Enum googapis::google::cloud::speech::v1::recognition_config::AudioEncoding [−][src]
#[repr(i32)]
pub enum AudioEncoding {
EncodingUnspecified,
Linear16,
Flac,
Mulaw,
Amr,
AmrWb,
OggOpus,
SpeexWithHeaderByte,
}
Expand description
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
, 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
Not specified.
Uncompressed 16-bit signed little-endian samples (Linear PCM).
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.
8-bit samples that compand 14-bit audio samples using G.711 PCMU/mu-law.
Adaptive Multi-Rate Narrowband codec. sample_rate_hertz
must be 8000.
Adaptive Multi-Rate Wideband codec. sample_rate_hertz
must be 16000.
Opus encoded audio frames in Ogg container
([OggOpus](https://wiki.xiph.org/OggOpus)).
sample_rate_hertz
must be one of 8000, 12000, 16000, 24000, or 48000.
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](https://speex.org/) 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.
Implementations
Trait Implementations
Returns the “default value” for a type. Read more
Performs the conversion.
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Auto Trait Implementations
impl RefUnwindSafe for AudioEncoding
impl Send for AudioEncoding
impl Sync for AudioEncoding
impl Unpin for AudioEncoding
impl UnwindSafe for AudioEncoding
Blanket Implementations
Mutably borrows from an owned value. Read more
Compare self to key
and return true
if they are equal.
Wrap the input message T
in a tonic::Request
pub fn vzip(self) -> V
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more