Develop Reference

Playing video files from custom local URL using Unity VideoPlayer component

I am trying to load a video file at runtime and play that video using the Unitys Video player component.The video is located in a folder on the mobile. i receive the URL to the file location(this is tested correct). While looking for the file Unity even finds the file at location but is not able to play it. I receive the following error :
AndroidVideoMedia: Error opening extractor: -10002
There is nothing on the internet regarding this issue as well. One page said something about changing gradle version.
Please note that this works fine on the editor. I have also noticed if putting a file in the persistent data path of the app, then loading and playing is fine. But if the file is kept in any other custom folder, then even after finding the video Unity is not able to play it.
Following is a snippet of the code :
void Start()
{
StartCoroutine("LoadVideoRoutine");
}
IEnumerator LoadVideoRoutine()
{
if(video==null)
yield return null;
string root = _arManager.VideoURLToPlay;
print("This is video url : " + root);
if(!File.Exists(root))
{
print("no video");
yield return null;
}
else if(File.Exists(root))
{
print("Found vid");
video.url = root;
video.Prepare();
// video.Play();
}
while(!video.isPrepared)
{
print("preparing");
yield return null;
}
print("playing");
video.Play();
// video.url = root;
// video.Play();
}
Following is a sample URL where the video is present :
"/storage/emulated/0/MyApp/RaceRecordings/3D2A4AF9-A6EB-4D48-92D2-1B2A6ADC968A.mp4"
In the logs, I got the "Found vid" log indicating that unity finds the file. But immediately when I am setting the URL I got the error.
I am not sure what this is and would appreciate some help in this regard.

Maybe try remove the .mp4. Maybe it doesn't belong to the URL but I don't know much about it.

use thisMagic Exo player library.
can play online and offline video and handle initializing and deint the payer on its own

Not able to open video files using OpenCV VideoCpature java class in Android

I am trying to load couple of AVI files from phone storage. Sample paths -
/storage/emulated/0/Download/received_files/video1.avi
/storage/emulated/0/Download/received_files/video2.avi
VideoCapture vc1 = new VideoCapture();
VideoCapture vc2 = new VideoCapture();
if (!vc1.open(video1)) {
Log.e(TAG, "Could not open the video file1");
} else {
Log.i(TAG, "Video1 loaded");
}
if (!vc2.open(video1)) {
Log.e(TAG, "Could not open the video file1");
} else {
Log.i(TAG, "Video2 loaded");
}
Needless to say it always returns "Could not open ..." message.
File paths are correct, I am able to create File object using above paths and File.exists() returns true.
I am using OpenCV 3.2.0. Am I missing something?
Thanks

OpenCV for Android supports only MJPEG codec in AVI container hence it will not open any video encoded with any other codec. (source opencv.org)
FFMPEG may be used to support other codecs.

Create video file from images in Android

I am reading found many articles and info about creating video from sequence of images. They all recommend to use ffmpeg. The thing is that this pretty complicated. There is simple way to do this without ffmpeg? I need that the result video will be readable to regular video player on the device.

Not sure what you mean by complicated. If you are not very comfortable with native layer then you might use javaCV. It provides java wrapper for ffmpeg among other open source library and works very well.

Possibly, you want to make use of the Movie. The reference is here:
http://developer.android.com/reference/android/graphics/Movie.html
And, a sample example is here:
https://code.google.com/p/animated-gifs-in-android/

You can use JCodec library.
It now supports android too.
You need to download the library and add it in your project.
here is an example of using the library:
SequenceEncoder se = null;
try {
se = new SequenceEncoder(new File(Environment.getExternalStorageDirectory(),
"jcodec_enc.mp4"));
File[] files = yourDirectory.listFiles();
for (int i = 0;i<files.length; i++) {
if (!files[i].exists())
break;
Bitmap frame = BitmapFactory.decodeFile(files[i]
.getAbsolutePath());
se.encodeImage(frame);
}
se.finish();
} catch (IOException e) {
Log.e(TAG, "IO", e);
}

Reading a video frame by frame with Android OpenCv

I have a set of videos stored in a folder on the android file system.
I would like to read each frame by frame so that i can perform some OpenCv functions on them and then display them in a Bitmap.
I'm not sure how to do this correctly, any help would be appreciated.

You can take a look at Javacv.
"JavaCV first provides wrappers to commonly used libraries by researchers in the field of computer vision: OpenCV, FFmpeg, libdc1394, PGR FlyCapture, OpenKinect, videoInput, and ARToolKitPlus"
To read each frame by frame you'd have to do something like below
FrameGrabber videoGrabber = new FFmpegFrameGrabber(videoFilePath);
try
{
videoGrabber.setFormat("video format goes here");//mp4 for example
videoGrabber.start();
} catch (com.googlecode.javacv.FrameGrabber.Exception e)
{
Log.e("javacv", "Failed to start grabber" + e);
return -1;
}
Frame vFrame = null;
do
{
try
{
vFrame = videoGrabber.grabFrame();
if(vFrame != null)
//do your magic here
} catch (com.googlecode.javacv.FrameGrabber.Exception e)
{
Log.e("javacv", "video grabFrame failed: "+ e);
}
}while(vFrame != null);
try
{
videoGrabber.stop();
}catch (com.googlecode.javacv.FrameGrabber.Exception e)
{
Log.e("javacv", "failed to stop video grabber", e);
return -1;
}
Hope that helps. Goodluck

i know it's to late but any one can use it if he need it
so you can use #Pawan Kumar code and you need to add read permession to your manifest file <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
and you will get it working.

I don´t know about Android but generally you would have to use VideoCapture::open to open your video and then use VideoCapture::grab to get the next frame. See the Documentation of OpenCV for more information on this.
Update:
It seems like camera access is not officially supported for Android at the moment, see this issue on the OpenCV Github: https://github.com/opencv/opencv/issues/11952
You can either try the unofficial branch linked in the issue: https://github.com/komakai/opencv/tree/android-ndk-camera
or use another library to read in the frames and then create an OpenCV image from the data buffer like in this question.

CvCaptureFromAVI problems - OpenCV Android

I need to capture frame by frame from a video stored in my sd card of the Android device (in this case my emulator). I am using Android and OpenCV through NDK. I pushed manually the file "SinglePerson.avi" inside the sdcard through file explorer of DDBS (eclipse) and I used the code below to read the file:
JNIEXPORT void JNICALL Java_org_opencv_samples_tutorial4_Sample4Mixed_VideoProcessing(JNIEnv*, jobject)
{
LOGI("INSIDE VideoProcessing ");
CvCapture* capture = cvCaptureFromAVI("/mnt/sdcard/SinglePerson.avi");
IplImage* img = 0;
if(!cvGrabFrame(capture)){ // capture a frame
LOGI("Inside the if");
printf("Could not grab a frame\n\7");
exit(0);
}
img=cvRetrieveFrame(capture);// retrieve the captured frame
cvReleaseCapture(&capture);
}
The problem is that cvGrabFrame(capture) results always false.
Any suggestion to correctly open the video and grab the frames?
Thanks in advance

Some versions of OpenCV (in package opencv2) build without video support. If it is your case you have to enable "-D WITH_FFMPEG=ON" in pkg's Makefile and recompile.
Look at "Displaying AVI Video using OpenCV" tutorial:
"You may need to ensure that ffmpeg has been successfully installed in order to allow video encoding and video decoding in different formats. Not having the ffmpeg functionality may cause problems when trying to run this simple example and produce a compilation errors".
Also check path in cvCaptureFromAVI for correctness.
Hope this will help!

The behavior you are observing is probably due to cvCaptureFromAVI() failing. You need to start coding safely and check the return of the calls you make:
CvCapture* capture = cvCaptureFromAVI("/mnt/sdcard/SinglePerson.avi");
if (!capture)
{
printf("!!! Failed to open video\n\7");
exit(0);
}
This function usually fails for 2 reasons:
When it's unable to access the file (due to wrong filesystem permissions);
Missing codecs on the system (or the video format is not supported by OpenCV).
If you are new to OpenCV, I suggest you test your OpenCV code on a desktop (PC) first.