On what I've read, by using setPreviewCallbackWithBuffer and addCallbackBuffer, I could add little blocks of buffers filled of YUV data by the CameraPreview.
If the added buffer is sized to be filled with X seconds of Preview, I could start reading Buffer1 while Camera is filling Buffer2.
Am I doing "fausse route" ?
I did not find any way of "Playing as video" a Yuv Buffer...