In commit a6ed749b12c63d252c6d893d5b5b62fcf35773d9 we used width of the
frame we copy into to calculate the source stride. This is a wrong
assumption as there might be implementations (e.g. GNOME) where we might
have to import a DMA-BUF with size of the whole screen and just having
information in SPA_META_VideoCrop metadata to get the real size of the
frame we will end up using. Given this, we always have to calculate
source stride using the size of the stream to not end up copying pixels
from the empty area of the imported DMA-BUF.
Also improve naming of variables to have names better describing what
they really represent and add some comments explaining why some things
are written the way they are.
Bug: chromium:1333304
Change-Id: I755a5139336c1da5abf95591a2b70a68659a255f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/267002
Commit-Queue: Jan Grulich <grulja@gmail.com>
Reviewed-by: Alexander Cooper <alcooper@chromium.org>
Cr-Commit-Position: refs/heads/main@{#37344}
450da27933