v4l2_stateful_encoder: Read frame into memory

The performance penalty for reading a file a byte at
a time is quite high.  This was done for interleaved
files.  Instead read the entire frame into memory in
at a time.  Then interleaving is a memory operation
and not a file operation

TEST=md5 sum matches encode before and after

Change-Id: I53a00093acd8f188e078136b15e76fa54f2ce98d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/drm-tests/+/3620842
Commit-Queue: Fritz Koenig <frkoenig@chromium.org>
Reviewed-by: Nathan Hebert <nhebert@chromium.org>
Tested-by: Fritz Koenig <frkoenig@chromium.org>
1 file changed