This is a followup patch for #700781, which is not quite correct.
The buffer handling is quite complicated here.
The original code intended to the the following:
- gst_v4l2_buffer_pool_process() calls QBUF and adds the buffer to the
local list.
- The sink calls gst_buffer_unref() which returns the buffer to the pool
but not the 'free list'.
- Some time later DQBUF returns the buffer and
gst_v4l2_buffer_pool_release_buffer() puts in on the 'free list'.
If the buffer must be copied then (parent_class)->acquire_buffer() is
called directly to keep the buffer in the pool.
This has two problems:
1. If gst_v4l2_buffer_pool_release_buffer() is called before the buffer is
returned to the pool, then the buffer is put on the 'free list' twice.
This can happen if a reference to the buffer is kept outside the sink,
of if DQBUF returns the buffer, that was just queued with QBUF.
2. If buffers are copied, then all buffers are in the pool at all times. As
a result gst_v4l2_buffer_pool_stop() and gst_v4l2_buffer_pool_dqbuf()
can access pool->buffers at the same time, which can lead to memory
corruption.
The patch for #700781 fixes those problems, but with the side effect that
there are always buffers outside the pool (because they are queued) and
the pool is never stopped.
This patch fixes this by releasing the reference to the buffer after
handling it (to avoid problem 2.) so it can be returned to the pool.
gst_v4l2_buffer_pool_release_buffer() is only called if the buffer is
already in the pool (to avoid problem 1.).
Fixes https://bugzilla.gnome.org/show_bug.cgi?id=701375
This reverts commit 61666898cf.
This commit changes what the set_sps_pps() function does, not it doesn't
set caps anymore (and should have been renamed). The main problem is that
not all call sites are updated and thus leak the string.
This makes it possible to set any controls that can be set with
VIDIOC_S_CTRL.
The controls are set when the property is set (if the device is open)
and when the device is opened.
https://bugzilla.gnome.org/show_bug.cgi?id=698837
It is not needed to do a state change from the _play() function on
ourselves. The state change function already did that and we don't want to
interfere with that (or use hacks to avoid interference).
Also send stream-start and segment event on the RTCP pad.
We don't need to send anything on the sync_src pad because we
already forwarded all incomming events.
The previous implementation had the formatting of SDP attributes happen
in each RTP payloader, now instead the constituent values are propagated
as caps fields. This allows for applications to do SDP offer/answer
based on caps negotiation.
Fixes https://bugzilla.gnome.org/show_bug.cgi?id=700748
The previous implementation had the formatting of SDP attributes happen
in each RTP payloader, now instead the constituent values are propagated
as caps fields. This allows for applications to do SDP offer/answer
based on caps negotiation.
Keep parsing a-framerate, x-framerate and x-dimensions in rtpjpegdepay
to be backwards compatible with previous payloaders.
Fixes https://bugzilla.gnome.org/show_bug.cgi?id=700748
Without this, a queued buffer may be required, filled and queued before it
is dequeued.
Calling gst_buffer_pool_acquire_buffer() ensures that the buffer is set up
correctly and gst_buffer_unref() calls buffer_release().
https://bugzilla.gnome.org/show_bug.cgi?id=700781
