使用 curl 仿 DLNA controller 指令播放影片: DLNA protocol + SOAP protocol

大概去年就拿 DLNA 當做個小題目研究了一下，最近工作又需要，再度翻出來複習一下。使用了別人寫的 python 小工具，非常小巧精美：github.com/cherezov/dlnap

裝置搜尋:

$ python dlnap.py
No compatible devices found.
$ python dlnap.py
Discovered devices:
 [a] Name1 @ 192.168.1.2
 [a] Name2 @ 192.168.1.3

播放影片:

$ python dlnap.py -d Name1 --play http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4
No compatible devices found.

$ python dlnap.py -d Name1 --play http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4
Name1 @ 192.168.1.2
POST AVTransport/control HTTP/1.1
User-Agent: dlnap.py/0.15
Accept: */*
Content-Type: text/xml; charset="utf-8"
HOST: 192.168.1.2:60099
Content-Length: 558
SOAPACTION: "urn:schemas-upnp-org:service:AVTransport:1#SetAVTransportURI"
Connection: close

<?xml version="1.0" encoding="utf-8"?>
         <s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
            <s:Body>
               <u:SetAVTransportURI xmlns:u="urn:schemas-upnp-org:service:AVTransport:1">
                  <InstanceID>0</InstanceID><CurrentURIMetaData></CurrentURIMetaData><CurrentURI>http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4</CurrentURI>
               </u:SetAVTransportURI>
            </s:Body>
         </s:Envelope>
POST AVTransport/control HTTP/1.1
User-Agent: dlnap.py/0.15
Accept: */*
Content-Type: text/xml; charset="utf-8"
HOST: 192.168.1.2:60099
Content-Length: 401
SOAPACTION: "urn:schemas-upnp-org:service:AVTransport:1#Play"
Connection: close

<?xml version="1.0" encoding="utf-8"?>
         <s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
            <s:Body>
               <u:Play xmlns:u="urn:schemas-upnp-org:service:AVTransport:1">
                  <InstanceID>0</InstanceID><Speed>1</Speed>
               </u:Play>
            </s:Body>
         </s:Envelope>

可惜的，在測試播放影片時總不太順利，推論應當是兩個指令太快，改用 curl 指令測試就很正常：

1. 先設定影片

$ cat SetAVTransportURI.record
<?xml version="1.0" encoding="utf-8"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<s:Body>
<u:SetAVTransportURI xmlns:u="urn:schemas-upnp-org:service:AVTransport:1">
<InstanceID>0</InstanceID>
<CurrentURIMetaData></CurrentURIMetaData>
<CurrentURI>http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4</CurrentURI>
</u:SetAVTransportURI>
</s:Body>
</s:Envelope>

$ curl -v -X POST --data @SetAVTransportURI.record  -H 'SOAPACTION: "urn:schemas-upnp-org:service:AVTransport:1#SetAVTransportURI"' -H 'Content-Type: text/xml; charset="utf-8"' http://192.168.1.2:60099/AVTransport/control
Note: Unnecessary use of -X or --request, POST is already inferred.
*   Trying 192.168.1.2:60099...
* TCP_NODELAY set
* Connected to 192.168.1.2 (192.168.1.2) port 60099 (#0)
> POST /AVTransport/control HTTP/1.1
> Host: 192.168.1.2:60099
> User-Agent: curl/7.68.0
> Accept: */*
> SOAPACTION: "urn:schemas-upnp-org:service:AVTransport:1#SetAVTransportURI"
> Content-Type: text/xml; charset="utf-8"
> Content-Length: 476
>
* upload completely sent off: 476 out of 476 bytes
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< EXT:
< CONTENT-TYPE: text/xml; charset="utf-8"
< SERVER: POSIX, UPnP/1.0, Intel MicroStack/1.0.2777
< Content-Length: 336
<
<?xml version="1.0" encoding="utf-8"?>
<s:Envelope s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Body>
      <u:SetAVTransportURIResponse xmlns:u="urn:schemas-upnp-org:service:AVTransport:1">

      </u:SetAVTransportURIResponse>
   </s:Body>
* Connection #0 to host 192.168.1.2 left intact
</s:Envelope>

2. 呼叫播放

$ cat Play.record
<?xml version="1.0" encoding="utf-8"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<s:Body>
<u:Play xmlns:u="urn:schemas-upnp-org:service:AVTransport:1">
<InstanceID>0</InstanceID>
<Speed>1</Speed>
</u:Play>
</s:Body>
</s:Envelope>

$ curl -v -X POST --data @Play.record  -H 'SOAPACTION: "urn:schemas-upnp-org:service:AVTransport:1#Play"' -H 'Content-Type: text/xml; charset="utf-8"' http://192.168.1.2:60099/AVTransport/control
Note: Unnecessary use of -X or --request, POST is already inferred.
*   Trying 192.168.1.2:60099...
* TCP_NODELAY set
* Connected to 192.168.1.2 (192.168.1.2) port 60099 (#0)
> POST /AVTransport/control HTTP/1.1
> Host: 192.168.1.2:60099
> User-Agent: curl/7.68.0
> Accept: */*
> SOAPACTION: "urn:schemas-upnp-org:service:AVTransport:1#Play"
> Content-Type: text/xml; charset="utf-8"
> Content-Length: 316
>
* upload completely sent off: 316 out of 316 bytes
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< EXT:
< CONTENT-TYPE: text/xml; charset="utf-8"
< SERVER: POSIX, UPnP/1.0, Intel MicroStack/1.0.2777
< Content-Length: 310
<
<?xml version="1.0" encoding="utf-8"?>
<s:Envelope s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Body>
      <u:PlayResponse xmlns:u="urn:schemas-upnp-org:service:AVTransport:1">

      </u:PlayResponse>
   </s:Body>
* Connection #0 to host 192.168.1.2 left intact
</s:Envelope>