objective-c - 通过 POST 命令将音频从 ios 流式传输到 REST 服务器

Question

如何将音频编码为 u-law g.711？然后通过 http 将该音频发送到远程服务器。

AUDIO STREAM: Send a continuous stream of audio to the currently viewed camera. Audio needs to be encoded at G711 mu-law at 64 kbit/s for transfer to the Axis camera at the bedside. send (this should be a POST URL in SSL to connected server): POST /transmitaudio?id= Content-type: audio/basic Content-Length: 99999 (length is ignored)

我在 google 和此处进行了搜索，但我发现的主要是从服务器流式传输到 I 设备的方法，而不是相反的方法。我确实找到了这个帖子(http://stackoverflow.com/questions/7750329/how-to-send-audio-file-through-http-post-to-a-server-from-ios)但是它似乎喜欢答案描述性不强，也没有任何一个被接受。

这是我目前所拥有的。

{
        NSNumber *formatObject;

        switch (self.recordEncoding) {
            case (ENC_AAC): 
                formatObject = [NSNumber numberWithInt: kAudioFormatMPEG4AAC];
                break;
            case (ENC_ALAC):
                formatObject = [NSNumber numberWithInt: kAudioFormatAppleLossless];
                break;
            case (ENC_IMA4):
                formatObject = [NSNumber numberWithInt: kAudioFormatAppleIMA4];
                break;
            case (ENC_ILBC):
                formatObject = [NSNumber numberWithInt: kAudioFormatiLBC];
                break;
            case (ENC_ULAW):
                formatObject = [NSNumber numberWithInt: kAudioFormatULaw];
                break;
            default:
                formatObject = [NSNumber numberWithInt: kAudioFormatAppleIMA4];
        }

        [recordSettings setObject:formatObject forKey: AVFormatIDKey];
        [recordSettings setObject:[NSNumber numberWithFloat:44100.0] forKey: AVSampleRateKey];
        [recordSettings setObject:[NSNumber numberWithInt:2] forKey:AVNumberOfChannelsKey];
        [recordSettings setObject:[NSNumber numberWithInt:12800] forKey:AVEncoderBitRateKey];
        [recordSettings setObject:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
        [recordSettings setObject:[NSNumber numberWithInt: AVAudioQualityHigh] forKey: AVEncoderAudioQualityKey];
    }

这似乎是 U-law(因此得名编码)，但是我对音频编解码器一无所知，也不知道 G711 mu-law 是否可以在 ios 上使用。
如何让我的音频以正确的格式编码？

然后如何将编码后的音频发送到服务器？现在我将它转到一个临时文件位置，但即使我更改了它，我也看不出这会有什么帮助。我知道这有很多要求，我不希望得到答案，但我需要一个起点，因为目前我完全不知道如何做到这一点。

Answer 1

录制完成后发送音频

 self.request = [client multipartFormRequestWithMethod:@"POST" path:[NSString stringWithFormat:@"transmitaudio?id=%@",self.restClient.sessionId] parameters:parameters constructingBodyWithBlock: ^(id <AFMultipartFormData>formData) 
                    {
                        NSError * error = [[NSError alloc]init];

                        [formData appendPartWithFileURL:self.audioHandler.soundFileURL name:@"sound.caf" error:&error];
                        //            NSLog(@"error %@", [error localizedDescription]);
                    }];

    AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:self.request];

    [self.queue addOperation:operation];