Wowza Community

Custom module to create single frame snapshots of live and VOD stream

The Wowza recording will have an .mp4 extension.

JW Player can play videos with mp4 or m4v extension. You should use the mp4: prefix in the “file” Flashvar.

Richard

Here is an example of iterating over the files in the content folder:

http://www.wowza.com/community/t/-/237&page=3#22

The ffmpeg command has to run on the server. So you would have to install ffmpeg on the server.

You could initiate from the client with NetConnection.call(serversideFunctionName), for example:

netconnection.call(“doFiles”);

You have to create an appllcation module with a “doFiles” method that iterates over the files in content folder and runs ffmpeg.

Richard

To call a function from a client with a netconnection, you have to use a Flash application. There is a great working reference for this in the Wowza install-dir example folder: ServerSideModules. This includes a Flash application and server-side module and shows just about every way to communicate and pass data between Flash and Wowza.

To interface with Wowza from an application server like .net using a server page like aspx, you need a HTTProvider. This is a good starting place for that:

http://www.wowza.com/community/t/-/245

There are other HTTProviders that might be useful reference in the same forum section:

http://www.wowza.com/community/c/-/10

Richard

I showed you the example we have for that already, “ModuleVideoNameList” This one:

http://www.wowza.com/community/t/-/237&page=3#22

Richard

This is an AS3 version. If you are using Flex, you an use the Bindable ArrayCollection with a ComboBox. In Flash CS you can change it to an Array

netconnection.call("getVideoNames",new Responder(videoNamesHandler));
[Bindable]
privat var recordedStreamsDP = new ArrayCollection();
private function videoNamesHandler(results:Object):void
{	
for( var item:String in results ) 
{
	var obj:ObjectProxy = new ObjectProxy(); // In Flex use ObjectProxy to populate Bindable ArrayCollection.
	obj.label = results[item];
	obj.value = item;
	recordedStreamsDP.addItemAt(obj,0);    
}
}

This should work in Flash AS3 or AS2:

var result:Object = new Object();
result.onResult = function(results:Object)
{
  for( var item:String in results ) 
{
	trace(results[item]);
	trace(item);
}  
}
netconnection.call("getVideoNames", result);

Richard

You can’t use an Application module with .net. You can use a HTTProvider or a Web Service. But this code could be made to work in a HTTProvider and output xml instead of returning an object. You would have to tell it what application is involved.

Since you will be passing data in, start with this post:

http://www.wowza.com/community/t/-/245

And since you will be building xml output, you can look at this post for reference:

http://www.wowza.com/forums/showthread.php?t=597

Richard

I really don’t have that exact thing. These are all the pieces, you just have to mix them together. The IDE has a Wizard for creating a new HTTProvider. The code in that module will work in a HTTProvider, except that where the Application is part of the context of a Module you will have to pass in the Application name and get a reference to it, there are examples of that in the HTTProvider examples.

Looks like I pasted in the wrong example for the 2nd link. I meant to give you this one:

http://www.wowza.com/community/t/-/60

Richard

If you mean a snapshot of a stream as in that post, that’s what we have for that purpose.

Richard

You can create an HTTProvider version of this application module.

https://www.wowza.com/docs/http-providers

You need the IDE:

http://wowza.com/ide.html

It would take some understanding of Wowza Application module and HTTProviders. There is a pretty good example of an HTTProvider version of an application Module in the LiveStreamRecord addon

Richard

Looking at the code, I think it will, but the output will be one frame flv.

Richard

No, I am pretty sure that is not possible.

Richard

However, on the camera side, try setting key frame interval to 60, and the FPS to 30. Then you will have a key frame every 2 seconds

Richard

You could lower bitrate or higher compression setting (If Axis cam) so you can set fps higher. I don’t know another solution otherwise

Richard

It opens in FFprobe and should be suitable to make a jpg from.

Richard

hi,

this should work for you :wink:

ffmpeg -i yourvideo.flv -s 160x120 -ss 00:00:02 -f mjpeg -t 0.001 -y yourthumbnail.jpg

hope this helps :wink:

koz

in fact this will work better, giving you better compresison on the JPEG

ffmpeg -i yourvideo.flv -vcodec mjpeg -vframes 1 -an -f rawvideo -s 160x120 -ss 00:00:02 -y yourthumbnail.jpg

this takes an image from two seconds in to the video and creates a 160x120 jpeg

hope this helps,

koz

thx, I’m really stupid. I don’t see it :stuck_out_tongue:

a new problem, it’s not relative to wowza server but to conversion with ffmpeg. I usually use :

ffmpeg -i file.flv -vcodec png -vframes 1 -ss 0:0:5.000 -an -f rawvideo -y snapshot.png

something which usally works fine. With the last version of wowza, there is now support for h264 so i try it and it’s really usefull. Streaming get a really better quality . But when I want to generate snapshots from those video, the command failed.

FFmpeg version SVN-r12665, Copyright (c) 2000-2008 Fabrice Bellard, et al.
  configuration: --enable-gpl --enable-postproc --enable-swscale --enable-avfilt
er-lavf --enable-pthreads --enable-liba52 --enable-avisynth --enable-libfaac --e
nable-libfaad --enable-libgsm --enable-memalign-hack --enable-libmp3lame --enabl
e-libnut --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid
 --cpu=i686 --extra-ldflags=-static
  libavutil version: 49.6.0
  libavcodec version: 51.54.0
  libavformat version: 52.13.0
  libavdevice version: 52.0.0
  built on Apr  2 2008 22:35:11, gcc: 4.2.3
[flv @ 00AA6C70]Unsupported video codec (7)
[flv @ 00AA6C70]Unsupported video codec (7)
[flv @ 00AA6C70]Unsupported video codec (7)
[flv @ 00AA6C70]Unsupported video codec (7)
[flv @ 00AA6C70]Unsupported video codec (7)
...
[flv @ 00AA6C70]Unsupported video codec (7)
[flv @ 00AA6C70]Unsupported video codec (7)
[flv @ 00AA6C70]Unsupported video codec (7)
[flv @ 00AA6C70]Unsupported video codec (7)
[flv @ 00AA6C70]Unsupported video codec (7)
Seems stream 0 codec frame rate differs from container frame rate: 1000.00 (1000
/1) -> 25.00 (25/1)
Input #0, flv, from 'file.flv':
  Duration: 00:00:50.3, start: 0.000000, bitrate: 80 kb/s
    Stream #0.0: Video: 0x0007, 25.00 tb(r)
    Stream #0.1: Audio: mp3, 22050 Hz, stereo, 80 kb/s
picture size invalid (0x0)
Cannot allocate temp picture, check pix fmt

it seems for me that ffmpeg doesn’t support H264, this is the only thing which change since before. But surprise, the documentation and official website of ffmpeg clearly say that flv & h264 is supported. If somebody get and idea or already get this error.

is it possible to show captured frame in the flash client?

I want to save snapshots of live streams to the database so that later i can see them from the admin panel which is a flex client.

Thanks

I modified the Java code in the first post. See if that does the trick. I did not have time to test it.

Charlie

Hi Charlie,

where do I find the code snippet, mentioned above?

Regards,

Markus