ibm-cloud-sdk-core
Version:
Core functionality to support SDKs generated with IBM's OpenAPI SDK Generator.
72 lines (71 loc) • 2.75 kB
JavaScript
/* eslint-disable prettier/prettier */
/**
* (C) Copyright IBM Corp. 2019, 2022.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import { extname } from 'path';
// This module attempts to identify common content-types based on the filename or header
// It is not exhaustive, and for best results, you should always manually specify the content-type option.
// See the complete list of supported content-types at
// https://cloud.ibm.com/docs/services/speech-to-text?topic=speech-to-text-input#formats
// *some* file types can be identified by the first 3-4 bytes of the file
const headerContentTypes = {
fLaC: 'audio/flac',
RIFF: 'audio/wav',
OggS: 'audio/ogg',
ID3: 'audio/mp3',
'\u001aEߣ': 'audio/webm' // String for first four hex's of webm: [1A][45][DF][A3] (https://www.matroska.org/technical/specs/index.html#EBML)
};
const filenameContentTypes = {
'.mp3': 'audio/mp3',
'.wav': 'audio/wav',
'.flac': 'audio/flac',
'.ogg': 'audio/ogg',
'.oga': 'audio/ogg',
'.opus': 'audio/ogg; codec=opus',
'.webm': 'audio/webm'
};
/**
* Takes the beginning of an audio file and returns the associated content-type / mime type
*
* @param buffer - a Buffer containing at least the first 4 bytes of the file
* @return sthe contentType or undefined
*/
const fromHeader = (buffer) => {
const headerStr = buffer
.slice(0, 4)
.toString()
.substr(0, 4);
// mp3's are only consistent for the first 3 characters
return (headerContentTypes[headerStr] || headerContentTypes[headerStr.substr(0, 3)]);
};
/**
* Guess the content type from the filename
*
* Note: Blob and File objects include a .type property, but we're ignoring it because it's frequently either
* incorrect (e.g. video/ogg instead of audio/ogg) or else a different format than what's expected (e.g. audio/x-wav)
*
* @param file - a String filename or url, or binary File/Blob object.
* @returns the content type
*/
const fromFilename = (file) => {
const ext = extname(
// eslint-disable-next-line @typescript-eslint/dot-notation
(typeof file === 'string' && file) || file['name'] || '');
return filenameContentTypes[ext];
};
export default {
fromFilename,
fromHeader
};