我已将 Objective-C 脚本转换为 Swift 以形成 AAC 帧的标题。但是,代码无法在应用程序中运行,并因 EXC_BAD_ACCESS 而崩溃。将代码复制到操场会输出我所期望的没有错误的结果。不知道该去哪里,因为它似乎应该工作。我总是可以使用 Objective-C 版本,但这感觉就像在解决这个问题。
func adtsDataForPacketLength(packetLength: Int) -> NSData {
let adtsLength = 7
let profile = 2
let freqIdx = 4
let chanCfg = 1
let fullLength = adtsLength + packetLength;
var packet = [UInt8]()
packet.append(UInt8(0xFF))
packet.append(UInt8(0xF9))
packet.append(UInt8(((profile-1)<<6) + (freqIdx<<2) + (chanCfg>>2)))
packet.append(UInt8(((chanCfg&3)<<6) + (fullLength>>11)))
packet.append(UInt8((fullLength&0x7FF) >> 3))
packet.append(UInt8(((fullLength&7)<<5) + 0x1F))
packet.append(0xFC)
return NSData(bytes: packet, length: packet.count)
}