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) {
                if (channels == 1) {
                        for (i = 0; i < samples; i++) {
                                int32_t z = 0;
                                for (j = 0; j < orig_channels; j++) {
                                        z += (int16_t) data[i * orig_channels + j];
                                }
                                switch_normalize_to_16bit(z);
                                data[i] = (int16_t) z;
                        }
                } else if (channels == 2) {
                        int mark_buf = 0;
                        for (i = 0; i < samples; i++) {
                                int32_t z_left = 0, z_right = 0;
                                for (j = 0; j < orig_channels; j++) {
                                        if (j % 2) {
                                                z_left += (int16_t) data[i * orig_channels + j];
                                        } else {
                                                z_right += (int16_t) data[i * orig_channels + j];
                                        }
                                }
                                /* mark_buf will always be smaller than the size of data in bytes because orig_channels > channels */
                                switch_normalize_to_16bit(z_left);
                                data[mark_buf++] = (int16_t) z_left;
                                switch_normalize_to_16bit(z_right);
                                data[mark_buf++] = (int16_t) z_right;
                        }
                } 
        } 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;
        // change in dB mapped to ratio for output sample
        // computed as (powf(10.0f, (float)(change_in_dB) / 20.0f))
        static const double pos[SWITCH_GRANULAR_VOLUME_MAX] = {
                  1.122018,   1.258925,   1.412538,   1.584893,   1.778279,   1.995262,   2.238721,   2.511887,   2.818383,   3.162278,
                  3.548134,   3.981072,   4.466835,   5.011872,   5.623413,   6.309574,   7.079458,   7.943282,   8.912509,  10.000000,
                 11.220183,  12.589254,  14.125375,  15.848933,  17.782795,  19.952621,  22.387213,  25.118862,  28.183832,  31.622776,
                 35.481335,  39.810719,  44.668358,  50.118729,  56.234131,  63.095726,  70.794586,  79.432816,  89.125107, 100.000000,
                112.201836, 125.892517, 141.253784, 158.489334, 177.827942, 199.526215, 223.872070, 251.188705, 281.838318, 316.227753
        };
        static const double neg[SWITCH_GRANULAR_VOLUME_MAX] = {
                0.891251, 0.794328, 0.707946, 0.630957, 0.562341, 0.501187, 0.446684, 0.398107, 0.354813, 0.316228,
                0.281838, 0.251189, 0.223872, 0.199526, 0.177828, 0.158489, 0.141254, 0.125893, 0.112202, 0.100000,
                0.089125, 0.079433, 0.070795, 0.063096, 0.056234, 0.050119, 0.044668, 0.039811, 0.035481, 0.031623,
                0.028184, 0.025119, 0.022387, 0.019953, 0.017783, 0.015849, 0.014125, 0.012589, 0.011220, 0.010000,
                0.008913, 0.007943, 0.007079, 0.006310, 0.005623, 0.005012, 0.004467, 0.003981, 0.003548, 0.000000  // NOTE mapped -50 dB ratio to total silence instead of 0.003162
        };
        const 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 < SWITCH_GRANULAR_VOLUME_MAX);

        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;
                }
        }
}

struct switch_agc_s {
        switch_memory_pool_t *pool;
        uint32_t energy_avg;
        uint32_t margin;
        uint32_t change_factor;
        char *token;
        int vol;
        uint32_t score;
        uint32_t score_count;
        uint32_t score_sum;
        uint32_t score_avg;
        uint32_t score_over;
        uint32_t score_under;
        uint32_t period_len;
        uint32_t low_energy_point;
};


SWITCH_DECLARE(void) switch_agc_set(switch_agc_t *agc, uint32_t energy_avg, 
                                                                                           uint32_t low_energy_point, uint32_t margin, uint32_t change_factor, uint32_t period_len)
{
        agc->energy_avg = energy_avg;
        agc->margin = margin;
        agc->change_factor = change_factor;
        agc->period_len = period_len;
        agc->low_energy_point = low_energy_point;

        agc->score = 0;
        agc->score_count = 0;
        agc->score_sum = 0;
        agc->score_avg = 0;
        agc->score_over = 0;
        agc->score_under = 0;
}

SWITCH_DECLARE(switch_status_t) switch_agc_create(switch_agc_t **agcP, uint32_t energy_avg, 
                                                                                                  uint32_t low_energy_point, uint32_t margin, uint32_t change_factor, uint32_t period_len)
{
        switch_agc_t *agc;
        switch_memory_pool_t *pool;
        char id[80] = "";

        switch_assert(agcP);

        switch_core_new_memory_pool(&pool);
        
        agc = switch_core_alloc(pool, sizeof(*agc));
        agc->pool = pool;

        switch_agc_set(agc, energy_avg, low_energy_point, margin, change_factor, period_len);


        switch_snprintf(id, sizeof(id), "%p", (void *)agc);
        switch_agc_set_token(agc, id);

        *agcP = agc;

        return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(void) switch_agc_destroy(switch_agc_t **agcP)
{
        switch_agc_t *agc;

        switch_assert(agcP);

        agc = *agcP;
        *agcP = NULL;

        if (agc) {
                switch_memory_pool_t *pool = agc->pool;
                switch_core_destroy_memory_pool(&pool);
        }
}

SWITCH_DECLARE(void) switch_agc_set_energy_avg(switch_agc_t *agc, uint32_t energy_avg)
{
        switch_assert(agc);

        agc->energy_avg = energy_avg;
}

SWITCH_DECLARE(void) switch_agc_set_energy_low(switch_agc_t *agc, uint32_t low_energy_point)
{
        switch_assert(agc);

        agc->low_energy_point = low_energy_point;
}

SWITCH_DECLARE(void) switch_agc_set_token(switch_agc_t *agc, const char *token)
{
        agc->token = switch_core_strdup(agc->pool, token);
}

SWITCH_DECLARE(switch_status_t) switch_agc_feed(switch_agc_t *agc, int16_t *data, uint32_t samples, uint32_t channels)
{
        
        if (!channels) channels = 1;

        if (agc->vol) {
                switch_change_sln_volume_granular(data, samples * channels, agc->vol);
        }
                                                        
        if (agc->energy_avg) {
                uint32_t energy = 0;
                int i;

                for (i = 0; i < samples * channels; i++) {
                        energy += abs(data[i]);
                }

                if (samples) { 
                        agc->score = energy / samples * channels;
                }
                agc->score_sum += agc->score;
                agc->score_count++;
                                                                
                if (agc->score_count > agc->period_len) {
                                                                        
                        agc->score_avg = (int)((double)agc->score_sum / agc->score_count);
                        agc->score_count = 0;
                        agc->score_sum = 0;
                                                                        
                        if (agc->score_avg > agc->energy_avg) {
                                if (agc->score_avg - agc->energy_avg > agc->margin) {
                                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] OVER++ SCORE AVG: %d ENERGY AVG: %d MARGIN: %d\n", 
                                                                          agc->token, agc->score_avg, agc->energy_avg, agc->margin);
                                        agc->score_over++;
                                } else {
                                        agc->score_over = 0;
                                }
                        } else {
                                agc->score_over = 0;
                        }

                        if (agc->score_avg < agc->low_energy_point) {
                                agc->score_under = agc->change_factor + 1;
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] BELOW LOW POINT, SCORE AVG: %d ENERGY AVG: %d MARGIN: %d\n", 
                                                                  agc->token, agc->score_avg, agc->energy_avg, agc->margin);
                        } else if (((agc->score_avg < agc->energy_avg) && (agc->energy_avg - agc->score_avg > agc->margin))) {
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] UNDER++ SCORE AVG: %d ENERGY AVG: %d MARGIN: %d\n", 
                                                                  agc->token, agc->score_avg, agc->energy_avg, agc->margin);
                                agc->score_under++;
                        } else {
                                agc->score_under = 0;
                        }

                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] AVG %d over: %d under: %d\n", 
                                                          agc->token, agc->score_avg, agc->score_over, agc->score_under);

                        if (agc->score_over > agc->change_factor) {
                                agc->vol--;
                                switch_normalize_volume_granular(agc->vol);
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] VOL DOWN %d\n", agc->token, agc->vol);
                                //agc->score_over = 0;
                        } else if (agc->score_under > agc->change_factor) {
                                agc->vol++;
                                switch_normalize_volume_granular(agc->vol);
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] VOL UP %d\n", agc->token, agc->vol);
                                //agc->score_under = 0;
                        }

                }

        }

        return SWITCH_STATUS_SUCCESS;
}


/* For Emacs:
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 * For VIM:
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