如何将音频blob从javascript发送到python

How to send audio blob from javascript to python?

本文关键字：python javascript 音频 blob      更新时间：2023-12-04

我想将一个音频blob从JS发送到python脚本（在服务器上运行）。我的JS ajax。。看起来像这样。

var fileType = 'audio';
var fileName = 'output.wav';
var formData = new FormData();
formData.append(fileType + '-filename', fileName);
formData.append(fileType + '-blob', blob);
    $.ajax({
    type: 'POST',
    url: 'http://localhost/python/audio.py',
    data: {audio:formData},
        success: function(response) {
        alert(respose);
    }
   });

我的python脚本是这样的。

#!/usr/bin/python3
print("Content-Type: text/html")
print()
import ssl
import cgi
import wave
import contextlib
form = cgi.FieldStorage()
fname = form.getvalue("audio", "error")
with contextlib.closing(wave.open(fname,'r')) as f:
    frames = f.getnframes()
    rate = f.getframerate()
    duration = frames / float(rate)
    print(duration)

现在，我只是在测试，所以它应该能给我音频文件的持续时间。blob是通过record.js 生成的

这不起作用，因为python无法识别文件。有什么解决方案吗？

PS：我正在使用Xampp服务器，在本地主机上运行。

回应Wojtek Marczenko：错误是

[Mon Apr 04 18:26:09.537912 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215: Traceback (most recent call last):: /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.537978 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:   File "/home/shashank/project/dutchman/python/audio.py", line 10, in <module>: /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538002 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:     with contextlib.closing(wave.open(fname,'r')) as f:: /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538024 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:   File "/usr/lib/python3.5/wave.py", line 499, in open: /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538036 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:     return Wave_read(f): /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538056 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:   File "/usr/lib/python3.5/wave.py", line 163, in __init__: /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538065 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:     self.initfp(f): /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538086 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:   File "/usr/lib/python3.5/wave.py", line 128, in initfp: /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538097 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:     self._file = Chunk(file, bigendian = 0): /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538110 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:   File "/usr/lib/python3.5/chunk.py", line 61, in __init__: /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538119 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215:     self.chunkname = file.read(4): /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html
[Mon Apr 04 18:26:09.538132 2016] [cgi:error] [pid 5330] [client ::1:60802] AH01215: AttributeError: 'NoneType' object has no attribute 'read': /home/shashank/project/dutchman/python/audio.py, referer: http://localhost/index.html

看起来您没有正确地将blob作为表单字段发送。将blob附加到FormData的正确方法是formData.append(fileType, blob, fileName);。此外，您应该只附加formData，而不是将其嵌套在另一个对象中：

var formData = new FormData();
formData.append(fileType, blob, fileName);
$.ajax({
    type: 'POST',
    url: 'http://localhost/python/audio.py',
    data: formData,
    processData: false,  // prevent jQuery from converting the data
    contentType: false,  // prevent jQuery from overriding content type
    success: function(response) {
        alert(response);
    }
});

来源：https://developer.mozilla.org/en-US/docs/Web/API/FormData/appendhttp://www.mattlunn.me.uk/blog/2012/05/sending-formdata-with-jquery-ajax/

在python方面，您需要根据python文档使用CGI模块（不能发布更多链接）。我相信正确的方法是这样的：

form = cgi.FieldStorage()
fname = form["audio"].filename
print "Got filename:", fname  # in case of problems see if this looks ok
with contextlib.closing(wave.open(fname,'r')) as f:
    ...

我在检索音频字节时出错，结果是光标问题，所以要小心。

FormData请求中的文件可以在request.files访问，然后您可以选择包含在FormData中的文件，例如request.files['audio']。

因此，现在如果您想访问文件的实际字节，在我们使用.stream的"音频"中，您应该首先确保您的光标指向第一个字节，而不是文件的末尾，在这种情况下，您将获得空字节。

因此，一个很好的方法：

file = request.files['audio']
file.stream.seek(0)
audio = file.read()
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