56 lines
1.5 KiB
JavaScript
56 lines
1.5 KiB
JavaScript
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/**
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* An example using node-lame and node-wav to decode an MP3 file and save it into
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* a WAVE file.
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*/
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var fs = require('fs');
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var lame = require('../');
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var wav = require('wav');
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var filename = process.argv[2];
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if (process.stdin.isTTY && !filename) {
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// print help
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console.error('usage:');
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console.error(' decode an mp3 file:');
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console.error(' $ %s <infile.mp3> <outfile.wav>', process.argv.join(' '));
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console.error(' or decode mp3 data from stdin:');
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console.error(' $ cat song.mp3 | %s | ffplay -', process.argv.join(' '));
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process.exit(1);
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}
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// first figure out if we're decoding from a filename, or from stdin
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var input;
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var output;
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if (filename) {
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var outfile = process.argv[3];
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if (!outfile) {
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console.error('FATAL: must specify an output .wav file!');
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process.exit(1);
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}
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console.error('encoding %j', filename);
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console.error('to %j', outfile);
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input = fs.createReadStream(filename);
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output = fs.createWriteStream(outfile);
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} else {
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input = process.stdin;
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output = process.stdout;
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}
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// start reading the MP3 file from the input
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var decoder = new lame.Decoder();
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// we have to wait for the "format" event before we can start encoding
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decoder.on('format', onFormat);
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// and start transferring the data
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input.pipe(decoder);
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function onFormat (format) {
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console.error('MP3 format: %j', format);
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// write the decoded MP3 data into a WAV file
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var writer = new wav.Writer(format);
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decoder.pipe(writer).pipe(output);
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}
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