When a subclass is blocking in _wait_preroll() in the _render method, make sure
we can unlock the subclass and detect this return value from the render method.
Update framestep document, we want to pass the flush flag in the step-done
message.
Add flush flag to the gstmessage.
Update examples to use the new step-done message api.
Implement framestep with playback rates < 0.0 too.
Make start and stop_stepping methods and move their invocation in the right
places.
Perform the atual stepping operation where we have full context about the
timestamps.
Unlock the prerolled frame and recheck if we need to step.
Keep a simple counter for the frames we're about to skip while stepping and
preroll/post step_done when stepping finished.
gst_adapter_masked_scan_uint32 could return values smaller than offset
if the first byte(s) of the mask are 0 and the pattern matches the
beginning of the adapter.
Added examples to documentation of gst_adapter_masked_scan_uint32().
Also added some more masked boundary tests.
Fixes#584118
Add a reasonably optimized new gst_adapter_masked_scan_uint32() function
to scan the adapter for a pattern after applying a mask.
Add some unit tests.
API: GstAdapter::gst_adapter_masked_scan_uint32()
Fixes#583187
Don't use realloc to grow the scratch area because we don't want the memcpy the
old useless data into the new area before we write our new stuff in it.
When a are requested to take a buffer from the adapter that is exactly the
headbuffer, don't make a subbuffer of it but return that head buffer.
Add a unit-test for this new optimisation.
Due to a typo basesink didn't do any emergency rendering of late buffers
if the only buffer ever rendered was the first one with timestamp 0. This
means that in cases where the decoder is very very slow, we'd never see
any buffers but the very first one rendered. Fixes#576381.
When we are not ready to handle a latency query (we are not yet prerolled) we
also don't try to forward the latency event because that might cause unexpected
errors when upstream is not yet linked.
Fix a regression introduced by fix for #567725 in commit
1c7ab4ed4f. We should only call the preroll
function once namely when we did not yet commit the state change.
Add a unit test to check that we call the preroll function when interrupting the
clock_wait (see #567725).
Add a unit test to check that we only call the preroll function once.
While reconfiguring a basetransform element we need also to recheck
the alloc request. Because it's possible that due to caps changes
the proxy_alloc state is not correct anymore.
(Re-commit after discusion with Wim on IRC)
While reconfiguring a basetransform element we need also to recheck
the alloc request. Because it's possible that due to caps changes
the proxy_alloc state is not correct anymore.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_commit_state),
(gst_base_sink_wait_clock):
* libs/gst/base/gstbasesink.h:
Fix documentation for the wait_clock method, rename basesink -> sink
for consistency.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_get_position_last),
(gst_base_sink_get_position_paused), (gst_base_sink_get_position):
Release the object lock before calling the query convert pad functions
to avoid deadlocks.
Original commit message from CVS:
* libs/gst/base/gstcollectpads.c: (gst_collect_pads_available):
Use the name of the pads instead of a pointer, helps in debugging.
Original commit message from CVS:
* gst/gstdebugutils.c:
Add some ideas, how to make the graph smaller.
* gst/gstutils.c:
Add a comment from a debug session.
* libs/gst/base/gstbasetransform.c:
Log more context.
* libs/gst/controller/gstinterpolationcontrolsource.c:
Indet.
* plugins/elements/gstcapsfilter.c:
Fix typo in docs.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_class_init),
(gst_base_sink_init), (gst_base_sink_set_property),
(gst_base_sink_get_property):
Expose the render-delay as a property so things like appsink can use it
to tweak the synchronisation.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_prepare_output_buffer),
(gst_base_transform_getrange), (gst_base_transform_chain):
* libs/gst/base/gstbasetransform.h:
Add vmethod that is called before we start the transform and which can
be used to configure the transform, such as dynamic properties.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_acceptcaps):
Revert quick accepcaps attempt, it's not fully equivalent to the old
behaviour and thus causes regressions.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c: (gst_base_transform_init),
(gst_base_transform_getcaps), (gst_base_transform_find_transform),
(gst_base_transform_acceptcaps), (gst_base_transform_getrange):
Add beginnings of a more optimized acceptcaps function than the default
core one.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_set_render_delay):
Changing the render delay changes the latency and so we must post a
latency message.
Original commit message from CVS:
* gst/gstbuffer.c: (gst_buffer_finalize):
Avoid costly typechecking for trivially correct pointers.
* gst/gstpoll.c: (gst_poll_wait):
Add some G_LIKELY here and there.
* libs/gst/base/gstadapter.c: (gst_adapter_push):
Add some debug info.
Original commit message from CVS:
* gst/gstbin.c: (bin_handle_async_start),
(gst_bin_handle_message_func), (gst_bin_query):
* libs/gst/base/gstbasesink.c: (gst_base_sink_render_object),
(gst_base_sink_event), (gst_base_sink_change_state):
* libs/gst/base/gstbasesrc.c: (gst_base_src_perform_seek),
(gst_base_src_loop), (gst_base_src_change_state):
Copy seqnums from events to messages so that they can all be related
back to eachother.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_find_transform), (gst_base_transform_getrange):
If we have a fixate function, call it even if we already have fixed caps
because the subclass might add some caps. Makes audioconvert add a
default channel layout.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_prepare_output_buffer),
(gst_base_transform_getrange):
Clear the output buffer variable.
Cleanups to the error path in the getrange function.
Fixes#557649.
Original commit message from CVS:
* docs/libs/gstreamer-libs-sections.txt:
* libs/gst/base/gstbytereader.c: (gst_byte_reader_get_data),
(gst_byte_reader_peek_data):
* libs/gst/base/gstbytereader.h:
* win32/common/libgstbase.def:
API: Add gst_byte_reader_get_data and gst_byte_reader_peek_data
to get a pointer to the data at the current position and have
a guaranteed size.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_prepare_output_buffer),
(gst_base_transform_buffer_alloc), (gst_base_transform_suggest):
Protect sink_alloc caps with the sinkpad lock to avoid nasty caps
refcount problems as seen in banshee and maybe also in farsight2.
Remove atomic int now that we need to take the lock anyways.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_default_do_seek),
(gst_base_sink_default_prepare_seek_segment),
(gst_base_sink_perform_seek), (gst_base_sink_get_position_last),
(gst_base_sink_get_position_paused), (gst_base_sink_get_position),
(gst_base_sink_query):
Implement more seeking in pull mode.
Use pad convert functions to convert position to the requested format.
Fix position/duration reporting in pull mode.
Implement position and duration reporting in other formats than time.
* libs/gst/base/gstbasesink.h:
Add member to keep track of when the segment is playing.
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c: (gst_base_src_default_do_seek);
Remove duplicated assignment and log a message in failure case.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_pad_activate_pull),
(gst_base_sink_query):
Query the total number of bytes when activating the pad in pull mode.
Implement duration query in pull mode by using the installed pad convert
function to convert from bytes to the requested format.
Original commit message from CVS:
* docs/libs/gstreamer-libs-sections.txt:
* libs/gst/base/gstbasesink.c: (gst_base_sink_do_preroll),
(gst_base_sink_flush_start), (gst_base_sink_flush_stop),
(gst_base_sink_event), (gst_base_sink_perform_seek),
(gst_base_sink_loop), (gst_base_sink_pad_activate_pull),
(gst_base_sink_send_event), (gst_base_sink_change_state):
* libs/gst/base/gstbasesink.h:
Add method to commit the state in subclasses.
Refactor the flush_start and flush_stop code because we need it for
flushing while seeking too.
Implement the beginnings of seeking in pull mode.
Use the segment last_stop field for the pulling offset.
Fix the pause method in pull mode.
Configure the segment to BYTES for pull mode.
API: GstBaseSink::gst_base_sink_do_preroll()
Original commit message from CVS:
* docs/design/part-negotiation.txt:
Update the docs some more.
* libs/gst/base/gsttypefindhelper.c: (helper_find_peek):
If we pull a buffer with non-trivial caps, suggest those caps with the
max probability.
Original commit message from CVS:
* gst/gstbin.c: (gst_bin_remove_func), (update_degree),
(gst_bin_handle_message_func):
The message src can be NULL, don't try to print the object names in that
case.
* libs/gst/base/gstbasesink.c: (gst_base_sink_pad_activate):
Add some more debug info.
* tests/check/pipelines/simple-launch-lines.c: (run_pipeline),
(GST_START_TEST):
Add some debug.
Fix the test, pull based sinks go ASYNC to PAUSED, just like other
scheduling modes.
Original commit message from CVS:
* docs/design/part-negotiation.txt:
Small doc update.
* docs/libs/gstreamer-libs-sections.txt:
* libs/gst/base/gstbasesink.c: (gst_base_sink_class_init),
(gst_base_sink_pad_getcaps), (gst_base_sink_pad_setcaps),
(gst_base_sink_init), (gst_base_sink_set_blocksize),
(gst_base_sink_get_blocksize), (gst_base_sink_set_property),
(gst_base_sink_get_property), (gst_base_sink_needs_preroll),
(gst_base_sink_loop), (gst_base_sink_pad_activate),
(gst_base_sink_negotiate_pull), (gst_base_sink_pad_activate_pull),
(gst_base_sink_change_state):
* libs/gst/base/gstbasesink.h:
Add blocksize property and methods to control the amount of data
to pull.
Negotiate first before activating upstream in pull mode so that they can
negotiate themselves.
When we operate in pull mode, we only accept the caps that we
negotiated.
Make the sink go ASYNC to PAUSED, like all other sinks.
API: GstBaseSink::gst_base_sink_set_blocksize()
API: GstBaseSink::gst_base_sink_get_blocksize()
API: GstBaseSink::blocksize
* libs/gst/base/gstbasesrc.c: (gst_base_src_wait_playing),
(gst_base_src_set_live), (gst_base_src_is_live),
(gst_base_src_set_format), (gst_base_src_query_latency),
(gst_base_src_set_blocksize), (gst_base_src_get_blocksize),
(gst_base_src_set_do_timestamp), (gst_base_src_get_do_timestamp),
(gst_base_src_set_property), (gst_base_src_get_property):
* libs/gst/base/gstbasesrc.h:
Add typechecking in public API functions.
Add methods to control the blocksize in subclasses.
API: GstBaseSrc::gst_base_src_set_blocksize()
API: GstBaseSrc::gst_base_src_get_blocksize()
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_send_event):
Forward LATENCY events upstreams so that elements know about the total
pipeline latency. Fixes#555307.
Original commit message from CVS:
* libs/gst/base/gstbytereader.c: (gst_byte_reader_get_uint24_le),
(gst_byte_reader_get_uint24_be), (gst_byte_reader_get_int24_le),
(gst_byte_reader_get_int24_be), (gst_byte_reader_peek_uint24_le),
(gst_byte_reader_peek_uint24_be), (gst_byte_reader_peek_int24_le),
(gst_byte_reader_peek_int24_be):
Use new GST_READ_UINT24_(LE|BE) macros.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_get_position),
(gst_base_sink_query):
Improve position reporting while flushing and other intermediate state
changes. Fixes#553874.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
* plugins/elements/gstcapsfilter.c:
* tests/check/Makefile.am:
* tests/check/elements/.cvsignore:
* tests/check/elements/capsfilter.c:
Fix assertion in basetransform when the subclass chooses not to
allocate a buffer in prepare_buffer(), and make capsfilter error out
cleanly if requested to apply caps that don't completely specify the
buffer. Fixes#551509
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_prepare_output_buffer):
Take new caps ref because our old one might have been gone when the
subclass performs a gst_pad_set_caps() on the srcpad. See #548764.
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c: (gst_base_src_default_negotiate):
Use the result from gst_pad_set_caps() instead of assuming the element
always accepted the caps computed by the default negotiate function.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_render_object),
(gst_base_sink_event), (gst_base_sink_chain_unlocked),
(gst_base_sink_negotiate_pull), (gst_base_sink_pad_activate_pull),
(gst_base_sink_get_position), (gst_base_sink_change_state):
Improve position reporting in the flushing state.
Also report the position when we are not yet prerolled but we
have a newsegment event. Fixes#543444.
Improve the pull-based negotiation code.
* tests/check/elements/fakesink.c: (GST_START_TEST),
(fakesink_suite):
Add testcase for position reporting while flushing in PAUSED and
PLAYING.
* tests/check/generic/sinks.c: (GST_START_TEST):
Update unit-test, we can now query the position as soon as we receive a
NEWSEGMENT event.
Original commit message from CVS:
Based on patch by: Jason Zhao <e3423c at motorola dot com>
* libs/gst/base/gstbasesink.c: (gst_base_sink_render_object):
When the subclass event handler releases the PREROLL_LOCK, we could be
in the flushing state and we have to ignore the event. Fixes#548394.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_prepare_output_buffer):
If the element is configured in passthrough mode but the
prepare_output_buffer gave us a new output buffer, discard that buffer
and reuse the input buffer.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_prepare_output_buffer),
(gst_base_transform_buffer_alloc):
Go over the buffer_alloc function again and make sure we always end up
allocating a buffer.
Add some more docs.
Avoid doing pad alloc when we have a pending suggestion because we
cannot yet deal with changing caps in that case. Fixes#547728
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_transform_caps),
(gst_base_transform_prepare_output_buffer),
(gst_base_transform_buffer_alloc), (gst_base_transform_suggest):
Don't overwrite the outsize when calculating the expected size of a new
buffer because we still need it in case we cannot process the new
buffer.
When converting the size of the new buffer to an upstream size, actually
use the expected size of the buffer, not some other random value.
Use an atomic int to signal that a new upstream caps suggestion is
available.
When we can convert the current buffer to a new format, check if the
buffer size is of the expected size and allocate a new buffer of the
expected size when this is not the case.
* tests/check/libs/transform1.c: (GST_START_TEST):
remove ifdeffed code from the unit test.
Original commit message from CVS:
* libs/gst/base/gsttypefindhelper.c: (helper_find_peek):
Increase code readability.
Don't try to compare buffer offsets when ther are invalid.
Original commit message from CVS:
* docs/libs/gstreamer-libs-sections.txt:
* libs/gst/base/gstbasesink.c: (gst_base_sink_init),
(gst_base_sink_query_latency), (gst_base_sink_set_render_delay),
(gst_base_sink_get_render_delay), (gst_base_sink_wait_eos),
(gst_base_sink_do_sync):
* libs/gst/base/gstbasesink.h:
* win32/common/libgstbase.def:
Add method to allow sinks to specify additional delay between the sync
times and the actual rendering of the data.
API: gst_base_sink_set_render_delay()
API: gst_base_sink_get_render_delay()
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_get_sync_times),
(gst_base_sink_wait_eos), (gst_base_sink_event):
If we have not seen a buffer before EOS, use the segment values to
report the current position instead of invalid positions.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_class_init), (gst_base_transform_init),
(gst_base_transform_transform_caps),
(gst_base_transform_prepare_output_buffer):
Add debug info.
When a buffer is writable, its metadata is also writable so we don't
need to subbuffer (which then makes the buffer not-writable anymore).
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_set_async_enabled),
(gst_base_sink_set_ts_offset), (gst_base_sink_perform_qos):
Add some debug.
Make sure we don't generate invalid QoS messages.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_get_sync_times),
(gst_base_sink_get_position):
The reported position must always be smaller than the last seen
timestamps (or timestamp + duration for reverse).
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_get_sync_times),
(gst_base_sink_get_position_last), (gst_base_sink_get_position):
Fix position query range checks in reverse playback.
Original commit message from CVS:
Based on patch by: Bjarne Rosengren <bjarne at axis dot com>
* libs/gst/base/gstbasesrc.c: (gst_base_src_send_event),
(gst_base_src_get_range), (gst_base_src_pad_get_range),
(gst_base_src_loop), (gst_base_src_set_flushing),
(gst_base_src_change_state):
Make sending an EOS event to the basesrc non-blocking even if the
implementation does blocking waits in the create function. This is done
by unlocking the create function when EOS is sent.
Fixes#535218.
Original commit message from CVS:
Patch by: Sjoerd Simons <sjoerd at luon dot net>
* libs/gst/base/gstbasesink.c: (gst_base_sink_get_sync_times):
If nothing else can be used, use the last buffer's start time as
the segment's last stop. Fixes bug #534258.
Original commit message from CVS:
Patch by: Tim-Philipp Müller <tim.muller at collabora co uk>
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_sink_event):
Unref events that the GstBaseTransform::event vfunc didn't want to
have forwarded by the base class. Closes a leak in identity.
Fixes bug #446763.
Original commit message from CVS:
* docs/libs/gstreamer-libs-sections.txt:
* libs/gst/base/gstbasesink.c: (gst_base_sink_wait_clock):
* libs/gst/base/gstbasesink.h:
Expose a method that was previously used internally to synchronize
against the clock because it can be useful for subclasses too.
GstBaseSink::gst_base_sink_wait_clock()
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_adjust_time),
(gst_base_sink_wait_clock), (gst_base_sink_wait_eos),
(gst_base_sink_do_sync), (gst_base_sink_chain_unlocked):
Refactor adjusting the running_time with latency and offset into a
separate method.
When doing clipping, we still want to use the subclass get_times method,
just in case the DURATION or TIMESTAMP are not set.
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c: (gst_base_src_start):
Use right error code when typefinding fails, so we can use
the default (translated) error messages.
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c: (gst_base_src_get_range),
(gst_base_src_start):
When the subclass did not set caps on outgoing buffers, configure the
caps we negotiated on the source pad.
When the typefind helper does not find caps, error out properly instead
of doing things with NULL caps.
Original commit message from CVS:
* libs/gst/base/gsttypefindhelper.c: (helper_find_peek):
Sort buffer cache list by end offsets. This makes sure that we don't
stop to search for a cached buffer that contains the requested data
too early.
Also read a minimum of 4k bytes instead of 512 bytes as this is a bit
more efficient. Fixes bug #459862.
Original commit message from CVS:
Patch by: Sjoerd Simons <sjoerd at luon dot net>
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_buffer_alloc):
Check the caps of the buffer returned by gst_pad_alloc_buffer() and
fall back to default negotiation in the chain function if the caps
are different from what was requested. Fixes bug #526768.
Original commit message from CVS:
Based on a patch by: Sjoerd Simons <sjoerd at luon dot net>
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_buffer_alloc):
Don't passthrough buffer allocation too easily if the caps change.
This breaks when working in passthrough mode and upstream changes
it's caps. Fixes bug #526768.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_query_latency),
(gst_base_sink_send_event):
Rearrange the latency query code. We always want to do the upstream
query, even if we are not live so that the upstream elements can get the
latency results too. If we fail doing the query and we are live, we
return TRUE afterwards.
Original commit message from CVS:
* gst/gstutils.c:
* gst/gstutils.h:
API: Deprecate gst_atomic_int_set(), g_atomic_int_set() should be used
now that we depend on new enough GLib.
* gst/gstcaps.c: (gst_static_caps_get):
* gst/gstclock.c: (gst_clock_entry_new):
* gst/gstinfo.c: (_gst_debug_init), (gst_debug_set_colored),
(gst_debug_set_default_threshold), (_gst_debug_category_new),
(gst_debug_category_set_threshold):
* libs/gst/base/gstbasesink.c: (gst_base_sink_init),
(gst_base_sink_set_qos_enabled):
* libs/gst/net/gstnettimeprovider.c:
(gst_net_time_provider_set_property):
Use g_atomic_int_set() instead of gst_atomic_int_set().
Original commit message from CVS:
* docs/design/part-buffering.txt:
Fix some typos and set the estimated total for push mode to -1.
* gst/gstquery.c: (gst_query_new_buffering):
Set buffering-left to 0 as we're not buffering by default.
* libs/gst/base/gstbasesrc.c: (gst_base_src_default_query):
Implement BUFFERING query.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_prepare_output_buffer):
Also unset the GAP flag on buffers if we're working inplace but
the element is not GAP-aware.
Mark a comment as FIXME 0.11.
Original commit message from CVS:
Patch by: Mark Nauwelaerts <manauw at skynet be>
* gst/gstclock.h:
* libs/gst/base/gstbasesrc.h:
* libs/gst/base/gstbasetransform.c:
* libs/gst/check/gstcheck.c:
Small documentation fixes. Fixes#523978.
Original commit message from CVS:
* libs/gst/base/gstbasesink.c: (gst_base_sink_loop),
(gst_base_sink_get_position_paused):
Add fixme regarding EOS in pull mode.
Fix position reporting in PAUSED for negative rates.
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c: (gst_base_src_perform_seek),
(gst_base_src_loop):
The start segment for reverse playback goes from start to last_stop.
Original commit message from CVS:
* libs/gst/base/gstbasetransform.c:
(gst_base_transform_transform_size):
Print element name with g_warning() if there's a problem
with the unit size.
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c: (gst_base_src_default_do_seek),
(gst_base_src_loop):
Don't update the last_stop position in do_seek, that's the position we
did a seek to.
Read backwards when we have a negative rate.
* tests/check/elements/filesrc.c: (event_func), (wait_eos),
(setup_filesrc), (cleanup_filesrc), (GST_START_TEST),
(filesrc_suite):
Add check for reverse reading.
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c: (gst_base_src_send_event),
(gst_base_src_get_range), (gst_base_src_pad_get_range),
(gst_base_src_loop), (gst_base_src_set_flushing),
(gst_base_src_change_state):
Allow sending EOS to the source to make it send out an EOS event from
the streaming thread.
Update docs and deprecate the old NULL/READY shutdown method.
* tests/check/libs/basesrc.c: (GST_START_TEST),
(gst_basesrc_suite):
Add unit test for controlled shutdown.
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c: (gst_base_src_wait_playing),
(gst_base_src_perform_seek), (gst_base_src_get_range),
(gst_base_src_set_playing), (gst_base_src_change_state):
Make _wait_playing() not check any variables so that we can call this
function from subclasses. Move the checks elsewhere similar to
_wait_preroll() in basesink.
Add some debugging.
Only signal the LIVE cond when we are going back to PLAYING.
Original commit message from CVS:
* docs/libs/gstreamer-libs-sections.txt:
* libs/gst/base/gstbasetransform.c: (gst_base_transform_init),
(gst_base_transform_prepare_output_buffer),
(gst_base_transform_set_gap_aware):
* libs/gst/base/gstbasetransform.h:
API: Add gst_base_transform_set_gap_aware() to control whether
the element correctly handles GST_BUFFER_FLAG_GAP or shouldn't
get buffers with this flag at all. Fixes#503231.
