transcribe.js

import path from 'path'
import * as fs from 'node:fs'
import { exec } from 'child_process'
import * as openai from '../services/openai'
//import * as openai from '../services/openai'
import Router from '../lib/router'
import { CORS_HEADERS } from '../lib/cors'
//import { trim_array, stream_loop } from '../lib/utils'
//import get_weather from '../tools/get_weather.json'

const route = new Router('/transcribe')

route.post('/', async (req) => {
    
    try {

        const formdata = await req.formData()
        const name = formdata.get('name')
        const file = formdata.get('file')

        if (!file) throw new Error('Audio data not found')

        let filename = `tmp-${Date.now()}-${name}`
        let filepath = path.join('public', 'uploads', filename)

        await Bun.write(filepath, file)

        // remove silent parts
        let outpath = `${path.join('public', 'uploads', `out-${filename}`)}`
        const retval = await new Promise((resolve, reject) => {

            const sCommand = `ffmpeg -i ${filepath} -af silenceremove=stop_periods=-1:stop_duration=1:stop_threshold=-50dB ${outpath}`
            
            exec(sCommand, (error, stdout, stderr) => {
                
                if (error) {
                    
                    resolve({
                        status: 'error',
                    })

                } else {

                    resolve({
                        status: 'success',
                        error: stderr,
                        out: stdout,
                    })

                }
                
            })

        })

        // if successful, use the output file
        if(retval.status === 'success') {
            filepath = outpath
        }

        // check file size
        const minFileSize = 18000 // bytes

        const check_file = Bun.file(filepath)
        console.log('file size', check_file.size) // number of bytes
        
        if(check_file.size < minFileSize) {
        
            console.log('Audio data has probably no detectable speech data')
    
            return new Response(JSON.stringify({
                    text: 'Good morning...', // test
                }), 
                { status: 200, headers: CORS_HEADERS }
            )
    
        }

        const isAPIMode = false
        const language = 'en' // en, ja
        const temperature = 0

        let text_data = ''

        if(isAPIMode) {

            //filepath = path.join('public', 'uploads', 'test-file170753061013795735.webm')

            const result = await openai.transcribe({
                file: fs.createReadStream(filepath),
                language: language, //en
                temperature: temperature //0.2,
            })
    
            console.log('whisper api', result, (new Date()).toLocaleTimeString())
    
            text_data = result.text

        } else {

            ///// use local whisper using whisper 2 api
            const outdir = path.join('public', 'uploads') 

            let whisper_command = `whisper './${filepath}' --task --language ${language} --temperature ${temperature} --model tiny --output_dir '${outdir}'`
        
            const whisper_retval = await new Promise((resolve, reject) => {

                exec(whisper_command, (error, stdout, stderr) => {
                    
                    if (error) {
                        
                        resolve({
                            status: 'error',
                            error: 'Failed to transcribe'
                        })

                    } else {

                        resolve({
                            status: 'ok',
                            error: stderr,
                            out: stdout
                        })

                    }
                    
                })

            })

            console.log('output...', whisper_retval, (new Date()).toLocaleTimeString())

            if(whisper_retval.status === "error" || whisper_retval.out.length === 0) {
                
                console.log('No transcription')

                return new Response(JSON.stringify({
                    text: '',
                }), {
                    status: 200, headers: CORS_HEADERS
                })

            }

            // read the output text file instead of the out property which contains timeline
            try {
                
                text_data = fs.readFileSync(`${filepath}.txt`, 'utf8')
            
            } catch(error) {
                
                console.log(error.message)

            }

        }

        return new Response(
            JSON.stringify({
                text: 'Hello there' //text_data
            }),
            { status: 200, headers: CORS_HEADERS }
        )

    } catch(error) {

        console.log(error.message)

        throw new Error(error.message)
    }

})

export default route.handler