How do I record video to a local disk in AIR?

问题:

I'm trying to record a webcam's video and audio to a FLV file stored on the users local hard disk. I have a version of this code working which uses NetConnection and NetStream to stream the video over a network to a FMS (Red5) server, but I'd like to be able to store the video locally for low bandwidth/flaky network situations. I'm using FLex 3.2 and AIR 1.5, so I don't believe there should be any sandbox restrictions which prevent this from occurring.

Things I've seen:

• FileStream - Allows reading.writing local files but no .attachCamera and .attachAudio methids for creating a FLV.
• flvrecorder - Produces screen grabs from the web cam and creates it's own flv file. Doesn't support Audio. License prohibits commercial use.
• SimpleFLVWriter.as - Similar to flvrecorder without the wierd license. Doesn't support audio.
• This stackoverflow post - Which demonstrates the playback of a video from local disk using a NetConnection/NetStream.

Given that I have a version already which uses NetStream to stream to the server I thought the last was most promising and went ahead and put together this demo application. The code compiles and runs without errors, but I don't have a FLV file on disk which the stop button is clicked. -

<mx:Script>
    <![CDATA[

        private var _diskStream:NetStream;
        private var _diskConn:NetConnection;
        private var _camera:Camera;
        private var _mic:Microphone; 

        public function cmdStart_Click():void {
            _camera = Camera.getCamera();
            _camera.setQuality(144000, 85);
            _camera.setMode(320, 240, 15);
            _camera.setKeyFrameInterval(60);

            _mic = Microphone.getMicrophone();

            videoDisplay.attachCamera(_camera);

            _diskConn = new NetConnection();
            _diskConn.connect(null);

            _diskStream = new NetStream(_diskConn);
            _diskStream.client = this;
            _diskStream.attachCamera(_camera);
            _diskStream.attachAudio(_mic);
            _diskStream.publish("file://c:/test.flv", "record");

        }

        public function cmdStop_Click() {
            _diskStream.close();
            videoDisplay.close();
        }

    ]]>
</mx:Script>    
    <mx:VideoDisplay x="10" y="10" width="320" height="240" id="videoDisplay" />
    <mx:Button x="10" y="258" label="Start" click="cmdStart_Click()" id="cmdStart"/>
    <mx:Button x="73" y="258" label="Stop" id="cmdStop" click="cmdStop_Click()"/>

</mx:WindowedApplication>

It seems to me that there's either something wrong with the above code which is preventing it from working, or NetStream just can't be abused in this wany to record video.

What I'd like to know is, a) What (if anything) is wrong with the code above? b) If NetStream doesn't support recording to disk, are there any other alternatives which capture Audio AND Video to a file on the users local hard disk?

Thanks in advance!

回答1:

It is not possible To stream video directly to the local disk without using some streaming service like Windows Media encoder, or Red5 or Adobe's media server or something else.

I have tried all the samples on the internet with no solution to date.

look at this link for another possibility:

http://www.zeropointnine.com/blog/updated-flv-encoder-alchem/

回答2:

My solution was to embed Red5 into AIR. Sharing with you my article

http://mydevrecords.blogspot.com/2012/01/local-recording-in-adobe-air-using-red5.html

In general, the solution is to embed free media server Red5 into AIR like an asset. So, the server will be present in AIR application folder. Then, through the NativeProcess, you can run Red5 and have its instance in memory. As result, you can have local video recording without any network issues.

回答3:

I am also trying to do the same thing, but I have been told from the developers of avchat.net that it is not possible to do this with AIR at the moment. If you do find out how to do it, I would love to know!

I also found this link, not sure how helpful it is http://www.zeropointnine.com/blog/webcam-dvr-for-apollo/

回答4:

Well, I just think that letting it connect to nothing(NULL) doesn't work. I've already let him try to connect to localhost, but that didn't work out either. I don't think this is even possible. Streaming video works only with Flash Media Server and Red5, not local. Maybe you could install Red5 on you PC?

回答5:

Sadly video support in flash from cameras is very poor. When you stream its raw so the issue is that you have to encode to FLV and doing it in real time takes a very fast computer. First gen concepts would write raw bitmaps to a file (or serialize an array) then a second method would convert the file to an FLV. Basically you have to poll the camera and save each frame as a bitmap then stack in an array. This is very limited and could not do audio. It was also very hard to get above 5-10fps.

The gent at zero point nine, came up with a new version and your on the right path. Look at the new flv recorder. I spent a lot of time working with this but never quite got it to work for my needs (two cameras). I just could not get the FPS i needed. But it might work for you. It was much faster than the original method.

The only other working option I know of is to have the Red5 save the video and download it back to the app.