X-Git-Url: http://git.ieval.ro/?a=blobdiff_plain;f=libsamplerate%2Fsrc%2Fsrc_sinc.c;fp=libsamplerate%2Fsrc%2Fsrc_sinc.c;h=1871684b793e0d62ac282e1a07d36e1d9ba9d08a;hb=8529da432e52c7903e8ef3488e60725a099e6e63;hp=0000000000000000000000000000000000000000;hpb=27013d8f68878b8ed2d3f747e26f562d08d7d678;p=audio-libsamplerate.git diff --git a/libsamplerate/src/src_sinc.c b/libsamplerate/src/src_sinc.c new file mode 100644 index 0000000..1871684 --- /dev/null +++ b/libsamplerate/src/src_sinc.c @@ -0,0 +1,1191 @@ +/* +** Copyright (c) 2002-2016, Erik de Castro Lopo +** All rights reserved. +** +** This code is released under 2-clause BSD license. Please see the +** file at : https://github.com/erikd/libsamplerate/blob/master/COPYING +*/ + +#include +#include +#include + +#include "config.h" +#include "float_cast.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) + +/*======================================================================================== +*/ + +typedef int32_t increment_t ; +typedef float coeff_t ; + +#include "fastest_coeffs.h" +#include "mid_qual_coeffs.h" +#include "high_qual_coeffs.h" + +typedef struct +{ int sinc_magic_marker ; + + int channels ; + 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 [128], right_calc [128] ; + + /* C99 struct flexible array. */ + float buffer [] ; +} SINC_FILTER ; + +static int sinc_multichan_vari_process (SRC_PRIVATE *psrc, SRC_DATA *data) ; +static int sinc_hex_vari_process (SRC_PRIVATE *psrc, SRC_DATA *data) ; +static int sinc_quad_vari_process (SRC_PRIVATE *psrc, SRC_DATA *data) ; +static int sinc_stereo_vari_process (SRC_PRIVATE *psrc, SRC_DATA *data) ; +static int sinc_mono_vari_process (SRC_PRIVATE *psrc, SRC_DATA *data) ; + +static int prepare_data (SINC_FILTER *filter, SRC_DATA *data, int half_filter_chan_len) WARN_UNUSED ; + +static void sinc_reset (SRC_PRIVATE *psrc) ; + +static inline increment_t +double_to_fp (double x) +{ return (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 */ + + +/*---------------------------------------------------------------------------------------- +*/ + +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 */ + +int +sinc_set_converter (SRC_PRIVATE *psrc, int src_enum) +{ SINC_FILTER *filter, temp_filter ; + increment_t count ; + int bits ; + + /* Quick sanity check. */ + if (SHIFT_BITS >= sizeof (increment_t) * 8 - 1) + return SRC_ERR_SHIFT_BITS ; + + if (psrc->private_data != NULL) + { free (psrc->private_data) ; + psrc->private_data = NULL ; + } ; + + memset (&temp_filter, 0, sizeof (temp_filter)) ; + + temp_filter.sinc_magic_marker = SINC_MAGIC_MARKER ; + temp_filter.channels = psrc->channels ; + + if (psrc->channels > ARRAY_LEN (temp_filter.left_calc)) + return SRC_ERR_BAD_CHANNEL_COUNT ; + else if (psrc->channels == 1) + { psrc->const_process = sinc_mono_vari_process ; + psrc->vari_process = sinc_mono_vari_process ; + } + else + if (psrc->channels == 2) + { psrc->const_process = sinc_stereo_vari_process ; + psrc->vari_process = sinc_stereo_vari_process ; + } + else + if (psrc->channels == 4) + { psrc->const_process = sinc_quad_vari_process ; + psrc->vari_process = sinc_quad_vari_process ; + } + else + if (psrc->channels == 6) + { psrc->const_process = sinc_hex_vari_process ; + psrc->vari_process = sinc_hex_vari_process ; + } + else + { psrc->const_process = sinc_multichan_vari_process ; + psrc->vari_process = sinc_multichan_vari_process ; + } ; + psrc->reset = sinc_reset ; + + switch (src_enum) + { case SRC_SINC_FASTEST : + temp_filter.coeffs = fastest_coeffs.coeffs ; + temp_filter.coeff_half_len = ARRAY_LEN (fastest_coeffs.coeffs) - 2 ; + temp_filter.index_inc = fastest_coeffs.increment ; + break ; + + case SRC_SINC_MEDIUM_QUALITY : + temp_filter.coeffs = slow_mid_qual_coeffs.coeffs ; + temp_filter.coeff_half_len = ARRAY_LEN (slow_mid_qual_coeffs.coeffs) - 2 ; + temp_filter.index_inc = slow_mid_qual_coeffs.increment ; + break ; + + case SRC_SINC_BEST_QUALITY : + temp_filter.coeffs = slow_high_qual_coeffs.coeffs ; + temp_filter.coeff_half_len = ARRAY_LEN (slow_high_qual_coeffs.coeffs) - 2 ; + temp_filter.index_inc = slow_high_qual_coeffs.increment ; + break ; + + default : + return SRC_ERR_BAD_CONVERTER ; + } ; + + /* + ** FIXME : This needs to be looked at more closely to see if there is + ** a better way. Need to look at prepare_data () at the same time. + */ + + temp_filter.b_len = lrint (2.5 * temp_filter.coeff_half_len / (temp_filter.index_inc * 1.0) * SRC_MAX_RATIO) ; + temp_filter.b_len = MAX (temp_filter.b_len, 4096) ; + temp_filter.b_len *= temp_filter.channels ; + + if ((filter = calloc (1, sizeof (SINC_FILTER) + sizeof (filter->buffer [0]) * (temp_filter.b_len + temp_filter.channels))) == NULL) + return SRC_ERR_MALLOC_FAILED ; + + *filter = temp_filter ; + memset (&temp_filter, 0xEE, sizeof (temp_filter)) ; + + psrc->private_data = filter ; + + sinc_reset (psrc) ; + + count = filter->coeff_half_len ; + for (bits = 0 ; (MAKE_INCREMENT_T (1) << bits) < count ; bits++) + count |= (MAKE_INCREMENT_T (1) << bits) ; + + if (bits + SHIFT_BITS - 1 >= (int) (sizeof (increment_t) * 8)) + return SRC_ERR_FILTER_LEN ; + + return SRC_ERR_NO_ERROR ; +} /* sinc_set_converter */ + +static void +sinc_reset (SRC_PRIVATE *psrc) +{ SINC_FILTER *filter ; + + filter = (SINC_FILTER*) psrc->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, filter->channels * sizeof (filter->buffer [0])) ; +} /* sinc_reset */ + +/*======================================================================================== +** 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 ; + + left = 0.0 ; + do + { fraction = fp_to_double (filter_index) ; + indx = fp_to_int (filter_index) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + left += icoeff * filter->buffer [data_index] ; + + filter_index -= increment ; + data_index = data_index + 1 ; + } + while (filter_index >= MAKE_INCREMENT_T (0)) ; + + /* 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) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + 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 int +sinc_mono_vari_process (SRC_PRIVATE *psrc, 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 (psrc->private_data == NULL) + return SRC_ERR_NO_PRIVATE ; + + filter = (SINC_FILTER*) psrc->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 * filter->channels ; + filter->out_count = data->output_frames * filter->channels ; + filter->in_used = filter->out_gen = 0 ; + + src_ratio = psrc->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 (psrc->last_ratio, data->src_ratio) < 1.0) + count /= MIN (psrc->last_ratio, data->src_ratio) ; + + /* Maximum coefficientson either side of center point. */ + half_filter_chan_len = filter->channels * (lrint (count) + 1) ; + + input_index = psrc->last_position ; + float_increment = filter->index_inc ; + + rem = fmod_one (input_index) ; + filter->b_current = (filter->b_current + filter->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 ((psrc->error = prepare_data (filter, data, half_filter_chan_len)) != 0) + return psrc->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 (psrc->last_ratio - data->src_ratio) > 1e-10) + src_ratio = psrc->last_ratio + filter->out_gen * (data->src_ratio - psrc->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 + filter->channels * lrint (input_index - rem)) % filter->b_len ; + input_index = rem ; + } ; + + psrc->last_position = input_index ; + + /* Save current ratio rather then target ratio. */ + psrc->last_ratio = src_ratio ; + + data->input_frames_used = filter->in_used / filter->channels ; + data->output_frames_gen = filter->out_gen / filter->channels ; + + return SRC_ERR_NO_ERROR ; +} /* sinc_mono_vari_process */ + +static inline void +calc_output_stereo (SINC_FILTER *filter, 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 - filter->channels * coeff_count ; + + left [0] = left [1] = 0.0 ; + do + { fraction = fp_to_double (filter_index) ; + indx = fp_to_int (filter_index) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + left [0] += icoeff * filter->buffer [data_index] ; + left [1] += icoeff * filter->buffer [data_index + 1] ; + + filter_index -= increment ; + data_index = data_index + 2 ; + } + while (filter_index >= MAKE_INCREMENT_T (0)) ; + + /* 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 + filter->channels * (1 + coeff_count) ; + + right [0] = right [1] = 0.0 ; + do + { fraction = fp_to_double (filter_index) ; + indx = fp_to_int (filter_index) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + right [0] += icoeff * filter->buffer [data_index] ; + right [1] += icoeff * filter->buffer [data_index + 1] ; + + filter_index -= increment ; + data_index = data_index - 2 ; + } + while (filter_index > MAKE_INCREMENT_T (0)) ; + + output [0] = scale * (left [0] + right [0]) ; + output [1] = scale * (left [1] + right [1]) ; +} /* calc_output_stereo */ + +static int +sinc_stereo_vari_process (SRC_PRIVATE *psrc, 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 (psrc->private_data == NULL) + return SRC_ERR_NO_PRIVATE ; + + filter = (SINC_FILTER*) psrc->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 * filter->channels ; + filter->out_count = data->output_frames * filter->channels ; + filter->in_used = filter->out_gen = 0 ; + + src_ratio = psrc->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 (psrc->last_ratio, data->src_ratio) < 1.0) + count /= MIN (psrc->last_ratio, data->src_ratio) ; + + /* Maximum coefficientson either side of center point. */ + half_filter_chan_len = filter->channels * (lrint (count) + 1) ; + + input_index = psrc->last_position ; + float_increment = filter->index_inc ; + + rem = fmod_one (input_index) ; + filter->b_current = (filter->b_current + filter->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 ((psrc->error = prepare_data (filter, data, half_filter_chan_len)) != 0) + return psrc->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 (psrc->last_ratio - data->src_ratio) > 1e-10) + src_ratio = psrc->last_ratio + filter->out_gen * (data->src_ratio - psrc->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, 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 + filter->channels * lrint (input_index - rem)) % filter->b_len ; + input_index = rem ; + } ; + + psrc->last_position = input_index ; + + /* Save current ratio rather then target ratio. */ + psrc->last_ratio = src_ratio ; + + data->input_frames_used = filter->in_used / filter->channels ; + data->output_frames_gen = filter->out_gen / filter->channels ; + + return SRC_ERR_NO_ERROR ; +} /* sinc_stereo_vari_process */ + +static inline void +calc_output_quad (SINC_FILTER *filter, 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 - filter->channels * coeff_count ; + + left [0] = left [1] = left [2] = left [3] = 0.0 ; + do + { fraction = fp_to_double (filter_index) ; + indx = fp_to_int (filter_index) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + left [0] += icoeff * filter->buffer [data_index] ; + left [1] += icoeff * filter->buffer [data_index + 1] ; + left [2] += icoeff * filter->buffer [data_index + 2] ; + left [3] += icoeff * filter->buffer [data_index + 3] ; + + filter_index -= increment ; + data_index = data_index + 4 ; + } + while (filter_index >= MAKE_INCREMENT_T (0)) ; + + /* 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 + filter->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) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + right [0] += icoeff * filter->buffer [data_index] ; + right [1] += icoeff * filter->buffer [data_index + 1] ; + right [2] += icoeff * filter->buffer [data_index + 2] ; + right [3] += icoeff * filter->buffer [data_index + 3] ; + + filter_index -= increment ; + data_index = data_index - 4 ; + } + while (filter_index > MAKE_INCREMENT_T (0)) ; + + output [0] = scale * (left [0] + right [0]) ; + output [1] = scale * (left [1] + right [1]) ; + output [2] = scale * (left [2] + right [2]) ; + output [3] = scale * (left [3] + right [3]) ; +} /* calc_output_quad */ + +static int +sinc_quad_vari_process (SRC_PRIVATE *psrc, 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 (psrc->private_data == NULL) + return SRC_ERR_NO_PRIVATE ; + + filter = (SINC_FILTER*) psrc->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 * filter->channels ; + filter->out_count = data->output_frames * filter->channels ; + filter->in_used = filter->out_gen = 0 ; + + src_ratio = psrc->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 (psrc->last_ratio, data->src_ratio) < 1.0) + count /= MIN (psrc->last_ratio, data->src_ratio) ; + + /* Maximum coefficientson either side of center point. */ + half_filter_chan_len = filter->channels * (lrint (count) + 1) ; + + input_index = psrc->last_position ; + float_increment = filter->index_inc ; + + rem = fmod_one (input_index) ; + filter->b_current = (filter->b_current + filter->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 ((psrc->error = prepare_data (filter, data, half_filter_chan_len)) != 0) + return psrc->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 (psrc->last_ratio - data->src_ratio) > 1e-10) + src_ratio = psrc->last_ratio + filter->out_gen * (data->src_ratio - psrc->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, 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 + filter->channels * lrint (input_index - rem)) % filter->b_len ; + input_index = rem ; + } ; + + psrc->last_position = input_index ; + + /* Save current ratio rather then target ratio. */ + psrc->last_ratio = src_ratio ; + + data->input_frames_used = filter->in_used / filter->channels ; + data->output_frames_gen = filter->out_gen / filter->channels ; + + return SRC_ERR_NO_ERROR ; +} /* sinc_quad_vari_process */ + +static inline void +calc_output_hex (SINC_FILTER *filter, 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 - filter->channels * coeff_count ; + + left [0] = left [1] = left [2] = left [3] = left [4] = left [5] = 0.0 ; + do + { fraction = fp_to_double (filter_index) ; + indx = fp_to_int (filter_index) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + left [0] += icoeff * filter->buffer [data_index] ; + left [1] += icoeff * filter->buffer [data_index + 1] ; + left [2] += icoeff * filter->buffer [data_index + 2] ; + left [3] += icoeff * filter->buffer [data_index + 3] ; + left [4] += icoeff * filter->buffer [data_index + 4] ; + left [5] += icoeff * filter->buffer [data_index + 5] ; + + filter_index -= increment ; + data_index = data_index + 6 ; + } + while (filter_index >= MAKE_INCREMENT_T (0)) ; + + /* 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 + filter->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) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + right [0] += icoeff * filter->buffer [data_index] ; + right [1] += icoeff * filter->buffer [data_index + 1] ; + right [2] += icoeff * filter->buffer [data_index + 2] ; + right [3] += icoeff * filter->buffer [data_index + 3] ; + right [4] += icoeff * filter->buffer [data_index + 4] ; + right [5] += icoeff * filter->buffer [data_index + 5] ; + + filter_index -= increment ; + data_index = data_index - 6 ; + } + while (filter_index > MAKE_INCREMENT_T (0)) ; + + output [0] = scale * (left [0] + right [0]) ; + output [1] = scale * (left [1] + right [1]) ; + output [2] = scale * (left [2] + right [2]) ; + output [3] = scale * (left [3] + right [3]) ; + output [4] = scale * (left [4] + right [4]) ; + output [5] = scale * (left [5] + right [5]) ; +} /* calc_output_hex */ + +static int +sinc_hex_vari_process (SRC_PRIVATE *psrc, 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 (psrc->private_data == NULL) + return SRC_ERR_NO_PRIVATE ; + + filter = (SINC_FILTER*) psrc->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 * filter->channels ; + filter->out_count = data->output_frames * filter->channels ; + filter->in_used = filter->out_gen = 0 ; + + src_ratio = psrc->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 (psrc->last_ratio, data->src_ratio) < 1.0) + count /= MIN (psrc->last_ratio, data->src_ratio) ; + + /* Maximum coefficientson either side of center point. */ + half_filter_chan_len = filter->channels * (lrint (count) + 1) ; + + input_index = psrc->last_position ; + float_increment = filter->index_inc ; + + rem = fmod_one (input_index) ; + filter->b_current = (filter->b_current + filter->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 ((psrc->error = prepare_data (filter, data, half_filter_chan_len)) != 0) + return psrc->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 (psrc->last_ratio - data->src_ratio) > 1e-10) + src_ratio = psrc->last_ratio + filter->out_gen * (data->src_ratio - psrc->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, 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 + filter->channels * lrint (input_index - rem)) % filter->b_len ; + input_index = rem ; + } ; + + psrc->last_position = input_index ; + + /* Save current ratio rather then target ratio. */ + psrc->last_ratio = src_ratio ; + + data->input_frames_used = filter->in_used / filter->channels ; + data->output_frames_gen = filter->out_gen / filter->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, ch ; + + 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 ; + + memset (left, 0, sizeof (left [0]) * channels) ; + + do + { fraction = fp_to_double (filter_index) ; + indx = fp_to_int (filter_index) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + /* + ** Duff's Device. + ** See : http://en.wikipedia.org/wiki/Duff's_device + */ + ch = channels ; + do + { + switch (ch % 8) + { default : + ch -- ; + left [ch] += icoeff * filter->buffer [data_index + ch] ; + case 7 : + ch -- ; + left [ch] += icoeff * filter->buffer [data_index + ch] ; + case 6 : + ch -- ; + left [ch] += icoeff * filter->buffer [data_index + ch] ; + case 5 : + ch -- ; + left [ch] += icoeff * filter->buffer [data_index + ch] ; + case 4 : + ch -- ; + left [ch] += icoeff * filter->buffer [data_index + ch] ; + case 3 : + ch -- ; + left [ch] += icoeff * filter->buffer [data_index + ch] ; + case 2 : + ch -- ; + left [ch] += icoeff * filter->buffer [data_index + ch] ; + case 1 : + ch -- ; + left [ch] += icoeff * filter->buffer [data_index + ch] ; + } ; + } + while (ch > 0) ; + + filter_index -= increment ; + data_index = data_index + channels ; + } + while (filter_index >= MAKE_INCREMENT_T (0)) ; + + /* 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) ; + + icoeff = filter->coeffs [indx] + fraction * (filter->coeffs [indx + 1] - filter->coeffs [indx]) ; + + ch = channels ; + do + { + switch (ch % 8) + { default : + ch -- ; + right [ch] += icoeff * filter->buffer [data_index + ch] ; + case 7 : + ch -- ; + right [ch] += icoeff * filter->buffer [data_index + ch] ; + case 6 : + ch -- ; + right [ch] += icoeff * filter->buffer [data_index + ch] ; + case 5 : + ch -- ; + right [ch] += icoeff * filter->buffer [data_index + ch] ; + case 4 : + ch -- ; + right [ch] += icoeff * filter->buffer [data_index + ch] ; + case 3 : + ch -- ; + right [ch] += icoeff * filter->buffer [data_index + ch] ; + case 2 : + ch -- ; + right [ch] += icoeff * filter->buffer [data_index + ch] ; + case 1 : + ch -- ; + right [ch] += icoeff * filter->buffer [data_index + ch] ; + } ; + } + while (ch > 0) ; + + filter_index -= increment ; + data_index = data_index - channels ; + } + while (filter_index > MAKE_INCREMENT_T (0)) ; + + ch = channels ; + do + { + switch (ch % 8) + { default : + ch -- ; + output [ch] = scale * (left [ch] + right [ch]) ; + case 7 : + ch -- ; + output [ch] = scale * (left [ch] + right [ch]) ; + case 6 : + ch -- ; + output [ch] = scale * (left [ch] + right [ch]) ; + case 5 : + ch -- ; + output [ch] = scale * (left [ch] + right [ch]) ; + case 4 : + ch -- ; + output [ch] = scale * (left [ch] + right [ch]) ; + case 3 : + ch -- ; + output [ch] = scale * (left [ch] + right [ch]) ; + case 2 : + ch -- ; + output [ch] = scale * (left [ch] + right [ch]) ; + case 1 : + ch -- ; + output [ch] = scale * (left [ch] + right [ch]) ; + } ; + } + while (ch > 0) ; + + return ; +} /* calc_output_multi */ + +static int +sinc_multichan_vari_process (SRC_PRIVATE *psrc, 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 (psrc->private_data == NULL) + return SRC_ERR_NO_PRIVATE ; + + filter = (SINC_FILTER*) psrc->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 * filter->channels ; + filter->out_count = data->output_frames * filter->channels ; + filter->in_used = filter->out_gen = 0 ; + + src_ratio = psrc->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 (psrc->last_ratio, data->src_ratio) < 1.0) + count /= MIN (psrc->last_ratio, data->src_ratio) ; + + /* Maximum coefficientson either side of center point. */ + half_filter_chan_len = filter->channels * (lrint (count) + 1) ; + + input_index = psrc->last_position ; + float_increment = filter->index_inc ; + + rem = fmod_one (input_index) ; + filter->b_current = (filter->b_current + filter->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 ((psrc->error = prepare_data (filter, data, half_filter_chan_len)) != 0) + return psrc->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 (psrc->last_ratio - data->src_ratio) > 1e-10) + src_ratio = psrc->last_ratio + filter->out_gen * (data->src_ratio - psrc->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, filter->channels, float_increment / filter->index_inc, data->data_out + filter->out_gen) ; + filter->out_gen += psrc->channels ; + + /* Figure out the next index. */ + input_index += 1.0 / src_ratio ; + rem = fmod_one (input_index) ; + + filter->b_current = (filter->b_current + filter->channels * lrint (input_index - rem)) % filter->b_len ; + input_index = rem ; + } ; + + psrc->last_position = input_index ; + + /* Save current ratio rather then target ratio. */ + psrc->last_ratio = src_ratio ; + + data->input_frames_used = filter->in_used / filter->channels ; + data->output_frames_gen = filter->out_gen / filter->channels ; + + return SRC_ERR_NO_ERROR ; +} /* sinc_multichan_vari_process */ + +/*---------------------------------------------------------------------------------------- +*/ + +static int +prepare_data (SINC_FILTER *filter, SRC_DATA *data, int half_filter_chan_len) +{ int len = 0 ; + + if (filter->b_real_end >= 0) + return 0 ; /* Should be terminating. Just return. */ + + 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 + filter->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 (filter->in_count - filter->in_used, len) ; + len -= (len % filter->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 0 ; +} /* prepare_data */ + +