百度语音识别API的使用样例（python实现）

百度给的样例程序，不论C还是Java版，都分为method1和method2两种

前者称为隐式（post的是json串，音频数据编码到json里），后者称为显式（post的就是音频数据）

一开始考虑到python wave包处理的都是“字符串”，担心跟C语言的数组不一致，所以选择低效但保险的method1，

即先将音频数据base64编码，再加上采样率、通道数等信息汇集成dict，最后总体编码成json串

结果老是报：

3300 输入参数不正确

先后试过urllib2和pycurl包，都是上面情况

不得已换用method2，成功（看来wave包对音频的存储并不是“字符串”）

#encoding=utf-8

import wave
import urllib, urllib2, pycurl
import base64
import json
## get access token by api key & secret key

def get_token():
    apiKey = "xxxxxxxx"
    secretKey = "xxxxxxxxx"

    auth_url = "https://openapi.baidu.com/oauth/2.0/token?grant_type=client_credentials&client_id=" + apiKey + "&client_secret=" + secretKey;

    res = urllib2.urlopen(auth_url)
    json_data = res.read()
    return json.loads(json_data)['access_token']

def dump_res(buf):
    print buf

## post audio to server
def use_cloud(token):
    fp = wave.open('vad_0.wav', 'rb')
    nf = fp.getnframes()
    f_len = nf * 2
    audio_data = fp.readframes(nf)

    cuid = "xxxxxxxxxx" #my xiaomi phone MAC
    srv_url = 'http://vop.baidu.com/server_api' + '?cuid=' + cuid + '&token=' + token
    http_header = [
        'Content-Type: audio/pcm; rate=8000',
        'Content-Length: %d' % f_len
    ]

    c = pycurl.Curl()
    c.setopt(pycurl.URL, str(srv_url)) #curl doesn't support unicode
    #c.setopt(c.RETURNTRANSFER, 1)
    c.setopt(c.HTTPHEADER, http_header)   #must be list, not dict
    c.setopt(c.POST, 1)
    c.setopt(c.CONNECTTIMEOUT, 30)
    c.setopt(c.TIMEOUT, 30)
    c.setopt(c.WRITEFUNCTION, dump_res)
    c.setopt(c.POSTFIELDS, audio_data)
    c.setopt(c.POSTFIELDSIZE, f_len)
    c.perform() #pycurl.perform() has no return val

if __name__ == "__main__":
    token = get_token()
    use_cloud(token)

运行结果

{"corpus_no":"6150045491002357923","err_msg":"success.","err_no":0,"result":["播放小苹果，"],"sn":"243903724071431919050"}