A copy paste error was leading to file descriptor leak. This was detected by
Coverity.

CID 1461285

In some scenarios the fakevideosink shouldn't advertize the overlay-composition
meta for instance, so that overlay elements perform subtitles blending
themselves.

According to the specification, the adaptation field length must be 183 if
there is no payload data and < 183 if the packet contains an adaptation
field and payload data.

Unfortunately some payloaders always set the flag for payload data, even if
the adaptation field length is 183.

Don't return with an error in this case. Clear the payload data flag
instead and parse the adaptation field as usual. This avoids visual
artefacts for such streams.

As per specification in A.3.1 h) and A.3.2 f), the maximum size of the DPB is
16. Fix the maximum in the fine and fix the formula to use MIN instead of MAX
so that we no longer always use the maximum for the profile/level.

The output formats are P012_LE for 12bit 420 and Y412_LE for 12bit 444.

No API/ABI changes https://github.com/notroj/neon/blob/0.31.0/NEWS#L3

We should directly check the values of the `debug` and `optimization`
options instead.

`get_option('buildtype')` will return `'custom'` for most combinations
of `-Doptimization` and `-Ddebug`, but those two will always be set
correctly if only `-Dbuildtype` is set. So we should look at those
options directly.

For the two-way mapping between `buildtype` and `optimization`
+ `debug`, see this table:
https://mesonbuild.com/Builtin-options.html#build-type-options

The video format is Y412_LE

In media driver, VA_FOURCC_Y416 is used for packed 12 bits 4:4:4:4 YUV
format, the corresponding RT format is VA_RT_FORMAT_YUV442_12

Y416 is used for packed 12 bits 4:4:4:4 YUV format in media driver, the
RT format is VA_RT_FORMAT_YUV444_12

MFX_FOURCC_Y416 is used for packed 12 bits 4:4:4:4 YUV format in
MediaSDK

The video format is Y212_LE

In media driver, VA_FOURCC_Y216 is used for packed 12 bits 4:2:2 YUV
format, the corresponding RT format is VA_RT_FORMAT_YUV422_12

In media driver, Y216 is used for packed 12 bits 4:2:2 format YUV
format, so the RT format is VA_RT_FORMAT_YUV422_12.

MFX_FOURCC_Y216 is used for packed 12 bits 422 YUV format in MediaSDK

Downstream demuxers will first send seek events upstream to us.
Do the right thing with instant rate change requests by handling them
immediately.

gst_segment_do_seek() can fail, so don't ignore the return result

Convert instant-rate-change seek events into a downstream
instant-rate-change event and skip any further local seek handling.

Functionally identical to that of msdkh264enc

Add an API to create raw SEI nal unit. This would be useful in case
an user want to create SEI nal data and inject the SEI nal data
into bitstream.

These are normal cases, so DEBUG level is enough.

Reordered packets producing decrypting errors are very normal,
so we should filter which errors are warning and which not.

Each srtp_stream_t is tied to an specific SSRC, so a
roc_changed flag should be kept per each SSRC in order to
properly reset RTP sequence number on ROC changes.

See the change of -base gst-plugins-base!594

See the change of -base gst-plugins-base!594

See the change of -base gst-plugins-base!594

See the change of -base gst-plugins-base!594

For interlaced video:
* set the interlace mode in the src caps
* double the height from SPS in the caps.
* set field latency, instead of frame latency.

Fix #778

The contents was cleared, but the array was never released.

This is not useful on any other OSs, it will also avoid potential build
failure as this code uses Linux specific calls.

This ensure that the registry cache get updated when a meaningful change is
made in /dev for files named media*.

This code add required mechanism to try and allocate (not implemented yet)
otherwise wait for more buffers. This also comes with mechanism to terminate
the wait on flush or PAUSED_TO_READY transitions.

This simply consit of cycling through STREAMOFF/STREAMON with stateless
decoders.

This add function to wait for buffers to get back into the pool along with a
set_flushing() method to allow unblocking this wait.

This simply create an empty GstBuffer when the pool is empty. This way it's up
to the allocator to grow or wait if we ran out of memory.