File i32_to_f32_core.h¶

FileList > i32_to_f32 > i32_to_f32_core.h

int32-to-float converter with configurable inverse scale. More...

#include "clib_common.h"
#include "jm_perf.h"

Classes¶

Type	Name
struct	i32_to_f32_state_t I32ToF32 state.

Public Functions¶

Type	Name
i32_to_f32_state_t *	i32_to_f32_create (float scale) Create a i32_to_f32 instance.
void	i32_to_f32_destroy (i32_to_f32_state_t * state) Destroy a i32_to_f32 instance and release all memory.
void	i32_to_f32_reset (i32_to_f32_state_t * state) Reset I32ToF32 to its post-create state.
JM_FORCEINLINE JM_HOT float	i32_to_f32_step (const i32_to_f32_state_t * state, int32_t x) Process one input sample.
void	i32_to_f32_steps (i32_to_f32_state_t * state, const int32_t * input, float * output, size_t n) Process a block of int32 samples to float32.

Detailed Description¶

Multiplies each int32 sample by 1/scale and returns a float32 result. The default scale of 2147483648.0 (2^31) maps the full int32 range [-2147483648, 2147483647] to [-1.0, ~+1.0), recovering the normalised float representation from a 32-bit fixed-point stream. Note: float32 has 23 mantissa bits, so int32 values beyond ±16777217 will be rounded to the nearest representable float. Use I32ToF32 when only the magnitude matters or the source is genuinely 32-bit fixed-point. The inverse scale is pre-computed at construction time.

Lifecycle: create -> [step / steps / reset]* -> destroy

>>> from doppler.cvt import I32ToF32
>>> import numpy as np
>>> obj = I32ToF32(scale=2147483648.0)
>>> float(obj.step(-2147483648))
-1.0
>>> float(obj.step(0))
0.0
>>> x = np.array([-2147483648, 0, 2147483647], dtype=np.int32)
>>> obj.steps(x).tolist()
[-1.0, 0.0, 1.0]

Public Functions Documentation¶

function i32_to_f32_create¶

Create a i32_to_f32 instance.

i32_to_f32_state_t * i32_to_f32_create (
    float scale
)

Pre-computes iscale = 1.0f / scale. Any non-zero finite float is a valid scale.

Parameters:

scale Denominator scale; 1/scale is applied to each sample (default: 2147483648.0f). Use 2^31 to recover normalised floats from a full-range int32 stream.

Returns:

Heap-allocated state, or NULL on allocation failure.

Note:

Caller must call i32_to_f32_destroy() when done.

function i32_to_f32_destroy¶

Destroy a i32_to_f32 instance and release all memory.

void i32_to_f32_destroy (
    i32_to_f32_state_t * state
)

Parameters:

state May be NULL.

function i32_to_f32_reset¶

Reset I32ToF32 to its post-create state.

void i32_to_f32_reset (
    i32_to_f32_state_t * state
)

No mutable state exists beyond the immutable iscale; reset is a no-op provided for lifecycle symmetry with other converters.

Parameters:

state Must be non-NULL.

function i32_to_f32_step¶

Process one input sample.

JM_FORCEINLINE  JM_HOT float i32_to_f32_step (
    const i32_to_f32_state_t * state,
    int32_t x
)

Returns ``(float)x * iscale.

Parameters:

state Must be non-NULL.
x Signed int32 input sample.

Returns:

Scaled float32 output.

function i32_to_f32_steps¶

Process a block of int32 samples to float32.

void i32_to_f32_steps (
    i32_to_f32_state_t * state,
    const int32_t * input,
    float * output,
    size_t n
)

Applies step() to every element. Accepts an optional pre-allocated output array; allocates a fresh one when output is NULL.

Parameters:

state Must be non-NULL.
input Input int32 array; must contain at least n elements.
output Output float32 array; must contain at least n elements.
n Number of samples to process.

>>> from doppler.cvt import I32ToF32
>>> import numpy as np
>>> I32ToF32().steps(np.array([0, 2**30, -2**31], dtype=np.int32)).tolist()
[0.0, 0.5, -1.0]

The documentation for this class was generated from the following file native/inc/i32_to_f32/i32_to_f32_core.h