samplerate.c File Reference

#include "precomp.h"

Include dependency graph for samplerate.c:

Go to the source code of this file.

Functions
static int	psrc_set_converter (SRC_PRIVATE *psrc, int converter_type)
SRC_STATE *	src_new (int converter_type, int channels, int *error)
SRC_STATE *	src_callback_new (src_callback_t func, int converter_type, int channels, int *error, void *cb_data)
SRC_STATE *	src_delete (SRC_STATE *state)
int	src_process (SRC_STATE *state, SRC_DATA *data)
long	src_callback_read (SRC_STATE *state, double src_ratio, long frames, float *data)
int	src_set_ratio (SRC_STATE *state, double new_ratio)
int	src_get_channels (SRC_STATE *state)
int	src_reset (SRC_STATE *state)
const char *	src_get_name (int converter_type)
const char *	src_get_description (int converter_type)
const char *	src_get_version (void)
int	src_is_valid_ratio (double ratio)
int	src_error (SRC_STATE *state)
const char *	src_strerror (int error)
int	src_simple (SRC_DATA *src_data, int converter, int channels)
void	src_short_to_float_array (const short *in, float *out, int len)
void	src_float_to_short_array (const float *in, short *out, int len)
void	src_int_to_float_array (const int *in, float *out, int len)
void	src_float_to_int_array (const float *in, int *out, int len)

Function Documentation

psrc_set_converter()

static int psrc_set_converter ( SRC_PRIVATE *  psrc, int  converter_type  )

static

Definition at line 519 of file samplerate.c.

{
    if (sinc_set_converter (psrc, converter_type) == SRC_ERR_NO_ERROR)
        return SRC_ERR_NO_ERROR ;

    if (zoh_set_converter (psrc, converter_type) == SRC_ERR_NO_ERROR)
        return SRC_ERR_NO_ERROR ;

    if (linear_set_converter (psrc, converter_type) == SRC_ERR_NO_ERROR)
        return SRC_ERR_NO_ERROR ;

    return SRC_ERR_BAD_CONVERTER ;
} /* psrc_set_converter */

Referenced by src_new().

src_callback_new()

SRC_STATE* src_callback_new	(	src_callback_t	func,
		int	converter_type,
		int	channels,
		int *	error,
		void *	cb_data
	)

Definition at line 49 of file samplerate.c.

{   SRC_STATE   *src_state ;

    if (func == NULL)
    {   if (error)
            *error = SRC_ERR_BAD_CALLBACK ;
        return NULL ;
        } ;

    if (error != NULL)
        *error = 0 ;

    if ((src_state = src_new (converter_type, channels, error)) == NULL)
        return NULL ;

    src_reset (src_state) ;

    ((SRC_PRIVATE*) src_state)->mode = SRC_MODE_CALLBACK ;
    ((SRC_PRIVATE*) src_state)->callback_func = func ;
    ((SRC_PRIVATE*) src_state)->user_callback_data = cb_data ;

    return src_state ;
} /* src_callback_new */

src_callback_read()

long src_callback_read	(	SRC_STATE *	state,
		double	src_ratio,
		long	frames,
		float *	data
	)

Definition at line 153 of file samplerate.c.

{   SRC_PRIVATE *psrc ;
    SRC_DATA    src_data ;

    long    output_frames_gen ;
    int     error = 0 ;

    if (state == NULL)
        return 0 ;

    if (frames <= 0)
        return 0 ;

    psrc = (SRC_PRIVATE*) state ;

    if (psrc->mode != SRC_MODE_CALLBACK)
    {   psrc->error = SRC_ERR_BAD_MODE ;
        return 0 ;
        } ;

    if (psrc->callback_func == NULL)
    {   psrc->error = SRC_ERR_NULL_CALLBACK ;
        return 0 ;
        } ;

    memset (&src_data, 0, sizeof (src_data)) ;

    /* Check src_ratio is in range. */
    if (is_bad_src_ratio (src_ratio))
    {   psrc->error = SRC_ERR_BAD_SRC_RATIO ;
        return 0 ;
        } ;

    /* Switch modes temporarily. */
    src_data.src_ratio = src_ratio ;
    src_data.data_out = data ;
    src_data.output_frames = frames ;

    src_data.data_in = psrc->saved_data ;
    src_data.input_frames = psrc->saved_frames ;

    output_frames_gen = 0 ;
    while (output_frames_gen < frames)
    {   /*  Use a dummy array for the case where the callback function
        **  returns without setting the ptr.
        */
        float dummy [1] ;

        if (src_data.input_frames == 0)
        {   float *ptr = dummy ;

            src_data.input_frames = psrc->callback_func (psrc->user_callback_data, &ptr) ;
            src_data.data_in = ptr ;

            if (src_data.input_frames == 0)
                src_data.end_of_input = 1 ;
            } ;

        /*
        ** Now call process function. However, we need to set the mode
        ** to SRC_MODE_PROCESS first and when we return set it back to
        ** SRC_MODE_CALLBACK.
        */
        psrc->mode = SRC_MODE_PROCESS ;
        error = src_process (state, &src_data) ;
        psrc->mode = SRC_MODE_CALLBACK ;

        if (error != 0)
            break ;

        src_data.data_in += src_data.input_frames_used * psrc->channels ;
        src_data.input_frames -= src_data.input_frames_used ;

        src_data.data_out += src_data.output_frames_gen * psrc->channels ;
        src_data.output_frames -= src_data.output_frames_gen ;

        output_frames_gen += src_data.output_frames_gen ;

        if (src_data.end_of_input == SRC_TRUE && src_data.output_frames_gen == 0)
            break ;
        } ;

    psrc->saved_data = src_data.data_in ;
    psrc->saved_frames = src_data.input_frames ;

    if (error != 0)
    {   psrc->error = error ;
        return 0 ;
        } ;

    return output_frames_gen ;
} /* src_callback_read */

src_delete()

SRC_STATE* src_delete

(

SRC_STATE *

state

)

Definition at line 74 of file samplerate.c.

{   SRC_PRIVATE *psrc ;

    psrc = (SRC_PRIVATE*) state ;
    if (psrc)
    {   if (psrc->private_data)
            free (psrc->private_data) ;
        memset (psrc, 0, sizeof (SRC_PRIVATE)) ;
        free (psrc) ;
        } ;

    return NULL ;
} /* src_state */

Referenced by PerformSampleRateConversion(), and src_simple().

src_error()

int src_error

(

SRC_STATE *

state

)

Definition at line 358 of file samplerate.c.

{   if (state)
        return ((SRC_PRIVATE*) state)->error ;
    return SRC_ERR_NO_ERROR ;
} /* src_error */

src_float_to_int_array()

void src_float_to_int_array	(	const float *	in,
		int *	out,
		int	len
	)

Definition at line 493 of file samplerate.c.

{   double scaled_value ;

    while (len)
    {   len -- ;

        scaled_value = in [len] * (8.0 * 0x10000000) ;
        if (CPU_CLIPS_POSITIVE == 0 && scaled_value >= (1.0 * 0x7FFFFFFF))
        {   out [len] = 0x7fffffff ;
            continue ;
            } ;
        if (CPU_CLIPS_NEGATIVE == 0 && scaled_value <= (-8.0 * 0x10000000))
        {   out [len] = -1 - 0x7fffffff ;
            continue ;
            } ;

        out [len] = lrint (scaled_value) ;
        } ;

} /* src_float_to_int_array */

Referenced by PerformSampleRateConversion().

src_float_to_short_array()

void src_float_to_short_array	(	const float *	in,
		short *	out,
		int	len
	)

Definition at line 460 of file samplerate.c.

{   double scaled_value ;

    while (len)
    {   len -- ;

        scaled_value = in [len] * (8.0 * 0x10000000) ;
        if (CPU_CLIPS_POSITIVE == 0 && scaled_value >= (1.0 * 0x7FFFFFFF))
        {   out [len] = 32767 ;
            continue ;
            } ;
        if (CPU_CLIPS_NEGATIVE == 0 && scaled_value <= (-8.0 * 0x10000000))
        {   out [len] = -32768 ;
            continue ;
            } ;

        out [len] = (short) (lrint (scaled_value) >> 16) ;
        } ;

} /* src_float_to_short_array */

Referenced by PerformSampleRateConversion().

src_get_channels()

int src_get_channels

(

SRC_STATE *

state

)

Definition at line 269 of file samplerate.c.

{   SRC_PRIVATE *psrc ;

    psrc = (SRC_PRIVATE*) state ;

    if (psrc == NULL)
        return SRC_ERR_BAD_STATE ;
    if (psrc->vari_process == NULL || psrc->const_process == NULL)
        return SRC_ERR_BAD_PROC_PTR ;

    return psrc->channels ;
} /* src_get_channels */

src_get_description()

const char* src_get_description

(

int

converter_type

)

Definition at line 324 of file samplerate.c.

{   const char *desc ;

    if ((desc = sinc_get_description (converter_type)) != NULL)
        return desc ;

    if ((desc = zoh_get_description (converter_type)) != NULL)
        return desc ;

    if ((desc = linear_get_description (converter_type)) != NULL)
        return desc ;

    return NULL ;
} /* src_get_description */

src_get_name()

const char* src_get_name

(

int

converter_type

)

Definition at line 308 of file samplerate.c.

{   const char *desc ;

    if ((desc = sinc_get_name (converter_type)) != NULL)
        return desc ;

    if ((desc = zoh_get_name (converter_type)) != NULL)
        return desc ;

    if ((desc = linear_get_name (converter_type)) != NULL)
        return desc ;

    return NULL ;
} /* src_get_name */

src_get_version()

const char* src_get_version

(

void

)

Definition at line 340 of file samplerate.c.

{   return PACKAGE "-" VERSION " (c) 2002-2008 Erik de Castro Lopo" ;
} /* src_get_version */

src_int_to_float_array()

void src_int_to_float_array	(	const int *	in,
		float *	out,
		int	len
	)

Definition at line 482 of file samplerate.c.

{
    while (len)
    {   len -- ;
        out [len] = (float) (in [len] / (8.0 * 0x10000000)) ;
        } ;

    return ;
} /* src_int_to_float_array */

Referenced by PerformSampleRateConversion().

src_is_valid_ratio()

int src_is_valid_ratio

(

double

ratio

)

Definition at line 345 of file samplerate.c.

{
    if (is_bad_src_ratio (ratio))
        return SRC_FALSE ;

    return SRC_TRUE ;
} /* src_is_valid_ratio */

src_new()

SRC_STATE* src_new	(	int	converter_type,
		int	channels,
		int *	error
	)

Definition at line 15 of file samplerate.c.

{   SRC_PRIVATE *psrc ;

    if (error)
        *error = SRC_ERR_NO_ERROR ;

    if (channels < 1)
    {   if (error)
            *error = SRC_ERR_BAD_CHANNEL_COUNT ;
        return NULL ;
        } ;

    if ((psrc = calloc (1, sizeof (*psrc))) == NULL)
    {   if (error)
            *error = SRC_ERR_MALLOC_FAILED ;
        return NULL ;
        } ;

    psrc->channels = channels ;
    psrc->mode = SRC_MODE_PROCESS ;

    if (psrc_set_converter (psrc, converter_type) != SRC_ERR_NO_ERROR)
    {   if (error)
            *error = SRC_ERR_BAD_CONVERTER ;
        free (psrc) ;
        psrc = NULL ;
        } ;

    src_reset ((SRC_STATE*) psrc) ;

    return (SRC_STATE*) psrc ;
} /* src_new */

Referenced by PerformSampleRateConversion(), src_callback_new(), and src_simple().

src_process()

int src_process	(	SRC_STATE *	state,
		SRC_DATA *	data
	)

Definition at line 89 of file samplerate.c.

{   SRC_PRIVATE *psrc ;
    int error ;

    psrc = (SRC_PRIVATE*) state ;

    if (psrc == NULL)
        return SRC_ERR_BAD_STATE ;
    if (psrc->vari_process == NULL || psrc->const_process == NULL)
        return SRC_ERR_BAD_PROC_PTR ;

    if (psrc->mode != SRC_MODE_PROCESS)
        return SRC_ERR_BAD_MODE ;

    /* Check for valid SRC_DATA first. */
    if (data == NULL)
        return SRC_ERR_BAD_DATA ;

    /* And that data_in and data_out are valid. */
    if (data->data_in == NULL || data->data_out == NULL)
        return SRC_ERR_BAD_DATA_PTR ;

    /* Check src_ratio is in range. */
    if (is_bad_src_ratio (data->src_ratio))
        return SRC_ERR_BAD_SRC_RATIO ;

    if (data->input_frames < 0)
        data->input_frames = 0 ;
    if (data->output_frames < 0)
        data->output_frames = 0 ;

    if (data->data_in < data->data_out)
    {   if (data->data_in + data->input_frames * psrc->channels > data->data_out)
        {   /*-printf ("\n\ndata_in: %p    data_out: %p\n",
                (void*) (data->data_in + data->input_frames * psrc->channels), (void*) data->data_out) ;-*/
            return SRC_ERR_DATA_OVERLAP ;
            } ;
        }
    else if (data->data_out + data->output_frames * psrc->channels > data->data_in)
    {   /*-printf ("\n\ndata_in : %p   ouput frames: %ld    data_out: %p\n", (void*) data->data_in, data->output_frames, (void*) data->data_out) ;

        printf ("data_out: %p (%p)    data_in: %p\n", (void*) data->data_out,
            (void*) (data->data_out + data->input_frames * psrc->channels), (void*) data->data_in) ;-*/
        return SRC_ERR_DATA_OVERLAP ;
        } ;

    /* Set the input and output counts to zero. */
    data->input_frames_used = 0 ;
    data->output_frames_gen = 0 ;

    /* Special case for when last_ratio has not been set. */
    if (psrc->last_ratio < (1.0 / SRC_MAX_RATIO))
        psrc->last_ratio = data->src_ratio ;

    /* Now process. */
    if (fabs (psrc->last_ratio - data->src_ratio) < 1e-15)
        error = psrc->const_process (psrc, data) ;
    else
        error = psrc->vari_process (psrc, data) ;

    return error ;
} /* src_process */

Referenced by PerformSampleRateConversion(), src_callback_read(), and src_simple().

src_reset()

int src_reset

(

SRC_STATE *

state

)

Definition at line 283 of file samplerate.c.

{   SRC_PRIVATE *psrc ;

    if ((psrc = (SRC_PRIVATE*) state) == NULL)
        return SRC_ERR_BAD_STATE ;

    if (psrc->reset != NULL)
        psrc->reset (psrc) ;

    psrc->last_position = 0.0 ;
    psrc->last_ratio = 0.0 ;

    psrc->saved_data = NULL ;
    psrc->saved_frames = 0 ;

    psrc->error = SRC_ERR_NO_ERROR ;

    return SRC_ERR_NO_ERROR ;
} /* src_reset */

Referenced by src_callback_new(), and src_new().

src_set_ratio()

int src_set_ratio	(	SRC_STATE *	state,
		double	new_ratio
	)

Definition at line 250 of file samplerate.c.

{   SRC_PRIVATE *psrc ;

    psrc = (SRC_PRIVATE*) state ;

    if (psrc == NULL)
        return SRC_ERR_BAD_STATE ;
    if (psrc->vari_process == NULL || psrc->const_process == NULL)
        return SRC_ERR_BAD_PROC_PTR ;

    if (is_bad_src_ratio (new_ratio))
        return SRC_ERR_BAD_SRC_RATIO ;

    psrc->last_ratio = new_ratio ;

    return SRC_ERR_NO_ERROR ;
} /* src_set_ratio */

src_short_to_float_array()

void src_short_to_float_array	(	const short *	in,
		float *	out,
		int	len
	)

Definition at line 449 of file samplerate.c.

{
    while (len)
    {   len -- ;
        out [len] = (float) (in [len] / (1.0 * 0x8000)) ;
        } ;

    return ;
} /* src_short_to_float_array */

Referenced by PerformSampleRateConversion().

src_simple()

int src_simple	(	SRC_DATA *	src_data,
		int	converter,
		int	channels
	)

Definition at line 432 of file samplerate.c.

{   SRC_STATE   *src_state ;
    int         error ;

    if ((src_state = src_new (converter, channels, &error)) == NULL)
        return error ;

    src_data->end_of_input = 1 ; /* Only one buffer worth of input. */

    error = src_process (src_state, src_data) ;

    src_delete (src_state) ;

    return error ;
} /* src_simple */

src_strerror()

const char* src_strerror

(

int

error

)

Definition at line 365 of file samplerate.c.

{
    switch (error)
    {   case SRC_ERR_NO_ERROR :
                return "No error." ;
        case SRC_ERR_MALLOC_FAILED :
                return "Malloc failed." ;
        case SRC_ERR_BAD_STATE :
                return "SRC_STATE pointer is NULL." ;
        case SRC_ERR_BAD_DATA :
                return "SRC_DATA pointer is NULL." ;
        case SRC_ERR_BAD_DATA_PTR :
                return "SRC_DATA->data_out or SRC_DATA->data_in is NULL." ;
        case SRC_ERR_NO_PRIVATE :
                return "Internal error. No private data." ;

        case SRC_ERR_BAD_SRC_RATIO :
                return "SRC ratio outside [1/" SRC_MAX_RATIO_STR ", " SRC_MAX_RATIO_STR "] range." ;

        case SRC_ERR_BAD_SINC_STATE :
                return "src_process() called without reset after end_of_input." ;
        case SRC_ERR_BAD_PROC_PTR :
                return "Internal error. No process pointer." ;
        case SRC_ERR_SHIFT_BITS :
                return "Internal error. SHIFT_BITS too large." ;
        case SRC_ERR_FILTER_LEN :
                return "Internal error. Filter length too large." ;
        case SRC_ERR_BAD_CONVERTER :
                return "Bad converter number." ;
        case SRC_ERR_BAD_CHANNEL_COUNT :
                return "Channel count must be >= 1." ;
        case SRC_ERR_SINC_BAD_BUFFER_LEN :
                return "Internal error. Bad buffer length. Please report this." ;
        case SRC_ERR_SIZE_INCOMPATIBILITY :
                return "Internal error. Input data / internal buffer size difference. Please report this." ;
        case SRC_ERR_BAD_PRIV_PTR :
                return "Internal error. Private pointer is NULL. Please report this." ;
        case SRC_ERR_DATA_OVERLAP :
                return "Input and output data arrays overlap." ;
        case SRC_ERR_BAD_CALLBACK :
                return "Supplied callback function pointer is NULL." ;
        case SRC_ERR_BAD_MODE :
                return "Calling mode differs from initialisation mode (ie process v callback)." ;
        case SRC_ERR_NULL_CALLBACK :
                return "Callback function pointer is NULL in src_callback_read ()." ;
        case SRC_ERR_NO_VARIABLE_RATIO :
                return "This converter only allows constant conversion ratios." ;
        case SRC_ERR_SINC_PREPARE_DATA_BAD_LEN :
                return "Internal error : Bad length in prepare_data ()." ;
        case SRC_ERR_BAD_INTERNAL_STATE :
                return "Error : Someone is trampling on my internal state." ;

        case SRC_ERR_MAX_ERROR :
                return "Placeholder. No error defined for this error number." ;

        default :                       break ;
        }

    return NULL ;
} /* src_strerror */