Nesta seção, demonstramos como transcrever áudio de streaming, como a entrada de um microfone, para texto.
O reconhecimento de voz por streaming permite que você faça streaming de áudio para Speech-to-Text e receba uma transmissão de reconhecimento de voz em tempo real conforme o áudio é processado. Consulte também os limites de áudio para transmissão de solicitações de reconhecimento de fala em streaming. O reconhecimento de fala em streaming só está disponível via gRPC.
Como realizar reconhecimento de fala em streaming em um arquivo local
Veja abaixo um exemplo de reconhecimento de fala em streaming em um arquivo de áudio
local. Há um limite de 10 MB em todas as solicitações de streaming enviadas à API. Esse
limite se aplica à solicitação StreamingRecognize
inicial e ao tamanho de cada mensagem individual no stream. Exceder esse limite
causará um erro.
Go
import (
"context"
"flag"
"fmt"
"io"
"log"
"os"
"path/filepath"
speech "cloud.google.com/go/speech/apiv1"
speechpb "google.golang.org/genproto/googleapis/cloud/speech/v1"
)
func main() {
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage: %s <AUDIOFILE>\n", filepath.Base(os.Args[0]))
fmt.Fprintf(os.Stderr, "<AUDIOFILE> must be a path to a local audio file. Audio file must be a 16-bit signed little-endian encoded with a sample rate of 16000.\n")
}
flag.Parse()
if len(flag.Args()) != 1 {
log.Fatal("Please pass path to your local audio file as a command line argument")
}
audioFile := flag.Arg(0)
ctx := context.Background()
client, err := speech.NewClient(ctx)
if err != nil {
log.Fatal(err)
}
stream, err := client.StreamingRecognize(ctx)
if err != nil {
log.Fatal(err)
}
// Send the initial configuration message.
if err := stream.Send(&speechpb.StreamingRecognizeRequest{
StreamingRequest: &speechpb.StreamingRecognizeRequest_StreamingConfig{
StreamingConfig: &speechpb.StreamingRecognitionConfig{
Config: &speechpb.RecognitionConfig{
Encoding: speechpb.RecognitionConfig_LINEAR16,
SampleRateHertz: 16000,
LanguageCode: "en-US",
},
},
},
}); err != nil {
log.Fatal(err)
}
f, err := os.Open(audioFile)
if err != nil {
log.Fatal(err)
}
defer f.Close()
go func() {
buf := make([]byte, 1024)
for {
n, err := f.Read(buf)
if n > 0 {
if err := stream.Send(&speechpb.StreamingRecognizeRequest{
StreamingRequest: &speechpb.StreamingRecognizeRequest_AudioContent{
AudioContent: buf[:n],
},
}); err != nil {
log.Printf("Could not send audio: %v", err)
}
}
if err == io.EOF {
// Nothing else to pipe, close the stream.
if err := stream.CloseSend(); err != nil {
log.Fatalf("Could not close stream: %v", err)
}
return
}
if err != nil {
log.Printf("Could not read from %s: %v", audioFile, err)
continue
}
}
}()
for {
resp, err := stream.Recv()
if err == io.EOF {
break
}
if err != nil {
log.Fatalf("Cannot stream results: %v", err)
}
if err := resp.Error; err != nil {
log.Fatalf("Could not recognize: %v", err)
}
for _, result := range resp.Results {
fmt.Printf("Result: %+v\n", result)
}
}
}
Java
/**
* Performs streaming speech recognition on raw PCM audio data.
*
* @param fileName the path to a PCM audio file to transcribe.
*/
public static void streamingRecognizeFile(String fileName) throws Exception, IOException {
Path path = Paths.get(fileName);
byte[] data = Files.readAllBytes(path);
// Instantiates a client with GOOGLE_APPLICATION_CREDENTIALS
try (SpeechClient speech = SpeechClient.create()) {
// Configure request with local raw PCM audio
RecognitionConfig recConfig =
RecognitionConfig.newBuilder()
.setEncoding(AudioEncoding.LINEAR16)
.setLanguageCode("en-US")
.setSampleRateHertz(16000)
.setModel("default")
.build();
StreamingRecognitionConfig config =
StreamingRecognitionConfig.newBuilder().setConfig(recConfig).build();
class ResponseApiStreamingObserver<T> implements ApiStreamObserver<T> {
private final SettableFuture<List<T>> future = SettableFuture.create();
private final List<T> messages = new java.util.ArrayList<T>();
@Override
public void onNext(T message) {
messages.add(message);
}
@Override
public void onError(Throwable t) {
future.setException(t);
}
@Override
public void onCompleted() {
future.set(messages);
}
// Returns the SettableFuture object to get received messages / exceptions.
public SettableFuture<List<T>> future() {
return future;
}
}
ResponseApiStreamingObserver<StreamingRecognizeResponse> responseObserver =
new ResponseApiStreamingObserver<>();
BidiStreamingCallable<StreamingRecognizeRequest, StreamingRecognizeResponse> callable =
speech.streamingRecognizeCallable();
ApiStreamObserver<StreamingRecognizeRequest> requestObserver =
callable.bidiStreamingCall(responseObserver);
// The first request must **only** contain the audio configuration:
requestObserver.onNext(
StreamingRecognizeRequest.newBuilder().setStreamingConfig(config).build());
// Subsequent requests must **only** contain the audio data.
requestObserver.onNext(
StreamingRecognizeRequest.newBuilder()
.setAudioContent(ByteString.copyFrom(data))
.build());
// Mark transmission as completed after sending the data.
requestObserver.onCompleted();
List<StreamingRecognizeResponse> responses = responseObserver.future().get();
for (StreamingRecognizeResponse response : responses) {
// For streaming recognize, the results list has one is_final result (if available) followed
// by a number of in-progress results (if iterim_results is true) for subsequent utterances.
// Just print the first result here.
StreamingRecognitionResult result = response.getResultsList().get(0);
// There can be several alternative transcripts for a given chunk of speech. Just use the
// first (most likely) one here.
SpeechRecognitionAlternative alternative = result.getAlternativesList().get(0);
System.out.printf("Transcript : %s\n", alternative.getTranscript());
}
}
}Node.js
const fs = require('fs');
// Imports the Google Cloud client library
const speech = require('@google-cloud/speech');
// Creates a client
const client = new speech.SpeechClient();
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const filename = 'Local path to audio file, e.g. /path/to/audio.raw';
// const encoding = 'Encoding of the audio file, e.g. LINEAR16';
// const sampleRateHertz = 16000;
// const languageCode = 'BCP-47 language code, e.g. en-US';
const request = {
config: {
encoding: encoding,
sampleRateHertz: sampleRateHertz,
languageCode: languageCode,
},
interimResults: false, // If you want interim results, set this to true
};
// Stream the audio to the Google Cloud Speech API
const recognizeStream = client
.streamingRecognize(request)
.on('error', console.error)
.on('data', data => {
console.log(
`Transcription: ${data.results[0].alternatives[0].transcript}`
);
});
// Stream an audio file from disk to the Speech API, e.g. "./resources/audio.raw"
fs.createReadStream(filename).pipe(recognizeStream);Python
def transcribe_streaming(stream_file):
"""Streams transcription of the given audio file."""
import io
from google.cloud import speech
client = speech.SpeechClient()
with io.open(stream_file, "rb") as audio_file:
content = audio_file.read()
# In practice, stream should be a generator yielding chunks of audio data.
stream = [content]
requests = (
speech.StreamingRecognizeRequest(audio_content=chunk) for chunk in stream
)
config = speech.RecognitionConfig(
encoding=speech.RecognitionConfig.AudioEncoding.LINEAR16,
sample_rate_hertz=16000,
language_code="en-US",
)
streaming_config = speech.StreamingRecognitionConfig(config=config)
# streaming_recognize returns a generator.
responses = client.streaming_recognize(
config=streaming_config,
requests=requests,
)
for response in responses:
# Once the transcription has settled, the first result will contain the
# is_final result. The other results will be for subsequent portions of
# the audio.
for result in response.results:
print("Finished: {}".format(result.is_final))
print("Stability: {}".format(result.stability))
alternatives = result.alternatives
# The alternatives are ordered from most likely to least.
for alternative in alternatives:
print("Confidence: {}".format(alternative.confidence))
print(u"Transcript: {}".format(alternative.transcript))
Ainda que seja possível fazer streaming de um arquivo de áudio local para a API Speech-to-Text, recomendamos realizar o reconhecimento de áudio síncrono ou assíncrono para receber os resultados no modo de lote.
Como realizar reconhecimento de fala em streaming em um stream de áudio
A Speech-to-Text também pode realizar reconhecimento em streaming, áudio em tempo real.
Este é um exemplo de reconhecimento de fala em streaming em um stream de áudio recebido de um microfone:
Go
import (
"context"
"fmt"
"io"
"log"
"os"
speech "cloud.google.com/go/speech/apiv1"
speechpb "google.golang.org/genproto/googleapis/cloud/speech/v1"
)
func main() {
ctx := context.Background()
client, err := speech.NewClient(ctx)
if err != nil {
log.Fatal(err)
}
stream, err := client.StreamingRecognize(ctx)
if err != nil {
log.Fatal(err)
}
// Send the initial configuration message.
if err := stream.Send(&speechpb.StreamingRecognizeRequest{
StreamingRequest: &speechpb.StreamingRecognizeRequest_StreamingConfig{
StreamingConfig: &speechpb.StreamingRecognitionConfig{
Config: &speechpb.RecognitionConfig{
Encoding: speechpb.RecognitionConfig_LINEAR16,
SampleRateHertz: 16000,
LanguageCode: "en-US",
},
},
},
}); err != nil {
log.Fatal(err)
}
go func() {
// Pipe stdin to the API.
buf := make([]byte, 1024)
for {
n, err := os.Stdin.Read(buf)
if n > 0 {
if err := stream.Send(&speechpb.StreamingRecognizeRequest{
StreamingRequest: &speechpb.StreamingRecognizeRequest_AudioContent{
AudioContent: buf[:n],
},
}); err != nil {
log.Printf("Could not send audio: %v", err)
}
}
if err == io.EOF {
// Nothing else to pipe, close the stream.
if err := stream.CloseSend(); err != nil {
log.Fatalf("Could not close stream: %v", err)
}
return
}
if err != nil {
log.Printf("Could not read from stdin: %v", err)
continue
}
}
}()
for {
resp, err := stream.Recv()
if err == io.EOF {
break
}
if err != nil {
log.Fatalf("Cannot stream results: %v", err)
}
if err := resp.Error; err != nil {
// Workaround while the API doesn't give a more informative error.
if err.Code == 3 || err.Code == 11 {
log.Print("WARNING: Speech recognition request exceeded limit of 60 seconds.")
}
log.Fatalf("Could not recognize: %v", err)
}
for _, result := range resp.Results {
fmt.Printf("Result: %+v\n", result)
}
}
}
Python
from __future__ import division
import re
import sys
from google.cloud import speech
import pyaudio
from six.moves import queue
# Audio recording parameters
RATE = 16000
CHUNK = int(RATE / 10) # 100ms
class MicrophoneStream(object):
"""Opens a recording stream as a generator yielding the audio chunks."""
def __init__(self, rate, chunk):
self._rate = rate
self._chunk = chunk
# Create a thread-safe buffer of audio data
self._buff = queue.Queue()
self.closed = True
def __enter__(self):
self._audio_interface = pyaudio.PyAudio()
self._audio_stream = self._audio_interface.open(
format=pyaudio.paInt16,
# The API currently only supports 1-channel (mono) audio
# https://goo.gl/z757pE
channels=1,
rate=self._rate,
input=True,
frames_per_buffer=self._chunk,
# Run the audio stream asynchronously to fill the buffer object.
# This is necessary so that the input device's buffer doesn't
# overflow while the calling thread makes network requests, etc.
stream_callback=self._fill_buffer,
)
self.closed = False
return self
def __exit__(self, type, value, traceback):
self._audio_stream.stop_stream()
self._audio_stream.close()
self.closed = True
# Signal the generator to terminate so that the client's
# streaming_recognize method will not block the process termination.
self._buff.put(None)
self._audio_interface.terminate()
def _fill_buffer(self, in_data, frame_count, time_info, status_flags):
"""Continuously collect data from the audio stream, into the buffer."""
self._buff.put(in_data)
return None, pyaudio.paContinue
def generator(self):
while not self.closed:
# Use a blocking get() to ensure there's at least one chunk of
# data, and stop iteration if the chunk is None, indicating the
# end of the audio stream.
chunk = self._buff.get()
if chunk is None:
return
data = [chunk]
# Now consume whatever other data's still buffered.
while True:
try:
chunk = self._buff.get(block=False)
if chunk is None:
return
data.append(chunk)
except queue.Empty:
break
yield b"".join(data)
def listen_print_loop(responses):
"""Iterates through server responses and prints them.
The responses passed is a generator that will block until a response
is provided by the server.
Each response may contain multiple results, and each result may contain
multiple alternatives; for details, see https://goo.gl/tjCPAU. Here we
print only the transcription for the top alternative of the top result.
In this case, responses are provided for interim results as well. If the
response is an interim one, print a line feed at the end of it, to allow
the next result to overwrite it, until the response is a final one. For the
final one, print a newline to preserve the finalized transcription.
"""
num_chars_printed = 0
for response in responses:
if not response.results:
continue
# The `results` list is consecutive. For streaming, we only care about
# the first result being considered, since once it's `is_final`, it
# moves on to considering the next utterance.
result = response.results[0]
if not result.alternatives:
continue
# Display the transcription of the top alternative.
transcript = result.alternatives[0].transcript
# Display interim results, but with a carriage return at the end of the
# line, so subsequent lines will overwrite them.
#
# If the previous result was longer than this one, we need to print
# some extra spaces to overwrite the previous result
overwrite_chars = " " * (num_chars_printed - len(transcript))
if not result.is_final:
sys.stdout.write(transcript + overwrite_chars + "\r")
sys.stdout.flush()
num_chars_printed = len(transcript)
else:
print(transcript + overwrite_chars)
# Exit recognition if any of the transcribed phrases could be
# one of our keywords.
if re.search(r"\b(exit|quit)\b", transcript, re.I):
print("Exiting..")
break
num_chars_printed = 0
def main():
# See http://g.co/cloud/speech/docs/languages
# for a list of supported languages.
language_code = "en-US" # a BCP-47 language tag
client = speech.SpeechClient()
config = speech.RecognitionConfig(
encoding=speech.RecognitionConfig.AudioEncoding.LINEAR16,
sample_rate_hertz=RATE,
language_code=language_code,
)
streaming_config = speech.StreamingRecognitionConfig(
config=config, interim_results=True
)
with MicrophoneStream(RATE, CHUNK) as stream:
audio_generator = stream.generator()
requests = (
speech.StreamingRecognizeRequest(audio_content=content)
for content in audio_generator
)
responses = client.streaming_recognize(streaming_config, requests)
# Now, put the transcription responses to use.
listen_print_loop(responses)
if __name__ == "__main__":
main()Java
/** Performs microphone streaming speech recognition with a duration of 1 minute. */
public static void streamingMicRecognize() throws Exception {
ResponseObserver<StreamingRecognizeResponse> responseObserver = null;
try (SpeechClient client = SpeechClient.create()) {
responseObserver =
new ResponseObserver<StreamingRecognizeResponse>() {
ArrayList<StreamingRecognizeResponse> responses = new ArrayList<>();
public void onStart(StreamController controller) {}
public void onResponse(StreamingRecognizeResponse response) {
responses.add(response);
}
public void onComplete() {
for (StreamingRecognizeResponse response : responses) {
StreamingRecognitionResult result = response.getResultsList().get(0);
SpeechRecognitionAlternative alternative = result.getAlternativesList().get(0);
System.out.printf("Transcript : %s\n", alternative.getTranscript());
}
}
public void onError(Throwable t) {
System.out.println(t);
}
};
ClientStream<StreamingRecognizeRequest> clientStream =
client.streamingRecognizeCallable().splitCall(responseObserver);
RecognitionConfig recognitionConfig =
RecognitionConfig.newBuilder()
.setEncoding(RecognitionConfig.AudioEncoding.LINEAR16)
.setLanguageCode("en-US")
.setSampleRateHertz(16000)
.build();
StreamingRecognitionConfig streamingRecognitionConfig =
StreamingRecognitionConfig.newBuilder().setConfig(recognitionConfig).build();
StreamingRecognizeRequest request =
StreamingRecognizeRequest.newBuilder()
.setStreamingConfig(streamingRecognitionConfig)
.build(); // The first request in a streaming call has to be a config
clientStream.send(request);
// SampleRate:16000Hz, SampleSizeInBits: 16, Number of channels: 1, Signed: true,
// bigEndian: false
AudioFormat audioFormat = new AudioFormat(16000, 16, 1, true, false);
DataLine.Info targetInfo =
new Info(
TargetDataLine.class,
audioFormat); // Set the system information to read from the microphone audio stream
if (!AudioSystem.isLineSupported(targetInfo)) {
System.out.println("Microphone not supported");
System.exit(0);
}
// Target data line captures the audio stream the microphone produces.
TargetDataLine targetDataLine = (TargetDataLine) AudioSystem.getLine(targetInfo);
targetDataLine.open(audioFormat);
targetDataLine.start();
System.out.println("Start speaking");
long startTime = System.currentTimeMillis();
// Audio Input Stream
AudioInputStream audio = new AudioInputStream(targetDataLine);
while (true) {
long estimatedTime = System.currentTimeMillis() - startTime;
byte[] data = new byte[6400];
audio.read(data);
if (estimatedTime > 60000) { // 60 seconds
System.out.println("Stop speaking.");
targetDataLine.stop();
targetDataLine.close();
break;
}
request =
StreamingRecognizeRequest.newBuilder()
.setAudioContent(ByteString.copyFrom(data))
.build();
clientStream.send(request);
}
} catch (Exception e) {
System.out.println(e);
}
responseObserver.onComplete();
}Node.js
Para essas amostras, é preciso que você instale o SoX e que ele esteja disponível no $PATH.
- Para Mac OS:
brew install sox. - Para a maioria das distribuições do Linux:
sudo apt-get install sox libsox-fmt-all. - Para Windows: faça o download dos binários.
Para mais informações sobre como instalar e criar um cliente Speech-to-Text, consulte Bibliotecas de cliente Speech-to-Text.
const recorder = require('node-record-lpcm16');
// Imports the Google Cloud client library
const speech = require('@google-cloud/speech');
// Creates a client
const client = new speech.SpeechClient();
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const encoding = 'Encoding of the audio file, e.g. LINEAR16';
// const sampleRateHertz = 16000;
// const languageCode = 'BCP-47 language code, e.g. en-US';
const request = {
config: {
encoding: encoding,
sampleRateHertz: sampleRateHertz,
languageCode: languageCode,
},
interimResults: false, // If you want interim results, set this to true
};
// Create a recognize stream
const recognizeStream = client
.streamingRecognize(request)
.on('error', console.error)
.on('data', data =>
process.stdout.write(
data.results[0] && data.results[0].alternatives[0]
? `Transcription: ${data.results[0].alternatives[0].transcript}\n`
: '\n\nReached transcription time limit, press Ctrl+C\n'
)
);
// Start recording and send the microphone input to the Speech API.
// Ensure SoX is installed, see https://www.npmjs.com/package/node-record-lpcm16#dependencies
recorder
.record({
sampleRateHertz: sampleRateHertz,
threshold: 0,
// Other options, see https://www.npmjs.com/package/node-record-lpcm16#options
verbose: false,
recordProgram: 'rec', // Try also "arecord" or "sox"
silence: '10.0',
})
.stream()
.on('error', console.error)
.pipe(recognizeStream);
console.log('Listening, press Ctrl+C to stop.');A seguir
- Saiba como transcrever um stream de áudio contínuo
Faça um teste
Se você é novo no Google Cloud, crie uma conta para avaliar o desempenho do Speech-to-Text em cenários reais. Clientes novos recebem US$ 300 em créditos para executar, testar e implantar cargas de trabalho.
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