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| ||||''Default,,s,, to LSB byte order'' -or- ''Basic'' ???|| ||AUDIO_U8||unsigned 8-bit samples.|| ||AUDIO_S8||signed 8-bit samples.|| ||AUDIO_U16 or AUDIO_U16LSB||not supported by all hardware (unsigned 16-bit little-endian)|| ||AUDIO_S16 or AUDIO_S16LSB||not supported by all hardware (signed 16-bit little-endian)|| ||AUDIO_U16MSB||not supported by all hardware (unsigned 16-bit big-endian)|| ||AUDIO_S16MSB||not supported by all hardware (signed 16-bit big-endian)|| ||||''int32 support''|| ||AUDIO_S32 or AUDIO_S32LSB||32-bit integer samples|| ||AUDIO_S32MSB||as above, but big-endian byte order|| ||||''float32 support''|| ||AUDIO_F32 or AUDIO_F32LSB||32-bit floating point samples|| ||AUDIO_F32MSB||as above, but big-endian byte order|| ||||''Native audio byte ordering''|| ||AUDIO_U16SYS||either AUDIO_U16LSB or AUDIO_U16MSB depending on hardware CPU endianness|| ||AUDIO_S16SYS||either AUDIO_S16LSB or AUDIO_S16MSB depending on hardware CPU endianness|| ||AUDIO_S32SYS||either AUDIO_S32LSB or AUDIO_S32MSB depending on hardware CPU endianness|| ||AUDIO_F32SYS||either AUDIO_F32LSB or AUDIO_F32MSB depending on hardware CPU endianness|| |
||||''Default,,s,, to LSB byte order'' -or- ''Basic'' ???|| ||AUDIO_U8||unsigned 8-bit samples.|| ||AUDIO_S8||signed 8-bit samples.|| ||AUDIO_U16 or AUDIO_U16LSB||not supported by all hardware (unsigned 16-bit little-endian)|| ||AUDIO_S16 or AUDIO_S16LSB||not supported by all hardware (signed 16-bit little-endian)|| ||AUDIO_U16MSB||not supported by all hardware (unsigned 16-bit big-endian)|| ||AUDIO_S16MSB||not supported by all hardware (signed 16-bit big-endian)|| ||||''int32 support''|| ||AUDIO_S32 or AUDIO_S32LSB||32-bit integer samples|| ||AUDIO_S32MSB||as above, but big-endian byte order|| ||||''float32 support''|| ||AUDIO_F32 or AUDIO_F32LSB||32-bit floating point samples|| ||AUDIO_F32MSB||as above, but big-endian byte order|| ||||''Native audio byte ordering''|| ||AUDIO_U16SYS||either AUDIO_U16LSB or AUDIO_U16MSB depending on hardware CPU endianness|| ||AUDIO_S16SYS||either AUDIO_S16LSB or AUDIO_S16MSB depending on hardware CPU endianness|| ||AUDIO_S32SYS||either AUDIO_S32LSB or AUDIO_S32MSB depending on hardware CPU endianness|| ||AUDIO_F32SYS||either AUDIO_F32LSB or AUDIO_F32MSB depending on hardware CPU endianness|| |
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| <<Color2(green,No page for SDL_Audio``Callback right? Is this sufficient?)>> <<Anchor(callback)>> '''callback''' is of the form: {{{#!highlight cpp ##alt 1st line from header rev 5387? typedef void (SDLCALL * SDL_AudioCallback)(void* userdata, ##w/ wiki formatting adjustments? void* SDL_AudioCallback(void* userdata, ##original content below void callback(void* userdata, Uint8* stream, int len); |
<<Anchor(callback)>> '''callback''' is of the form: {{{ void SDL_AudioCallback(void* userdata, Uint8* stream, int len) |
DRAFT |
SDL_AudioSpec
A structure that contains the audio output format. It also contains a callback that is called when the audio device needs more data.
Data Fields
<<Color2: execution failed [No argument named "Can '''channels''' only be 1 or 2 or can it handle more? Old wiki lists 4 for surround and 6 for surround w/ center and lfe (sub?). Should it be 1"] (see also the log)>>
int |
freq |
DSP frequency (samples per second); see Remarks for details |
format |
audio data format; see Remarks for details |
|
Uint8 |
channels |
number of channels: 1 mono, 2 stereo; see Remarks for details |
Uint8 |
silence |
audio buffer silence value (calculated) |
Uint16 |
samples |
audio buffer size in samples (power of 2); see Remarks for details |
Uint32 |
size |
audio buffer size in bytes (calculated) |
SDL_AudioCallback |
callback |
a function that is called when the audio device needs more data; see Remarks for details |
void* |
userdata |
a pointer that is passed as the first parameter to callback |
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Code Examples
You can add your code example here
Remarks
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*
The SDL_AudioSpec structure is used to describe the format of some audio data. This structure is used by SDL_OpenAudio() and SDL_LoadWAV(). While all fields are used by SDL_OpenAudio(), only freq, format, channels, and samples are used by SDL_LoadWAV(). We will detail these common members here:
freq specifies the number of samples sent to the sound device every per second. Common values are 11025, 22050 and 44100. The higher the better. green
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format specifies the size and type of each sample element. Values it can take are: Audio format flags may be one of the following values:
Defaults to LSB byte order -or- Basic ???
AUDIO_U8
unsigned 8-bit samples.
AUDIO_S8
signed 8-bit samples.
AUDIO_U16 or AUDIO_U16LSB
not supported by all hardware (unsigned 16-bit little-endian)
AUDIO_S16 or AUDIO_S16LSB
not supported by all hardware (signed 16-bit little-endian)
AUDIO_U16MSB
not supported by all hardware (unsigned 16-bit big-endian)
AUDIO_S16MSB
not supported by all hardware (signed 16-bit big-endian)
int32 support
AUDIO_S32 or AUDIO_S32LSB
32-bit integer samples
AUDIO_S32MSB
as above, but big-endian byte order
float32 support
AUDIO_F32 or AUDIO_F32LSB
32-bit floating point samples
AUDIO_F32MSB
as above, but big-endian byte order
Native audio byte ordering
AUDIO_U16SYS
either AUDIO_U16LSB or AUDIO_U16MSB depending on hardware CPU endianness
AUDIO_S16SYS
either AUDIO_S16LSB or AUDIO_S16MSB depending on hardware CPU endianness
AUDIO_S32SYS
either AUDIO_S32LSB or AUDIO_S32MSB depending on hardware CPU endianness
AUDIO_F32SYS
either AUDIO_F32LSB or AUDIO_F32MSB depending on hardware CPU endianness
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channels specifies the number of separate sound channels. 1 is mono (single channel), 2 is stereo (dual channel). green
samples specifies a unit of audio data. When used with SDL_OpenAudio() this refers to the size of the audio buffer in samples. A sample is a chunk of audio data of the size specified in format multiplied by the number of channels. When the SDL_AudioSpec is used with SDL_LoadWAV() samples is set to 4096. green
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The calculated values silence and size are calculated by SDL_OpenAudio().
Stereo samples are stored in a LRLRLR ordering.
callback is of the form:
void SDL_AudioCallback(void* userdata, Uint8* stream, int len)with the following parameters:
userdata
an application-specific parameter saved in the SDL_AudioSpec structure
stream
a pointer to the audio data buffer filled in by the callback
len
the length of that buffer in bytes
Once the callback returns, the buffer will no longer be valid.
