
502 | ctx->pe.min = FFMIN(pe, ctx->pe.min); | |
503 | ||
504 | return FFMIN(ctx->frame_bits * bit_factor, ctx->frame_bits + size - bits); | |
505 | } | |
506 | ||
507 | static float calc_pe_3gpp(AacPsyBand *band) | |
508 | { | |
509 | float pe, a; | |
510 | ||
511 | band->pe = 0.0f; | |
512 | band->pe_const = 0.0f; | |
513 | band->active_lines = 0.0f; | |
514 | if (band->energy > band->thr) { | |
515 | a = log2f(band->energy); | |
516 | pe = a - log2f(band->thr); | |
517 | band->active_lines = band->nz_lines; | |
518 | if (pe < PSY_3GPP_C1) { | |
519 | pe = pe * PSY_3GPP_C3 + PSY_3GPP_C2; | |
520 | a = a * PSY_3GPP_C3 + PSY_3GPP_C2; | |
521 | band->active_lines *= PSY_3GPP_C3; | |
522 | } | |
523 | band->pe = pe * band->nz_lines; | |
524 | band->pe_const = a * band->nz_lines; | |
525 | } | |
526 | ||
527 | return band->pe; | |
528 | } | |
529 | ||
530 | static float calc_reduction_3gpp(float a, float desired_pe, float pe, | |
531 | float active_lines) | |
532 | { | |
533 | float thr_avg, reduction; | |
534 | ||
535 | if(active_lines == 0.0) | |
536 | return 0; | |
537 | ||
538 | thr_avg = exp2f((a - pe) / (4.0f * active_lines)); | |
539 | reduction = exp2f((a - desired_pe) / (4.0f * active_lines)) - thr_avg; | |
540 | ||
541 | return FFMAX(reduction, 0.0f); | |
542 | } | |
543 | ||
544 | static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr, | |
545 | float reduction) | |
546 | { | |
547 | float thr = band->thr; | |
548 | ||
549 | if (band->energy > thr) { | |
550 | thr = sqrtf(thr); | |
551 | thr = sqrtf(thr) + reduction; | |
552 | thr *= thr; | |
553 | thr *= thr; | |
554 | ||
555 | /* This deviates from the 3GPP spec to match the reference encoder. | |
556 | * It performs min(thr_reduced, max(thr, energy/min_snr)) only for bands | |
557 | * that have hole avoidance on (active or inactive). It always reduces the | |
558 | * threshold of bands with hole avoidance off. | |
559 | */ | |
560 | if (thr > band->energy * min_snr && band->avoid_holes != PSY_3GPP_AH_NONE) { | |
561 | thr = FFMAX(band->thr, band->energy * min_snr); | |
562 | band->avoid_holes = PSY_3GPP_AH_ACTIVE; | |
563 | } | |
564 | } | |
565 | ||
566 | return thr; | |
567 | } | |
568 | ||
569 | #ifndef calc_thr_3gpp | |
570 | static void calc_thr_3gpp(const FFPsyWindowInfo *wi, const int num_bands, AacPsyChannel *pch, | |
571 | const uint8_t *band_sizes, const float *coefs) | |
572 | { | |
573 | int i, w, g; | |
574 | int start = 0; | |
575 | for (w = 0; w < wi->num_windows*16; w += 16) { | |
576 | for (g = 0; g < num_bands; g++) { | |
577 | AacPsyBand *band = &pch->band[w+g]; | |
578 | ||
579 | float form_factor = 0.0f; | |
580 | float Temp; | |
581 | band->energy = 0.0f; | |
582 | for (i = 0; i < band_sizes[g]; i++) { | |
583 | band->energy += coefs[start+i] * coefs[start+i]; | |
584 | form_factor += sqrtf(fabs(coefs[start+i])); | |
585 | } | |
586 | Temp = band->energy > 0 ? sqrtf((float)band_sizes[g] / band->energy) : 0; | |
587 | band->thr = band->energy * 0.001258925f; | |
588 | band->nz_lines = form_factor * sqrtf(Temp); | |
589 | ||
590 | start += band_sizes[g]; | |
591 | } | |
592 | } | |
593 | } | |
594 | #endif /* calc_thr_3gpp */ | |
595 | ||
596 | #ifndef psy_hp_filter | |
597 | static void psy_hp_filter(const float *firbuf, float *hpfsmpl, const float *psy_fir_coeffs) | |
598 | { | |
599 | int i, j; | |
600 | for (i = 0; i < AAC_BLOCK_SIZE_LONG; i++) { | |
601 | float sum1, sum2; | |
602 | sum1 = firbuf[i + (PSY_LAME_FIR_LEN - 1) / 2]; | |
603 | sum2 = 0.0; | |
604 | for (j = 0; j < ((PSY_LAME_FIR_LEN - 1) / 2) - 1; j += 2) { | |
605 | sum1 += psy_fir_coeffs[j] * (firbuf[i + j] + firbuf[i + PSY_LAME_FIR_LEN - j]); | |
606 | sum2 += psy_fir_coeffs[j + 1] * (firbuf[i + j + 1] + firbuf[i + PSY_LAME_FIR_LEN - j - 1]); | |
607 | } | |
608 | /* NOTE: The LAME psymodel expects it's input in the range -32768 to 32768. | |
609 | * Tuning this for normalized floats would be difficult. */ | |
610 | hpfsmpl[i] = (sum1 + sum2) * 32768.0f; | |
611 | } | |
612 | } | |
613 | #endif /* psy_hp_filter */ | |
614 | ||
615 | /** | |
616 | * Calculate band thresholds as suggested in 3GPP TS26.403 | |
617 | */ | |
618 | static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel, | |
619 | const float *coefs, const FFPsyWindowInfo *wi) | |
620 | { | |
621 | AacPsyContext *pctx = (AacPsyContext*) ctx->model_priv_data; | |
622 | AacPsyChannel *pch = &pctx->ch[channel]; | |
623 | int i, w, g; | |
624 | float desired_bits, desired_pe, delta_pe, reduction= NAN, spread_en[128] = {0}; | |
625 | float a = 0.0f, active_lines = 0.0f, norm_fac = 0.0f; | |
626 | float pe = pctx->chan_bitrate > 32000 ? 0.0f : FFMAX(50.0f, 100.0f - pctx->chan_bitrate * 100.0f / 32000.0f); | |
627 | const int num_bands = ctx->num_bands[wi->num_windows == 8]; | |
628 | const uint8_t *band_sizes = ctx->bands[wi->num_windows == 8]; | |
629 | AacPsyCoeffs *coeffs = pctx->psy_coef[wi->num_windows == 8]; | |
630 | const float avoid_hole_thr = wi->num_windows == 8 ? PSY_3GPP_AH_THR_SHORT : PSY_3GPP_AH_THR_LONG; | |
631 | ||
632 | //calculate energies, initial thresholds and related values - 5.4.2 "Threshold Calculation" | |
633 | calc_thr_3gpp(wi, num_bands, pch, band_sizes, coefs); | |
634 | ||
635 | //modify thresholds and energies - spread, threshold in quiet, pre-echo control | |
636 | for (w = 0; w < wi->num_windows*16; w += 16) { | |
637 | AacPsyBand *bands = &pch->band[w]; | |
638 | ||
639 | /* 5.4.2.3 "Spreading" & 5.4.3 "Spread Energy Calculation" */ | |
640 | spread_en[0] = bands[0].energy; | |
641 | for (g = 1; g < num_bands; g++) { | |
642 | bands[g].thr = FFMAX(bands[g].thr, bands[g-1].thr * coeffs[g].spread_hi[0]); | |
643 | spread_en[w+g] = FFMAX(bands[g].energy, spread_en[w+g-1] * coeffs[g].spread_hi[1]); | |
644 | } | |
645 | for (g = num_bands - 2; g >= 0; g--) { | |
646 | bands[g].thr = FFMAX(bands[g].thr, bands[g+1].thr * coeffs[g].spread_low[0]); | |
647 | spread_en[w+g] = FFMAX(spread_en[w+g], spread_en[w+g+1] * coeffs[g].spread_low[1]); | |
648 | } | |
649 | //5.4.2.4 "Threshold in quiet" | |
650 | for (g = 0; g < num_bands; g++) { | |
651 | AacPsyBand *band = &bands[g]; | |
652 | ||
653 | band->thr_quiet = band->thr = FFMAX(band->thr, coeffs[g].ath); | |
654 | //5.4.2.5 "Pre-echo control" | |
655 | if (!(wi->window_type[0] == LONG_STOP_SEQUENCE || (wi->window_type[1] == LONG_START_SEQUENCE && !w))) | |
656 | band->thr = FFMAX(PSY_3GPP_RPEMIN*band->thr, FFMIN(band->thr, | |
657 | PSY_3GPP_RPELEV*pch->prev_band[w+g].thr_quiet)); | |
658 | ||
659 | /* 5.6.1.3.1 "Preparatory steps of the perceptual entropy calculation" */ | |
660 | pe += calc_pe_3gpp(band); | |
661 | a += band->pe_const; | |
662 | active_lines += band->active_lines; | |
663 | ||
664 | /* 5.6.1.3.3 "Selection of the bands for avoidance of holes" */ | |
665 | if (spread_en[w+g] * avoid_hole_thr > band->energy || coeffs[g].min_snr > 1.0f) | |
666 | band->avoid_holes = PSY_3GPP_AH_NONE; | |
667 | else | |
668 | band->avoid_holes = PSY_3GPP_AH_INACTIVE; | |
669 | } | |
670 | } | |
671 | ||
672 | /* 5.6.1.3.2 "Calculation of the desired perceptual entropy" */ | |
673 | ctx->ch[channel].entropy = pe; | |
674 | desired_bits = calc_bit_demand(pctx, pe, ctx->bitres.bits, ctx->bitres.size, wi->num_windows == 8); | |
675 | desired_pe = PSY_3GPP_BITS_TO_PE(desired_bits); | |
676 | /* NOTE: PE correction is kept simple. During initial testing it had very | |
677 | * little effect on the final bitrate. Probably a good idea to come | |
678 | * back and do more testing later. | |
679 | */ | |
680 | if (ctx->bitres.bits > 0) | |
681 | desired_pe *= av_clipf(pctx->pe.previous / PSY_3GPP_BITS_TO_PE(ctx->bitres.bits), | |
682 | 0.85f, 1.15f); | |
683 | pctx->pe.previous = PSY_3GPP_BITS_TO_PE(desired_bits); | |
684 | ||
685 | if (desired_pe < pe) { | |
686 | /* 5.6.1.3.4 "First Estimation of the reduction value" */ | |
687 | for (w = 0; w < wi->num_windows*16; w += 16) { | |
688 | reduction = calc_reduction_3gpp(a, desired_pe, pe, active_lines); | |
689 | pe = 0.0f; | |
690 | a = 0.0f; | |
691 | active_lines = 0.0f; | |
692 | for (g = 0; g < num_bands; g++) { | |
693 | AacPsyBand *band = &pch->band[w+g]; | |
694 | ||
695 | band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction); | |
696 | /* recalculate PE */ | |
697 | pe += calc_pe_3gpp(band); | |
698 | a += band->pe_const; | |
699 | active_lines += band->active_lines; | |
700 | } | |
701 | } | |
702 | ||
703 | /* 5.6.1.3.5 "Second Estimation of the reduction value" */ | |
704 | for (i = 0; i < 2; i++) { | |
705 | float pe_no_ah = 0.0f, desired_pe_no_ah; | |
706 | active_lines = a = 0.0f; | |
707 | for (w = 0; w < wi->num_windows*16; w += 16) { | |
708 | for (g = 0; g < num_bands; g++) { | |
709 | AacPsyBand *band = &pch->band[w+g]; | |
710 | ||
711 | if (band->avoid_holes != PSY_3GPP_AH_ACTIVE) { | |
712 | pe_no_ah += band->pe; | |
713 | a += band->pe_const; | |
714 | active_lines += band->active_lines; | |
715 | } | |
716 | } | |
717 | } | |
718 | desired_pe_no_ah = FFMAX(desired_pe - (pe - pe_no_ah), 0.0f); | |
719 | if (active_lines > 0.0f) | |
720 | reduction += calc_reduction_3gpp(a, desired_pe_no_ah, pe_no_ah, active_lines); | |
721 | ||
722 | pe = 0.0f; | |
723 | for (w = 0; w < wi->num_windows*16; w += 16) { | |
724 | for (g = 0; g < num_bands; g++) { | |
725 | AacPsyBand *band = &pch->band[w+g]; | |
726 | ||
727 | if (active_lines > 0.0f) | |
728 | band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction); | |
729 | pe += calc_pe_3gpp(band); | |
730 | band->norm_fac = band->active_lines / band->thr; | |
731 | norm_fac += band->norm_fac; | |
732 | } | |
733 | } | |
734 | delta_pe = desired_pe - pe; | |
735 | if (fabs(delta_pe) > 0.05f * desired_pe) | |
736 | break; | |
737 | } | |
738 | ||
739 | if (pe < 1.15f * desired_pe) { | |
740 | /* 6.6.1.3.6 "Final threshold modification by linearization" */ | |
741 | norm_fac = 1.0f / norm_fac; | |
742 | for (w = 0; w < wi->num_windows*16; w += 16) { | |
743 | for (g = 0; g < num_bands; g++) { | |
744 | AacPsyBand *band = &pch->band[w+g]; | |
745 | ||
746 | if (band->active_lines > 0.5f) { | |
747 | float delta_sfb_pe = band->norm_fac * norm_fac * delta_pe; | |
748 | float thr = band->thr; | |
749 | ||
750 | thr *= exp2f(delta_sfb_pe / band->active_lines); | |
751 | if (thr > coeffs[g].min_snr * band->energy && band->avoid_holes == PSY_3GPP_AH_INACTIVE) | |
752 | thr = FFMAX(band->thr, coeffs[g].min_snr * band->energy); | |
753 | band->thr = thr; | |
754 | } | |
755 | } | |
756 | } | |
757 | } else { | |
758 | /* 5.6.1.3.7 "Further perceptual entropy reduction" */ | |
759 | g = num_bands; | |
760 | while (pe > desired_pe && g--) { | |
761 | for (w = 0; w < wi->num_windows*16; w+= 16) { | |
762 | AacPsyBand *band = &pch->band[w+g]; | |
763 | if (band->avoid_holes != PSY_3GPP_AH_NONE && coeffs[g].min_snr < PSY_SNR_1DB) { | |
764 | coeffs[g].min_snr = PSY_SNR_1DB; | |
765 | band->thr = band->energy * PSY_SNR_1DB; | |
766 | pe += band->active_lines * 1.5f - band->pe; | |
767 | } | |
768 | } | |
769 | } | |
770 | /* TODO: allow more holes (unused without mid/side) */ | |
771 | } | |
772 | } | |
773 | ||
774 | for (w = 0; w < wi->num_windows*16; w += 16) { | |
775 | for (g = 0; g < num_bands; g++) { | |
776 | AacPsyBand *band = &pch->band[w+g]; | |
777 | FFPsyBand *psy_band = &ctx->ch[channel].psy_bands[w+g]; | |
778 | ||
779 | psy_band->threshold = band->thr; | |
780 | psy_band->energy = band->energy; | |
781 | } | |
782 | } | |
783 | ||
784 | memcpy(pch->prev_band, pch->band, sizeof(pch->band)); | |
785 | } | |
786 | ||
787 | static void psy_3gpp_analyze(FFPsyContext *ctx, int channel, | |
788 | const float **coeffs, const FFPsyWindowInfo *wi) | |
789 | { | |
790 | int ch; | |
791 | FFPsyChannelGroup *group = ff_psy_find_group(ctx, channel); | |
792 | ||
793 | for (ch = 0; ch < group->num_ch; ch++) | |
794 | psy_3gpp_analyze_channel(ctx, channel + ch, coeffs[ch], &wi[ch]); | |
795 | } | |
796 | ||
797 | static av_cold void psy_3gpp_end(FFPsyContext *apc) | |
798 | { | |
799 | AacPsyContext *pctx = (AacPsyContext*) apc->model_priv_data; | |
800 | av_freep(&pctx->ch); | |
801 | av_freep(&apc->model_priv_data); | |
802 | } | |
803 | ||
804 | static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock) | |
805 | { | |
806 | int blocktype = ONLY_LONG_SEQUENCE; | |
807 | if (uselongblock) { | |
808 | if (ctx->next_window_seq == EIGHT_SHORT_SEQUENCE) | |
809 | blocktype = LONG_STOP_SEQUENCE; | |
810 | } else { | |
811 | blocktype = EIGHT_SHORT_SEQUENCE; | |
812 | if (ctx->next_window_seq == ONLY_LONG_SEQUENCE) | |
813 | ctx->next_window_seq = LONG_START_SEQUENCE; | |
814 | if (ctx->next_window_seq == LONG_STOP_SEQUENCE) | |
815 | ctx->next_window_seq = EIGHT_SHORT_SEQUENCE; | |
816 | } | |
817 | ||
818 | wi->window_type[0] = ctx->next_window_seq; | |
819 | ctx->next_window_seq = blocktype; | |
820 | } | |
821 | ||
822 | static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio, | |
823 | const float *la, int channel, int prev_type) | |
824 | { | |
825 | AacPsyContext *pctx = (AacPsyContext*) ctx->model_priv_data; | |
826 | AacPsyChannel *pch = &pctx->ch[channel]; | |
827 | int grouping = 0; | |
828 | int uselongblock = 1; | |
829 | int attacks[AAC_NUM_BLOCKS_SHORT + 1] = { 0 }; | |
830 | int i; | |
831 | FFPsyWindowInfo wi = { { 0 } }; | |
832 | ||
833 | if (la) { | |
834 | float hpfsmpl[AAC_BLOCK_SIZE_LONG]; | |
835 | float const *pf = hpfsmpl; | |
836 | float attack_intensity[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS]; | |
837 | float energy_subshort[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS]; | |
838 | float energy_short[AAC_NUM_BLOCKS_SHORT + 1] = { 0 }; | |
839 | const float *firbuf = la + (AAC_BLOCK_SIZE_SHORT/4 - PSY_LAME_FIR_LEN); | |
840 | int att_sum = 0; | |
841 | ||
842 | /* LAME comment: apply high pass filter of fs/4 */ | |
843 | psy_hp_filter(firbuf, hpfsmpl, psy_fir_coeffs); | |
844 | ||
845 | /* Calculate the energies of each sub-shortblock */ | |
846 | for (i = 0; i < PSY_LAME_NUM_SUBBLOCKS; i++) { | |
847 | energy_subshort[i] = pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 1) * PSY_LAME_NUM_SUBBLOCKS)]; | |
848 | assert(pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)] > 0); | |
849 | attack_intensity[i] = energy_subshort[i] / pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)]; | |
850 | energy_short[0] += energy_subshort[i]; | |
851 | } | |
852 | ||
853 | for (i = 0; i < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; i++) { | |
854 | float const *const pfe = pf + AAC_BLOCK_SIZE_LONG / (AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS); | |
855 | float p = 1.0f; | |
856 | for (; pf < pfe; pf++) | |
857 | p = FFMAX(p, fabsf(*pf)); | |
858 | pch->prev_energy_subshort[i] = energy_subshort[i + PSY_LAME_NUM_SUBBLOCKS] = p; | |
859 | energy_short[1 + i / PSY_LAME_NUM_SUBBLOCKS] += p; | |
860 | /* NOTE: The indexes below are [i + 3 - 2] in the LAME source. | |
861 | * Obviously the 3 and 2 have some significance, or this would be just [i + 1] | |
862 | * (which is what we use here). What the 3 stands for is ambiguous, as it is both | |
863 | * number of short blocks, and the number of sub-short blocks. | |
864 | * It seems that LAME is comparing each sub-block to sub-block + 1 in the | |
865 | * previous block. | |
866 | */ | |
867 | if (p > energy_subshort[i + 1]) | |
868 | p = p / energy_subshort[i + 1]; | |
869 | else if (energy_subshort[i + 1] > p * 10.0f) | |
870 | p = energy_subshort[i + 1] / (p * 10.0f); | |
871 | else | |
872 | p = 0.0; | |
873 | attack_intensity[i + PSY_LAME_NUM_SUBBLOCKS] = p; | |
874 | } | |
875 | ||
876 | /* compare energy between sub-short blocks */ | |
877 | for (i = 0; i < (AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS; i++) | |
878 | if (!attacks[i / PSY_LAME_NUM_SUBBLOCKS]) | |
879 | if (attack_intensity[i] > pch->attack_threshold) | |
880 | attacks[i / PSY_LAME_NUM_SUBBLOCKS] = (i % PSY_LAME_NUM_SUBBLOCKS) + 1; | |
881 | ||
882 | /* should have energy change between short blocks, in order to avoid periodic signals */ | |
883 | /* Good samples to show the effect are Trumpet test songs */ | |
884 | /* GB: tuned (1) to avoid too many short blocks for test sample TRUMPET */ | |
885 | /* RH: tuned (2) to let enough short blocks through for test sample FSOL and SNAPS */ | |
886 | for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++) { | |
887 | float const u = energy_short[i - 1]; | |
888 | float const v = energy_short[i]; | |
889 | float const m = FFMAX(u, v); | |
890 | if (m < 40000) { /* (2) */ | |
891 | if (u < 1.7f * v && v < 1.7f * u) { /* (1) */ | |
892 | if (i == 1 && attacks[0] < attacks[i]) | |
893 | attacks[0] = 0; | |
894 | attacks[i] = 0; | |
895 | } | |
896 | } | |
897 | att_sum += attacks[i]; | |
898 | } | |
899 | ||
900 | if (attacks[0] <= pch->prev_attack) | |
901 | attacks[0] = 0; | |
902 | ||
903 | att_sum += attacks[0]; | |
904 | /* 3 below indicates the previous attack happened in the last sub-block of the previous sequence */ | |
905 | if (pch->prev_attack == 3 || att_sum) { | |
906 | uselongblock = 0; | |
907 | ||
908 | for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++) | |
909 | if (attacks[i] && attacks[i-1]) | |
910 | attacks[i] = 0; | |
911 | } | |
912 | } else { | |
913 | /* We have no lookahead info, so just use same type as the previous sequence. */ | |
914 | uselongblock = !(prev_type == EIGHT_SHORT_SEQUENCE); | |
915 | } | |
916 | ||
917 | lame_apply_block_type(pch, &wi, uselongblock); | |
918 | ||
919 | wi.window_type[1] = prev_type; | |
920 | if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) { | |
921 | wi.num_windows = 1; | |
922 | wi.grouping[0] = 1; | |
923 | if (wi.window_type[0] == LONG_START_SEQUENCE) | |
924 | wi.window_shape = 0; | |
925 | else | |
926 | wi.window_shape = 1; | |
927 | } else { | |
928 | int lastgrp = 0; | |
929 | ||
930 | wi.num_windows = 8; | |
931 | wi.window_shape = 0; | |
932 | for (i = 0; i < 8; i++) { | |
933 | if (!((pch->next_grouping >> i) & 1)) | |
934 | lastgrp = i; | |
935 | wi.grouping[lastgrp]++; | |
936 | } | |
937 | } | |
938 | ||
939 | /* Determine grouping, based on the location of the first attack, and save for | |
940 | * the next frame. | |
941 | * FIXME: Move this to analysis. | |
942 | * TODO: Tune groupings depending on attack location | |
943 | * TODO: Handle more than one attack in a group | |
944 | */ | |
945 | for (i = 0; i < 9; i++) { | |
946 | if (attacks[i]) { | |
947 | grouping = i; | |
948 | break; | |
949 | } | |
950 | } | |
951 | pch->next_grouping = window_grouping[grouping]; | |
952 | ||
953 | pch->prev_attack = attacks[8]; | |
954 | ||
955 | return wi; | |
956 | } | |
957 | ||
958 | const FFPsyModel ff_aac_psy_model = | |
959 | { | |
960 | .name = "3GPP TS 26.403-inspired model", | |
961 | .init = psy_3gpp_init, | |
962 | .window = psy_lame_window, | |
963 | .analyze = psy_3gpp_analyze, | |
964 | .end = psy_3gpp_end, | |
965 | }; |