/* Copyright (C) 2007-2008 Jean-Marc Valin Copyright (C) 2008 Thorvald Natvig File: resample.c Arbitrary resampling code Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* The design goals of this code are: - Very fast algorithm - SIMD-friendly algorithm - Low memory requirement - Good *perceptual* quality (and not best SNR) Warning: This resampler is relatively new. Although I think I got rid of all the major bugs and I don't expect the API to change anymore, there may be something I've missed. So use with caution. This algorithm is based on this original resampling algorithm: Smith, Julius O. Digital Audio Resampling Home Page Center for Computer Research in Music and Acoustics (CCRMA), Stanford University, 2007. Web published at http://www-ccrma.stanford.edu/~jos/resample/. There is one main difference, though. This resampler uses cubic interpolation instead of linear interpolation in the above paper. This makes the table much smaller and makes it possible to compute that table on a per-stream basis. In turn, being able to tweak the table for each stream makes it possible to both reduce complexity on simple ratios (e.g. 2/3), and get rid of the rounding operations in the inner loop. The latter both reduces CPU time and makes the algorithm more SIMD-friendly. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #ifdef OUTSIDE_SPEEX #include <stdlib.h> #ifdef HAVE_STRING_H #include <string.h> #endif #include <glib.h> #ifdef HAVE_ORC #include <orc/orc.h> #endif #define EXPORT G_GNUC_INTERNAL #ifdef _USE_SSE #ifndef HAVE_XMMINTRIN_H #undef _USE_SSE #endif #endif #ifdef _USE_SSE2 #ifndef HAVE_EMMINTRIN_H #undef _USE_SSE2 #endif #endif static inline void * speex_alloc (int size) { return g_malloc0 (size); } static inline void * speex_realloc (void *ptr, int size) { return g_realloc (ptr, size); } static inline void speex_free (void *ptr) { g_free (ptr); } #include "speex_resampler.h" #include "arch.h" #else /* OUTSIDE_SPEEX */ #include "../include/speex/speex_resampler.h" #include "arch.h" #include "os_support.h" #endif /* OUTSIDE_SPEEX */ #include <math.h> #ifdef FIXED_POINT #define WORD2INT(x) ((x) < -32767 ? -32768 : ((x) > 32766 ? 32767 : (x))) #else #define WORD2INT(x) ((x) < -32767.5f ? -32768 : ((x) > 32766.5f ? 32767 : floor(.5+(x)))) #endif #define IMAX(a,b) ((a) > (b) ? (a) : (b)) #define IMIN(a,b) ((a) < (b) ? (a) : (b)) #ifndef NULL #define NULL 0 #endif #if defined _USE_SSE || defined _USE_SSE2 #include "resample_sse.h" #endif /* Numer of elements to allocate on the stack */ #ifdef VAR_ARRAYS #define FIXED_STACK_ALLOC 8192 #else #define FIXED_STACK_ALLOC 1024 #endif /* Allow selecting SSE or not when compiled with SSE support */ #ifdef _USE_SSE #define SSE_FALLBACK(macro) \ if (st->use_sse) goto sse_##macro##_sse; { #define SSE_IMPLEMENTATION(macro) \ goto sse_##macro##_end; } sse_##macro##_sse: { #define SSE_END(macro) sse_##macro##_end:; } #else #define SSE_FALLBACK(macro) #endif #ifdef _USE_SSE2 #define SSE2_FALLBACK(macro) \ if (st->use_sse2) goto sse2_##macro##_sse2; { #define SSE2_IMPLEMENTATION(macro) \ goto sse2_##macro##_end; } sse2_##macro##_sse2: { #define SSE2_END(macro) sse2_##macro##_end:; } #else #define SSE2_FALLBACK(macro) #endif typedef int (*resampler_basic_func) (SpeexResamplerState *, spx_uint32_t, const spx_word16_t *, spx_uint32_t *, spx_word16_t *, spx_uint32_t *); struct SpeexResamplerState_ { spx_uint32_t in_rate; spx_uint32_t out_rate; spx_uint32_t num_rate; spx_uint32_t den_rate; int quality; spx_uint32_t nb_channels; spx_uint32_t filt_len; spx_uint32_t mem_alloc_size; spx_uint32_t buffer_size; int int_advance; int frac_advance; float cutoff; spx_uint32_t oversample; int initialised; int started; /* These are per-channel */ spx_int32_t *last_sample; spx_uint32_t *samp_frac_num; spx_uint32_t *magic_samples; spx_word16_t *mem; spx_word16_t *sinc_table; spx_uint32_t sinc_table_length; resampler_basic_func resampler_ptr; int in_stride; int out_stride; int use_sse:1; int use_sse2:1; }; static double kaiser12_table[68] = { 0.99859849, 1.00000000, 0.99859849, 0.99440475, 0.98745105, 0.97779076, 0.96549770, 0.95066529, 0.93340547, 0.91384741, 0.89213598, 0.86843014, 0.84290116, 0.81573067, 0.78710866, 0.75723148, 0.72629970, 0.69451601, 0.66208321, 0.62920216, 0.59606986, 0.56287762, 0.52980938, 0.49704014, 0.46473455, 0.43304576, 0.40211431, 0.37206735, 0.34301800, 0.31506490, 0.28829195, 0.26276832, 0.23854851, 0.21567274, 0.19416736, 0.17404546, 0.15530766, 0.13794294, 0.12192957, 0.10723616, 0.09382272, 0.08164178, 0.07063950, 0.06075685, 0.05193064, 0.04409466, 0.03718069, 0.03111947, 0.02584161, 0.02127838, 0.01736250, 0.01402878, 0.01121463, 0.00886058, 0.00691064, 0.00531256, 0.00401805, 0.00298291, 0.00216702, 0.00153438, 0.00105297, 0.00069463, 0.00043489, 0.00025272, 0.00013031, 0.0000527734, 0.00001000, 0.00000000 }; /* static double kaiser12_table[36] = { 0.99440475, 1.00000000, 0.99440475, 0.97779076, 0.95066529, 0.91384741, 0.86843014, 0.81573067, 0.75723148, 0.69451601, 0.62920216, 0.56287762, 0.49704014, 0.43304576, 0.37206735, 0.31506490, 0.26276832, 0.21567274, 0.17404546, 0.13794294, 0.10723616, 0.08164178, 0.06075685, 0.04409466, 0.03111947, 0.02127838, 0.01402878, 0.00886058, 0.00531256, 0.00298291, 0.00153438, 0.00069463, 0.00025272, 0.0000527734, 0.00000500, 0.00000000}; */ static double kaiser10_table[36] = { 0.99537781, 1.00000000, 0.99537781, 0.98162644, 0.95908712, 0.92831446, 0.89005583, 0.84522401, 0.79486424, 0.74011713, 0.68217934, 0.62226347, 0.56155915, 0.50119680, 0.44221549, 0.38553619, 0.33194107, 0.28205962, 0.23636152, 0.19515633, 0.15859932, 0.12670280, 0.09935205, 0.07632451, 0.05731132, 0.04193980, 0.02979584, 0.02044510, 0.01345224, 0.00839739, 0.00488951, 0.00257636, 0.00115101, 0.00035515, 0.00000000, 0.00000000 }; static double kaiser8_table[36] = { 0.99635258, 1.00000000, 0.99635258, 0.98548012, 0.96759014, 0.94302200, 0.91223751, 0.87580811, 0.83439927, 0.78875245, 0.73966538, 0.68797126, 0.63451750, 0.58014482, 0.52566725, 0.47185369, 0.41941150, 0.36897272, 0.32108304, 0.27619388, 0.23465776, 0.19672670, 0.16255380, 0.13219758, 0.10562887, 0.08273982, 0.06335451, 0.04724088, 0.03412321, 0.02369490, 0.01563093, 0.00959968, 0.00527363, 0.00233883, 0.00050000, 0.00000000 }; static double kaiser6_table[36] = { 0.99733006, 1.00000000, 0.99733006, 0.98935595, 0.97618418, 0.95799003, 0.93501423, 0.90755855, 0.87598009, 0.84068475, 0.80211977, 0.76076565, 0.71712752, 0.67172623, 0.62508937, 0.57774224, 0.53019925, 0.48295561, 0.43647969, 0.39120616, 0.34752997, 0.30580127, 0.26632152, 0.22934058, 0.19505503, 0.16360756, 0.13508755, 0.10953262, 0.08693120, 0.06722600, 0.05031820, 0.03607231, 0.02432151, 0.01487334, 0.00752000, 0.00000000 }; struct FuncDef { double *table; int oversample; }; static struct FuncDef _KAISER12 = { kaiser12_table, 64 }; #define KAISER12 (&_KAISER12) /*static struct FuncDef _KAISER12 = {kaiser12_table, 32}; #define KAISER12 (&_KAISER12)*/ static struct FuncDef _KAISER10 = { kaiser10_table, 32 }; #define KAISER10 (&_KAISER10) static struct FuncDef _KAISER8 = { kaiser8_table, 32 }; #define KAISER8 (&_KAISER8) static struct FuncDef _KAISER6 = { kaiser6_table, 32 }; #define KAISER6 (&_KAISER6) struct QualityMapping { int base_length; int oversample; float downsample_bandwidth; float upsample_bandwidth; struct FuncDef *window_func; }; /* This table maps conversion quality to internal parameters. There are two reasons that explain why the up-sampling bandwidth is larger than the down-sampling bandwidth: 1) When up-sampling, we can assume that the spectrum is already attenuated close to the Nyquist rate (from an A/D or a previous resampling filter) 2) Any aliasing that occurs very close to the Nyquist rate will be masked by the sinusoids/noise just below the Nyquist rate (guaranteed only for up-sampling). */ static const struct QualityMapping quality_map[11] = { {8, 4, 0.830f, 0.860f, KAISER6}, /* Q0 */ {16, 4, 0.850f, 0.880f, KAISER6}, /* Q1 */ {32, 4, 0.882f, 0.910f, KAISER6}, /* Q2 *//* 82.3% cutoff ( ~60 dB stop) 6 */ {48, 8, 0.895f, 0.917f, KAISER8}, /* Q3 *//* 84.9% cutoff ( ~80 dB stop) 8 */ {64, 8, 0.921f, 0.940f, KAISER8}, /* Q4 *//* 88.7% cutoff ( ~80 dB stop) 8 */ {80, 16, 0.922f, 0.940f, KAISER10}, /* Q5 *//* 89.1% cutoff (~100 dB stop) 10 */ {96, 16, 0.940f, 0.945f, KAISER10}, /* Q6 *//* 91.5% cutoff (~100 dB stop) 10 */ {128, 16, 0.950f, 0.950f, KAISER10}, /* Q7 *//* 93.1% cutoff (~100 dB stop) 10 */ {160, 16, 0.960f, 0.960f, KAISER10}, /* Q8 *//* 94.5% cutoff (~100 dB stop) 10 */ {192, 32, 0.968f, 0.968f, KAISER12}, /* Q9 *//* 95.5% cutoff (~100 dB stop) 10 */ {256, 32, 0.975f, 0.975f, KAISER12}, /* Q10 *//* 96.6% cutoff (~100 dB stop) 10 */ }; /*8,24,40,56,80,104,128,160,200,256,320*/ #ifdef DOUBLE_PRECISION static double compute_func (double x, struct FuncDef *func) { double y, frac; #else static double compute_func (float x, struct FuncDef *func) { float y, frac; #endif double interp[4]; int ind; y = x * func->oversample; ind = (int) floor (y); frac = (y - ind); /* CSE with handle the repeated powers */ interp[3] = -0.1666666667 * frac + 0.1666666667 * (frac * frac * frac); interp[2] = frac + 0.5 * (frac * frac) - 0.5 * (frac * frac * frac); /*interp[2] = 1.f - 0.5f*frac - frac*frac + 0.5f*frac*frac*frac; */ interp[0] = -0.3333333333 * frac + 0.5 * (frac * frac) - 0.1666666667 * (frac * frac * frac); /* Just to make sure we don't have rounding problems */ interp[1] = 1.f - interp[3] - interp[2] - interp[0]; /*sum = frac*accum[1] + (1-frac)*accum[2]; */ return interp[0] * func->table[ind] + interp[1] * func->table[ind + 1] + interp[2] * func->table[ind + 2] + interp[3] * func->table[ind + 3]; } #if 0 #include <stdio.h> int main (int argc, char **argv) { int i; for (i = 0; i < 256; i++) { printf ("%f\n", compute_func (i / 256., KAISER12)); } return 0; } #endif #ifdef FIXED_POINT /* The slow way of computing a sinc for the table. Should improve that some day */ static spx_word16_t sinc (float cutoff, float x, int N, struct FuncDef *window_func) { /*fprintf (stderr, "%f ", x); */ float xx = x * cutoff; if (fabs (x) < 1e-6f) return WORD2INT (32768. * cutoff); else if (fabs (x) > .5f * N) return 0; /*FIXME: Can it really be any slower than this? */ return WORD2INT (32768. * cutoff * sin (G_PI * xx) / (G_PI * xx) * compute_func (fabs (2. * x / N), window_func)); } #else /* The slow way of computing a sinc for the table. Should improve that some day */ #ifdef DOUBLE_PRECISION static spx_word16_t sinc (double cutoff, double x, int N, struct FuncDef *window_func) { /*fprintf (stderr, "%f ", x); */ double xx = x * cutoff; #else static spx_word16_t sinc (float cutoff, float x, int N, struct FuncDef *window_func) { /*fprintf (stderr, "%f ", x); */ float xx = x * cutoff; #endif if (fabs (x) < 1e-6) return cutoff; else if (fabs (x) > .5 * N) return 0; /*FIXME: Can it really be any slower than this? */ return cutoff * sin (G_PI * xx) / (G_PI * xx) * compute_func (fabs (2. * x / N), window_func); } #endif #ifdef FIXED_POINT static void cubic_coef (spx_word16_t x, spx_word16_t interp[4]) { /* Compute interpolation coefficients. I'm not sure whether this corresponds to cubic interpolation but I know it's MMSE-optimal on a sinc */ spx_word16_t x2, x3; x2 = MULT16_16_P15 (x, x); x3 = MULT16_16_P15 (x, x2); interp[0] = PSHR32 (MULT16_16 (QCONST16 (-0.16667f, 15), x) + MULT16_16 (QCONST16 (0.16667f, 15), x3), 15); interp[1] = EXTRACT16 (EXTEND32 (x) + SHR32 (SUB32 (EXTEND32 (x2), EXTEND32 (x3)), 1)); interp[3] = PSHR32 (MULT16_16 (QCONST16 (-0.33333f, 15), x) + MULT16_16 (QCONST16 (.5f, 15), x2) - MULT16_16 (QCONST16 (0.16667f, 15), x3), 15); /* Just to make sure we don't have rounding problems */ interp[2] = Q15_ONE - interp[0] - interp[1] - interp[3]; if (interp[2] < 32767) interp[2] += 1; } #else static void cubic_coef (spx_word16_t frac, spx_word16_t interp[4]) { /* Compute interpolation coefficients. I'm not sure whether this corresponds to cubic interpolation but I know it's MMSE-optimal on a sinc */ interp[0] = -0.16667f * frac + 0.16667f * frac * frac * frac; interp[1] = frac + 0.5f * frac * frac - 0.5f * frac * frac * frac; /*interp[2] = 1.f - 0.5f*frac - frac*frac + 0.5f*frac*frac*frac; */ interp[3] = -0.33333f * frac + 0.5f * frac * frac - 0.16667f * frac * frac * frac; /* Just to make sure we don't have rounding problems */ interp[2] = 1. - interp[0] - interp[1] - interp[3]; } #endif #ifndef DOUBLE_PRECISION static int resampler_basic_direct_single (SpeexResamplerState * st, spx_uint32_t channel_index, const spx_word16_t * in, spx_uint32_t * in_len, spx_word16_t * out, spx_uint32_t * out_len) { const int N = st->filt_len; int out_sample = 0; int last_sample = st->last_sample[channel_index]; spx_uint32_t samp_frac_num = st->samp_frac_num[channel_index]; const spx_word16_t *sinc_table = st->sinc_table; const int out_stride = st->out_stride; const int int_advance = st->int_advance; const int frac_advance = st->frac_advance; const spx_uint32_t den_rate = st->den_rate; spx_word32_t sum; int j; while (!(last_sample >= (spx_int32_t) * in_len || out_sample >= (spx_int32_t) * out_len)) { const spx_word16_t *sinc = &sinc_table[samp_frac_num * N]; const spx_word16_t *iptr = &in[last_sample]; SSE_FALLBACK (INNER_PRODUCT_SINGLE) sum = 0; for (j = 0; j < N; j++) sum += MULT16_16 (sinc[j], iptr[j]); /* This code is slower on most DSPs which have only 2 accumulators. Plus this this forces truncation to 32 bits and you lose the HW guard bits. I think we can trust the compiler and let it vectorize and/or unroll itself. spx_word32_t accum[4] = {0,0,0,0}; for(j=0;j<N;j+=4) { accum[0] += MULT16_16(sinc[j], iptr[j]); accum[1] += MULT16_16(sinc[j+1], iptr[j+1]); accum[2] += MULT16_16(sinc[j+2], iptr[j+2]); accum[3] += MULT16_16(sinc[j+3], iptr[j+3]); } sum = accum[0] + accum[1] + accum[2] + accum[3]; */ #ifdef OVERRIDE_INNER_PRODUCT_SINGLE SSE_IMPLEMENTATION (INNER_PRODUCT_SINGLE) sum = inner_product_single (sinc, iptr, N); SSE_END(INNER_PRODUCT_SINGLE) #endif out[out_stride * out_sample++] = SATURATE32 (PSHR32 (sum, 15), 32767); last_sample += int_advance; samp_frac_num += frac_advance; if (samp_frac_num >= den_rate) { samp_frac_num -= den_rate; last_sample++; } } st->last_sample[channel_index] = last_sample; st->samp_frac_num[channel_index] = samp_frac_num; return out_sample; } #endif #ifdef FIXED_POINT #else /* This is the same as the previous function, except with a double-precision accumulator */ static int resampler_basic_direct_double (SpeexResamplerState * st, spx_uint32_t channel_index, const spx_word16_t * in, spx_uint32_t * in_len, spx_word16_t * out, spx_uint32_t * out_len) { const int N = st->filt_len; int out_sample = 0; int last_sample = st->last_sample[channel_index]; spx_uint32_t samp_frac_num = st->samp_frac_num[channel_index]; const spx_word16_t *sinc_table = st->sinc_table; const int out_stride = st->out_stride; const int int_advance = st->int_advance; const int frac_advance = st->frac_advance; const spx_uint32_t den_rate = st->den_rate; double sum; int j; while (!(last_sample >= (spx_int32_t) * in_len || out_sample >= (spx_int32_t) * out_len)) { const spx_word16_t *sinc = &sinc_table[samp_frac_num * N]; const spx_word16_t *iptr = &in[last_sample]; SSE2_FALLBACK (INNER_PRODUCT_DOUBLE) double accum[4] = { 0, 0, 0, 0 }; for (j = 0; j < N; j += 4) { accum[0] += sinc[j] * iptr[j]; accum[1] += sinc[j + 1] * iptr[j + 1]; accum[2] += sinc[j + 2] * iptr[j + 2]; accum[3] += sinc[j + 3] * iptr[j + 3]; } sum = accum[0] + accum[1] + accum[2] + accum[3]; #ifdef OVERRIDE_INNER_PRODUCT_DOUBLE SSE2_IMPLEMENTATION (INNER_PRODUCT_DOUBLE) sum = inner_product_double (sinc, iptr, N); SSE2_END (INNER_PRODUCT_DOUBLE) #endif out[out_stride * out_sample++] = PSHR32 (sum, 15); last_sample += int_advance; samp_frac_num += frac_advance; if (samp_frac_num >= den_rate) { samp_frac_num -= den_rate; last_sample++; } } st->last_sample[channel_index] = last_sample; st->samp_frac_num[channel_index] = samp_frac_num; return out_sample; } #endif #ifndef DOUBLE_PRECISION static int resampler_basic_interpolate_single (SpeexResamplerState * st, spx_uint32_t channel_index, const spx_word16_t * in, spx_uint32_t * in_len, spx_word16_t * out, spx_uint32_t * out_len) { const int N = st->filt_len; int out_sample = 0; int last_sample = st->last_sample[channel_index]; spx_uint32_t samp_frac_num = st->samp_frac_num[channel_index]; const int out_stride = st->out_stride; const int int_advance = st->int_advance; const int frac_advance = st->frac_advance; const spx_uint32_t den_rate = st->den_rate; int j; spx_word32_t sum; while (!(last_sample >= (spx_int32_t) * in_len || out_sample >= (spx_int32_t) * out_len)) { const spx_word16_t *iptr = &in[last_sample]; const int offset = samp_frac_num * st->oversample / st->den_rate; #ifdef FIXED_POINT const spx_word16_t frac = PDIV32 (SHL32 ((samp_frac_num * st->oversample) % st->den_rate, 15), st->den_rate); #else const spx_word16_t frac = ((float) ((samp_frac_num * st->oversample) % st->den_rate)) / st->den_rate; #endif spx_word16_t interp[4]; SSE_FALLBACK (INTERPOLATE_PRODUCT_SINGLE) spx_word32_t accum[4] = { 0, 0, 0, 0 }; for (j = 0; j < N; j++) { const spx_word16_t curr_in = iptr[j]; accum[0] += MULT16_16 (curr_in, st->sinc_table[4 + (j + 1) * st->oversample - offset - 2]); accum[1] += MULT16_16 (curr_in, st->sinc_table[4 + (j + 1) * st->oversample - offset - 1]); accum[2] += MULT16_16 (curr_in, st->sinc_table[4 + (j + 1) * st->oversample - offset]); accum[3] += MULT16_16 (curr_in, st->sinc_table[4 + (j + 1) * st->oversample - offset + 1]); } cubic_coef (frac, interp); sum = MULT16_32_Q15 (interp[0], SHR32 (accum[0], 1)) + MULT16_32_Q15 (interp[1], SHR32 (accum[1], 1)) + MULT16_32_Q15 (interp[2], SHR32 (accum[2], 1)) + MULT16_32_Q15 (interp[3], SHR32 (accum[3], 1)); #ifdef OVERRIDE_INTERPOLATE_PRODUCT_SINGLE SSE_IMPLEMENTATION (INTERPOLATE_PRODUCT_SINGLE) cubic_coef (frac, interp); sum = interpolate_product_single (iptr, st->sinc_table + st->oversample + 4 - offset - 2, N, st->oversample, interp); SSE_END (INTERPOLATE_PRODUCT_SINGLE) #endif out[out_stride * out_sample++] = SATURATE32 (PSHR32 (sum, 14), 32767); last_sample += int_advance; samp_frac_num += frac_advance; if (samp_frac_num >= den_rate) { samp_frac_num -= den_rate; last_sample++; } } st->last_sample[channel_index] = last_sample; st->samp_frac_num[channel_index] = samp_frac_num; return out_sample; } #endif #ifdef FIXED_POINT #else /* This is the same as the previous function, except with a double-precision accumulator */ static int resampler_basic_interpolate_double (SpeexResamplerState * st, spx_uint32_t channel_index, const spx_word16_t * in, spx_uint32_t * in_len, spx_word16_t * out, spx_uint32_t * out_len) { const int N = st->filt_len; int out_sample = 0; int last_sample = st->last_sample[channel_index]; spx_uint32_t samp_frac_num = st->samp_frac_num[channel_index]; const int out_stride = st->out_stride; const int int_advance = st->int_advance; const int frac_advance = st->frac_advance; const spx_uint32_t den_rate = st->den_rate; int j; spx_word32_t sum; while (!(last_sample >= (spx_int32_t) * in_len || out_sample >= (spx_int32_t) * out_len)) { const spx_word16_t *iptr = &in[last_sample]; const int offset = samp_frac_num * st->oversample / st->den_rate; #ifdef FIXED_POINT const spx_word16_t frac = PDIV32 (SHL32 ((samp_frac_num * st->oversample) % st->den_rate, 15), st->den_rate); #else #ifdef DOUBLE_PRECISION const spx_word16_t frac = ((double) ((samp_frac_num * st->oversample) % st->den_rate)) / st->den_rate; #else const spx_word16_t frac = ((float) ((samp_frac_num * st->oversample) % st->den_rate)) / st->den_rate; #endif #endif spx_word16_t interp[4]; SSE2_FALLBACK (INTERPOLATE_PRODUCT_DOUBLE) double accum[4] = { 0, 0, 0, 0 }; for (j = 0; j < N; j++) { const double curr_in = iptr[j]; accum[0] += MULT16_16 (curr_in, st->sinc_table[4 + (j + 1) * st->oversample - offset - 2]); accum[1] += MULT16_16 (curr_in, st->sinc_table[4 + (j + 1) * st->oversample - offset - 1]); accum[2] += MULT16_16 (curr_in, st->sinc_table[4 + (j + 1) * st->oversample - offset]); accum[3] += MULT16_16 (curr_in, st->sinc_table[4 + (j + 1) * st->oversample - offset + 1]); } cubic_coef (frac, interp); sum = MULT16_32_Q15 (interp[0], accum[0]) + MULT16_32_Q15 (interp[1], accum[1]) + MULT16_32_Q15 (interp[2], accum[2]) + MULT16_32_Q15 (interp[3], accum[3]); #ifdef OVERRIDE_INTERPOLATE_PRODUCT_DOUBLE SSE2_IMPLEMENTATION (INTERPOLATE_PRODUCT_DOUBLE) cubic_coef (frac, interp); sum = interpolate_product_double (iptr, st->sinc_table + st->oversample + 4 - offset - 2, N, st->oversample, interp); SSE2_END (INTERPOLATE_PRODUCT_DOUBLE) #endif out[out_stride * out_sample++] = PSHR32 (sum, 15); last_sample += int_advance; samp_frac_num += frac_advance; if (samp_frac_num >= den_rate) { samp_frac_num -= den_rate; last_sample++; } } st->last_sample[channel_index] = last_sample; st->samp_frac_num[channel_index] = samp_frac_num; return out_sample; } #endif static void update_filter (SpeexResamplerState * st) { spx_uint32_t old_length; old_length = st->filt_len; st->oversample = quality_map[st->quality].oversample; st->filt_len = quality_map[st->quality].base_length; if (st->num_rate > st->den_rate) { /* down-sampling */ st->cutoff = quality_map[st->quality].downsample_bandwidth * st->den_rate / st->num_rate; /* FIXME: divide the numerator and denominator by a certain amount if they're too large */ st->filt_len = st->filt_len * st->num_rate / st->den_rate; /* Round down to make sure we have a multiple of 4 */ st->filt_len &= (~0x3); if (2 * st->den_rate < st->num_rate) st->oversample >>= 1; if (4 * st->den_rate < st->num_rate) st->oversample >>= 1; if (8 * st->den_rate < st->num_rate) st->oversample >>= 1; if (16 * st->den_rate < st->num_rate) st->oversample >>= 1; if (st->oversample < 1) st->oversample = 1; } else { /* up-sampling */ st->cutoff = quality_map[st->quality].upsample_bandwidth; } /* Choose the resampling type that requires the least amount of memory */ if (st->den_rate <= st->oversample) { spx_uint32_t i; if (!st->sinc_table) st->sinc_table = (spx_word16_t *) speex_alloc (st->filt_len * st->den_rate * sizeof (spx_word16_t)); else if (st->sinc_table_length < st->filt_len * st->den_rate) { st->sinc_table = (spx_word16_t *) speex_realloc (st->sinc_table, st->filt_len * st->den_rate * sizeof (spx_word16_t)); st->sinc_table_length = st->filt_len * st->den_rate; } for (i = 0; i < st->den_rate; i++) { spx_int32_t j; for (j = 0; j < st->filt_len; j++) { st->sinc_table[i * st->filt_len + j] = sinc (st->cutoff, ((j - (spx_int32_t) st->filt_len / 2 + 1) - #ifdef DOUBLE_PRECISION ((double) i) / st->den_rate), st->filt_len, #else ((float) i) / st->den_rate), st->filt_len, #endif quality_map[st->quality].window_func); } } #ifdef FIXED_POINT st->resampler_ptr = resampler_basic_direct_single; #else #ifdef DOUBLE_PRECISION st->resampler_ptr = resampler_basic_direct_double; #else if (st->quality > 8) st->resampler_ptr = resampler_basic_direct_double; else st->resampler_ptr = resampler_basic_direct_single; #endif #endif /*fprintf (stderr, "resampler uses direct sinc table and normalised cutoff %f\n", cutoff); */ } else { spx_int32_t i; if (!st->sinc_table) st->sinc_table = (spx_word16_t *) speex_alloc ((st->filt_len * st->oversample + 8) * sizeof (spx_word16_t)); else if (st->sinc_table_length < st->filt_len * st->oversample + 8) { st->sinc_table = (spx_word16_t *) speex_realloc (st->sinc_table, (st->filt_len * st->oversample + 8) * sizeof (spx_word16_t)); st->sinc_table_length = st->filt_len * st->oversample + 8; } for (i = -4; i < (spx_int32_t) (st->oversample * st->filt_len + 4); i++) st->sinc_table[i + 4] = #ifdef DOUBLE_PRECISION sinc (st->cutoff, (i / (double) st->oversample - st->filt_len / 2), #else sinc (st->cutoff, (i / (float) st->oversample - st->filt_len / 2), #endif st->filt_len, quality_map[st->quality].window_func); #ifdef FIXED_POINT st->resampler_ptr = resampler_basic_interpolate_single; #else #ifdef DOUBLE_PRECISION st->resampler_ptr = resampler_basic_interpolate_double; #else if (st->quality > 8) st->resampler_ptr = resampler_basic_interpolate_double; else st->resampler_ptr = resampler_basic_interpolate_single; #endif #endif /*fprintf (stderr, "resampler uses interpolated sinc table and normalised cutoff %f\n", cutoff); */ } st->int_advance = st->num_rate / st->den_rate; st->frac_advance = st->num_rate % st->den_rate; /* Here's the place where we update the filter memory to take into account the change in filter length. It's probably the messiest part of the code due to handling of lots of corner cases. */ if (!st->mem) { spx_uint32_t i; st->mem_alloc_size = st->filt_len - 1 + st->buffer_size; st->mem = (spx_word16_t *) speex_alloc (st->nb_channels * st->mem_alloc_size * sizeof (spx_word16_t)); for (i = 0; i < st->nb_channels * st->mem_alloc_size; i++) st->mem[i] = 0; /*speex_warning("init filter"); */ } else if (!st->started) { spx_uint32_t i; st->mem_alloc_size = st->filt_len - 1 + st->buffer_size; st->mem = (spx_word16_t *) speex_realloc (st->mem, st->nb_channels * st->mem_alloc_size * sizeof (spx_word16_t)); for (i = 0; i < st->nb_channels * st->mem_alloc_size; i++) st->mem[i] = 0; /*speex_warning("reinit filter"); */ } else if (st->filt_len > old_length) { spx_int32_t i; /* Increase the filter length */ /*speex_warning("increase filter size"); */ int old_alloc_size = st->mem_alloc_size; if ((st->filt_len - 1 + st->buffer_size) > st->mem_alloc_size) { st->mem_alloc_size = st->filt_len - 1 + st->buffer_size; st->mem = (spx_word16_t *) speex_realloc (st->mem, st->nb_channels * st->mem_alloc_size * sizeof (spx_word16_t)); } for (i = st->nb_channels - 1; i >= 0; i--) { spx_int32_t j; spx_uint32_t olen = old_length; /*if (st->magic_samples[i]) */ { /* Try and remove the magic samples as if nothing had happened */ /* FIXME: This is wrong but for now we need it to avoid going over the array bounds */ olen = old_length + 2 * st->magic_samples[i]; for (j = old_length - 2 + st->magic_samples[i]; j >= 0; j--) st->mem[i * st->mem_alloc_size + j + st->magic_samples[i]] = st->mem[i * old_alloc_size + j]; for (j = 0; j < st->magic_samples[i]; j++) st->mem[i * st->mem_alloc_size + j] = 0; st->magic_samples[i] = 0; } if (st->filt_len > olen) { /* If the new filter length is still bigger than the "augmented" length */ /* Copy data going backward */ for (j = 0; j < olen - 1; j++) st->mem[i * st->mem_alloc_size + (st->filt_len - 2 - j)] = st->mem[i * st->mem_alloc_size + (olen - 2 - j)]; /* Then put zeros for lack of anything better */ for (; j < st->filt_len - 1; j++) st->mem[i * st->mem_alloc_size + (st->filt_len - 2 - j)] = 0; /* Adjust last_sample */ st->last_sample[i] += (st->filt_len - olen) / 2; } else { /* Put back some of the magic! */ st->magic_samples[i] = (olen - st->filt_len) / 2; for (j = 0; j < st->filt_len - 1 + st->magic_samples[i]; j++) st->mem[i * st->mem_alloc_size + j] = st->mem[i * st->mem_alloc_size + j + st->magic_samples[i]]; } } } else if (st->filt_len < old_length) { spx_uint32_t i; /* Reduce filter length, this a bit tricky. We need to store some of the memory as "magic" samples so they can be used directly as input the next time(s) */ for (i = 0; i < st->nb_channels; i++) { spx_uint32_t j; spx_uint32_t old_magic = st->magic_samples[i]; st->magic_samples[i] = (old_length - st->filt_len) / 2; /* We must copy some of the memory that's no longer used */ /* Copy data going backward */ for (j = 0; j < st->filt_len - 1 + st->magic_samples[i] + old_magic; j++) st->mem[i * st->mem_alloc_size + j] = st->mem[i * st->mem_alloc_size + j + st->magic_samples[i]]; st->magic_samples[i] += old_magic; } } } EXPORT SpeexResamplerState * speex_resampler_init (spx_uint32_t nb_channels, spx_uint32_t in_rate, spx_uint32_t out_rate, int quality, int *err) { return speex_resampler_init_frac (nb_channels, in_rate, out_rate, in_rate, out_rate, quality, err); } #if defined HAVE_ORC && !defined DISABLE_ORC static void check_insn_set (SpeexResamplerState * st, const char *name) { if (!name) return; if (!strcmp (name, "sse")) st->use_sse = 1; if (!strcmp (name, "sse2")) st->use_sse = st->use_sse2 = 1; } #endif EXPORT SpeexResamplerState * speex_resampler_init_frac (spx_uint32_t nb_channels, spx_uint32_t ratio_num, spx_uint32_t ratio_den, spx_uint32_t in_rate, spx_uint32_t out_rate, int quality, int *err) { spx_uint32_t i; SpeexResamplerState *st; if (quality > 10 || quality < 0) { if (err) *err = RESAMPLER_ERR_INVALID_ARG; return NULL; } st = (SpeexResamplerState *) speex_alloc (sizeof (SpeexResamplerState)); st->initialised = 0; st->started = 0; st->in_rate = 0; st->out_rate = 0; st->num_rate = 0; st->den_rate = 0; st->quality = -1; st->sinc_table_length = 0; st->mem_alloc_size = 0; st->filt_len = 0; st->mem = 0; st->resampler_ptr = 0; st->cutoff = 1.f; st->nb_channels = nb_channels; st->in_stride = 1; st->out_stride = 1; #ifdef FIXED_POINT st->buffer_size = 160; #else st->buffer_size = 160; #endif st->use_sse = st->use_sse2 = 0; #if defined HAVE_ORC && !defined DISABLE_ORC orc_init (); { OrcTarget *target = orc_target_get_default (); if (target) { unsigned int flags = orc_target_get_default_flags (target); check_insn_set (st, orc_target_get_name (target)); for (i = 0; i < 32; ++i) { if (flags & (1 << i)) { check_insn_set (st, orc_target_get_flag_name (target, i)); } } } } #endif /* Per channel data */ st->last_sample = (spx_int32_t *) speex_alloc (nb_channels * sizeof (int)); st->magic_samples = (spx_uint32_t *) speex_alloc (nb_channels * sizeof (int)); st->samp_frac_num = (spx_uint32_t *) speex_alloc (nb_channels * sizeof (int)); for (i = 0; i < nb_channels; i++) { st->last_sample[i] = 0; st->magic_samples[i] = 0; st->samp_frac_num[i] = 0; } speex_resampler_set_quality (st, quality); speex_resampler_set_rate_frac (st, ratio_num, ratio_den, in_rate, out_rate); update_filter (st); st->initialised = 1; if (err) *err = RESAMPLER_ERR_SUCCESS; return st; } EXPORT void speex_resampler_destroy (SpeexResamplerState * st) { speex_free (st->mem); speex_free (st->sinc_table); speex_free (st->last_sample); speex_free (st->magic_samples); speex_free (st->samp_frac_num); speex_free (st); } static int speex_resampler_process_native (SpeexResamplerState * st, spx_uint32_t channel_index, spx_uint32_t * in_len, spx_word16_t * out, spx_uint32_t * out_len) { int j = 0; const int N = st->filt_len; int out_sample = 0; spx_word16_t *mem = st->mem + channel_index * st->mem_alloc_size; spx_uint32_t ilen; st->started = 1; /* Call the right resampler through the function ptr */ out_sample = st->resampler_ptr (st, channel_index, mem, in_len, out, out_len); if (st->last_sample[channel_index] < (spx_int32_t) * in_len) *in_len = st->last_sample[channel_index]; *out_len = out_sample; st->last_sample[channel_index] -= *in_len; ilen = *in_len; for (j = 0; j < N - 1; ++j) mem[j] = mem[j + ilen]; return RESAMPLER_ERR_SUCCESS; } static int speex_resampler_magic (SpeexResamplerState * st, spx_uint32_t channel_index, spx_word16_t ** out, spx_uint32_t out_len) { spx_uint32_t tmp_in_len = st->magic_samples[channel_index]; spx_word16_t *mem = st->mem + channel_index * st->mem_alloc_size; const int N = st->filt_len; speex_resampler_process_native (st, channel_index, &tmp_in_len, *out, &out_len); st->magic_samples[channel_index] -= tmp_in_len; /* If we couldn't process all "magic" input samples, save the rest for next time */ if (st->magic_samples[channel_index]) { spx_uint32_t i; for (i = 0; i < st->magic_samples[channel_index]; i++) mem[N - 1 + i] = mem[N - 1 + i + tmp_in_len]; } *out += out_len * st->out_stride; return out_len; } #ifdef FIXED_POINT EXPORT int speex_resampler_process_int (SpeexResamplerState * st, spx_uint32_t channel_index, const spx_int16_t * in, spx_uint32_t * in_len, spx_int16_t * out, spx_uint32_t * out_len) #else #ifdef DOUBLE_PRECISION EXPORT int speex_resampler_process_float (SpeexResamplerState * st, spx_uint32_t channel_index, const double *in, spx_uint32_t * in_len, double *out, spx_uint32_t * out_len) #else EXPORT int speex_resampler_process_float (SpeexResamplerState * st, spx_uint32_t channel_index, const float *in, spx_uint32_t * in_len, float *out, spx_uint32_t * out_len) #endif #endif { int j; spx_uint32_t ilen = *in_len; spx_uint32_t olen = *out_len; spx_word16_t *x = st->mem + channel_index * st->mem_alloc_size; const int filt_offs = st->filt_len - 1; const spx_uint32_t xlen = st->mem_alloc_size - filt_offs; const int istride = st->in_stride; if (st->magic_samples[channel_index]) olen -= speex_resampler_magic (st, channel_index, &out, olen); if (!st->magic_samples[channel_index]) { while (ilen && olen) { spx_uint32_t ichunk = (ilen > xlen) ? xlen : ilen; spx_uint32_t ochunk = olen; if (in) { for (j = 0; j < ichunk; ++j) x[j + filt_offs] = in[j * istride]; } else { for (j = 0; j < ichunk; ++j) x[j + filt_offs] = 0; } speex_resampler_process_native (st, channel_index, &ichunk, out, &ochunk); ilen -= ichunk; olen -= ochunk; out += ochunk * st->out_stride; if (in) in += ichunk * istride; } } *in_len -= ilen; *out_len -= olen; return RESAMPLER_ERR_SUCCESS; } #ifdef FIXED_POINT EXPORT int speex_resampler_process_float (SpeexResamplerState * st, spx_uint32_t channel_index, const float *in, spx_uint32_t * in_len, float *out, spx_uint32_t * out_len) #else EXPORT int speex_resampler_process_int (SpeexResamplerState * st, spx_uint32_t channel_index, const spx_int16_t * in, spx_uint32_t * in_len, spx_int16_t * out, spx_uint32_t * out_len) #endif { int j; const int istride_save = st->in_stride; const int ostride_save = st->out_stride; spx_uint32_t ilen = *in_len; spx_uint32_t olen = *out_len; spx_word16_t *x = st->mem + channel_index * st->mem_alloc_size; const spx_uint32_t xlen = st->mem_alloc_size - (st->filt_len - 1); #ifdef VAR_ARRAYS const unsigned int ylen = (olen < FIXED_STACK_ALLOC) ? olen : FIXED_STACK_ALLOC; VARDECL (spx_word16_t * ystack); ALLOC (ystack, ylen, spx_word16_t); #else const unsigned int ylen = FIXED_STACK_ALLOC; spx_word16_t ystack[FIXED_STACK_ALLOC]; #endif st->out_stride = 1; while (ilen && olen) { spx_word16_t *y = ystack; spx_uint32_t ichunk = (ilen > xlen) ? xlen : ilen; spx_uint32_t ochunk = (olen > ylen) ? ylen : olen; spx_uint32_t omagic = 0; if (st->magic_samples[channel_index]) { omagic = speex_resampler_magic (st, channel_index, &y, ochunk); ochunk -= omagic; olen -= omagic; } if (!st->magic_samples[channel_index]) { if (in) { for (j = 0; j < ichunk; ++j) #ifdef FIXED_POINT x[j + st->filt_len - 1] = WORD2INT (in[j * istride_save]); #else x[j + st->filt_len - 1] = in[j * istride_save]; #endif } else { for (j = 0; j < ichunk; ++j) x[j + st->filt_len - 1] = 0; } speex_resampler_process_native (st, channel_index, &ichunk, y, &ochunk); } else { ichunk = 0; ochunk = 0; } for (j = 0; j < ochunk + omagic; ++j) #ifdef FIXED_POINT out[j * ostride_save] = ystack[j]; #else out[j * ostride_save] = WORD2INT (ystack[j]); #endif ilen -= ichunk; olen -= ochunk; out += (ochunk + omagic) * ostride_save; if (in) in += ichunk * istride_save; } st->out_stride = ostride_save; *in_len -= ilen; *out_len -= olen; return RESAMPLER_ERR_SUCCESS; } #ifdef DOUBLE_PRECISION EXPORT int speex_resampler_process_interleaved_float (SpeexResamplerState * st, const double *in, spx_uint32_t * in_len, double *out, spx_uint32_t * out_len) #else EXPORT int speex_resampler_process_interleaved_float (SpeexResamplerState * st, const float *in, spx_uint32_t * in_len, float *out, spx_uint32_t * out_len) #endif { spx_uint32_t i; int istride_save, ostride_save; spx_uint32_t bak_len = *out_len; istride_save = st->in_stride; ostride_save = st->out_stride; st->in_stride = st->out_stride = st->nb_channels; for (i = 0; i < st->nb_channels; i++) { *out_len = bak_len; if (in != NULL) speex_resampler_process_float (st, i, in + i, in_len, out + i, out_len); else speex_resampler_process_float (st, i, NULL, in_len, out + i, out_len); } st->in_stride = istride_save; st->out_stride = ostride_save; return RESAMPLER_ERR_SUCCESS; } EXPORT int speex_resampler_process_interleaved_int (SpeexResamplerState * st, const spx_int16_t * in, spx_uint32_t * in_len, spx_int16_t * out, spx_uint32_t * out_len) { spx_uint32_t i; int istride_save, ostride_save; spx_uint32_t bak_len = *out_len; istride_save = st->in_stride; ostride_save = st->out_stride; st->in_stride = st->out_stride = st->nb_channels; for (i = 0; i < st->nb_channels; i++) { *out_len = bak_len; if (in != NULL) speex_resampler_process_int (st, i, in + i, in_len, out + i, out_len); else speex_resampler_process_int (st, i, NULL, in_len, out + i, out_len); } st->in_stride = istride_save; st->out_stride = ostride_save; return RESAMPLER_ERR_SUCCESS; } EXPORT int speex_resampler_set_rate (SpeexResamplerState * st, spx_uint32_t in_rate, spx_uint32_t out_rate) { return speex_resampler_set_rate_frac (st, in_rate, out_rate, in_rate, out_rate); } EXPORT void speex_resampler_get_rate (SpeexResamplerState * st, spx_uint32_t * in_rate, spx_uint32_t * out_rate) { *in_rate = st->in_rate; *out_rate = st->out_rate; } EXPORT int speex_resampler_set_rate_frac (SpeexResamplerState * st, spx_uint32_t ratio_num, spx_uint32_t ratio_den, spx_uint32_t in_rate, spx_uint32_t out_rate) { spx_uint32_t fact; spx_uint32_t old_den; spx_uint32_t i; if (st->in_rate == in_rate && st->out_rate == out_rate && st->num_rate == ratio_num && st->den_rate == ratio_den) return RESAMPLER_ERR_SUCCESS; old_den = st->den_rate; st->in_rate = in_rate; st->out_rate = out_rate; st->num_rate = ratio_num; st->den_rate = ratio_den; /* FIXME: This is terribly inefficient, but who cares (at least for now)? */ for (fact = 2; fact <= IMIN (st->num_rate, st->den_rate); fact++) { while ((st->num_rate % fact == 0) && (st->den_rate % fact == 0)) { st->num_rate /= fact; st->den_rate /= fact; } } if (old_den > 0) { for (i = 0; i < st->nb_channels; i++) { st->samp_frac_num[i] = st->samp_frac_num[i] * st->den_rate / old_den; /* Safety net */ if (st->samp_frac_num[i] >= st->den_rate) st->samp_frac_num[i] = st->den_rate - 1; } } if (st->initialised) update_filter (st); return RESAMPLER_ERR_SUCCESS; } EXPORT void speex_resampler_get_ratio (SpeexResamplerState * st, spx_uint32_t * ratio_num, spx_uint32_t * ratio_den) { *ratio_num = st->num_rate; *ratio_den = st->den_rate; } EXPORT int speex_resampler_set_quality (SpeexResamplerState * st, int quality) { if (quality > 10 || quality < 0) return RESAMPLER_ERR_INVALID_ARG; if (st->quality == quality) return RESAMPLER_ERR_SUCCESS; st->quality = quality; if (st->initialised) update_filter (st); return RESAMPLER_ERR_SUCCESS; } EXPORT void speex_resampler_get_quality (SpeexResamplerState * st, int *quality) { *quality = st->quality; } EXPORT void speex_resampler_set_input_stride (SpeexResamplerState * st, spx_uint32_t stride) { st->in_stride = stride; } EXPORT void speex_resampler_get_input_stride (SpeexResamplerState * st, spx_uint32_t * stride) { *stride = st->in_stride; } EXPORT void speex_resampler_set_output_stride (SpeexResamplerState * st, spx_uint32_t stride) { st->out_stride = stride; } EXPORT void speex_resampler_get_output_stride (SpeexResamplerState * st, spx_uint32_t * stride) { *stride = st->out_stride; } EXPORT int speex_resampler_get_input_latency (SpeexResamplerState * st) { return st->filt_len / 2; } EXPORT int speex_resampler_get_output_latency (SpeexResamplerState * st) { return ((st->filt_len / 2) * st->den_rate + (st->num_rate >> 1)) / st->num_rate; } EXPORT int speex_resampler_get_filt_len (SpeexResamplerState * st) { return st->filt_len; } EXPORT int speex_resampler_skip_zeros (SpeexResamplerState * st) { spx_uint32_t i; for (i = 0; i < st->nb_channels; i++) st->last_sample[i] = st->filt_len / 2; return RESAMPLER_ERR_SUCCESS; } EXPORT int speex_resampler_reset_mem (SpeexResamplerState * st) { spx_uint32_t i; for (i = 0; i < st->nb_channels * (st->filt_len - 1); i++) st->mem[i] = 0; return RESAMPLER_ERR_SUCCESS; } EXPORT const char * speex_resampler_strerror (int err) { switch (err) { case RESAMPLER_ERR_SUCCESS: return "Success."; case RESAMPLER_ERR_ALLOC_FAILED: return "Memory allocation failed."; case RESAMPLER_ERR_BAD_STATE: return "Bad resampler state."; case RESAMPLER_ERR_INVALID_ARG: return "Invalid argument."; case RESAMPLER_ERR_PTR_OVERLAP: return "Input and output buffers overlap."; default: return "Unknown error. Bad error code or strange version mismatch."; } }