How to save SurfaceTexture as bitmap

android opengl-es-2.0 android-mediacodec decoder
feisal picture feisal · Oct 14, 2013 · Viewed 15.6k times · Source

When I decode a video to a surface I want to save the frames i want as bitmap/jpeg files. I don't want to draw on the screen and just want to save the content of the SurfaceTexture as an image file.

Answer

fadden picture fadden · Oct 15, 2013

You have to render the texture.

If it were a normal texture, and you were using GLES 2 or later, you could attach it to an FBO and read directly from that. A SurfaceTexture is backed by an "external texture", and might be in a format that the GL driver doesn't support a full set of operations on, so you can't do that. You need to render it, and read the result.

FWIW, the way you go about saving the frame can have a significant performance impact. A full example demonstrating the use of MediaExtractor, MediaCodec, glReadPixels(), and PNG file creation is now up on bigflake (ExtractMpegFramesTest).

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