Function sdl2_sys::SDL_LoadWAV_RW
source · pub unsafe extern "C" fn SDL_LoadWAV_RW(
src: *mut SDL_RWops,
freesrc: c_int,
spec: *mut SDL_AudioSpec,
audio_buf: *mut *mut Uint8,
audio_len: *mut Uint32,
) -> *mut SDL_AudioSpec
Expand description
Load the audio data of a WAVE file into memory.
Loading a WAVE file requires src
, spec
, audio_buf
and audio_len
to
be valid pointers. The entire data portion of the file is then loaded into
memory and decoded if necessary.
If freesrc
is non-zero, the data source gets automatically closed and
freed before the function returns.
Supported formats are RIFF WAVE files with the formats PCM (8, 16, 24, and 32 bits), IEEE Float (32 bits), Microsoft ADPCM and IMA ADPCM (4 bits), and A-law and mu-law (8 bits). Other formats are currently unsupported and cause an error.
If this function succeeds, the pointer returned by it is equal to spec
and the pointer to the audio data allocated by the function is written to
audio_buf
and its length in bytes to audio_len
. The SDL_AudioSpec
members freq
, channels
, and format
are set to the values of the audio
data in the buffer. The samples
member is set to a sane default and all
others are set to zero.
It’s necessary to use SDL_FreeWAV() to free the audio data returned in
audio_buf
when it is no longer used.
Because of the underspecification of the .WAV format, there are many
problematic files in the wild that cause issues with strict decoders. To
provide compatibility with these files, this decoder is lenient in regards
to the truncation of the file, the fact chunk, and the size of the RIFF
chunk. The hints SDL_HINT_WAVE_RIFF_CHUNK_SIZE
,
SDL_HINT_WAVE_TRUNCATION
, and SDL_HINT_WAVE_FACT_CHUNK
can be used to
tune the behavior of the loading process.
Any file that is invalid (due to truncation, corruption, or wrong values in
the headers), too big, or unsupported causes an error. Additionally, any
critical I/O error from the data source will terminate the loading process
with an error. The function returns NULL on error and in all cases (with
the exception of src
being NULL), an appropriate error message will be
set.
It is required that the data source supports seeking.
Example:
SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, &spec, &buf, &len);
Note that the SDL_LoadWAV macro does this same thing for you, but in a less messy way:
SDL_LoadWAV("sample.wav", &spec, &buf, &len);
\param src The data source for the WAVE data
\param freesrc If non-zero, SDL will always free the data source
\param spec An SDL_AudioSpec that will be filled in with the wave file’s
format details
\param audio_buf A pointer filled with the audio data, allocated by the
function.
\param audio_len A pointer filled with the length of the audio data buffer
in bytes
\returns This function, if successfully called, returns spec
, which will
be filled with the audio data format of the wave source data.
audio_buf
will be filled with a pointer to an allocated buffer
containing the audio data, and audio_len
is filled with the
length of that audio buffer in bytes.
This function returns NULL if the .WAV file cannot be opened, uses
an unknown data format, or is corrupt; call SDL_GetError() for
more information.
When the application is done with the data returned in
`audio_buf`, it should call SDL_FreeWAV() to dispose of it.
\since This function is available since SDL 2.0.0.
\sa SDL_FreeWAV \sa SDL_LoadWAV