Audio file streaming recognition using the API v3
Below, we provide an example of streaming recognition of speech from an audio file using the SpeechKit API v3. This example uses the following parameters:
- Language: Russian.
- Format of the audio stream: LPCM with a sampling rate of 8000 Hz.
- Number of audio channels: 1 (default).
- Profanity filter enabled.
- Other parameters are left at their defaults.
Authentication is performed under a service account using an API key or IAM token. Learn more about authentication in the SpeechKit API.
To implement an example from this section:
-
Create a service account to work with the SpeechKit API.
-
Assign the service account the
ai.speechkit-stt.user
role or higher for the folder where it was created. -
Download a sample
audio file for recognition or use your own one. -
Create a client application:
Python 3Java-
Clone the Yandex Cloud API
repository:git clone https://github.com/yandex-cloud/cloudapi
-
Use the pip package
manager to install thegrpcio-tools
package:pip install grpcio-tools
-
Go to the folder hosting the cloned Yandex Cloud API repository, create a folder named
output
, and generate the client interface code there:cd <path_to_cloudapi_directory> mkdir output python3 -m grpc_tools.protoc -I . -I third_party/googleapis \ --python_out=output \ --grpc_python_out=output \ google/api/http.proto \ google/api/annotations.proto \ yandex/cloud/api/operation.proto \ google/rpc/status.proto \ yandex/cloud/operation/operation.proto \ yandex/cloud/validation.proto \ yandex/cloud/ai/stt/v3/stt_service.proto \ yandex/cloud/ai/stt/v3/stt.proto
As a result, the
stt_pb2.py
,stt_pb2_grpc.py
,stt_service_pb2.py
, andstt_service_pb2_grpc.py
client interface files, as well as dependency files, will be created in theoutput
folder. -
Create a file (e.g.,
test.py
) in theoutput
folder root, and add the following code to it:#coding=utf8 import argparse import grpc import yandex.cloud.ai.stt.v3.stt_pb2 as stt_pb2 import yandex.cloud.ai.stt.v3.stt_service_pb2_grpc as stt_service_pb2_grpc CHUNK_SIZE = 4000 def gen(audio_file_name): # Specify recognition settings. recognize_options = stt_pb2.StreamingOptions( recognition_model=stt_pb2.RecognitionModelOptions( audio_format=stt_pb2.AudioFormatOptions( raw_audio=stt_pb2.RawAudio( audio_encoding=stt_pb2.RawAudio.LINEAR16_PCM, sample_rate_hertz=8000, audio_channel_count=1 ) ), text_normalization=stt_pb2.TextNormalizationOptions( text_normalization=stt_pb2.TextNormalizationOptions.TEXT_NORMALIZATION_ENABLED, profanity_filter=True, literature_text=False ), language_restriction=stt_pb2.LanguageRestrictionOptions( restriction_type=stt_pb2.LanguageRestrictionOptions.WHITELIST, language_code=['ru-RU'] ), audio_processing_type=stt_pb2.RecognitionModelOptions.REAL_TIME ) ) # Send a message with recognition settings. yield stt_pb2.StreamingRequest(session_options=recognize_options) # Read the audio file and send its contents in chunks. with open(audio_file_name, 'rb') as f: data = f.read(CHUNK_SIZE) while data != b'': yield stt_pb2.StreamingRequest(chunk=stt_pb2.AudioChunk(data=data)) data = f.read(CHUNK_SIZE) # Provide api_key instead of iam_token when authorizing with an API key # as a service account. # def run(api_key, audio_file_name): def run(iam_token, audio_file_name): # Establish a connection with the server. cred = grpc.ssl_channel_credentials() channel = grpc.secure_channel('stt.api.cloud.yandex.net:443', cred) stub = stt_service_pb2_grpc.RecognizerStub(channel) # Send data for recognition. it = stub.RecognizeStreaming(gen(audio_file_name), metadata=( # Parameters for authorization with an IAM token ('authorization', f'Bearer {iam_token}'), # Parameters for authorization with an API key as a service account # ('authorization', f'Api-Key {api_key}'), )) # Process the server responses and output the result to the console. try: for r in it: event_type, alternatives = r.WhichOneof('Event'), None if event_type == 'partial' and len(r.partial.alternatives) > 0: alternatives = [a.text for a in r.partial.alternatives] if event_type == 'final': alternatives = [a.text for a in r.final.alternatives] if event_type == 'final_refinement': alternatives = [a.text for a in r.final_refinement.normalized_text.alternatives] print(f'type={event_type}, alternatives={alternatives}') except grpc._channel._Rendezvous as err: print(f'Error code {err._state.code}, message: {err._state.details}') raise err if __name__ == '__main__': parser = argparse.ArgumentParser() parser.add_argument('--token', required=True, help='IAM token or API key') parser.add_argument('--path', required=True, help='audio file path') args = parser.parse_args() run(args.token, args.path)
Where:
audio_encoding
: Audio stream format.sample_rate_hertz
: Audio stream sampling rate.audio_channel_count
: Number of audio channels.profanity_filter
: Profanity filter.literature_text
: Flag to present the recognized text in a literary style.language_code
: Recognition language.
-
Use the IAM token of the service account:
export IAM_TOKEN=<service_account_IAM_token>
-
Run the created file:
python3 output/test.py --token ${IAM_TOKEN} --path <path_to_speech.pcm_file>
Where
--path
is the path to the audio file for recognition.Result:
type=status_code, alternatives=None type=partial, alternatives=None type=partial, alternatives=[hello wor] type=final, alternatives=[hello world] type=final_refinement, alternatives=[Hello world] type=eou_update, alternatives=None type=partial, alternatives=None type=status_code, alternatives=None
-
Install the dependencies:
sudo apt update && sudo apt install --yes default-jdk maven
-
Clone the repository
with a Java application configuration:git clone https://github.com/yandex-cloud-examples/yc-speechkit-stt-java
-
Go to the repository directory:
cd yc-speechkit-stt-java
-
Download a sample
audio file in the WAV format . Save the audio file to the directory with the repository. -
Compile a project in this directory:
mvn clean install
-
Go to the
target
directory you created:cd target
-
Specify the service account's API key:
export API_KEY=<API_key>
-
Run the Java program for speech recognition:
java -cp speechkit_examples-1.0-SNAPSHOT.jar yandex.cloud.speechkit.examples.SttV3Client <path_to_the_audio_file>
In the command, specify the absolute path to the sample audio file you downloaded.
Result:
sending initial request Done sending Stt stream completed Recognized text is "i'm yandex speechkit i can turn any text into speech now you can too"
-