Rename start and stop methods to open and close because that is what they do.
After setting the format on the device object, setup the bufferpools. Move this
code from the v4l2src_calls.c file, it is shared between source and sink.
Make new device start and stop method that merges various bits of common code
spread over several files.
We want to keep the default strides in the videoinfo. Keep the stride of the
video frames separate so that we can use both to copy a video frame and do
correct stride conversion.
Use GstVideoInfo to store the parsed caps.
Remove outsize from the caps parsing code, it's wrong because it does not use
the stride given by the driver.
Move the configuration of the framerate to where we set the other format
parameters.
Remove hack to check if the device is active.
Store streamparm in the device info.
Use some macros to access the current device configuration.
Remove some duplicate fields in src and sink and use the device configuration
instead.
Pass the caps to the set_format function and make _set_format parse the caps.
Also keep the parsed values in the v4l2object so that we can refer to them when
we want.
Keep track of the currently configured format and setting in the
v4l2object.
Pass the v4l2object to the bufferpool constructor so that the bufferpool can
know everything about the currently configured settings. This also allows us
to remove some awkward code.
Create a new pool in setcaps and stop/destroy the old one.
Remove buffer_alloc functions.
Check that we have v4l2 metadata in show_frame and fall back to memcpy into a
buffer from our pool if we don't receive one of our own buffers.
Various cleanups, avoids useless casts, move error handling outside of the main
code flow.
Negotiate to a resonable resolution instead of the max resolution.
Based on a patch by Guennadi Liakhovetski.
v2: updates because I forgot to add GstTuner interface to v4l2sink
v3: update to add all possible values to norm enum
Commit 6c8268dbfd5c88fac28c882ef2e4598a6522e2d6 broke recording
from interlaced v4l2 source (e.g. typical tv capture card) since
V4L2_FIELD_SEQ_TB (with fields stored separately) does not map
to currently defined interlaced format (fields stored interleaved).
Besides this mismatch, hardware might quite likely not support or
appreciate this field value, since querying supported formats mapped
_INTERLACED field formats to interlaced=true caps (so the latter should
not be mapped to field value that is not known to be supported).
