70 lines
3.2 KiB
C
70 lines
3.2 KiB
C
/*
|
|
Simple DirectMedia Layer
|
|
Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>
|
|
|
|
This software is provided 'as-is', without any express or implied
|
|
warranty. In no event will the authors be held liable for any damages
|
|
arising from the use of this software.
|
|
|
|
Permission is granted to anyone to use this software for any purpose,
|
|
including commercial applications, and to alter it and redistribute it
|
|
freely, subject to the following restrictions:
|
|
|
|
1. The origin of this software must not be misrepresented; you must not
|
|
claim that you wrote the original software. If you use this software
|
|
in a product, an acknowledgment in the product documentation would be
|
|
appreciated but is not required.
|
|
2. Altered source versions must be plainly marked as such, and must not be
|
|
misrepresented as being the original software.
|
|
3. This notice may not be removed or altered from any source distribution.
|
|
*/
|
|
|
|
/**
|
|
* \brief Upper limit of filters in SDL_AudioCVT
|
|
*
|
|
* The maximum number of SDL_AudioFilter functions in SDL_AudioCVT is
|
|
* currently limited to 9. The SDL_AudioCVT.filters array has 10 pointers,
|
|
* one of which is the terminating NULL pointer.
|
|
*/
|
|
#define SDL_AUDIOCVT_MAX_FILTERS 9
|
|
|
|
/**
|
|
* \struct SDL_AudioCVT
|
|
* \brief A structure to hold a set of audio conversion filters and buffers.
|
|
*
|
|
* Note that various parts of the conversion pipeline can take advantage
|
|
* of SIMD operations (like SSE2, for example). SDL_AudioCVT doesn't require
|
|
* you to pass it aligned data, but can possibly run much faster if you
|
|
* set both its (buf) field to a pointer that is aligned to 16 bytes, and its
|
|
* (len) field to something that's a multiple of 16, if possible.
|
|
*/
|
|
#if defined(__GNUC__) && !defined(__CHERI_PURE_CAPABILITY__)
|
|
/* This structure is 84 bytes on 32-bit architectures, make sure GCC doesn't
|
|
pad it out to 88 bytes to guarantee ABI compatibility between compilers.
|
|
This is not a concern on CHERI architectures, where pointers must be stored
|
|
at aligned locations otherwise they will become invalid, and thus structs
|
|
containing pointers cannot be packed without giving a warning or error.
|
|
vvv
|
|
The next time we rev the ABI, make sure to size the ints and add padding.
|
|
*/
|
|
#define SDL_AUDIOCVT_PACKED __attribute__((packed))
|
|
#else
|
|
#define SDL_AUDIOCVT_PACKED
|
|
#endif
|
|
/* */
|
|
typedef struct SDL_AudioCVT
|
|
{
|
|
int needed; /**< Set to 1 if conversion possible */
|
|
SDL_AudioFormat src_format; /**< Source audio format */
|
|
SDL_AudioFormat dst_format; /**< Target audio format */
|
|
double rate_incr; /**< Rate conversion increment */
|
|
Uint8 *buf; /**< Buffer to hold entire audio data */
|
|
int len; /**< Length of original audio buffer */
|
|
int len_cvt; /**< Length of converted audio buffer */
|
|
int len_mult; /**< buffer must be len*len_mult big */
|
|
double len_ratio; /**< Given len, final size is len*len_ratio */
|
|
SDL_AudioFilter filters[SDL_AUDIOCVT_MAX_FILTERS + 1]; /**< NULL-terminated list of filter functions */
|
|
int filter_index; /**< Current audio conversion function */
|
|
} SDL_AUDIOCVT_PACKED SDL_AudioCVT;
|
|
|