[PD] pix_buffer question

[jim]

I wanted to create a fixed size pix_buffer which is continually fed, so
for example if I have an index from 0 to 1000 once it is filled the most
recent image always has the index 1000 and the oldest 0 indexed image is
discarded and replaced by the second oldest image ie image with index 1.
Is there a simple way to do this or do I have to do a pix_buffer_read
and pix_buffer_write on all 1000 images stored to re-index them each
time a new image is stored in the buffer? Thanks . I am assuming this is
more or less how pix_delay works.
Thanks,
Jim