1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20*/
21#include "SDL_internal.h"
22
23#ifndef SDL_audioresample_h_
24#define SDL_audioresample_h_
25
26// Internal functions used by SDL_AudioStream for resampling audio.
27// The resampler uses 32:32 fixed-point arithmetic to track its position.
28
29Sint64 SDL_GetResampleRate(int src_rate, int dst_rate);
30
31int SDL_GetResamplerHistoryFrames(void);
32int SDL_GetResamplerPaddingFrames(Sint64 resample_rate);
33
34Sint64 SDL_GetResamplerInputFrames(Sint64 output_frames, Sint64 resample_rate, Sint64 resample_offset);
35Sint64 SDL_GetResamplerOutputFrames(Sint64 input_frames, Sint64 resample_rate, Sint64 *inout_resample_offset);
36
37// Resample some audio.
38// REQUIRES: `inframes >= SDL_GetResamplerInputFrames(outframes)`
39// REQUIRES: At least `SDL_GetResamplerPaddingFrames(...)` extra frames to the left of src, and right of src+inframes
40void SDL_ResampleAudio(int chans, const float *src, int inframes, float *dst, int outframes,
41 Sint64 resample_rate, Sint64 *inout_resample_offset);
42
43#endif // SDL_audioresample_h_
44