您好，

我用Ruby写的REST语音识别程序总是返回错误码3300，我的程序参考的是如下的网页

http://yuyin.baidu.com/docs/asr/57

代码如下

==========>

require 'net/http'
require 'uri'
require 'json'
require 'base64'

post_json = JSON.generate({
                            'format' => 'pcm',
                            'rate' => '16000',
                            'channel' => '1',
                            'cuid' => '7c:e9:d3:ef:9f:56',
                            'token' => '24.86c1594cc8f542a4ee8aa38a284a3199.2592000.1444799958.282335-6833638',
                            'speech' => Base64.encode64(IO.read('sample.pcm')),
                            'len' => File.new('sample.pcm').stat().size
                          })

#puts post_json.to_s

http = Net::HTTP.new('vop.baidu.com', 80)
http_resp = http.post('/server_api', post_json, {'Content-Type' =>'application/json'})

# 打印返回码，Content-Type和返回的正文
puts http_resp.code
puts http_resp['content-type']
puts http_resp.body

<==========

返回的结果一直是

200
application/json
{"err_msg":"parameters error.","err_no":3300,"sn":"278222462971442216203"}

请问这个程序的调用方式是不是有问题？

另外有没有REST语音识别相关的例子？其它编程语言的例子也可以

多谢了