By using a map container, we can easily insert/remove buffers from the buffer list. This will be required to track buffers allocated externally and passed to the pipeline handler through a Request. Replace the buffer index tracking with an id generated internally by the stream object. Signed-off-by: Naushir Patuck <naush@raspberrypi.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>