How to save SurfaceTexture as bitmap
android, android-mediacodec, decoder, opengl-es-2.0
Solution
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).
Problem
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.