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Lately I was working with MediaRecorder to capture videos and handle them in the output. However as it turns out, there were security restrictions, which didn't allow me to catch the outputstream from the MediaRecorder (the problem presented in the link below):

"Seekable" file descriptor to use with MediaRecorder Android 6.0 (API 23)

So I had to elaborate another solution and decided to work with Camer API and and get the stream there. So the first way was to work with onPreviewFrame, catch the frames in a file and convert colors and formats (MediaCodec). Luckely the problem with color conversion could be circumvented by getting the video from the e.g SuraceTexture, as described e.g. in bigflakes project:

https://bigflake.com/mediacodec/CameraToMpegTest.java.txt

I am not a total newbie in Android Java, but this is really overwhelming me. I dont want a ready receipt for that and I am pretty okay with sitting and working the next whole week and cracking that code, but firstly my question is: how you guys got to understand MediaCodec taking the video from e.g. SurfaceTexture and later put it in MediaMuxer and secondly could you recommend some tutorials, where you begin with the simpliest project on that topic and then gradually expand the code?

I really try to work on bigflakes project, but I am helpless even because the onCreate method is missing.. and the best part begins when he begins to render the video.

KOalaDelYtaPLaYa
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  • By camera API, do you mean Camera2 API. Also, what is your objective in wanting to use MediaCodec, to simply save the frame (as image or video) or to process each frame's data or to convert said data into a suitable format to funnel somewhere else? – Chrisvin Jem May 24 '19 at 15:33
  • Thank you for the response. Using the MediaRecorder and FileDescriptor I was able to catch the outputstream (already converted in Mp4), but this does not work on Nougat and Marshmallow. So now the idea is to use Camera API 1 and catch the frames on onPreviewFrame and convert them later to mp4 (or any playable format in AndroidView. Through bigflake I got know that u can access the stream on SurfaceTexture and from there convert it with all the steps between to e.g to Mp4. And if possible before saving this final output I again want to catch the stream in bytes and funnel it somewhere else. – KOalaDelYtaPLaYa May 24 '19 at 21:32

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Bigflakes MediaCodec page contains mostly tests for MediaCodec, if you still insist on using that as a reference then start from encodeCameraToMpeg() in CameraToMpegTest, also take a look at EncodeAndMux to get an idea on how to set up the MediaCodec encoder.

For a working video capture sample, take a look at taehwandev's MediaCodecExample. For an example on how to decode your recorded video, take a look at the BasicMediaDecode provided in the Google Samples repo.

The advantage of using MediaCodec along with Camera1 API would be that you'll be able to support devices with API level 18 and upwards. If you're only targeting API levels 21 and upwards, then Camera2 should work, here's a Android Camera2Video Sample for you to refer to if needed.

Finally, it might also be worthwhile to look at the new CameraX API, although it shouldn't be used in production yet, that's the direction that android's camera API is moving towards. So it's probably worth taking a look at the official documentation and going through a guide or two (eg: Exploring CameraX) to get the basic idea ahead of time.

NOTE - Do not use CameraX API in production code yet, as the CameraX library is in alpha stage and its API surfaces aren't yet finalized. I merely provided it as an option for you keep tabs on for future reference.

Chrisvin Jem
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