Question

我正在使用录音机以咖啡格式录制来自iPhone的声音。然后，我希望它是wav格式。所以我用网上的代码转换它：

AudioChannelLayout channelLayout;
memset(&channelLayout, 0, sizeof(AudioChannelLayout));
channelLayout.mChannelLayoutTag = kAudioChannelLayoutTag_Mono;
NSMutableDictionary *outputSettings = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                       [NSNumber numberWithInt:audioFormat], AVFormatIDKey,
                                       [NSNumber numberWithFloat:16000.0], AVSampleRateKey,
                                       [NSNumber numberWithInt:1], AVNumberOfChannelsKey,
                                       [NSData dataWithBytes:&channelLayout length:sizeof(AudioChannelLayout)], AVChannelLayoutKey,
                                       nil];

但问题是文件get是这样的：（afinfo）

File type ID:   WAVE
Num Tracks:     1
----
Data format:     1 ch,  16000 Hz, 'lpcm' (0x0000000C) 16-bit little-endian signed integer
Channel layout: Mono
estimated duration: 2.229125 sec
audio bytes: 71332
audio packets: 35666
bit rate: 256000 bits per second
packet size upper bound: 2
maximum packet size: 2
audio data file offset: 4096
optimized
source bit depth: I16

我需要一个这样的文件：

File type ID:   WAVE
Num Tracks:     1
----
Data format:     1 ch,  16000 Hz, 'lpcm' (0x0000000C) 16-bit little-endian signed integer
           no channel layout.
estimated duration: 2.229125 sec
audio bytes: 71332
audio packets: 35666
bit rate: 256000 bits per second
packet size upper bound: 2
maximum packet size: 2
audio data file offset: 44
optimized
source bit depth: I16

如您所见，主要区别在于一个是“音频数据文件偏移：44”而另一个是“音频数据文件偏移：4096” 还有channelLayout，一个Mono（错误的）和另一个“无通道布局”

请帮助我，我真的很失望..只是为了频道布局，我怎么没有频道？

Answer 1

我使用[NSData dataWithBytes：nil length：0]而不是[NSData dataWithBytes：＆amp; channelLayout length：sizeof（AudioChannelLayout）]，这导致没有频道布局。

NSMutableDictionary *outputSettings = [NSMutableDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:audioFormat], AVFormatIDKey,
[NSNumber numberWithFloat:16000.0], AVSampleRateKey,
[NSNumber numberWithInt:1], AVNumberOfChannelsKey,
[NSData dataWithBytes:nil length:0], AVChannelLayoutKey,
                                   nil];

将CAF转换为WAV，通道布局iOS

1 个答案: