Query the amount of available buffers when doing set_config(). This allows us to
configure the parent bufferpool with the number of buffers to preallocate.
Keep track of the provided allocator and use it when we need to allocate a
buffer in RW mode.
When we are can not allocate the requested max_buffers amount of buffers, make
sure we keep 2 buffers around in the pool and copy them into an output buffer.
This makes sure that we always have a buffer to capture into. We also need to
detect those copied buffers and unref them when they return to the pool.
Only free the queued buffers that we keep track of in our buffer array. for rw
io-mode, we do allocate buffers but we don't keep track of them in the buffer
array.
This is not enough to properly support H264 cameras, but it will
allow an H264 stream to be generated by v4l2src using the default
settings of the camera. If used with the pre-set-format signal, the
H264 encoder can be fully configured.
Conflicts:
sys/v4l2/gstv4l2object.c
In order to support UVC H264 encoding cameras, an H264 Probe&Commit
must happen before the normal v4l2 set-format. This new signal is
meant to allow an external application or bin to do it.
It also serves to expose the file descriptor used by v4l2src in case
some custom ioctls need to be called.
Conflicts:
sys/v4l2/Makefile.am
sys/v4l2/gstv4l2src.c
sys/v4l2/v4l2src_calls.c
The tuner marshal and enumtypes are autogenerated, and they need
to be created before the compilation of gstv4l2tuner.c
This patch adds the automake instruction for ensuring the
autogeneration of those files previous the compilation.
The base class may have set the DISCONT flag on the first buffer pushed
out. We need to clear that when recycling buffers back into the buffer
pool, otherwise we constantly push out buffers with the discont flag
set, which might upset downstream elements, esp. for compressed
formats like mpeg-ts.
Make sure we always call munmap() with the same size we called mmap()
with before.
Current v4l2src uses the same structure for VIDIOC_QUERYBUF, VIDIOC_QBUF
and v4l2_munmap calls. The problem is that the video buffer size (length)
may vary for compressed or emulated bufs. VIDIOC_QBUF will change it if
we pass the pointer of a v4l2_buffer. This is why we should avoid using
same variable for mmap and video buffers.
https://bugzilla.gnome.org/show_bug.cgi?id=671126
