ref: aa6f7617d9297b9fe90863dcf02e9d0cbcb2daad
dir: /src/src_sinc.c/
/* ** Copyright (c) 2002-2016, Erik de Castro Lopo <[email protected]> ** All rights reserved. ** ** This code is released under 2-clause BSD license. Please see the ** file at : https://github.com/libsndfile/libsamplerate/blob/master/COPYING */ #include <assert.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include "src_config.h" #include "common.h" #define SINC_MAGIC_MARKER MAKE_MAGIC (' ', 's', 'i', 'n', 'c', ' ') /*======================================================================================== */ #define MAKE_INCREMENT_T(x) ((increment_t) (x)) #define SHIFT_BITS 12 #define FP_ONE ((double) (((increment_t) 1) << SHIFT_BITS)) #define INV_FP_ONE (1.0 / FP_ONE) /* Customixe max channls from Kconfig. */ #ifndef CONFIG_CHAN_NR #define MAX_CHANNELS 128 #else #define MAX_CHANNELS CONFIG_CHAN_NR #endif /*======================================================================================== */ typedef int32_t increment_t ; typedef float coeff_t ; typedef int _CHECK_SHIFT_BITS[2 * (SHIFT_BITS < sizeof (increment_t) * 8 - 1) - 1]; /* sanity check. */ #include "fastest_coeffs.h" #include "mid_qual_coeffs.h" #include "high_qual_coeffs.h" typedef struct { int sinc_magic_marker ; long in_count, in_used ; long out_count, out_gen ; int coeff_half_len, index_inc ; double src_ratio, input_index ; coeff_t const *coeffs ; int b_current, b_end, b_real_end, b_len ; /* Sure hope noone does more than 128 channels at once. */ double left_calc [MAX_CHANNELS], right_calc [MAX_CHANNELS] ; float *buffer ; } SINC_FILTER ; static SRC_ERROR sinc_multichan_vari_process (SRC_STATE *state, SRC_DATA *data) ; static SRC_ERROR sinc_hex_vari_process (SRC_STATE *state, SRC_DATA *data) ; static SRC_ERROR sinc_quad_vari_process (SRC_STATE *state, SRC_DATA *data) ; static SRC_ERROR sinc_stereo_vari_process (SRC_STATE *state, SRC_DATA *data) ; static SRC_ERROR sinc_mono_vari_process (SRC_STATE *state, SRC_DATA *data) ; static SRC_ERROR prepare_data (SINC_FILTER *filter, int channels, SRC_DATA *data, int half_filter_chan_len) WARN_UNUSED ; static void sinc_reset (SRC_STATE *state) ; static SRC_STATE *sinc_copy (SRC_STATE *state) ; static void sinc_close (SRC_STATE *state) ; static SRC_STATE_VT sinc_multichan_state_vt = { sinc_multichan_vari_process, sinc_multichan_vari_process, sinc_reset, sinc_copy, sinc_close } ; static SRC_STATE_VT sinc_hex_state_vt = { sinc_hex_vari_process, sinc_hex_vari_process, sinc_reset, sinc_copy, sinc_close } ; static SRC_STATE_VT sinc_quad_state_vt = { sinc_quad_vari_process, sinc_quad_vari_process, sinc_reset, sinc_copy, sinc_close } ; static SRC_STATE_VT sinc_stereo_state_vt = { sinc_stereo_vari_process, sinc_stereo_vari_process, sinc_reset, sinc_copy, sinc_close } ; static SRC_STATE_VT sinc_mono_state_vt = { sinc_mono_vari_process, sinc_mono_vari_process, sinc_reset, sinc_copy, sinc_close } ; static inline increment_t double_to_fp (double x) { return (increment_t) (lrint ((x) * FP_ONE)) ; } /* double_to_fp */ static inline increment_t int_to_fp (int x) { return (((increment_t) (x)) << SHIFT_BITS) ; } /* int_to_fp */ static inline int fp_to_int (increment_t x) { return (((x) >> SHIFT_BITS)) ; } /* fp_to_int */ static inline increment_t fp_fraction_part (increment_t x) { return ((x) & ((((increment_t) 1) << SHIFT_BITS) - 1)) ; } /* fp_fraction_part */ static inline double fp_to_double (increment_t x) { return fp_fraction_part (x) * INV_FP_ONE ; } /* fp_to_double */ static inline int int_div_ceil (int divident, int divisor) /* == (int) ceil ((float) divident / divisor) */ { assert (divident >= 0 && divisor > 0) ; /* For positive numbers only */ return (divident + (divisor - 1)) / divisor ; } /*---------------------------------------------------------------------------------------- */ const char* sinc_get_name (int src_enum) { switch (src_enum) { case SRC_SINC_BEST_QUALITY : return "Best Sinc Interpolator" ; case SRC_SINC_MEDIUM_QUALITY : return "Medium Sinc Interpolator" ; case SRC_SINC_FASTEST : return "Fastest Sinc Interpolator" ; default: break ; } ; return NULL ; } /* sinc_get_descrition */ const char* sinc_get_description (int src_enum) { switch (src_enum) { case SRC_SINC_FASTEST : return "Band limited sinc interpolation, fastest, 97dB SNR, 80% BW." ; case SRC_SINC_MEDIUM_QUALITY : return "Band limited sinc interpolation, medium quality, 121dB SNR, 90% BW." ; case SRC_SINC_BEST_QUALITY : return "Band limited sinc interpolation, best quality, 144dB SNR, 96% BW." ; default : break ; } ; return NULL ; } /* sinc_get_descrition */ static SINC_FILTER * sinc_filter_new (int converter_type, int channels) { assert (converter_type == SRC_SINC_FASTEST || converter_type == SRC_SINC_MEDIUM_QUALITY || converter_type == SRC_SINC_BEST_QUALITY) ; assert (channels > 0 && channels <= MAX_CHANNELS) ; SINC_FILTER *priv = (SINC_FILTER *) calloc (1, sizeof (SINC_FILTER)) ; if (priv) { priv->sinc_magic_marker = SINC_MAGIC_MARKER ; switch (converter_type) { case SRC_SINC_FASTEST : priv->coeffs = fastest_coeffs.coeffs ; priv->coeff_half_len = ARRAY_LEN (fastest_coeffs.coeffs) - 2 ; priv->index_inc = fastest_coeffs.increment ; break ; case SRC_SINC_MEDIUM_QUALITY : priv->coeffs = slow_mid_qual_coeffs.coeffs ; priv->coeff_half_len = ARRAY_LEN (slow_mid_qual_coeffs.coeffs) - 2 ; priv->index_inc = slow_mid_qual_coeffs.increment ; break ; case SRC_SINC_BEST_QUALITY : priv->coeffs = slow_high_qual_coeffs.coeffs ; priv->coeff_half_len = ARRAY_LEN (slow_high_qual_coeffs.coeffs) - 2 ; priv->index_inc = slow_high_qual_coeffs.increment ; break ; } priv->b_len = 3 * (int) lrint ((priv->coeff_half_len + 2.0) / priv->index_inc * SRC_MAX_RATIO + 1) ; priv->b_len = MAX (priv->b_len, 4096) ; priv->b_len *= channels ; priv->b_len += 1 ; // There is a <= check against samples_in_hand requiring a buffer bigger than the calculation above priv->buffer = (float *) calloc (priv->b_len + channels, sizeof (float)) ; if (!priv->buffer) { free (priv) ; priv = NULL ; } } return priv ; } SRC_STATE * sinc_state_new (int converter_type, int channels, SRC_ERROR *error) { assert (converter_type == SRC_SINC_FASTEST || converter_type == SRC_SINC_MEDIUM_QUALITY || converter_type == SRC_SINC_BEST_QUALITY) ; assert (channels > 0) ; assert (error != NULL) ; if (channels > MAX_CHANNELS) { *error = SRC_ERR_BAD_CHANNEL_COUNT ; return NULL ; } SRC_STATE *state = (SRC_STATE *) calloc (1, sizeof (SRC_STATE)) ; if (!state) { *error = SRC_ERR_MALLOC_FAILED ; return NULL ; } state->channels = channels ; state->mode = SRC_MODE_PROCESS ; if (state->channels == 1) state->vt = &sinc_mono_state_vt ; else if (state->channels == 2) state->vt = &sinc_stereo_state_vt ; else if (state->channels == 4) state->vt = &sinc_quad_state_vt ; else if (state->channels == 6) state->vt = &sinc_hex_state_vt ; else state->vt = &sinc_multichan_state_vt ; state->private_data = sinc_filter_new (converter_type, state->channels) ; if (!state->private_data) { free (state) ; *error = SRC_ERR_MALLOC_FAILED ; return NULL ; } sinc_reset (state) ; *error = SRC_ERR_NO_ERROR ; return state ; } static void sinc_reset (SRC_STATE *state) { SINC_FILTER *filter ; filter = (SINC_FILTER*) state->private_data ; if (filter == NULL) return ; filter->b_current = filter->b_end = 0 ; filter->b_real_end = -1 ; filter->src_ratio = filter->input_index = 0.0 ; memset (filter->buffer, 0, filter->b_len * sizeof (filter->buffer [0])) ; /* Set this for a sanity check */ memset (filter->buffer + filter->b_len, 0xAA, state->channels * sizeof (filter->buffer [0])) ; } /* sinc_reset */ static SRC_STATE * sinc_copy (SRC_STATE *state) { assert (state != NULL) ; if (state->private_data == NULL) return NULL ; SRC_STATE *to = (SRC_STATE *) calloc (1, sizeof (SRC_STATE)) ; if (!state) return NULL ; memcpy (to, state, sizeof (SRC_STATE)) ; SINC_FILTER* from_filter = (SINC_FILTER*) state->private_data ; SINC_FILTER *to_filter = (SINC_FILTER *) calloc (1, sizeof (SINC_FILTER)) ; if (!to_filter) { free (to) ; return NULL ; } memcpy (to_filter, from_filter, sizeof (SINC_FILTER)) ; to_filter->buffer = (float *) malloc (sizeof (float) * (from_filter->b_len + state->channels)) ; if (!to_filter->buffer) { free (to) ; free (to_filter) ; return NULL ; } memcpy (to_filter->buffer, from_filter->buffer, sizeof (float) * (from_filter->b_len + state->channels)) ; to->private_data = to_filter ; return to ; } /* sinc_copy */ /*======================================================================================== ** Beware all ye who dare pass this point. There be dragons here. */ static inline double calc_output_single (SINC_FILTER *filter, increment_t increment, increment_t start_filter_index) { double fraction, left, right, icoeff ; increment_t filter_index, max_filter_index ; int data_index, coeff_count, indx ; /* Convert input parameters into fixed point. */ max_filter_index = int_to_fp (filter->coeff_half_len) ; /* First apply the left half of the filter. */ filter_index = start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current - coeff_count ; if (data_index < 0) /* Avoid underflow access to filter->buffer. */ { int steps = -data_index ; /* If the assert triggers we would have to take care not to underflow/overflow */ assert (steps <= int_div_ceil (filter_index, increment)) ; filter_index -= increment * steps ; data_index += steps ; } left = 0.0 ; while (filter_index >= MAKE_INCREMENT_T (0)) { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index < filter->b_len) ; assert (data_index < filter->b_end) ; left += icoeff * filter->buffer [data_index] ; filter_index -= increment ; data_index = data_index + 1 ; } ; /* Now apply the right half of the filter. */ filter_index = increment - start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current + 1 + coeff_count ; right = 0.0 ; do { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index < filter->b_len) ; assert (data_index < filter->b_end) ; right += icoeff * filter->buffer [data_index] ; filter_index -= increment ; data_index = data_index - 1 ; } while (filter_index > MAKE_INCREMENT_T (0)) ; return (left + right) ; } /* calc_output_single */ static SRC_ERROR sinc_mono_vari_process (SRC_STATE *state, SRC_DATA *data) { SINC_FILTER *filter ; double input_index, src_ratio, count, float_increment, terminate, rem ; increment_t increment, start_filter_index ; int half_filter_chan_len, samples_in_hand ; if (state->private_data == NULL) return SRC_ERR_NO_PRIVATE ; filter = (SINC_FILTER*) state->private_data ; /* If there is not a problem, this will be optimised out. */ if (sizeof (filter->buffer [0]) != sizeof (data->data_in [0])) return SRC_ERR_SIZE_INCOMPATIBILITY ; filter->in_count = data->input_frames * state->channels ; filter->out_count = data->output_frames * state->channels ; filter->in_used = filter->out_gen = 0 ; src_ratio = state->last_ratio ; if (is_bad_src_ratio (src_ratio)) return SRC_ERR_BAD_INTERNAL_STATE ; /* Check the sample rate ratio wrt the buffer len. */ count = (filter->coeff_half_len + 2.0) / filter->index_inc ; if (MIN (state->last_ratio, data->src_ratio) < 1.0) count /= MIN (state->last_ratio, data->src_ratio) ; /* Maximum coefficientson either side of center point. */ half_filter_chan_len = state->channels * (int) (lrint (count) + 1) ; input_index = state->last_position ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; terminate = 1.0 / src_ratio + 1e-20 ; /* Main processing loop. */ while (filter->out_gen < filter->out_count) { /* Need to reload buffer? */ samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) { if ((state->error = prepare_data (filter, state->channels, data, half_filter_chan_len)) != 0) return state->error ; samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) break ; } ; /* This is the termination condition. */ if (filter->b_real_end >= 0) { if (filter->b_current + input_index + terminate > filter->b_real_end) break ; } ; if (filter->out_count > 0 && fabs (state->last_ratio - data->src_ratio) > 1e-10) src_ratio = state->last_ratio + filter->out_gen * (data->src_ratio - state->last_ratio) / filter->out_count ; float_increment = filter->index_inc * (src_ratio < 1.0 ? src_ratio : 1.0) ; increment = double_to_fp (float_increment) ; start_filter_index = double_to_fp (input_index * float_increment) ; data->data_out [filter->out_gen] = (float) ((float_increment / filter->index_inc) * calc_output_single (filter, increment, start_filter_index)) ; filter->out_gen ++ ; /* Figure out the next index. */ input_index += 1.0 / src_ratio ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; } ; state->last_position = input_index ; /* Save current ratio rather then target ratio. */ state->last_ratio = src_ratio ; data->input_frames_used = filter->in_used / state->channels ; data->output_frames_gen = filter->out_gen / state->channels ; return SRC_ERR_NO_ERROR ; } /* sinc_mono_vari_process */ static inline void calc_output_stereo (SINC_FILTER *filter, int channels, increment_t increment, increment_t start_filter_index, double scale, float * output) { double fraction, left [2], right [2], icoeff ; increment_t filter_index, max_filter_index ; int data_index, coeff_count, indx ; /* Convert input parameters into fixed point. */ max_filter_index = int_to_fp (filter->coeff_half_len) ; /* First apply the left half of the filter. */ filter_index = start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current - channels * coeff_count ; if (data_index < 0) /* Avoid underflow access to filter->buffer. */ { int steps = int_div_ceil (-data_index, 2) ; /* If the assert triggers we would have to take care not to underflow/overflow */ assert (steps <= int_div_ceil (filter_index, increment)) ; filter_index -= increment * steps ; data_index += steps * 2; } left [0] = left [1] = 0.0 ; while (filter_index >= MAKE_INCREMENT_T (0)) { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index + 1 < filter->b_len) ; assert (data_index + 1 < filter->b_end) ; for (int ch = 0; ch < 2; ch++) left [ch] += icoeff * filter->buffer [data_index + ch] ; filter_index -= increment ; data_index = data_index + 2 ; } ; /* Now apply the right half of the filter. */ filter_index = increment - start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current + channels * (1 + coeff_count) ; right [0] = right [1] = 0.0 ; do { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index + 1 < filter->b_len) ; assert (data_index + 1 < filter->b_end) ; for (int ch = 0; ch < 2; ch++) right [ch] += icoeff * filter->buffer [data_index + ch] ; filter_index -= increment ; data_index = data_index - 2 ; } while (filter_index > MAKE_INCREMENT_T (0)) ; for (int ch = 0; ch < 2; ch++) output [ch] = (float) (scale * (left [ch] + right [ch])) ; } /* calc_output_stereo */ SRC_ERROR sinc_stereo_vari_process (SRC_STATE *state, SRC_DATA *data) { SINC_FILTER *filter ; double input_index, src_ratio, count, float_increment, terminate, rem ; increment_t increment, start_filter_index ; int half_filter_chan_len, samples_in_hand ; if (state->private_data == NULL) return SRC_ERR_NO_PRIVATE ; filter = (SINC_FILTER*) state->private_data ; /* If there is not a problem, this will be optimised out. */ if (sizeof (filter->buffer [0]) != sizeof (data->data_in [0])) return SRC_ERR_SIZE_INCOMPATIBILITY ; filter->in_count = data->input_frames * state->channels ; filter->out_count = data->output_frames * state->channels ; filter->in_used = filter->out_gen = 0 ; src_ratio = state->last_ratio ; if (is_bad_src_ratio (src_ratio)) return SRC_ERR_BAD_INTERNAL_STATE ; /* Check the sample rate ratio wrt the buffer len. */ count = (filter->coeff_half_len + 2.0) / filter->index_inc ; if (MIN (state->last_ratio, data->src_ratio) < 1.0) count /= MIN (state->last_ratio, data->src_ratio) ; /* Maximum coefficientson either side of center point. */ half_filter_chan_len = state->channels * (int) (lrint (count) + 1) ; input_index = state->last_position ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; terminate = 1.0 / src_ratio + 1e-20 ; /* Main processing loop. */ while (filter->out_gen < filter->out_count) { /* Need to reload buffer? */ samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) { if ((state->error = prepare_data (filter, state->channels, data, half_filter_chan_len)) != 0) return state->error ; samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) break ; } ; /* This is the termination condition. */ if (filter->b_real_end >= 0) { if (filter->b_current + input_index + terminate >= filter->b_real_end) break ; } ; if (filter->out_count > 0 && fabs (state->last_ratio - data->src_ratio) > 1e-10) src_ratio = state->last_ratio + filter->out_gen * (data->src_ratio - state->last_ratio) / filter->out_count ; float_increment = filter->index_inc * (src_ratio < 1.0 ? src_ratio : 1.0) ; increment = double_to_fp (float_increment) ; start_filter_index = double_to_fp (input_index * float_increment) ; calc_output_stereo (filter, state->channels, increment, start_filter_index, float_increment / filter->index_inc, data->data_out + filter->out_gen) ; filter->out_gen += 2 ; /* Figure out the next index. */ input_index += 1.0 / src_ratio ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; } ; state->last_position = input_index ; /* Save current ratio rather then target ratio. */ state->last_ratio = src_ratio ; data->input_frames_used = filter->in_used / state->channels ; data->output_frames_gen = filter->out_gen / state->channels ; return SRC_ERR_NO_ERROR ; } /* sinc_stereo_vari_process */ static inline void calc_output_quad (SINC_FILTER *filter, int channels, increment_t increment, increment_t start_filter_index, double scale, float * output) { double fraction, left [4], right [4], icoeff ; increment_t filter_index, max_filter_index ; int data_index, coeff_count, indx ; /* Convert input parameters into fixed point. */ max_filter_index = int_to_fp (filter->coeff_half_len) ; /* First apply the left half of the filter. */ filter_index = start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current - channels * coeff_count ; if (data_index < 0) /* Avoid underflow access to filter->buffer. */ { int steps = int_div_ceil (-data_index, 4) ; /* If the assert triggers we would have to take care not to underflow/overflow */ assert (steps <= int_div_ceil (filter_index, increment)) ; filter_index -= increment * steps ; data_index += steps * 4; } left [0] = left [1] = left [2] = left [3] = 0.0 ; while (filter_index >= MAKE_INCREMENT_T (0)) { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index + 3 < filter->b_len) ; assert (data_index + 3 < filter->b_end) ; for (int ch = 0; ch < 4; ch++) left [ch] += icoeff * filter->buffer [data_index + ch] ; filter_index -= increment ; data_index = data_index + 4 ; } ; /* Now apply the right half of the filter. */ filter_index = increment - start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current + channels * (1 + coeff_count) ; right [0] = right [1] = right [2] = right [3] = 0.0 ; do { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index + 3 < filter->b_len) ; assert (data_index + 3 < filter->b_end) ; for (int ch = 0; ch < 4; ch++) right [ch] += icoeff * filter->buffer [data_index + ch] ; filter_index -= increment ; data_index = data_index - 4 ; } while (filter_index > MAKE_INCREMENT_T (0)) ; for (int ch = 0; ch < 4; ch++) output [ch] = (float) (scale * (left [ch] + right [ch])) ; } /* calc_output_quad */ SRC_ERROR sinc_quad_vari_process (SRC_STATE *state, SRC_DATA *data) { SINC_FILTER *filter ; double input_index, src_ratio, count, float_increment, terminate, rem ; increment_t increment, start_filter_index ; int half_filter_chan_len, samples_in_hand ; if (state->private_data == NULL) return SRC_ERR_NO_PRIVATE ; filter = (SINC_FILTER*) state->private_data ; /* If there is not a problem, this will be optimised out. */ if (sizeof (filter->buffer [0]) != sizeof (data->data_in [0])) return SRC_ERR_SIZE_INCOMPATIBILITY ; filter->in_count = data->input_frames * state->channels ; filter->out_count = data->output_frames * state->channels ; filter->in_used = filter->out_gen = 0 ; src_ratio = state->last_ratio ; if (is_bad_src_ratio (src_ratio)) return SRC_ERR_BAD_INTERNAL_STATE ; /* Check the sample rate ratio wrt the buffer len. */ count = (filter->coeff_half_len + 2.0) / filter->index_inc ; if (MIN (state->last_ratio, data->src_ratio) < 1.0) count /= MIN (state->last_ratio, data->src_ratio) ; /* Maximum coefficientson either side of center point. */ half_filter_chan_len = state->channels * (int) (lrint (count) + 1) ; input_index = state->last_position ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; terminate = 1.0 / src_ratio + 1e-20 ; /* Main processing loop. */ while (filter->out_gen < filter->out_count) { /* Need to reload buffer? */ samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) { if ((state->error = prepare_data (filter, state->channels, data, half_filter_chan_len)) != 0) return state->error ; samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) break ; } ; /* This is the termination condition. */ if (filter->b_real_end >= 0) { if (filter->b_current + input_index + terminate >= filter->b_real_end) break ; } ; if (filter->out_count > 0 && fabs (state->last_ratio - data->src_ratio) > 1e-10) src_ratio = state->last_ratio + filter->out_gen * (data->src_ratio - state->last_ratio) / filter->out_count ; float_increment = filter->index_inc * (src_ratio < 1.0 ? src_ratio : 1.0) ; increment = double_to_fp (float_increment) ; start_filter_index = double_to_fp (input_index * float_increment) ; calc_output_quad (filter, state->channels, increment, start_filter_index, float_increment / filter->index_inc, data->data_out + filter->out_gen) ; filter->out_gen += 4 ; /* Figure out the next index. */ input_index += 1.0 / src_ratio ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; } ; state->last_position = input_index ; /* Save current ratio rather then target ratio. */ state->last_ratio = src_ratio ; data->input_frames_used = filter->in_used / state->channels ; data->output_frames_gen = filter->out_gen / state->channels ; return SRC_ERR_NO_ERROR ; } /* sinc_quad_vari_process */ static inline void calc_output_hex (SINC_FILTER *filter, int channels, increment_t increment, increment_t start_filter_index, double scale, float * output) { double fraction, left [6], right [6], icoeff ; increment_t filter_index, max_filter_index ; int data_index, coeff_count, indx ; /* Convert input parameters into fixed point. */ max_filter_index = int_to_fp (filter->coeff_half_len) ; /* First apply the left half of the filter. */ filter_index = start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current - channels * coeff_count ; if (data_index < 0) /* Avoid underflow access to filter->buffer. */ { int steps = int_div_ceil (-data_index, 6) ; /* If the assert triggers we would have to take care not to underflow/overflow */ assert (steps <= int_div_ceil (filter_index, increment)) ; filter_index -= increment * steps ; data_index += steps * 6; } left [0] = left [1] = left [2] = left [3] = left [4] = left [5] = 0.0 ; while (filter_index >= MAKE_INCREMENT_T (0)) { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index + 5 < filter->b_len) ; assert (data_index + 5 < filter->b_end) ; for (int ch = 0; ch < 6; ch++) left [ch] += icoeff * filter->buffer [data_index + ch] ; filter_index -= increment ; data_index = data_index + 6 ; } ; /* Now apply the right half of the filter. */ filter_index = increment - start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current + channels * (1 + coeff_count) ; right [0] = right [1] = right [2] = right [3] = right [4] = right [5] = 0.0 ; do { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index + 5 < filter->b_len) ; assert (data_index + 5 < filter->b_end) ; for (int ch = 0; ch < 6; ch++) right [ch] += icoeff * filter->buffer [data_index + ch] ; filter_index -= increment ; data_index = data_index - 6 ; } while (filter_index > MAKE_INCREMENT_T (0)) ; for (int ch = 0; ch < 6; ch++) output [ch] = (float) (scale * (left [ch] + right [ch])) ; } /* calc_output_hex */ SRC_ERROR sinc_hex_vari_process (SRC_STATE *state, SRC_DATA *data) { SINC_FILTER *filter ; double input_index, src_ratio, count, float_increment, terminate, rem ; increment_t increment, start_filter_index ; int half_filter_chan_len, samples_in_hand ; if (state->private_data == NULL) return SRC_ERR_NO_PRIVATE ; filter = (SINC_FILTER*) state->private_data ; /* If there is not a problem, this will be optimised out. */ if (sizeof (filter->buffer [0]) != sizeof (data->data_in [0])) return SRC_ERR_SIZE_INCOMPATIBILITY ; filter->in_count = data->input_frames * state->channels ; filter->out_count = data->output_frames * state->channels ; filter->in_used = filter->out_gen = 0 ; src_ratio = state->last_ratio ; if (is_bad_src_ratio (src_ratio)) return SRC_ERR_BAD_INTERNAL_STATE ; /* Check the sample rate ratio wrt the buffer len. */ count = (filter->coeff_half_len + 2.0) / filter->index_inc ; if (MIN (state->last_ratio, data->src_ratio) < 1.0) count /= MIN (state->last_ratio, data->src_ratio) ; /* Maximum coefficientson either side of center point. */ half_filter_chan_len = state->channels * (int) (lrint (count) + 1) ; input_index = state->last_position ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; terminate = 1.0 / src_ratio + 1e-20 ; /* Main processing loop. */ while (filter->out_gen < filter->out_count) { /* Need to reload buffer? */ samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) { if ((state->error = prepare_data (filter, state->channels, data, half_filter_chan_len)) != 0) return state->error ; samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) break ; } ; /* This is the termination condition. */ if (filter->b_real_end >= 0) { if (filter->b_current + input_index + terminate >= filter->b_real_end) break ; } ; if (filter->out_count > 0 && fabs (state->last_ratio - data->src_ratio) > 1e-10) src_ratio = state->last_ratio + filter->out_gen * (data->src_ratio - state->last_ratio) / filter->out_count ; float_increment = filter->index_inc * (src_ratio < 1.0 ? src_ratio : 1.0) ; increment = double_to_fp (float_increment) ; start_filter_index = double_to_fp (input_index * float_increment) ; calc_output_hex (filter, state->channels, increment, start_filter_index, float_increment / filter->index_inc, data->data_out + filter->out_gen) ; filter->out_gen += 6 ; /* Figure out the next index. */ input_index += 1.0 / src_ratio ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; } ; state->last_position = input_index ; /* Save current ratio rather then target ratio. */ state->last_ratio = src_ratio ; data->input_frames_used = filter->in_used / state->channels ; data->output_frames_gen = filter->out_gen / state->channels ; return SRC_ERR_NO_ERROR ; } /* sinc_hex_vari_process */ static inline void calc_output_multi (SINC_FILTER *filter, increment_t increment, increment_t start_filter_index, int channels, double scale, float * output) { double fraction, icoeff ; /* The following line is 1999 ISO Standard C. If your compiler complains, get a better compiler. */ double *left, *right ; increment_t filter_index, max_filter_index ; int data_index, coeff_count, indx ; left = filter->left_calc ; right = filter->right_calc ; /* Convert input parameters into fixed point. */ max_filter_index = int_to_fp (filter->coeff_half_len) ; /* First apply the left half of the filter. */ filter_index = start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current - channels * coeff_count ; if (data_index < 0) /* Avoid underflow access to filter->buffer. */ { int steps = int_div_ceil (-data_index, channels) ; /* If the assert triggers we would have to take care not to underflow/overflow */ assert (steps <= int_div_ceil (filter_index, increment)) ; filter_index -= increment * steps ; data_index += steps * channels ; } memset (left, 0, sizeof (left [0]) * channels) ; while (filter_index >= MAKE_INCREMENT_T (0)) { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index + channels - 1 < filter->b_len) ; assert (data_index + channels - 1 < filter->b_end) ; for (int ch = 0; ch < channels; ch++) left [ch] += icoeff * filter->buffer [data_index + ch] ; filter_index -= increment ; data_index = data_index + channels ; } ; /* Now apply the right half of the filter. */ filter_index = increment - start_filter_index ; coeff_count = (max_filter_index - filter_index) / increment ; filter_index = filter_index + coeff_count * increment ; data_index = filter->b_current + channels * (1 + coeff_count) ; memset (right, 0, sizeof (right [0]) * channels) ; do { fraction = fp_to_double (filter_index) ; indx = fp_to_int (filter_index) ; assert (indx >= 0 && indx + 1 < filter->coeff_half_len + 2) ; icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; assert (data_index >= 0 && data_index + channels - 1 < filter->b_len) ; assert (data_index + channels - 1 < filter->b_end) ; for (int ch = 0; ch < channels; ch++) right [ch] += icoeff * filter->buffer [data_index + ch] ; filter_index -= increment ; data_index = data_index - channels ; } while (filter_index > MAKE_INCREMENT_T (0)) ; for(int ch = 0; ch < channels; ch++) output [ch] = (float) (scale * (left [ch] + right [ch])) ; return ; } /* calc_output_multi */ static SRC_ERROR sinc_multichan_vari_process (SRC_STATE *state, SRC_DATA *data) { SINC_FILTER *filter ; double input_index, src_ratio, count, float_increment, terminate, rem ; increment_t increment, start_filter_index ; int half_filter_chan_len, samples_in_hand ; if (state->private_data == NULL) return SRC_ERR_NO_PRIVATE ; filter = (SINC_FILTER*) state->private_data ; /* If there is not a problem, this will be optimised out. */ if (sizeof (filter->buffer [0]) != sizeof (data->data_in [0])) return SRC_ERR_SIZE_INCOMPATIBILITY ; filter->in_count = data->input_frames * state->channels ; filter->out_count = data->output_frames * state->channels ; filter->in_used = filter->out_gen = 0 ; src_ratio = state->last_ratio ; if (is_bad_src_ratio (src_ratio)) return SRC_ERR_BAD_INTERNAL_STATE ; /* Check the sample rate ratio wrt the buffer len. */ count = (filter->coeff_half_len + 2.0) / filter->index_inc ; if (MIN (state->last_ratio, data->src_ratio) < 1.0) count /= MIN (state->last_ratio, data->src_ratio) ; /* Maximum coefficientson either side of center point. */ half_filter_chan_len = state->channels * (int) (lrint (count) + 1) ; input_index = state->last_position ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; terminate = 1.0 / src_ratio + 1e-20 ; /* Main processing loop. */ while (filter->out_gen < filter->out_count) { /* Need to reload buffer? */ samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) { if ((state->error = prepare_data (filter, state->channels, data, half_filter_chan_len)) != 0) return state->error ; samples_in_hand = (filter->b_end - filter->b_current + filter->b_len) % filter->b_len ; if (samples_in_hand <= half_filter_chan_len) break ; } ; /* This is the termination condition. */ if (filter->b_real_end >= 0) { if (filter->b_current + input_index + terminate >= filter->b_real_end) break ; } ; if (filter->out_count > 0 && fabs (state->last_ratio - data->src_ratio) > 1e-10) src_ratio = state->last_ratio + filter->out_gen * (data->src_ratio - state->last_ratio) / filter->out_count ; float_increment = filter->index_inc * (src_ratio < 1.0 ? src_ratio : 1.0) ; increment = double_to_fp (float_increment) ; start_filter_index = double_to_fp (input_index * float_increment) ; calc_output_multi (filter, increment, start_filter_index, state->channels, float_increment / filter->index_inc, data->data_out + filter->out_gen) ; filter->out_gen += state->channels ; /* Figure out the next index. */ input_index += 1.0 / src_ratio ; rem = fmod_one (input_index) ; filter->b_current = (filter->b_current + state->channels * lrint (input_index - rem)) % filter->b_len ; input_index = rem ; } ; state->last_position = input_index ; /* Save current ratio rather then target ratio. */ state->last_ratio = src_ratio ; data->input_frames_used = filter->in_used / state->channels ; data->output_frames_gen = filter->out_gen / state->channels ; return SRC_ERR_NO_ERROR ; } /* sinc_multichan_vari_process */ /*---------------------------------------------------------------------------------------- */ static SRC_ERROR prepare_data (SINC_FILTER *filter, int channels, SRC_DATA *data, int half_filter_chan_len) { int len = 0 ; if (filter->b_real_end >= 0) return SRC_ERR_NO_ERROR ; /* Should be terminating. Just return. */ if (data->data_in == NULL) return SRC_ERR_NO_ERROR ; if (filter->b_current == 0) { /* Initial state. Set up zeros at the start of the buffer and ** then load new data after that. */ len = filter->b_len - 2 * half_filter_chan_len ; filter->b_current = filter->b_end = half_filter_chan_len ; } else if (filter->b_end + half_filter_chan_len + channels < filter->b_len) { /* Load data at current end position. */ len = MAX (filter->b_len - filter->b_current - half_filter_chan_len, 0) ; } else { /* Move data at end of buffer back to the start of the buffer. */ len = filter->b_end - filter->b_current ; memmove (filter->buffer, filter->buffer + filter->b_current - half_filter_chan_len, (half_filter_chan_len + len) * sizeof (filter->buffer [0])) ; filter->b_current = half_filter_chan_len ; filter->b_end = filter->b_current + len ; /* Now load data at current end of buffer. */ len = MAX (filter->b_len - filter->b_current - half_filter_chan_len, 0) ; } ; len = MIN ((int) (filter->in_count - filter->in_used), len) ; len -= (len % channels) ; if (len < 0 || filter->b_end + len > filter->b_len) return SRC_ERR_SINC_PREPARE_DATA_BAD_LEN ; memcpy (filter->buffer + filter->b_end, data->data_in + filter->in_used, len * sizeof (filter->buffer [0])) ; filter->b_end += len ; filter->in_used += len ; if (filter->in_used == filter->in_count && filter->b_end - filter->b_current < 2 * half_filter_chan_len && data->end_of_input) { /* Handle the case where all data in the current buffer has been ** consumed and this is the last buffer. */ if (filter->b_len - filter->b_end < half_filter_chan_len + 5) { /* If necessary, move data down to the start of the buffer. */ len = filter->b_end - filter->b_current ; memmove (filter->buffer, filter->buffer + filter->b_current - half_filter_chan_len, (half_filter_chan_len + len) * sizeof (filter->buffer [0])) ; filter->b_current = half_filter_chan_len ; filter->b_end = filter->b_current + len ; } ; filter->b_real_end = filter->b_end ; len = half_filter_chan_len + 5 ; if (len < 0 || filter->b_end + len > filter->b_len) len = filter->b_len - filter->b_end ; memset (filter->buffer + filter->b_end, 0, len * sizeof (filter->buffer [0])) ; filter->b_end += len ; } ; return SRC_ERR_NO_ERROR ; } /* prepare_data */ static void sinc_close (SRC_STATE *state) { if (state) { SINC_FILTER *sinc = (SINC_FILTER *) state->private_data ; if (sinc) { if (sinc->buffer) { free (sinc->buffer) ; sinc->buffer = NULL ; } ; free (sinc) ; sinc = NULL ; } } } /* sinc_close */