Most important part here is special-casing "device busy" so the application
is able to provide better feedback when another application is using the
device.
Original commit message from CVS:
* sys/winks/gstksvideodevice.c (GST_DEBUG_IS_ENABLED, last_timestamp,
gst_ks_video_device_prepare_buffers, gst_ks_video_device_create_pin,
gst_ks_video_device_set_state, gst_ks_video_device_request_frame,
gst_ks_video_device_read_frame):
Guard against capturing old frames by keeping track of the last
timestamp and also zero-fill the buffers before each capture.
Only assign a master clock if the pin hasn't already got one.
Actually free buffers on the way down to avoid a huge memory leak,
as this was previously done when changing state to ACQUIRE downwards
and we now skip that state on the way down.
Add some debug.
* sys/winks/gstksvideosrc.c (DEFAULT_DEVICE_PATH, DEFAULT_DEVICE_NAME,
DEFAULT_DEVICE_INDEX, KS_WORKER_LOCK, KS_WORKER_UNLOCK,
KS_WORKER_WAIT, KS_WORKER_NOTIFY, KS_WORKER_WAIT_FOR_RESULT,
KS_WORKER_NOTIFY_RESULT, KS_WORKER_STATE_STARTING,
KS_WORKER_STATE_READY, KS_WORKER_STATE_STOPPING,
KS_WORKER_STATE_ERROR, KsWorkerState, device_path, device_name,
device_index, running, worker_thread, worker_lock,
worker_notify_cond, worker_result_cond, worker_state,
worker_pending_caps, worker_setcaps_result, worker_pending_run,
worker_run_result, gst_ks_video_src_reset,
gst_ks_video_src_apply_driver_quirks, gst_ks_video_src_open_device,
gst_ks_video_src_close_device, gst_ks_video_src_worker_func,
gst_ks_video_src_start_worker, gst_ks_video_src_stop_worker,
gst_ks_video_src_change_state, gst_ks_video_src_set_clock,
gst_ks_video_src_set_caps, gst_ks_video_src_timestamp_buffer,
gst_ks_video_src_create):
Remove ENABLE_CLOCK_DEBUG define, it's GST_LEVEL_DEBUG after all.
Get rid of PROP_ENSLAVE_KSCLOCK and always slave the ks clock to the
GStreamer clock, it doesn't seem to hurt and matches DirectShow's
behavior. As an added bonus we usually get PresentationTime set for
each frame, so we can expand on this later for smarter latency
reporting (by looking at the diff between the timestamp from the
driver and the time according to the GStreamer clock).
Use an internal worker thread for opening the device, setting caps,
changing its state and closing it. This way we're a lot more
compatible with drivers that rely on hacks to do video-effects
between the low-level NT API and the application. Ick.
Start the ks clock and set the pin to KSSTATE_RUN on the first
create() so that we'll hopefully get hold of the GStreamer clock
from the very beginning. This way there's no chance that the
timestamps will make a sudden jump in the beginning of the stream
when we're running with a clock.
* sys/winks/kshelpers.c (CHECK_OPTIONS_FLAG,
ks_options_flags_to_string):
Reorder the flags to match the headerfile order, and make the string
a bit more compact.
* sys/winks/ksvideohelpers.c (ks_video_probe_filter_for_caps):
Avoid leaking KSPROPERTY_PIN_DATARANGES.
Original commit message from CVS:
* configure.ac:
* sys/Makefile.am:
* sys/winks/Makefile.am:
* sys/winks/gstksclock.c:
* sys/winks/gstksclock.h:
* sys/winks/gstksvideodevice.c:
* sys/winks/gstksvideodevice.h:
* sys/winks/gstksvideosrc.c:
* sys/winks/gstksvideosrc.h:
* sys/winks/kshelpers.c:
* sys/winks/kshelpers.h:
* sys/winks/ksvideohelpers.c:
* sys/winks/ksvideohelpers.h:
New plugin for low-latency video capture on Windows (#519935).
Uses Kernel Streaming, the lowest level API for doing video capture
on Windows (more or less just raw ioctls).
