Improve decide allocation so it properly configure both local and downstream
buffer pools. Also read back the pool config if it was changed to to driver
limitations.
Pre-configuring the pool is error prone, since it may hide a configuration failure and
endup with a pool that is not configured the way it should (e.g. no video meta, wrong
queue size, etc.)
Catch short allocation after saving the format. This is not a catch all, but should catch
most of the miss-behaving drivers when doing S_FMT/G_FMT and avoid potential crash.
This goal of this allocator is mainly to allow tracking the memory.
Currently, when a buffer memory has been modified, the buffer and it's
memory is disposed and lost until the stream is restarted.
Some well known decoder wrongly set num_planes to 0 in their format instead of
one. In this case we would endup with no size when deciding buffer allocation.
In order to correctly set the pool min/max, we need to probe for CREATE_BUFS
ioctl. This can be done as soon as the format has been negotiated using a
count of 0.
Now that we might be copying out buffer (e.g. downstream don't support video
meta bug we need it) we need to move the EOS handling inside the process
method.
As soon a the alpha component can be set, we can expose the RGB32 and BGR32
format as ARGB and BGRA as long we can deterministically set the alpha padding
value.
In certain cases we cannot live without video meta and/or crop meta
being enabled in our internal buffer pool. Ensure this is always the case,
regardless of having support for allocation query.
Upon error, the pools might not have been allocated yet, hence we should not
try and flush them (even though we still want to make sure the processing thread
is fully stopped).
Buffer pool was guessing wrongly the number of planes rather
then reading the value from obj->n_v4l2_planes. This was causing
format YU12 (I420) to fail upon check.
The complex mechanic to try and choose the right thing did not work. Instead,
simply probe the non-contiguous format first and then the contiguous one.
This is in fact very low overhead, as there is a relatively small number of
pixel format supported by each devices.
