switch_resample.c

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/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005-2014, Anthony Minessale II <anthm@freeswitch.org>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthm@freeswitch.org>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * 
 * Anthony Minessale II <anthm@freeswitch.org>
 *
 *
 * switch_resample.c -- Resampler
 *
 */

#include <switch.h>
#include <switch_resample.h>
#ifndef WIN32
#include <switch_private.h>
#endif
#include <speex/speex_resampler.h>

#define NORMFACT (float)0x8000
#define MAXSAMPLE (float)0x7FFF
#define MAXSAMPLEC (char)0x7F
#define QUALITY 0

#ifndef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#endif

#ifndef MAX
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif

#define resample_buffer(a, b, c) a > b ? ((a / 1000) / 2) * c : ((b / 1000) / 2) * c

SWITCH_DECLARE(switch_status_t) switch_resample_perform_create(switch_audio_resampler_t **new_resampler,
                                                                                                                           uint32_t from_rate, uint32_t to_rate,
                                                                                                                           uint32_t to_size,
                                                                                                                           int quality, uint32_t channels, const char *file, const char *func, int line)
{
        int err = 0;
        switch_audio_resampler_t *resampler;
        double lto_rate, lfrom_rate;

        switch_zmalloc(resampler, sizeof(*resampler));

        if (!channels) channels = 1;
        
        resampler->resampler = speex_resampler_init(channels, from_rate, to_rate, quality, &err);

        if (!resampler->resampler) {
                free(resampler);
                return SWITCH_STATUS_GENERR;
        }

        *new_resampler = resampler;
        lto_rate = (double) resampler->to_rate;
        lfrom_rate = (double) resampler->from_rate;
        resampler->from_rate = from_rate;
        resampler->to_rate = to_rate;
        resampler->factor = (lto_rate / lfrom_rate);
        resampler->rfactor = (lfrom_rate / lto_rate);
        resampler->channels = channels;
        
        //resampler->to_size = resample_buffer(to_rate, from_rate, (uint32_t) to_size);

        resampler->to_size = switch_resample_calc_buffer_size(resampler->to_rate, resampler->from_rate, to_size) / 2;
        resampler->to = malloc(resampler->to_size * sizeof(int16_t) * resampler->channels);
        switch_assert(resampler->to);

        return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(uint32_t) switch_resample_process(switch_audio_resampler_t *resampler, int16_t *src, uint32_t srclen)
{
        int to_size = switch_resample_calc_buffer_size(resampler->to_rate, resampler->from_rate, srclen) / 2;

        if (to_size > resampler->to_size) {
                resampler->to_size = to_size;
                resampler->to = realloc(resampler->to, resampler->to_size * sizeof(int16_t) * resampler->channels);
                switch_assert(resampler->to);
        }
        
        resampler->to_len = resampler->to_size;
        speex_resampler_process_interleaved_int(resampler->resampler, src, &srclen, resampler->to, &resampler->to_len);
        return resampler->to_len;
}

SWITCH_DECLARE(void) switch_resample_destroy(switch_audio_resampler_t **resampler)
{

        if (resampler && *resampler) {
                if ((*resampler)->resampler) {
                        speex_resampler_destroy((*resampler)->resampler);
                }
                free((*resampler)->to);
                free(*resampler);
                *resampler = NULL;
        }
}

SWITCH_DECLARE(switch_size_t) switch_float_to_short(float *f, short *s, switch_size_t len)
{
        switch_size_t i;
        float ft;
        for (i = 0; i < len; i++) {
                ft = f[i] * NORMFACT;
                if (ft >= 0) {
                        s[i] = (short) (ft + 0.5);
                } else {
                        s[i] = (short) (ft - 0.5);
                }
                if ((float) s[i] > MAXSAMPLE)
                        s[i] = (short) MAXSAMPLE / 2;
                if (s[i] < (short) -MAXSAMPLE)
                        s[i] = (short) -MAXSAMPLE / 2;
        }
        return len;
}

SWITCH_DECLARE(int) switch_char_to_float(char *c, float *f, int len)
{
        int i;

        if (len % 2) {
                return (-1);
        }

        for (i = 1; i < len; i += 2) {
                f[(int) (i / 2)] = (float) (((c[i]) * 0x100) + c[i - 1]);
                f[(int) (i / 2)] /= NORMFACT;
                if (f[(int) (i / 2)] > MAXSAMPLE)
                        f[(int) (i / 2)] = MAXSAMPLE;
                if (f[(int) (i / 2)] < -MAXSAMPLE)
                        f[(int) (i / 2)] = -MAXSAMPLE;
        }
        return len / 2;
}

SWITCH_DECLARE(int) switch_float_to_char(float *f, char *c, int len)
{
        int i;
        float ft;
        long l;
        for (i = 0; i < len; i++) {
                ft = f[i] * NORMFACT;
                if (ft >= 0) {
                        l = (long) (ft + 0.5);
                } else {
                        l = (long) (ft - 0.5);
                }
                c[i * 2] = (unsigned char) ((l) & 0xff);
                c[i * 2 + 1] = (unsigned char) (((l) >> 8) & 0xff);
        }
        return len * 2;
}

SWITCH_DECLARE(int) switch_short_to_float(short *s, float *f, int len)
{
        int i;

        for (i = 0; i < len; i++) {
                f[i] = (float) (s[i]) / NORMFACT;
                /* f[i] = (float) s[i]; */
        }
        return len;
}


SWITCH_DECLARE(void) switch_swap_linear(int16_t *buf, int len)
{
        int i;
        for (i = 0; i < len; i++) {
                buf[i] = ((buf[i] >> 8) & 0x00ff) | ((buf[i] << 8) & 0xff00);
        }
}


SWITCH_DECLARE(void) switch_generate_sln_silence(int16_t *data, uint32_t samples, uint32_t channels, uint32_t divisor)
{
        int16_t s;
        uint32_t x, i, j;
        int sum_rnd = 0;
        int16_t rnd2 = (int16_t) switch_micro_time_now() + (int16_t) (intptr_t) data;

        if (channels == 0) channels = 1;

        assert(divisor);

        if (divisor == (uint32_t)-1) {
                memset(data, 0, samples * 2);
                return;
        }

        for (i = 0; i < samples; i++, sum_rnd = 0) {
                for (x = 0; x < 6; x++) {
                        rnd2 = rnd2 * 31821U + 13849U;
                        sum_rnd += rnd2;
                }

                s = (int16_t) ((int16_t) sum_rnd / (int) divisor);              

                for (j = 0; j < channels; j++) {
                        *data = s;
                        data++;                 
                }


        }
}

SWITCH_DECLARE(uint32_t) switch_merge_sln(int16_t *data, uint32_t samples, int16_t *other_data, uint32_t other_samples, int channels)
{
        int i;
        int32_t x, z;

        if (channels == 0) channels = 1;

        if (samples > other_samples) {
                x = other_samples;
        } else {
                x = samples;
        }

        for (i = 0; i < x * channels; i++) {
                z = data[i] + other_data[i];
                switch_normalize_to_16bit(z);
                data[i] = (int16_t) z;
        }

        return x;
}


SWITCH_DECLARE(uint32_t) switch_unmerge_sln(int16_t *data, uint32_t samples, int16_t *other_data, uint32_t other_samples, int channels)
{
        int i;
        int32_t x;

        if (channels == 0) channels = 1;

        if (samples > other_samples) {
                x = other_samples;
        } else {
                x = samples;
        }

        for (i = 0; i < x * channels; i++) {
                data[i] -= other_data[i];
        }

        return x;
}

SWITCH_DECLARE(void) switch_mux_channels(int16_t *data, switch_size_t samples, uint32_t orig_channels, uint32_t channels)
{
        switch_size_t i = 0;
        uint32_t j = 0;

        switch_assert(channels < 11);

        if (orig_channels > channels) {
                for (i = 0; i < samples; i++) {
                        int32_t z = 0;
                        for (j = 0; j < orig_channels; j++) {
                                z += data[i * orig_channels + j];
                                switch_normalize_to_16bit(z);
                                data[i] = (int16_t) z;
                        }
                }
        } else if (orig_channels < channels) {

                /* interesting problem... take a give buffer and double up every sample in the buffer without using any other buffer.....
                   This way beats the other i think bacause there is no malloc but I do have to copy the data twice */
#if 1
                uint32_t k = 0, len = samples * orig_channels;

                for (i = 0; i < len; i++) {
                        data[i+len] = data[i];
                }

                for (i = 0; i < samples; i++) {
                        for (j = 0; j < channels; j++) { 
                                data[k++] = data[i + samples];
                        }
                }

#else 
                uint32_t k = 0, len = samples * 2 * orig_channels;
                int16_t *orig = NULL;

                switch_zmalloc(orig, len);
                memcpy(orig, data, len);

                for (i = 0; i < samples; i++) {
                        for (j = 0; j < channels; j++) { 
                                data[k++] = orig[i];
                        }
                }
                
                free(orig);
#endif

        }
}

SWITCH_DECLARE(void) switch_change_sln_volume_granular(int16_t *data, uint32_t samples, int32_t vol)
{
        double newrate = 0;
        double pos[13] = {1.25, 1.50, 1.75, 2.0, 2.25, 2.50, 2.75, 3.0, 3.25, 3.50, 3.75, 4.0, 4.5};
        double neg[13] = {.917, .834, .751, .668, .585, .502, .419, .336, .253, .087, .017, .004, 0.0};
        double *chart;
        uint32_t i;

        if (vol == 0) return;

        switch_normalize_volume_granular(vol);

        if (vol > 0) {
                chart = pos;
        } else {
                chart = neg;
        }
        
        i = abs(vol) - 1;
        
        switch_assert(i < 13);

        newrate = chart[i];

        if (newrate) {
                int32_t tmp;
                uint32_t x;
                int16_t *fp = data;

                for (x = 0; x < samples; x++) {
                        tmp = (int32_t) (fp[x] * newrate);
                        switch_normalize_to_16bit(tmp);
                        fp[x] = (int16_t) tmp;
                }
        } else {
                memset(data, 0, samples * 2);
        }
}

SWITCH_DECLARE(void) switch_change_sln_volume(int16_t *data, uint32_t samples, int32_t vol)
{
        double newrate = 0;
        double pos[4] = {1.3, 2.3, 3.3, 4.3};
        double neg[4] = {.80, .60, .40, .20};
        double *chart;
        uint32_t i;

        if (vol == 0) return;

        switch_normalize_volume(vol);

        if (vol > 0) {
                chart = pos;
        } else {
                chart = neg;
        }
        
        i = abs(vol) - 1;
        
        switch_assert(i < 4);

        newrate = chart[i];

        if (newrate) {
                int32_t tmp;
                uint32_t x;
                int16_t *fp = data;

                for (x = 0; x < samples; x++) {
                        tmp = (int32_t) (fp[x] * newrate);
                        switch_normalize_to_16bit(tmp);
                        fp[x] = (int16_t) tmp;
                }
        }
}

/* For Emacs:
 * Local Variables:
 * mode:c
 * indent-tabs-mode:t
 * tab-width:4
 * c-basic-offset:4
 * End:
 * For VIM:
 * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
 */