_MEMSOUND

The _MEMSOUND function returns a _MEM value referring to a sound's raw data in memory using a designated sound handle created by the _SNDOPEN function.

Syntax

soundBlock = _MEMSOUND[(soundHandle&, channel%)]

Parameters

The soundBlock _MEM type variable holds the read-only elements .OFFSET, .SIZE, .ELEMENTSIZE, .TYPE and .SOUND.
- .OFFSET is the starting memory address of the sound sample data.
- .SIZE is the size of the sample data in bytes
- .ELEMENTSIZE will contain the number of bytes-per-sample the audio contains.
  - Can return 1 (8-bit mono), 2 (8-bit stereo), 2 (16-bit mono), 4 (16-bit stereo), 4 (32-bit mono) or 8 (32-bit stereo).
  - Use .TYPE to determine the data type of the sample data.
- .TYPE will contain the data type of the sample data. See _MEM for details.
- .SOUND will contain the same handle value as returned by the _SNDOPEN function.
The second parameter channel% must be 0 (interleaved/mono; version 3.1.0 and up), 1 (left channel/mono) or 2 (right channel, for stereo files).

Description

Use the function to access raw sound data in memory for direct access.
Sound handle values and the memory used must still be freed using _SNDCLOSE when no longer required.
If .SIZE returns 0, that means the data could not be accessed. It may happen if you try to access the right channel in a mono file, for example.

Availability

QB64 1.5 and up (QB64 Team)
QBPE 0.5 and up (QB64 Phoenix Edition)

Examples

Example 1: Checking that a sound file is stereo.

OPTION _EXPLICIT

PRINT "Loading...";
DIM Song AS LONG
Song = _SNDOPEN("onward_ride1.flac") ' Replace file name with your sound file
IF Song < 1 THEN
    PRINT "Failed to load sound!"
    END
END IF
PRINT "Done!"

DIM Channels AS _UNSIGNED _BYTE
Channels = SndChannels(Song)

IF Channels = 2 THEN
    PRINT "This file is STEREO"
ELSEIF Channels = 1 THEN
    PRINT "This file is MONO"
ELSE
    PRINT "An error occurred."
END IF

_SNDCLOSE Song 'closing the sound releases the mem blocks

END


' This function returns the number of sound channels for a valid sound "handle"
' 2 = stereo, 1 = mono, 0 = error
FUNCTION SndChannels~%% (handle AS LONG)
    DIM SampleData AS _MEM

    SndChannels = 0 ' Assume failure

    ' Check if the sound is valid
    SampleData = _MEMSOUND(handle, 1)
    IF SampleData.SIZE = 0 THEN
        EXIT FUNCTION
    END IF

    ' Check the data type and then decide if the sound is stereo or mono
    IF SampleData.TYPE = 260 THEN ' 32-bit floating point
        IF SampleData.ELEMENTSIZE = 4 THEN
            SndChannels = 1
        ELSEIF SampleData.ELEMENTSIZE = 8 THEN
            SndChannels = 2
        END IF
    ELSEIF SampleData.TYPE = 132 THEN ' 32-bit integer
        IF SampleData.ELEMENTSIZE = 4 THEN
            SndChannels = 1
        ELSEIF SampleData.ELEMENTSIZE = 8 THEN
            SndChannels = 2
        END IF
    ELSEIF SampleData.TYPE = 130 THEN ' 16-bit integer
        IF SampleData.ELEMENTSIZE = 2 THEN
            SndChannels = 1
        ELSEIF SampleData.ELEMENTSIZE = 4 THEN
            SndChannels = 2
        END IF
    ELSEIF SampleData.TYPE = 1153 THEN ' 8-bit unsigned integer
        IF SampleData.ELEMENTSIZE = 1 THEN
            SndChannels = 1
        ELSEIF SampleData.ELEMENTSIZE = 2 THEN
            SndChannels = 2
        END IF
    ELSEIF SampleData.TYPE = 0 THEN ' This means this is an OpenAL sound handle
        DIM RightChannel AS _MEM
        RightChannel = _MEMSOUND(handle, 2)
        IF RightChannel.SIZE > 0 THEN
            SndChannels = 2
        ELSE
            SndChannels = 1
        END IF
    END IF
END FUNCTION

Example 2: Plotting a sound's waves.

DEFLNG A-Z
OPTION _EXPLICIT
OPTION _EXPLICITARRAY

SCREEN _NEWIMAGE(800, 327, 32)

PRINT "Loading...";
DIM Song AS LONG
Song = _SNDOPEN("OPL3 Groove.rad") ' Replace this with your (rad, mid, it, xm, s3m, mod, mp3, flac, ogg, wav) sound file
IF Song < 1 THEN
    PRINT "Failed to load song!"
    END
END IF
PRINT "Done!"

_SNDPLAY Song

DIM SampleData AS _MEM
SampleData = _MEMSOUND(Song, 1) ' This can now be 0 or 1
IF SampleData.SIZE = 0 THEN
    PRINT "Failed to access sound sample data."
    END
END IF

DIM x AS LONG, i AS _UNSIGNED _INTEGER64, sf AS SINGLE, si AS INTEGER
DIM sz AS _UNSIGNED _INTEGER64

sz = _CV(_UNSIGNED _INTEGER64, _MK$(_OFFSET, SampleData.ELEMENTSIZE)) ' sz is the total size of the sound in bytes

DO UNTIL _KEYHIT = 27 OR NOT _SNDPLAYING(Song) OR i + (_WIDTH * sz) > SampleData.SIZE
    CLS
    LOCATE 1, 1: PRINT i; "/"; SampleData.SIZE, "Frame Size ="; sz, "Data Type ="; SampleData.TYPE

    $CHECKING:OFF
    IF SampleData.TYPE = 130 THEN ' integer stereo or mono
        FOR x = 0 TO _WIDTH - 1
            si = _MEMGET(SampleData, SampleData.OFFSET + i + x * sz, INTEGER) 'get sound data
            LINE (x, _HEIGHT / 2)-STEP(0, 300 * si / 32768), _RGB32(0, 111, 0) 'plot wave
        NEXT
    ELSEIF SampleData.TYPE = 260 THEN ' floating point stereo or mono
        FOR x = 0 TO _WIDTH - 1
            sf = _MEMGET(SampleData, SampleData.OFFSET + i + x * sz, SINGLE) 'get sound data
            LINE (x, _HEIGHT / 2)-STEP(0, sf * 300), _RGB32(0, 111, 0) 'plot wave
        NEXT
    ELSEIF sz = 2 AND SampleData.TYPE = 0 THEN ' integer mono (QB64 OpenAL stuff)
        FOR x = 0 TO _WIDTH - 1
            si = _MEMGET(SampleData, SampleData.OFFSET + i + x * sz, INTEGER) 'get sound data
            LINE (x, _HEIGHT / 2)-STEP(0, 300 * si / 32768), _RGB32(0, 111, 0) 'plot wave
        NEXT
    END IF
    $CHECKING:ON

    _DISPLAY
    _LIMIT 60

    i = FIX(_SNDGETPOS(Song) * _SNDRATE) * sz ' Calculate the new sample frame position
LOOP

_SNDCLOSE Song 'closing the sound releases the mem blocks
_AUTODISPLAY
END

_MEMSOUND

Contents

Syntax

Parameters

Description

Availability

Examples

See also

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_MEMSOUND

Syntax

Parameters

Description

Availability

Examples

See also

Navigation menu

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