Enums

Four backed enums define the core types used throughout the library.

AudioFormat

Major audio container formats. Values are libsndfile SF_FORMAT_* constants masked against SF_FORMAT_TYPEMASK ( 0x0FFF0000).

Cases

Case	Hex Value	Extension
Wav	0x010000	wav
Aiff	0x020000	aiff
Au	0x030000	au
Raw	0x040000	raw
Flac	0x170000	flac
Ogg	0x200000	ogg
Mpeg	0x230000	mp3
Caf	0x180000	caf

Full cases: Paf, Svx, Nist, Voc, Ircam, W64, Mat4, Mat5, Pvf, Xi, Htk, Sds, Avr, Wavex, Sd2, Wve, Mpc2k, Rf64.

Methods

AudioFormat::Wav->extension();                               // 'wav'
AudioFormat::fromExtension('flac');                          // AudioFormat::Flac
AudioFormat::fromPath('song.mp3');                           // AudioFormat::Mpeg
AudioFormat::Wav->defaultSampleFormat();                     // SampleFormat::Pcm16
AudioFormat::Wav->compatibleSampleFormats();                 // [PcmS8, Pcm16, ...]
AudioFormat::fromSndfileFormat($combinedFormat);             // Extract from sf format value

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SampleFormat

Audio encoding subtypes. Values are libsndfile SF_FORMAT_* constants masked against SF_FORMAT_SUBMASK ( 0x0000FFFF).

Common cases

Case	Hex Value	Bit Depth	Integer
PcmS8	0x0001	8	Yes
Pcm16	0x0002	16	Yes
Pcm24	0x0003	24	Yes
Pcm32	0x0004	32	Yes
Float	0x0006	32	No
Double	0x0007	64	No
Vorbis	0x0060	0	No
MpegLayerIII	0x0082	0	No

Full cases: PcmU8, ULaw, ALaw, ImaAdpcm, MsAdpcm, Gsm610, Dwvw12, Dwvw16, Dwvw24, DwvwN, MpegLayerI, MpegLayerII.

Methods

SampleFormat::Pcm16->bitDepth();            // 16
SampleFormat::Pcm16->isInteger();           // true
SampleFormat::Float->isPcm();               // false
SampleFormat::Float->toDtype();             // DType::Float32
SampleFormat::fromDtype(DType::Int16);      // SampleFormat::Pcm16
SampleFormat::fromSndfileFormat(0x010006);  // SampleFormat::Float

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FileMode

File open modes matching libsndfile's SFM_READ / SFM_WRITE / SFM_RDWR.

Case	Value	Description
Read	0x10	Open for reading
Write	0x20	Open for writing (creates or truncates)
ReadWrite	0x30	Open for both reading and writing

use PhpMlKit\SoundFile\Enums\FileMode;

$sf = new SoundFile('file.wav', FileMode::Read);

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ResampleQuality

libsamplerate converter quality levels.

Case	Value	Description
Best	0	Band-limited sinc, highest quality, slowest
Medium	1	Band-limited sinc, medium quality
Fastest	2	Band-limited sinc, fastest
Linear	3	Linear interpolation, fastest but lowest quality

use PhpMlKit\SoundFile\Enums\ResampleQuality;

$r = sf_resample($audio, 44100, 22050, quality: ResampleQuality::Fastest);