qapi: qapi for audio backends

This patch adds structures into qapi to replace the existing
configuration structures used by audio backends currently. This qapi
will be the base of the -audiodev command line parameter (that replaces
the old environment variables based config).

This is not a 1:1 translation of the old options, I've tried to make
them much more consistent (e.g. almost every backend had an option to
specify buffer size, but the name was different for every backend, and
some backends required usecs, while some other required frames, samples
or bytes). Also tried to reduce the number of abbreviations used by the
config keys.

Some of the more important changes:
* use `in` and `out` instead of `ADC` and `DAC`, as the former is more
  user friendly imho
* moved buffer settings into the global setting area (so it's the same
  for all backends that support it. Backends that can't change buffer
  size will simply ignore them). Also using usecs, as it's probably more
  user friendly than samples or bytes.
* try-poll is now an alsa backend specific option (as all other backends
  currently ignore it)

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 5461b514dbf3e0bc31b0abb6498a9b3a008c271e.1552083282.git.DirtY.iCE.hu@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 304 insertions, 0 deletions

diff --git a/qapi/audio.json b/qapi/audio.json
new file mode 100644
index 0000000000..97aee37288
--- /dev/null
+++ b/qapi/audio.json
@@ -0,0 +1,304 @@
+# -*- mode: python -*-
+#
+# Copyright (C) 2015-2019 Zoltán Kővágó <DirtY.iCE.hu@gmail.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or later.
+# See the COPYING file in the top-level directory.
+
+##
+# @AudiodevPerDirectionOptions:
+#
+# General audio backend options that are used for both playback and
+# recording.
+#
+# @fixed-settings: use fixed settings for host input/output. When off,
+#                  frequency, channels and format must not be
+#                  specified (default true)
+#
+# @frequency: frequency to use when using fixed settings
+#             (default 44100)
+#
+# @channels: number of channels when using fixed settings (default 2)
+#
+# @voices: number of voices to use (default 1)
+#
+# @format: sample format to use when using fixed settings
+#          (default s16)
+#
+# @buffer-length: the buffer length in microseconds
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevPerDirectionOptions',
+  'data': {
+    '*fixed-settings': 'bool',
+    '*frequency':      'uint32',
+    '*channels':       'uint32',
+    '*voices':         'uint32',
+    '*format':         'AudioFormat',
+    '*buffer-length':  'uint32' } }
+
+##
+# @AudiodevGenericOptions:
+#
+# Generic driver-specific options.
+#
+# @in: options of the capture stream
+#
+# @out: options of the playback stream
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevGenericOptions',
+  'data': {
+    '*in':  'AudiodevPerDirectionOptions',
+    '*out': 'AudiodevPerDirectionOptions' } }
+
+##
+# @AudiodevAlsaPerDirectionOptions:
+#
+# Options of the ALSA backend that are used for both playback and
+# recording.
+#
+# @dev: the name of the ALSA device to use (default 'default')
+#
+# @period-length: the period length in microseconds
+#
+# @try-poll: attempt to use poll mode, falling back to non-polling
+#            access on failure (default true)
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevAlsaPerDirectionOptions',
+  'base': 'AudiodevPerDirectionOptions',
+  'data': {
+    '*dev':           'str',
+    '*period-length': 'uint32',
+    '*try-poll':      'bool' } }
+
+##
+# @AudiodevAlsaOptions:
+#
+# Options of the ALSA audio backend.
+#
+# @in: options of the capture stream
+#
+# @out: options of the playback stream
+#
+# @threshold: set the threshold (in microseconds) when playback starts
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevAlsaOptions',
+  'data': {
+    '*in':        'AudiodevAlsaPerDirectionOptions',
+    '*out':       'AudiodevAlsaPerDirectionOptions',
+    '*threshold': 'uint32' } }
+
+##
+# @AudiodevCoreaudioPerDirectionOptions:
+#
+# Options of the Core Audio backend that are used for both playback and
+# recording.
+#
+# @buffer-count: number of buffers
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevCoreaudioPerDirectionOptions',
+  'base': 'AudiodevPerDirectionOptions',
+  'data': {
+    '*buffer-count': 'uint32' } }
+
+##
+# @AudiodevCoreaudioOptions:
+#
+# Options of the coreaudio audio backend.
+#
+# @in: options of the capture stream
+#
+# @out: options of the playback stream
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevCoreaudioOptions',
+  'data': {
+    '*in':  'AudiodevCoreaudioPerDirectionOptions',
+    '*out': 'AudiodevCoreaudioPerDirectionOptions' } }
+
+##
+# @AudiodevDsoundOptions:
+#
+# Options of the DirectSound audio backend.
+#
+# @in: options of the capture stream
+#
+# @out: options of the playback stream
+#
+# @latency: add extra latency to playback in microseconds
+#           (default 10000)
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevDsoundOptions',
+  'data': {
+    '*in':      'AudiodevPerDirectionOptions',
+    '*out':     'AudiodevPerDirectionOptions',
+    '*latency': 'uint32' } }
+
+##
+# @AudiodevOssPerDirectionOptions:
+#
+# Options of the OSS backend that are used for both playback and
+# recording.
+#
+# @dev: file name of the OSS device (default '/dev/dsp')
+#
+# @buffer-count: number of buffers
+#
+# @try-poll: attempt to use poll mode, falling back to non-polling
+#            access on failure (default true)
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevOssPerDirectionOptions',
+  'base': 'AudiodevPerDirectionOptions',
+  'data': {
+    '*dev':          'str',
+    '*buffer-count': 'uint32',
+    '*try-poll':     'bool' } }
+
+##
+# @AudiodevOssOptions:
+#
+# Options of the OSS audio backend.
+#
+# @in: options of the capture stream
+#
+# @out: options of the playback stream
+#
+# @try-mmap: try using memory-mapped access, falling back to
+#            non-memory-mapped access on failure (default true)
+#
+# @exclusive: open device in exclusive mode (vmix won't work)
+#             (default false)
+#
+# @dsp-policy: set the timing policy of the device (between 0 and 10,
+#              where smaller number means smaller latency but higher
+#              CPU usage) or -1 to use fragment mode (option ignored
+#              on some platforms) (default 5)
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevOssOptions',
+  'data': {
+    '*in':         'AudiodevOssPerDirectionOptions',
+    '*out':        'AudiodevOssPerDirectionOptions',
+    '*try-mmap':   'bool',
+    '*exclusive':  'bool',
+    '*dsp-policy': 'uint32' } }
+
+##
+# @AudiodevPaPerDirectionOptions:
+#
+# Options of the Pulseaudio backend that are used for both playback and
+# recording.
+#
+# @name: name of the sink/source to use
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevPaPerDirectionOptions',
+  'base': 'AudiodevPerDirectionOptions',
+  'data': {
+    '*name': 'str' } }
+
+##
+# @AudiodevPaOptions:
+#
+# Options of the PulseAudio audio backend.
+#
+# @in: options of the capture stream
+#
+# @out: options of the playback stream
+#
+# @server: PulseAudio server address (default: let PulseAudio choose)
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevPaOptions',
+  'data': {
+    '*in':     'AudiodevPaPerDirectionOptions',
+    '*out':    'AudiodevPaPerDirectionOptions',
+    '*server': 'str' } }
+
+##
+# @AudiodevWavOptions:
+#
+# Options of the wav audio backend.
+#
+# @in: options of the capture stream
+#
+# @out: options of the playback stream
+#
+# @path: name of the wav file to record (default 'qemu.wav')
+#
+# Since: 4.0
+##
+{ 'struct': 'AudiodevWavOptions',
+  'data': {
+    '*in':   'AudiodevPerDirectionOptions',
+    '*out':  'AudiodevPerDirectionOptions',
+    '*path': 'str' } }
+
+
+##
+# @AudioFormat:
+#
+# An enumeration of possible audio formats.
+#
+# Since: 4.0
+##
+{ 'enum': 'AudioFormat',
+  'data': [ 'u8', 's8', 'u16', 's16', 'u32', 's32' ] }
+
+##
+# @AudiodevDriver:
+#
+# An enumeration of possible audio backend drivers.
+#
+# Since: 4.0
+##
+{ 'enum': 'AudiodevDriver',
+  'data': [ 'none', 'alsa', 'coreaudio', 'dsound', 'oss', 'pa', 'sdl',
+            'spice', 'wav' ] }
+
+##
+# @Audiodev:
+#
+# Options of an audio backend.
+#
+# @id: identifier of the backend
+#
+# @driver: the backend driver to use
+#
+# @timer-period: timer period (in microseconds, 0: use lowest possible)
+#
+# Since: 4.0
+##
+{ 'union': 'Audiodev',
+  'base': {
+    'id':            'str',
+    'driver':        'AudiodevDriver',
+    '*timer-period': 'uint32' },
+  'discriminator': 'driver',
+  'data': {
+    'none':      'AudiodevGenericOptions',
+    'alsa':      'AudiodevAlsaOptions',
+    'coreaudio': 'AudiodevCoreaudioOptions',
+    'dsound':    'AudiodevDsoundOptions',
+    'oss':       'AudiodevOssOptions',
+    'pa':        'AudiodevPaOptions',
+    'sdl':       'AudiodevGenericOptions',
+    'spice':     'AudiodevGenericOptions',
+    'wav':       'AudiodevWavOptions' } }