git ssb

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var ffmpeg = require('./exec-ffmpeg')
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module.exports = function (path, cb) {
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  var count = 200
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  ffmpeg([
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    '-i', path,
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    '-ac', 1,
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    '-filter:a', 'aresample=1000',
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    '-map', '0:a',
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    '-c:a', 'pcm_s8',
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    '-f', 's8',
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    'pipe:1'
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  ], function (err, stdout, stderr) {
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    if (err) return cb(err)
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    var durationMatch = stderr.toString().match(/Duration: ([0-9]+):([0-9]{2}):([0-9]{2}.[0-9]{2})/)
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    var duration = (parseInt(durationMatch[1], 10) * 3600) + (parseInt(durationMatch[2], 10) * 60) + parseFloat(durationMatch[3])
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    var samples = new Int8Array(stdout.buffer)
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    var frameLength = Math.floor(samples.length / count)
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    var bins = new Uint8Array(count)
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    for (var i = 0; i < count; i += 1) {
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      var sum = 0
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      for (var x = 0; x < frameLength; x++) {
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        sum += Math.abs(samples[i * frameLength + x] * 2)
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      }
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      bins[i] = Math.floor(sum / frameLength)
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    }
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    cb(null, {
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      overview: Buffer.from(bins.buffer).toString('base64'),
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      duration: duration
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    })
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  })
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}
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