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Add JUNK and BEXT wav format compatibility + promisified + cleaning #25

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191 changes: 103 additions & 88 deletions wav-file-info.js
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Original file line number Diff line number Diff line change
@@ -1,101 +1,116 @@
// Hi Welcome to WFI by David Jones / RackFX, LLC
var fs = require('fs');
var wfi = {}
/* eslint-disable no-inner-declarations */
const fs = require('fs');
const util = require('util');

wfi.infoByFilename = function(filename, cb){
var stats = fs.statSync(filename)
var buffer = new Buffer(40); // first 40 bytes are RIFF header
fs.open(filename, 'r', function(err, fd) {
if(err) return cb(err); // error probably TODO:check this!
const readFile = util.promisify(fs.read);
const openFile = util.promisify(fs.open);

// ex error -
// { [Error: ENOENT: no such file or directory, open './test.wav'] errno: -2, code: 'ENOENT', syscall: 'open', path: './test.wav' }
var read_result = {}


// this a list of sequenced bytes in the 40 byte header. This builds the read_result object.
// Property name / Data type / Length
var reads = [
['riff_head', 'string', 4],
['chunk_size','uinteger', 4],
['wave_identifier', 'string', 4],
['fmt_identifier', 'string', 4],
['subchunk_size','integer',4],
['audio_format','integer',2],
['num_channels','integer',2],
['sample_rate','uinteger',4],
['byte_rate','integer',4],
['block_align','integer',2],
['bits_per_sample','integer',2],
//['uhm','integer',2],
['data_identifier','string', 4],
//['sub_chunk2_size', 'integer', 4],

]
fs.read(fd, buffer, 0, 40, 0, function(err, num) {
module.exports = {
/** Read wav file infos asynchronously (use await infoByFilename() OR use the second param callback)
* @param {String} filenameAbsolute
* @param {Function} callback (optionnal)
* @returns {Object} {
header: read_result,
stats: stats,
duration: ((read_result.chunk_size) / (read_result.sample_rate * read_result.num_channels * (read_result.bits_per_sample / 8)))
}
*/
async infoByFilename(filenameAbsolute, callback) {
const totalAnalysedBytes = 1500;
const stats = fs.statSync(filenameAbsolute);
const buffer = new Buffer.alloc(totalAnalysedBytes); // first 40 bytes are RIFF header
const fd = await openFile(filenameAbsolute, 'r');
await readFile(fd, buffer, 0, totalAnalysedBytes, 0);
// ex error -
// { [Error: ENOENT: no such file or directory, open './test.wav'] errno: -2, code: 'ENOENT', syscall: 'open', path: './test.wav' }
const read_result = {};

var i=0;
var pointer = 0;
function read_wav(){
var read = reads[i];
// this a list of sequenced bytes in the 40 byte header. This builds the read_result object.
// Property name / Data type / Length
var reads = [
['riff_head', 'string', 4],
['chunk_size', 'uinteger', 4],
['wave_identifier', 'string', 4],
['fmt_identifier', 'string', 4],
['subchunk_size', 'integer', 4],
['audio_format', 'integer', 2],
['num_channels', 'integer', 2],
['sample_rate', 'uinteger', 4],
['byte_rate', 'integer', 4],
['block_align', 'integer', 2],
['bits_per_sample', 'integer', 2],
//['uhm','integer',2],
['data_identifier', 'string', 4],
//['sub_chunk2_size', 'integer', 4],
];

i++;
if(read[1]=='string'){
read_result[read[0]] = buffer.toString('ascii', pointer , pointer + read[2]);
pointer = pointer + read[2]; // pointer = pointer plus # bytes
}
else if(read[1]=='integer'){
var i = 0;
var pointer = 0;

read_result[read[0]] = buffer.readUInt16LE(pointer, read[2])
pointer = pointer + read[2];
}
else if(read[1]=='uinteger'){
function readWavChunk() {
var read = reads[i];
const nbBytesActualChunk = typeof read[2] === 'function' ? read[2](read_result) : read[2];

read_result[read[0]] = buffer.readInt32LE(pointer, read[2])
pointer = pointer + read[2];
// dynamically find "fmt " chunk because JUNK and BEXT wav
// format put a lot of metadata between wave_identifier AND fmt_identifier
if (read[0] === 'fmt_identifier') pointer = buffer.indexOf('666d7420', pointer, 'hex'); // looks for the string "fmt " in the next bytes
if (pointer < 0 || pointer >= totalAnalysedBytes) return;
i++;
// if(pointer > 40) return;
switch (read[1]) {
case 'string':
read_result[read[0]] = buffer.toString('ascii', pointer, pointer + nbBytesActualChunk);
pointer += nbBytesActualChunk; // pointer = pointer plus # bytes
break;
case 'integer':
read_result[read[0]] = buffer.readUInt16LE(pointer, nbBytesActualChunk);
pointer += nbBytesActualChunk;
break;
case 'uinteger':
read_result[read[0]] = buffer.readInt32LE(pointer, nbBytesActualChunk);
pointer += nbBytesActualChunk;
break;
}
if (i < reads.length) return readWavChunk();
}
if(i < reads.length) { return read_wav()}
else { return fs.close(fd, post_process); }

}
//console.log(i)
read_wav();
}); // end fs.read

function post_process(){
var error = false;
var invalid_reasons = []
readWavChunk();

if (read_result.riff_head != "RIFF") invalid_reasons.push("Expected \"RIFF\" string at 0" )
if (read_result.wave_identifier != "WAVE") invalid_reasons.push("Expected \"WAVE\" string at 4")
if (read_result.fmt_identifier != "fmt ") invalid_reasons.push("Expected \"fmt \" string at 8")
if (
(read_result.audio_format != 1) && // Wav PCM
(read_result.audio_format != 65534) && // Extensible PCM
(read_result.audio_format != 2) && // Wav
(read_result.audio_format != 6) && // Wav ALAW
(read_result.audio_format != 7) && // Wav MULAW
(read_result.audio_format != 22127) && // Vorbis ?? (issue #11)
(read_result.audio_format != 3)) // Wav
invalid_reasons.push("Unknown format: "+read_result.audio_format)
if ((read_result.chunk_size + 8) !== stats.size) invalid_reasons.push("chunk_size does not match file size")
//if ((read_result.data_identifier) != "data") invalid_reasons.push("Expected data identifier at the end of the header")
// POST PROCESS
let error = false;
let fileInfos;
const invalid_reasons = [];

if (invalid_reasons.length > 0) error = true;
if (read_result.riff_head != 'RIFF') invalid_reasons.push('Expected "RIFF" string at 0');
if (read_result.wave_identifier != 'WAVE') invalid_reasons.push('Expected "WAVE" string at 4');
if (read_result.fmt_identifier != 'fmt ') invalid_reasons.push('No "fmt " chunk found');
if (read_result.audio_format != 1 && read_result.audio_format != 3) invalid_reasons.push('Unknwon format: ' + read_result.audio_format);
if (read_result.chunk_size + 8 !== stats.size) invalid_reasons.push('chunk_size does not match file size');
//if ((read_result.data_identifier) != "data") invalid_reasons.push("Expected data identifier at the end of the header")

if (error) return cb({
error : true,
invalid_reasons: invalid_reasons,
header: read_result,
stats: stats
});
if (invalid_reasons.length > 0) {
error = {
error: true,
invalid_reasons: invalid_reasons,
header: read_result,
stats: stats
};
} else {
fileInfos = {
header: read_result,
stats: stats,
duration: ((read_result.chunk_size) / (read_result.sample_rate * read_result.num_channels * (read_result.bits_per_sample / 8)))
};
}

cb(null, {
header: read_result,
stats: stats,
duration: ((read_result.chunk_size) / (read_result.sample_rate * read_result.num_channels * (read_result.bits_per_sample / 8)))
});
if (typeof callback === 'function') {
// CALLBACK
if (error) return callback(error);
else return callback(null, fileInfos);
} else {
// ASYNC
if (error) throw new Error(error);
else return fileInfos;
}
}
});
}
module.exports = wfi;
};