Lame python bindings

lame.py

#coding:utf-8

# from: http://z4none.me/2014/07/09/Python-%E4%B8%AD%E4%BD%BF%E7%94%A8-libmp3lame-%E8%BF%9B%E8%A1%8C-mp3-%E7%BC%96%E8%A7%A3%E7%A0%81/

import time
import ctypes

class LameEncoder():
    def __init__(self, sample_rate, channel_count, bit_rate):
        self.dll  = ctypes.CDLL("libmp3lame.dll")
        self.lame = self.dll.lame_init()
        self.dll.lame_set_in_samplerate(self.lame, sample_rate);
        self.dll.lame_set_num_channels(self.lame, channel_count);
        self.dll.lame_set_brate(self.lame, bit_rate);
        self.dll.lame_set_quality(self.lame, 3);
        self.dll.lame_init_params(self.lame);

    def encode(self, pcm_data):
        sample_count    = len(pcm_data) /2
        output_buff_len = int(1.25 * sample_count + 7200)
        output_buff     = ctypes.create_string_buffer(output_buff_len)
        output_size     = self.dll.lame_encode_buffer(self.lame, ctypes.create_string_buffer(pcm_data), 0, sample_count, output_buff, output_buff_len);
        return output_buff.raw[:output_size]

class LameDecoder():
    def __init__(self, sample_rate, channel_count, bit_rate):
        self.dll  = ctypes.CDLL("libmp3lame.dll")
        self.lame = self.dll.lame_init()
        self.hip  = self.dll.hip_decode_init()
        self.dll.lame_set_in_samplerate(self.lame, sample_rate)
        self.dll.lame_set_num_channels(self.lame, channel_count)
        self.dll.lame_set_brate(self.lame, bit_rate)
        self.dll.lame_set_mode(self.lame, 3)
        self.dll.lame_set_quality(self.lame, 3)
        self.dll.lame_init_params(self.lame)
        self.dll.lame_get_framesize(self.lame)

    def decode(self, mp3_data):
        output_buff_len =  self.dll.lame_get_framesize(self.lame) * 2
        output_buff     = ctypes.create_string_buffer(output_buff_len)
        output_size     = self.dll.hip_decode1(self.hip, ctypes.create_string_buffer(mp3_data), len(mp3_data), output_buff, 0);
        return output_buff.raw[:output_size * 2]
        
    def flush(self):
        output_buff_len =  self.dll.lame_get_framesize(self.lame) * 2
        output_buff     = ctypes.create_string_buffer(output_buff_len)
        output_size     = self.dll.hip_decode1(self.hip, ctypes.create_string_buffer(""), 0, output_buff, 0);
        return output_buff.raw[:output_size * 2]

if __name__ == "__main__":
    def test_enc():
        print "test encode ..."
        lame = LameEncoder(8000, 1, 8)
        input_file  = open("1.pcm", "rb")
        output_file = open("1.mp3", "wb+")
        while 1: 
            data = input_file.read(256)
            if data:
                output = lame.encode(data)
                output_file.write(output)
            else:
                break
        input_file.close()
        output_file.close()
        print "test encode done"
        
    def test_dec():
        print "test decode ..."
        lame = LameDecoder(8000, 1, 8)
        input_file  = open("1.mp3", "rb")
        output_file = open("2.pcm", "wb+")
        while 1: 
            data = input_file.read(512)
            if data:
                output = lame.decode(data)
                if output:
                    output_file.write(output)
                    while 1:
                        output = lame.flush()
                        if output:
                            output_file.write(output)
                        else:
                            break
            else:
                break
        input_file.close()
        output_file.close()
        print "test decode done"
        
    test_enc()
    test_dec()