pool = Pool()
    startTime = float(opt.startTime)
    endTime = float(opt.endTime)

    # compute descriptors

    readMetadata(input_file, pool)
    INFO('Process step 1: Replay Gain')
    replaygain.compute(input_file, pool, startTime, endTime)

    segments_namespace=[]
    if opt.segmentation:
        INFO('Process step 2: Low Level')
        computeLowLevel(input_file, pool, startTime, endTime)
        segmentation.compute(input_file, pool, startTime, endTime)
        segments = pool['segmentation.timestamps']
        for i in xrange(len(segments)-1):
            startTime = segments[i]
            endTime = segments[i+1]

            INFO('**************************************************************************')
            INFO('Segment ' + str(i) + ': processing audio from ' + str(startTime) + 's to ' + str(endTime) + 's')
            INFO('**************************************************************************')

            # set segment name:
            segment_name = 'segment_'+ str(i)
            pool.set('segments.'+segment_name+'.name', segment_name)
            # set segment scope:
            pool.set('segments.'+segment_name+'.scope', numpy.array([startTime, endTime]))
            # compute descriptors:
    pool = Pool()
    startTime = float(opt.startTime)
    endTime = float(opt.endTime)

    # compute descriptors

    readMetadata(input_file, pool)
    INFO('Process step 1: Replay Gain')
    replaygain.compute(input_file, pool, startTime, endTime)

    segments_namespace = []
    if opt.segmentation:
        INFO('Process step 2: Low Level')
        computeLowLevel(input_file, pool, startTime, endTime)
        segmentation.compute(input_file, pool, startTime, endTime)
        segments = pool['segmentation.timestamps']
        for i in xrange(len(segments) - 1):
            startTime = segments[i]
            endTime = segments[i + 1]

            INFO(
                '**************************************************************************'
            )
            INFO('Segment ' + str(i) + ': processing audio from ' +
                 str(startTime) + 's to ' + str(endTime) + 's')
            INFO(
                '**************************************************************************'
            )

            # set segment name: