What to use to watch a video from multiple angles - unity3d

I am trying to create an app &/or web based online school that I am filming instruction from four different angels. I can't find anything that I could code to allow the user to select a different camera view and progress during the video.
Ideally there will be four cameras filming the exact technique but the user should be able to jump to different views throughout the video without having to start again.
I have searched online for three days now but cannot find anything to what I want/need.
I just want the video to play and the user to be able to switch to different camera views.

You can set the property:
VideoPlayer.frame
When the user "changes camera angle", record the frame of the currently playing video, stop it, start playing the new video from the different angle and set it's frame property to match the last video.

Related

How to make video captured by front camera not being inverse Android?

I recording video using MediaRecorder.When using back-camera,it working fine,but when using front camera,the video captured is being flipped/inverse.Means that the item in right,will appear on the left.The camera preview is working fine,just final captured video flipped.
Here is the camera preview looks like
But the final video appear like this(all the item in left hand side,appear on right hand side)
What I tried so far:
I tried to apply the matrix when prepare recorder,but it seems does change anything.
private boolean prepareRecorder(int cameraId){
//# Create a new instance of MediaRecorder
mRecorder = new MediaRecorder();
setCameraDisplayOrientation(this,cameraId,mCamera);
int angle = getVideoOrientationAngle(this,cameraId);
mRecorder.setOrientationHint(angle);
if(cameraId == Camera.CameraInfo.CAMERA_FACING_FRONT){
Matrix matrix = new Matrix();
matrix.preScale(1.0f,-1.0f);
}
//all other code to prepare recorder here
}
I already read for all this question below,but all this seems didnt solve my problem.For information,I using SurfaceView for the camera preview,so this question here doesn't help.
1) Android flip front camera mirror flipped video
2) How to keep android from inverting the image from the front facing camera?
3) Prevent flipping of the front facing camera
So my question is :
1) How to capture a video by front camera which the video not being inverse(exactly the same with camera preview)?
2) How to achieve this when the Camera preview is using SurfaceView but not TextureView ? (cause all the question I mention above,tell about using TextureView)
All possible solution is mostly welcome..Tq
EDIT
I made 2 short video clip to clarify the problem,please download and take a look
1) The video during camera preview of recording
2) The video of the final product of recording
So, if the system camera app produces video similar to your app, you didn't do something wrong. Now it's time to understand what happens to front-facing camera video recording.
The front facing camera is not different from the rear facing camera in the way it captures still pictures or video. There is a difference how the phone displays camera preview on the screen. To make it look more natural to the user, Android (and all other systems) mirrors the preview, so that you can see yourself as if in a mirror.
It is important to understand that this only applies to the way the preview is presented to you. If you pick up any video conferencing app, connect two devices that you hold in two hands, and look at yourself, you will see to your surprise that the two instances of yourself are flipped.
This is not a bug, this is the natural way to present the video to the other party.
See the sketch:
This is how you see the scene:
This is how your peer sees the same scene
Normally, recording of a video is done from the point if view of your peer, as in the second picture. This is the natural setup for, e.g., video conferencing.
But Snapchat and some other social apps choose to store the front-facing video clip as if you record it from the mirror (as if the recorder is in your hand on the first picture). Some people like this feature, others hate it (see https://forums.androidcentral.com/general-help-how/664539-front-camera-pics-mirrored-reversed-only-snapchat.html and https://www.reddit.com/r/nexus6/comments/3846ay/has_anyone_found_a_fix_for_snapchat_flipping)
You cannot use MediaRecorder for that. You can use the lower-level API of MediaCodec to record processed frames. You need to flip each frame 'manually', and this may be a significant performance hit, because normally the MediaRecorder 'connects' the camera to hardware encoder in a very efficient way, without need even to copy the pixels to user memory. This answer shows how you can manipulate the way camera is rendered to texture.
You can achieve this by recording video manually from surface view.
In such case preview and recording will match exactly.
I've been using this library for this purpose:
https://github.com/spaceLenny/recordablesurfaceview
Here is the guide how to use it (not with camera but with OpenGL drawing): https://withintent.uncorkedstudios.com/recording-screen-video-on-android-with-recordablesurfaceview-451c9daa213e

add more than 1 video player in iphone

Is there any way to add more than 1 video player in a single View? I am getting the .m4v list from server adn have to display that much videos in single page.
It doesnot matter if I play 1 video at a time but which ever video I want must play there itself.
So the videos are placed one below other.
I have tried using mpmoviecontroller but it's drawback is it can have only one instance in the whole applicaiton So if i try to alloc 2 players in a view then the first one does not work and only one player works..
Is there any legal alternate way for the same?
MPMoviePlayerController will allow multiple instances, but only one of them can be playing their movie at any given time.
Please check the link : http://developer.apple.com/library/ios/#documentation/mediaplayer/reference/MPMoviePlayerController_Class/MPMoviePlayerController/MPMoviePlayerController.html
I used AVPlayer class (which also MPMoviePlayerController uses under the hood) to successfully play multiple videos from multiple source.
The process of using it is more involved than MPMoviePlayerController, but I would say it is definitely worth to look at if you want some customized behavior in your player. The official programming guide is a good start.

Capture video without displaying the actual video feed

So I have an application that can currently capture video with the front facing iphone camera and then do some processing on the video feed real-time. What I'm trying to do, however, is make this process run in the background and put other controls onscreen. So for example, say I'd like to run the camera and process the image feed, but I want the user to see a black screen with some buttons on it. Any ideas on how to do this?
Just so we get terminology right, by "in the background", you mean running the camera capture while your application is in the foreground, but not displaying the actual video feed. This is possible, but I wanted to make clear that if you move your whole application into the background you will not have access to the camera then.
There are a few ways to do this, but the one that I've spent the most time with is grabbing frames of video (or photos) via AV Foundation. Using an AVCaptureDevice and AVCaptureSession, you can grab the frames of video and route them to an encoder for saving to disk or for processing using your own custom code. None of this requires the camera feed to be displayed onscreen, so you can put up whatever interface you like and do this video recording or photo capture without any onscreen indication.
I would caution that you should make it explicit to your users what you are doing, so that you do not run the risk of violating someone's privacy. Apple does not react kindly to those who do this (for good reason).
I encapsulate a lot of this within my open source GPUImage video and photo processing framework, so you could look at the code for the GPUImageVideoCamera class there to see how I configure the capture inputs. I hand the video frames off to OpenGL ES for the application of filters and other processing operations, but you could ignore that portion of it if you just wanted to do your own encoding or processing.
Heres an exemple code from Apple's doc:
http://developer.apple.com/library/ios/#samplecode/PhotoPicker/Introduction/Intro.html
there is also the way to customize the camera interface.

Playing a real time video stream from iPhone camera on a 20 second delay

I am trying to see if it is possible to record a video from the iPhone's camera and write this to a file. I then want the video to start playing on the screen a set time after. This all needs to happen continuously. For example, I want the video on the screen to always be 20 seconds behind what the camera is recording.
Some background:
I have a friend who is a coach and would like for his players to be able to see their last play. This could be accomplished by a feed going to a TV from an iPad always 20 seconds behind what is recorded. This needs to continually run until practice is over. (I would connect the iPad to the TV either with a cable or AirPlay to an Apple TV). The video would never need to be saved and should just be discarded after playing.
Is this even possible with the APIs AVFoundation offers? Will the iPhone let you write to a file and read from a file at the same time to accomplish this? Any other better way to accomplish this?
Thanks for your time.
Instead of writing to a file, how about saving your frames in a circular buffer big enough to hold X seconds of video?
The way I would start to do this would be to look at what's provided in AVCaptureVideoDataOutput and its delegate methods (where you can get the frame data from).

Is it possible to play a video on iPhone and have a subtitles synchronized with it show up?

I want to add a "subtitles" to a video played in an iPhone app. I don't want those subtitles encoded into the video itself - ideally I'd love to have a view showing the video (with pause, play, volume and such standard controls) together with a view displaying the text that changes together with movie time changing.
If I drawn that, it's something like this,
So, basicly, I would need a way to get a method called when movie is playing, and then synchronize the text displayed on the label with the movie timing.
Anyone used a solution that was able to do it?
I've recently done something that syncs graphics to times in an audio track. The way I did it was by using the currentPlaybackTime property of the MPMediaPlayback interface (which the MoviePlayer controller should also conform to). This returns the seconds elapsed in the media, in a double (typedef'ed as NSTimeInterval). The actual synchronisation in my app was not done in notifications, as I couldn't find any resembling a "tick", but instead I created a timer, calling a function queried the currentPlaybackTime, and updated the graphics based on this.
In terms of your implementation, I would assume you have some kind of system for associating label text (subtitles) with a particular time. You could then compare the text's time range with the time returned from currentPlaybackTime to find the correct text to display.