gstreamer/sys/wasapi2/gstwasapi2ringbuffer.h
Seungha Yang a8ec40c850 wasapi2: Rewrite plugin and implement audioringbuffer subclass
... based on MediaFoundation work queue API.

By this commit, wasapi2 plugin will make use of pull mode scheduling
with audioringbuffer subclass.
There are several drawbacks of audiosrc/audiosink subclassing
(not audiobasesrc/audiobasesink) for WASAPI API, which are:
* audiosrc/audiosink classes try to set high priority to
  read/write thread via MMCSS (Multimedia Class Scheduler Service)
  but it's not allowed in case of UWP application.
  In order to use MMCSS in UWP, application should use MediaFoundation
  work queue indirectly.
  Since audiosrc/audiosink scheduling model is not compatible with
  MediaFoundation's work queue model, audioringbuffer subclassing
  is required.
* WASAPI capture device might report larger packet size than expected
  (i.e., larger frames we can read than expected frame size per period).
  Meanwhile, in any case, application should drain all packets at that moment.
  In order to handle the case, wasapi/wasapi2 plugins were making use of
  GstAdapter which is obviously sub-optimal because it requires additional
  memory allocation and copy.
  By implementing audioringbuffer subclassing, we can avoid such inefficiency.

In this commit, all the device read/write operations will be moved
to newly implemented wasapi2ringbuffer class and
existing wasapi2client class will take care of device enumeration
and activation parts only.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2306>
2021-06-08 19:39:27 +09:00

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2.3 KiB
C

/* GStreamer
* Copyright (C) 2021 Seungha Yang <seungha@centricular.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_WASAPI2_RING_BUFFER_H__
#define __GST_WASAPI2_RING_BUFFER_H__
#include <gst/gst.h>
#include <gst/audio/audio.h>
#include "gstwasapi2client.h"
G_BEGIN_DECLS
#define GST_TYPE_WASAPI2_RING_BUFFER (gst_wasapi2_ring_buffer_get_type())
G_DECLARE_FINAL_TYPE (GstWasapi2RingBuffer, gst_wasapi2_ring_buffer,
GST, WASAPI2_RING_BUFFER, GstAudioRingBuffer);
GstAudioRingBuffer * gst_wasapi2_ring_buffer_new (GstWasapi2ClientDeviceClass device_class,
gboolean low_latency,
const gchar *device_id,
gpointer dispatcher,
const gchar * name);
GstCaps * gst_wasapi2_ring_buffer_get_caps (GstWasapi2RingBuffer * buf);
HRESULT gst_wasapi2_ring_buffer_set_mute (GstWasapi2RingBuffer * buf,
gboolean mute);
HRESULT gst_wasapi2_ring_buffer_get_mute (GstWasapi2RingBuffer * buf,
gboolean * mute);
HRESULT gst_wasapi2_ring_buffer_set_volume (GstWasapi2RingBuffer * buf,
gfloat volume);
HRESULT gst_wasapi2_ring_buffer_get_volume (GstWasapi2RingBuffer * buf,
gfloat * volume);
G_END_DECLS
#endif /* __GST_WASAPI2_RING_BUFFER_H__ */