fileinfo

#!/usr/bin/python
# -*- coding: utf-8 -*-
"""fileinfo module.

Author: Jan Milik <milikjan@fit.cvut.cz>
"""


import os
import sys
import struct


def show_file_info(file_name):
    stat = os.stat(file_name)
    print "Filename: %s" % (file_name, )
    print "File size: %d B" % (stat.st_size, )
    
    if file_name.endswith(".wav"):
        show_wav_info(file_name)


def show_wav_info(file_name):
    with open(file_name, "rb") as f:
        data = f.read()
        
        # print repr(struct.unpack("<4sI4s4sI", data[:20]))
        
        riff_chunk_id = struct.unpack("<4s", data[:4])[0]
        if riff_chunk_id <> "RIFF":
            print "ERROR: Invalid RIFF chunk id (%r)." % (riff_chunk_id, )
            return
        
        chunk_size = struct.unpack("<I", data[4:8])[0]
        
        wave_id = struct.unpack("<4s", data[8:12])[0]
        if wave_id <> "WAVE":
            print "ERROR: Invalid WAVE ID."
            return
        
        offset = 12
        while offset - 8 < chunk_size:
            subchunk_id, subchunk_size = struct.unpack("<4sI", data[offset:offset + 8])
            offset += 8
            if subchunk_id <> "fmt ":
                offset += subchunk_size
                continue
            fmt, num_channels, sample_rate, byte_rate, block_align, bits_per_sample = struct.unpack("<HHIIHH", data[offset:offset + 16])
            
            fmt_name = {
                0x0001: "PCM",
                0x0003: "IEEE FLOAT",
                0x0006: "ALAW",
                0x0007: "MULAW",
                0xfffe: "EXTENSIBLE",
            }.get(fmt, None)
            
            if fmt_name is None:
                print "Format: %d" % (fmt, )
            else:
                print "Format: %s (%d)" % (fmt_name, fmt, )
            
            print "Number of channels: %d" % (num_channels, )
            print "Sample rate: %d" % (sample_rate, )
            print "Byte rate: %d" % (byte_rate, )
            print "Block align: %d" % (block_align, )
            print "Bits per sample: %d" % (bits_per_sample, )
            return


def main():
    for arg in sys.argv[1:]:
        show_file_info(arg)


if __name__ == "__main__":
    main()