Differences between revisions 6 and 7

SDL_AudioFormat

A typedef that contains audio format data and flags.

Contents

SDL_AudioFormat

Values

Bit Meanings

These are what the 16 bits in SDL_AudioFormat currently mean:

 +----------------------sample is signed if set
 |
 |        +----------sample is bigendian if set
 |        |
 |        |           +--sample is float if set
 |        |           |
 |        |           |  +--sample bit size---+
 |        |           |  |                    |
15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0

Unspecified bits are always zero. There are macros in SDL 1.3 and later to query these bits.

Audio flags

SDL_AUDIO_MASK_BITSIZE	(0xFF)
SDL_AUDIO_MASK_DATATYPE	(1<<8)
SDL_AUDIO_MASK_ENDIAN	(1<<12)
SDL_AUDIO_MASK_SIGNED	(1<<15)
SDL_AUDIO_BITSIZE(x)	(x & SDL_AUDIO_MASK_BITSIZE)
SDL_AUDIO_ISFLOAT(x)	(x & SDL_AUDIO_MASK_DATATYPE)
SDL_AUDIO_ISBIGENDIAN(x)	(x & SDL_AUDIO_MASK_ENDIAN)
SDL_AUDIO_ISSIGNED(x)	(x & SDL_AUDIO_MASK_SIGNED)
SDL_AUDIO_ISINT(x)	(!SDL_AUDIO_ISFLOAT(x))
SDL_AUDIO_ISLITTLEENDIAN(x)	(!SDL_AUDIO_ISBIGENDIAN(x))
SDL_AUDIO_ISUNSIGNED(x)	(!SDL_AUDIO_ISSIGNED(x))

Audio format flags

AUDIO_S8	signed 8-bit samples
AUDIO_U8	unsigned 8-bit samples
AUDIO_S16LSB	signed 16-bit samples in little-endian order
AUDIO_S16MSB	signed 16-bit samples int big-endian byte order
AUDIO_S16SYS	signed 16-bit samples in native byte order
AUDIO_U16LSB	unsigned 16-bit samples in little-endian order
AUDIO_U16MSB	unsigned 16-bit samples in big-endian byte order
AUDIO_U16SYS	unsigned 16-bit samples in native byte order
AUDIO_U16	AUDIO_U16LSB
AUDIO_S16	AUDIO_S16LSB

int32 support

(New to SDL 1.3)

AUDIO_S32LSB	32-bit integer samples
AUDIO_S32MSB	as above, but big-endian byte order
AUDIO_S32	AUDIO_S32LSB

float32 support

(New to SDL 1.3)

AUDIO_F32LSB	32-bit floating point samples
AUDIO_F32MSB	as above, but big-endian byte order
AUDIO_F32	AUDIO_F32LSB

Native audio byte ordering

#if SDL_BYTEORDER == SDL_LIL_ENDIAN
#define AUDIO_S32SYS AUDIO_S32LSB
#define AUDIO_F32SYS AUDIO_F32LSB
#else
#define AUDIO_S32SYS AUDIO_S32MSB
#define AUDIO_F32SYS AUDIO_F32MSB
#endif

Allow change flags

Which audio format changes are allowed when opening a device.

SDL_AUDIO_ALLOW_FREQUENCY_CHANGE	0x00000001
SDL_AUDIO_ALLOW_FORMAT_CHANGE	0x00000002
SDL_AUDIO_ALLOW_CHANNELS_CHANGE	0x00000004
SDL_AUDIO_ALLOW_ANY_CHANGE	(SDL_AUDIO_ALLOW_FREQUENCY_CHANGE\|SDL_AUDIO_ALLOW_FORMAT_CHANGE\|SDL_AUDIO_ALLOW_CHANNELS_CHANGE)

Code Examples

You can add your code example here

-  ⇤ ← Revision 6 as of 2009-12-20 04:16:56 → 
  Size: 3063
  Editor: ip68-4-123-62
  Comment: null
+   ← Revision 7 as of 2009-12-20 04:23:59 → ⇥
  Size: 3091
  Editor: ip68-4-123-62
  Comment: null
-Deletions are marked like this.
+Additions are marked like this.
 Line 39:
+||AUDIO_S8||signed 8-bit samples||
-Line 40:
+Line 41:
-||AUDIO_S8||signed 8-bit samples||
||AUDIO_U16LSB||unsigned 16-bit samples||
||AUDIO_S16LSB||signed 16-bit samples||
||AUDIO_U16MSB||as above, but big-endian byte order||
||AUDIO_S16MSB||as above, but big-endian byte order||
+||AUDIO_S16LSB||signed 16-bit samples in little-endian order||
||AUDIO_S16MSB||signed 16-bit samples int big-endian byte order||
||AUDIO_S16SYS||signed 16-bit samples in native byte order||
||AUDIO_U16LSB||unsigned 16-bit samples in little-endian order||
||AUDIO_U16MSB||unsigned 16-bit samples in big-endian byte order||
||AUDIO_U16SYS||unsigned 16-bit samples in native byte order||
-Line 47:
+Line 49:
-Defaults to LSB byte order.
-Line 64:
+Line 65:
-#define AUDIO_U16SYS AUDIO_U16LSB
#define AUDIO_S16SYS AUDIO_S16LSB
-Line 69:
+Line 68:
-#define AUDIO_U16SYS AUDIO_U16MSB
#define AUDIO_S16SYS AUDIO_S16MSB

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