When we don't have the requested data in the ringbuffer and we move our read
pointer to the requested position, signal the delete cond to inform the writer
that we changed the current fill level. If we don't, the writer might stay
blocked and we might wait forever.
When we don't have enough bytes in the ringbuffer to satisfy the current
request, first update the current read position before waiting. If we don't do
that, the ringbuffer might appear full and the writer will never write more
bytes to wake us up.
Only add the range when we receive a segment event on the sinkpad. The add_range
method will modify the write position, which only makes sense to do on the
sinkpad.
Set the seeking flag right before we send a seek event upstream and discard all
data untill we see a flush-stop again. We need to do this because we activate
the range that we seek to immediately after sending the seek event and it is
possible that we receive data in our chain function from before the seek
which would then be added to the wrong range resulting in data corruption.
When using the ringbuffer, handle the newsegment event like we handle it when
using the temp-file mode: create a new range for the new byte segment. The new
segment should normally already be created when we do a seek.
Add gst_element_class_{add,set}_metadata() variants for static strings,
so we can avoid unnecessary g_strdup()s.
API: gst_element_class_add_static_metadata()
API: gst_element_class_set_static_metadata()
After a writer has written to its reserved write location, it can only make the
location available for reading if all of the writers with lower locations have
finished.
Fix a race where the reader would see the updated the tail pointer before the
write could write the data into the queue. Fix this by having a separate reader
tail pointer that is only incremented after the writer wrote the data.
Doesn't actually change the default value, just makes use of the
define there is. Superficial testing with fakesink and jpegdec did
not reveal improved performance for bigger block sizes, so leave
default as it is.
