switch_resample.c File Reference

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

Include dependency graph for switch_resample.c:

Go to the source code of this file.

Macros
#define	NORMFACT   (float)0x8000
#define	MAXSAMPLE   (float)0x7FFF
#define	MAXSAMPLEC   (char)0x7F
#define	QUALITY   0
#define	MIN(a, b)   ((a) < (b) ? (a) : (b))
#define	MAX(a, b)   ((a) > (b) ? (a) : (b))
#define	resample_buffer(a, b, c)   a > b ? ((a / 1000) / 2) * c : ((b / 1000) / 2) * c

Functions
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)
	Prepare a new resampler handle. More...
uint32_t	switch_resample_process (switch_audio_resampler_t *resampler, int16_t *src, uint32_t srclen)
	Resample one float buffer into another using specifications of a given handle. More...
void	switch_resample_destroy (switch_audio_resampler_t **resampler)
	Destroy an existing resampler handle. More...
switch_size_t	switch_float_to_short (float *f, short *s, switch_size_t len)
	Convert an array of floats to an array of shorts. More...
int	switch_char_to_float (char *c, float *f, int len)
	Convert an array of chars to an array of floats. More...
int	switch_float_to_char (float *f, char *c, int len)
	Convert an array of floats to an array of chars. More...
int	switch_short_to_float (short *s, float *f, int len)
	Convert an array of shorts to an array of floats. More...
void	switch_swap_linear (int16_t *buf, int len)
	Perform a byteswap on a buffer of 16 bit samples. More...
void	switch_generate_sln_silence (int16_t *data, uint32_t samples, uint32_t channels, uint32_t divisor)
	Generate static noise. More...
uint32_t	switch_merge_sln (int16_t *data, uint32_t samples, int16_t *other_data, uint32_t other_samples, int channels)
uint32_t	switch_unmerge_sln (int16_t *data, uint32_t samples, int16_t *other_data, uint32_t other_samples, int channels)
void	switch_mux_channels (int16_t *data, switch_size_t samples, uint32_t orig_channels, uint32_t channels)
void	switch_change_sln_volume_granular (int16_t *data, uint32_t samples, int32_t vol)
	Change the volume of a signed linear audio frame with more granularity. More...
void	switch_change_sln_volume (int16_t *data, uint32_t samples, int32_t vol)
	Change the volume of a signed linear audio frame. More...

Macro Definition Documentation

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

Definition at line 50 of file switch_resample.c.

#define MAXSAMPLE   (float)0x7FFF

Definition at line 41 of file switch_resample.c.

Referenced by switch_char_to_float(), and switch_float_to_short().

#define MAXSAMPLEC   (char)0x7F

Definition at line 42 of file switch_resample.c.

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

Definition at line 46 of file switch_resample.c.

#define NORMFACT   (float)0x8000

Definition at line 40 of file switch_resample.c.

Referenced by switch_char_to_float(), switch_float_to_char(), switch_float_to_short(), and switch_short_to_float().

#define QUALITY   0

Definition at line 43 of file switch_resample.c.

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

Definition at line 53 of file switch_resample.c.

Function Documentation

uint32_t switch_merge_sln	(	int16_t *	data,
		uint32_t	samples,
		int16_t *	other_data,
		uint32_t	other_samples,
		int	channels
	)

Definition at line 231 of file switch_resample.c.

References switch_normalize_to_16bit.

Referenced by eavesdrop_callback().

{
        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;
}

void switch_mux_channels	(	int16_t *	data,
		switch_size_t	samples,
		uint32_t	orig_channels,
		uint32_t	channels
	)

Definition at line 274 of file switch_resample.c.

References switch_assert, switch_normalize_to_16bit, and switch_zmalloc.

Referenced by switch_core_file_read(), switch_core_session_read_frame(), switch_core_session_write_frame(), switch_core_speech_read_tts(), switch_ivr_eavesdrop_session(), and teletone_handler().

{
        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

        }
}

uint32_t switch_unmerge_sln	(	int16_t *	data,
		uint32_t	samples,
		int16_t *	other_data,
		uint32_t	other_samples,
		int	channels
	)

Definition at line 254 of file switch_resample.c.

Referenced by switch_core_session_read_frame().

{
        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;
}