CODEWITHSUNDEEP
androidandroid-cameraandroid-mediacodec
xiaowoo
xiaowoo

Reputation: 2308

How to scale the byte[] data on android Camera's onPreviewFrame to a lower resolution

Android camera have a onPreviewFrame call back which gives you back a frame as byte[] data.

I have set up my Camera to return data (in NV21 format) byte[] data at 1280 x 720.

What I wanted to do:

I would like to keep some of the frames at 1280 x 720 resolution(to jpeg).

And generate a mp4 elementary stream at a lower resolution(something like 720 x 480).

Problem

MediaCodec would error out if the MediaFormat.Key_Width and MediaFormat.Key_Height is not equal to the onPreviewFrame's width and height.

I would like to know if its possible to scale my byte[] data(NV21) from 1280 x 720 to something lower like 720 x 480 resolution and then feed it to the encoder?

If it is possible, what are the steps for converting a byte[] data of NV21 at 1280 x 720 resolution to a lower resolution.

thanks for reading, and would appreciate any suggestions or helps.

Upvotes: 1

Views: 1455

Answers (1)

user2399321
user2399321

Reputation: 637

Yes, it is possible. Have a look at library https://code.google.com/p/libyuv/. It can scale yuv images, convert between different color formats also it has SIMD optimisations (it is pretty fast).

Upvotes: 0

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