Make separate payload for the header.
Make release-fd payloads
capture_buffer -> peek_buffer to avoid a copy
remove release-buffer, we really need to release each fd in the buffer
separately.
provide_buffer -> send_buffer so that we can also use this to send the
release-fd messages.
in pinossrc, send back release-fd messages when the fd is no longer in
use.
Rename the payloader and depayloader to pinospay/pinosdepay because they
now store data in a pinos specific format.
Subclass GstElement because they are not real transform elements.
Rework/remove some buffer functions that are not used by some more
performant ones.
Use BufferIter and BufferBuilder instead of Packet*
Make separate method to set the header so you can set it later and not
only at builder init time.
Add method to clear the builder if you want to abort.
Add method to add fd to builder instead of in _add_fd_payload. This
would make it easier to add multiple fd-payloads using data from the
same fd.
Pass PinosPacketFDPayload to add_fd_payload to make it symetric with the
parsing code. We should be able to get the size from the VERSION passed
when the builder was made.
Add ideas about releasing the fds back to the server.
Send a command stream over the socket.
Implement a new buffer object that holds the data and commands.
Make iterator and builders to parse and construct buffers.
Rework gstreamer elements to use new API for creating and parsing
buffers.
Add _release_buffer to notify a stream when we are done processing the
buffer. This will eventually go all the way to the server and will allow
us to do more complicated buffer management.
