IOS - 德code PCM字节数组 [英] IOS - Decode PCM byte array
问题描述
林停留在一个问题上我的目标C应用程序。
Im stuck on an issue on my objective C App.
我在读从serveur(插槽C#)一个字节数组,谁给我一个PCM连接$ C $的CD音响,目前我正在寻找一个样本code是德code对我来说这个字节数组(NSData的),并播放它。
I'm reading a byte array from a serveur (Socket c#) who send me an PCM encoded sound, and i'm currently looking for a sample code that decode for me this byte array (NSData), and play it.
有谁知道一个解决方案吗?或者我怎么可以读取U-法音?
Does anyone know a solution ? Or how can I read a u-Law audio?
非常感谢! :D
推荐答案
该链接有关于μ定律编码和解码的信息:
This link has information about mu-law encoding and decoding:
的http://dystopian$c$c.blogspot.com.es/2012/02/pcm-law-and-u-law-companding-algorithms.html
#define MULAW_BIAS 33
/*
* Description:
* Decodes an 8-bit unsigned integer using the mu-Law.
* Parameters:
* number - the number who will be decoded
* Returns:
* The decoded number
*/
int16_t MuLaw_Decode(int8_t number)
{
uint8_t sign = 0, position = 0;
int16_t decoded = 0;
number=~number;
if(number&0x80)
{
number&=~(1<<7);
sign = -1;
}
position = ((number & 0xF0) >>4) + 5;
decoded = ((1<<position)|((number&0x0F)<<(position-4))|(1<<(position-5)))
- MULAW_BIAS;
return (sign==0)?(decoded):(-(decoded));
}
当你有uncom pressed音频,你应该能够使用音频队列API来播放它。
When you have the uncompressed audio you should be able to play it using the Audio Queue API.
祝你好运!
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