add a realtimeStreaming example

[wangxi761]

#1633

first , add a realtimeStreaming example than can Simulate the "-re" parameter in ffmpeg

[saudet]

Thanks! Could you instead put that directly in FFmpegFrameGrabber.grab() with a new flag like boolean atFrameRate though?

[wangxi761]

@saudet
sure，Originally planned。
but It takes me some time to finish it ， so I will give an example first

[saudet]

Thanks! If you're having problems building JavaCV or something, let me know and I'll help you out.

[wangxi761]

    public synchronized Frame grabFrame(boolean doAudio, boolean doVideo, boolean doProcessing, boolean keyFrames, boolean doData) 

this methond may be a bad design ，As a low-level execution method, it uses the public declare。if we add a param to this ,
Other people's call may be broken.
do you think so? i would make it private in other method and Keep its reference
@saudet

[saudet]

Just add another overload like was done for doData. :)

[wangxi761]

build project with some dependency error

[wangxi761]

another question , i want to write some unit test in /platform/test
but how can i read file in ci process @saudet

[saudet]

build project with some dependency error

You can ignore that class, it's deprecated.

another question , i want to write some unit test in /platform/test
but how can i read file in ci process @saudet

What do you mean? It's just a normal machine, we can read files normally.

[wangxi761]

while all test is ok , in my local machine . I don't know if the file for the build machine exists . like such code in FrameGrabberTest.java

        File tempFile = new File(Loader.getTempDir(), "test.mkv");

Does it run unit tests when it is built? If not, I will ignore it

[wangxi761]

well ,function has been implemented,we can use it by two way

FFmpegFrameGrabber.grabFrame(true,true,true,false,true,true))

or

FFmpegFrameGrabber.setOption("re","true");

[saudet]

while all test is ok , in my local machine . I don't know if the file for the build machine exists . like such code in FrameGrabberTest.java

        File tempFile = new File(Loader.getTempDir(), "test.mkv");

Does it run unit tests when it is built? If not, I will ignore it

The file will exist if you create it. I still don't understand what you're worried about. Just try it and if it doesn't work, then we can look at the error message.

FFmpegFrameGrabber.setOption("re","true");

Please don't do that, create a new property like isAtFrameRate() and setAtFrameRate() for that please, and then remove the atFrameRate flag from grab().

[wangxi761]

@saudet
It's done and the local test has passed

[saudet]

Since this doesn't depend on FFmpeg and we can use it with others like OpenCVFrameGrabber, how about we move this to the parent class FrameGrabber?

[wangxi761]

According to the current FrameGrabber design, it is not easy. Different subclasses like OpenCVFrameGrabber/FFmpegFrameGrabber directly implement the grab() method.
If the grab() method of the parent class is transformed into a template method pattern, we can implement it in the parent class, but I don't know much about other implementations, do they need such a function?

[saudet]

I would just add a grabAtFrameRate() method that calls grab(). What do you say?

[wangxi761]

Do all subclasses need this parameter？ if not

[saudet]

I would do this without a new property, just one new method.

[wangxi761]

well , add a method to FrameGrabber and a unit test FrameGrabberRealTimeTest

[saudet]

Looks good, thanks! But the test is failing...

[wangxi761]

because i remove the video path and rtmp server path when i commit ，They only exist in my local