如何檢查播放器是否正在使用？

Question

我試圖通過使用MPMusicPlayerController播放音樂在電視上播放音樂。如何檢查其他輸入是否正在使用播放？

Answer 1

現有柱的夫婦其可以是使用的：

Is there any notification for detecting AirPlay in Objective-C?

How to customize the Airplay button when airplay is active

有在限定方法- (BOOL)isAirPlayActive整齊地使用AudioSession框架，以確定所述第二鏈路的交當前音頻輸出路由。

Answer 2

這裏是另一種解決方案，以檢測是否單曲是活動

- (BOOL)isAirPlayActive 
{ 
    AVAudioSession* audioSession = [AVAudioSession sharedInstance]; 
    AVAudioSessionRouteDescription* currentRoute = audioSession.currentRoute; 
    AVAudioSessionPortDescription* output = [currentRoute.outputs firstObject]; 
    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil]; 
    [[AVAudioSession sharedInstance] setActive: YES error: nil]; 
    return [output.portType isEqualToString:AVAudioSessionPortAirPlay]; 
} 

Answer 3

我有這個問題爲好，我結束了使用ARP -n以獲取點播設備的MAC地址，然後用tcpdump程序嗅交通到它：

ipaddress=$(ping -c 1 $tvhostname | awk -F'[()]' '/PING/{print $2}') 
arp -n $ipaddress &> /var/tmp/arp-output 
fieldindex='$4' 
# Parse something of the form ? (10.37.109.150) at 40:33:1a:3d:e6:ee on en0 ifscope [ethernet] 
# The awk quotes get a bit messy with the variable substitution, so split the expression up 
echo Parsing mac address from line `awk -F"[ ]" "/\($ipaddress\)/{print}" /var/tmp/arp-output` 
macaddress=`awk -F"[ ]" "/($ipaddress)/{print $fieldindex}" /var/tmp/arp-output` 

sudo tcpdump -i $wifidevice -I ether dst $macaddress &> /var/tmp/airplay-tcpdump-output 
# Get the PID of the tcpdump command 
pid=$! 
# Capture 10 seconds of output, then kill the job 
sleep 10 
sudo kill $pid 
# Process the output file to see how many packets are reported captured 
packetcount=`awk -F'[ ]' '/captured/{print $1}' /var/tmp/airplay-tcpdump-output` 
echo Finished sniffing packets - there were $packetcount. 

完整的劇本最終是有點麻煩，所以我在寫blog post它。