(This is the documentation for SDL3, which is under heavy development and the API is changing! SDL2 is the current stable version!)

SDL_LoadWAV_IO

Load the audio data of a WAVE file into memory.

Header File

Syntax

int SDL_LoadWAV_IO(SDL_IOStream * src, SDL_bool closeio,
                   SDL_AudioSpec * spec, Uint8 ** audio_buf,
                   Uint32 * audio_len);

Function Parameters

src	The data source for the WAVE data
closeio	If SDL_TRUE, calls SDL_CloseIO() on `src` before returning, even in the case of an error
spec	A pointer to an SDL_AudioSpec that will be set to the WAVE data's format details on successful return
audio_buf	A pointer filled with the audio data, allocated by the function
audio_len	A pointer filled with the length of the audio data buffer in bytes

Return Value

Returns 0 on success. 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 -1 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_free() to dispose of it.

Remarks

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.

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 return value is zero 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.

It's necessary to use SDL_free() 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_IO(SDL_IOFromFile("sample.wav", "rb"), 1, &spec, &buf, &len);

Note that the SDL_LoadWAV function does this same thing for you, but in a less messy way:

SDL_LoadWAV("sample.wav", &spec, &buf, &len);

Thread Safety

It is safe to call this function from any thread.

Version

This function is available since SDL 3.0.0.