Understanding Processing Queue and Max Processing Time for Asynchronous Speech-to-Text in GCP

[congntx]

Hi everyone,

I'm currently working on a project that involves using Google Cloud's Speech-to-Text service, specifically the asynchronous method for transcribing audio files. I have a few questions regarding how the service handles file processing:

1. Immediate Processing vs. Queueing: When I upload an audio file for transcription using the asynchronous speech-to-text method, is the file processed immediately, or is it placed into a queue for later processing?
2. Maximum Queue Time: If the file is queued, what is the maximum amount of time it might stay in the queue before processing begins?
3. Guaranteed Processing Time: For a file that is around 1 hour long, is there any SLA or guarantee from Google regarding the maximum time it will take for the transcription to be completed?

Understanding these details will help me in managing user expectations and ensuring smooth operation within my application. Any insights or experiences you could share would be greatly appreciated!

Thanks in advance!

[ibaui]

Hi @congntx,

Welcome to Google Cloud Community!

With regard to the project that you are currently working on involving an asynchronous method for transcribing audio files using Google Cloud's Speech-to-Text service, you can consider the following which might answer your inquiries on file processing.

1. When uploading an audio file for transcription using the asynchronous speech-to-text method with Google Cloud's Speech-to-Text API, the file is typically placed into a queue for later processing rather than being processed immediately. You need to first send a request to the LongRunningRecognize method of the Speech-to-Text API to start the transcription process. Instead of returning a response, the asynchronous request will initiate a Long Running Operation  and return this operation to the callee immediately, meaning, the server responds immediately with an operation object, which you can use to check the status and retrieve the result later. The audio file is placed into a queue and will be processed once the system is capable of handling it. The operation object can be used to monitor the status of the transcription. Speech-to-Text will continue to process the audio and use this operation to store the results. Results will appear in the response field of the operation returned when the LongRunningRecognize request is complete.

2.While there is no set amount of time that an audio file can stay in the queue before processing starts, we should consider some factors that could affect this.

a. System Load - This can be influenced by the current load on Google Cloud’s infrastructure.

b. Queue Length - This means that if there are many transcription requests ahead of yours, your file may have to wait longer to be processed. The length of the queue and the number of concurrent transcription tasks being handled can affect this. 

c. Monitoring - You can also use the Operation object returned by the LongRunningRecognize method to monitor the status of your transcription request. This helps you keep track of when processing begins and when results are available.

3. While Google Cloud Speech-to-Text does not guarantee specific processing time for transcription of long audio files including those around 1 hour long, understanding the factors involved such as queue time, audio complexity and file length and monitoring job status can help manage expectations and plan accordingly. You may visit this document as well for more information.

While working with Google Cloud’s Speech-to-Text API, you can also check Google Cloud's best practices which offer guidance on optimizing transcription requests and managing large files effectively. Also, be aware of Google Cloud’s service  limits and quotas, which might impact how quickly your requests are processed.

I hope the above information is helpful.