Zero shutter lag in Android camera

Question

With a normal shutter lag, the sensor driver provides a buffer with an encrypted image up to v4l2, and here the jpeg (hardware) header adds some additional data (exif info and thumbnail), and this layer gives the image buffer for viewing the heap (in the HAL layer) for further processing . but what is the shooting process in the absence of a shutter shutter. Is this the same as normal shutter lag? How to reduce the time between snapshot and image processing. if not explain.

Answer 1

To achieve zero shutter lag, the camera driver must support a small round buffer pool containing full-size frames. Images are recorded at the speed of the sensor and sent to the preview and to the round buffer pool (either as a raw buyer or as a processed / semi-professional YUV). When use presses the shutter, a new buffer in the circular pool is retrieved, processed and compressed as a JPEG. On older cameras for mobile phones, the sensor is not able to capture full-resolution frames with a sufficiently high frame rate, so ZSL cannot be implemented.