6ecbb7556a
This provides much lower latency compared to opening in shared mode, but it also means that the device cannot be opened by any other application. The advantage is that the achievable latency is much lower. In shared mode, WASAPI's engine period is 10ms, and so that is the lowest latency achievable. In exclusive mode, the limit is the device period itself, which in my testing with USB DACs, on-board PCI sound-cards, and HDMI cards is between 2ms and 3.33ms. We set our audioringbuffer limits to match the device, so the achievable sink latency is 6-9ms. Further improvements can be made if needed. https://bugzilla.gnome.org/show_bug.cgi?id=793289
75 lines
2.3 KiB
C
75 lines
2.3 KiB
C
/*
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* Copyright (C) 2008 Ole André Vadla Ravnås <ole.andre.ravnas@tandberg.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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* Boston, MA 02110-1301, USA.
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*/
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#ifndef __GST_WASAPI_SINK_H__
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#define __GST_WASAPI_SINK_H__
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#include "gstwasapiutil.h"
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G_BEGIN_DECLS
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#define GST_TYPE_WASAPI_SINK \
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(gst_wasapi_sink_get_type ())
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#define GST_WASAPI_SINK(obj) \
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(G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_WASAPI_SINK, GstWasapiSink))
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#define GST_WASAPI_SINK_CLASS(klass) \
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(G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_WASAPI_SINK, GstWasapiSinkClass))
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#define GST_IS_WASAPI_SINK(obj) \
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(G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_WASAPI_SINK))
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#define GST_IS_WASAPI_SINK_CLASS(klass) \
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(G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_WASAPI_SINK))
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typedef struct _GstWasapiSink GstWasapiSink;
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typedef struct _GstWasapiSinkClass GstWasapiSinkClass;
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struct _GstWasapiSink
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{
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GstAudioSink parent;
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IMMDevice *device;
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IAudioClient *client;
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IAudioRenderClient *render_client;
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HANDLE event_handle;
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/* Actual size of the allocated buffer */
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guint buffer_frame_count;
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/* The mix format that wasapi prefers in shared mode */
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WAVEFORMATEX *mix_format;
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/* The probed caps that we can accept */
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GstCaps *cached_caps;
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/* The channel positions in the data to be written to the device we
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* will pass this to GstAudioRingbuffer so it can to it translate
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* from the native GStreamer channel layout. */
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GstAudioChannelPosition *positions;
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/* properties */
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gint role;
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gint sharemode;
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gboolean mute;
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wchar_t *device_strid;
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};
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struct _GstWasapiSinkClass
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{
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GstAudioSinkClass parent_class;
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};
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GType gst_wasapi_sink_get_type (void);
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G_END_DECLS
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#endif /* __GST_WASAPI_SINK_H__ */
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