Enum gcp_client::google::cloud::speech::v1p1beta1::recognition_config::AudioEncoding

#[repr(i32)]pub enum AudioEncoding {
    EncodingUnspecified,
    Linear16,
    Flac,
    Mulaw,
    Amr,
    AmrWb,
    OggOpus,
    SpeexWithHeaderByte,
    Mp3,
}

The encoding of the audio data sent in the request.

All encodings support only 1 channel (mono) audio, unless the audio_channel_count and enable_separate_recognition_per_channel fields are set.

For best results, the audio source should be captured and transmitted using a lossless encoding (FLAC or LINEAR16). The accuracy of the speech recognition can be reduced if lossy codecs are used to capture or transmit audio, particularly if background noise is present. Lossy codecs include MULAW, AMR, AMR_WB, OGG_OPUS, SPEEX_WITH_HEADER_BYTE, and MP3.

The FLAC and WAV audio file formats include a header that describes the included audio content. You can request recognition for WAV files that contain either LINEAR16 or MULAW encoded audio. If you send FLAC or WAV audio file format in your request, you do not need to specify an AudioEncoding; the audio encoding format is determined from the file header. If you specify an AudioEncoding when you send send FLAC or WAV audio, the encoding configuration must match the encoding described in the audio header; otherwise the request returns an [google.rpc.Code.INVALID_ARGUMENT][google.rpc.Code.INVALID_ARGUMENT] error code.

Variants

EncodingUnspecified

Not specified.

Linear16

Uncompressed 16-bit signed little-endian samples (Linear PCM).

Flac

FLAC (Free Lossless Audio Codec) is the recommended encoding because it is lossless--therefore recognition is not compromised--and requires only about half the bandwidth of LINEAR16. FLAC stream encoding supports 16-bit and 24-bit samples, however, not all fields in STREAMINFO are supported.

Mulaw

8-bit samples that compand 14-bit audio samples using G.711 PCMU/mu-law.

Amr

Adaptive Multi-Rate Narrowband codec. sample_rate_hertz must be 8000.

AmrWb

Adaptive Multi-Rate Wideband codec. sample_rate_hertz must be 16000.

OggOpus

Opus encoded audio frames in Ogg container (OggOpus). sample_rate_hertz must be one of 8000, 12000, 16000, 24000, or 48000.

SpeexWithHeaderByte

Although the use of lossy encodings is not recommended, if a very low bitrate encoding is required, OGG_OPUS is highly preferred over Speex encoding. The Speex encoding supported by Cloud Speech API has a header byte in each block, as in MIME type audio/x-speex-with-header-byte. It is a variant of the RTP Speex encoding defined in RFC 5574. The stream is a sequence of blocks, one block per RTP packet. Each block starts with a byte containing the length of the block, in bytes, followed by one or more frames of Speex data, padded to an integral number of bytes (octets) as specified in RFC 5574. In other words, each RTP header is replaced with a single byte containing the block length. Only Speex wideband is supported. sample_rate_hertz must be 16000.

Mp3

MP3 audio. Support all standard MP3 bitrates (which range from 32-320 kbps). When using this encoding, sample_rate_hertz has to match the sample rate of the file being used.

Implementations

impl AudioEncoding

pub fn is_valid(value: i32) -> bool

Returns true if value is a variant of AudioEncoding.

pub fn from_i32(value: i32) -> Option<AudioEncoding>

Converts an i32 to a AudioEncoding, or None if value is not a valid variant.

Trait Implementations

impl Clone for AudioEncoding

fn clone(&self) -> AudioEncoding

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for AudioEncoding

impl Debug for AudioEncoding

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Default for AudioEncoding

fn default() -> AudioEncoding

Returns the "default value" for a type.

impl Eq for AudioEncoding

impl From<AudioEncoding> for i32

fn from(value: AudioEncoding) -> i32

Performs the conversion.

impl Hash for AudioEncoding

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl Ord for AudioEncoding

fn cmp(&self, other: &AudioEncoding) -> Ordering

This method returns an [Ordering] between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialEq<AudioEncoding> for AudioEncoding

fn eq(&self, other: &AudioEncoding) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<AudioEncoding> for AudioEncoding

fn partial_cmp(&self, other: &AudioEncoding) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralEq for AudioEncoding

impl StructuralPartialEq for AudioEncoding