start/end parameters for audio file conversion

Author: ftreml

README.md

@@ -144,6 +144,10 @@ This project is standing on the shoulders of giants.
 
 ## Changelog
 
+### 2020-03-05
+
+* Optional _start_/_end_ parameters for audio file conversion to trim an audio file by time codes formatted as mm:ss (_01:32_)
+
 ### 2020-02-22
 
 * Additional endpoint to calculate the Word Error Rate (Levenshtein Distance) between two texts

frontend/src/convert/sox.js

@@ -4,11 +4,18 @@ const { spawn } = require('child_process')
 const uuidv1 = require('uuid/v1')
 const debug = require('debug')('botium-speech-processing-convert-sox')
 
-const runsox = (cmdLine, inputBuffer) => {
+const runsox = (cmdLine, { inputBuffer, start, end }) => {
   return new Promise((resolve, reject) => {
     const output = `/tmp/${uuidv1()}.wav`
-
-    const cmdLineSox = Mustache.render(cmdLine, { output })
+    
+    let cmdLineSox = Mustache.render(cmdLine, { output })
+    if (start && end) {
+      cmdLineSox = `${cmdLineSox} trim ${start} ${end}`
+    } else if (start && !end) {
+      cmdLineSox = `${cmdLineSox} trim ${start}`
+    } else if (!start && end) {
+      cmdLineSox = `${cmdLineSox} trim 0 ${end}`
+    }
     debug(`cmdLineSox: ${cmdLineSox}`)
     const cmdLineSoxParts = cmdLineSox.split(' ')
     const sox = spawn(cmdLineSoxParts[0], cmdLineSoxParts.slice(1))

frontend/src/routes.js

@@ -4,7 +4,7 @@ const mkdirp = require('mkdirp')
 const crypto = require('crypto')
 const express = require('express')
 const sanitize = require('sanitize-filename')
-const { runsox } = require('./convert/sox.js')
+const { runsox } = require('./convert/sox')
 const { wer } = require('./utils')
 const debug = require('debug')('botium-speech-processing-routes')
 
@@ -234,6 +234,18 @@ router.get('/api/tts/:language', async (req, res, next) => {
  *         required: true
  *         schema:
  *           type: string
+ *       - name: start
+ *         description: Start Timecode within audio stream (01:32)
+ *         in: query
+ *         schema:
+ *           type: string
+ *           pattern: '^([0-5][0-9]):([0-5][0-9])$'
+ *       - name: end
+ *         description: End Timecode within audio stream (02:48)
+ *         in: query
+ *         schema:
+ *           type: string
+ *           pattern: '^([0-5][0-9]):([0-5][0-9])$'
  *     requestBody:
  *       description: Audio file
  *       content:
@@ -264,7 +276,7 @@ router.post('/api/convert/:profile', async (req, res, next) => {
   }
 
   try {
-    const outputBuffer = await runsox(process.env[envVarSox], req.body)
+    const outputBuffer = await runsox(process.env[envVarSox], { inputBuffer: req.body, start: req.query.start, end: req.query.end })
     res.writeHead(200, {
       'Content-disposition': `attachment; filename="${process.env[envVarOutput]}"`,
       'Content-Length': outputBuffer.length

frontend/src/swagger.json

@@ -184,6 +184,24 @@
             "schema": {
               "type": "string"
             }
+          },
+          {
+            "name": "start",
+            "description": "Start Timecode within audio stream (01:32)",
+            "in": "query",
+            "schema": {
+              "type": "string",
+              "pattern": "^([0-5][0-9]):([0-5][0-9])$"
+            }
+          },
+          {
+            "name": "end",
+            "description": "End Timecode within audio stream (02:48)",
+            "in": "query",
+            "schema": {
+              "type": "string",
+              "pattern": "^([0-5][0-9]):([0-5][0-9])$"
+            }
           }
         ],
         "requestBody": {