| Message ID | c374ab1ece7bfc933669d8807a54bf362d715a23.1545598229.git.DirtY.iCE.hu@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Audio 5.1 patches | expand |
On 12/23/18 2:52 PM, Kővágó, Zoltán wrote: > This will allow us to disable mixeng when we use a decent backend. > > Disabling mixeng have a few advantages: > * we no longer convert the audio output from one format to another, when > the underlying audio system would just convert it to a third format. > We no longer convert, only the underlying system, when needed. > * the underlying system probably has better resampling and sample format > converting methods anyway... > * we may support formats that the mixeng currently does not support (S24 > or float samples, more than two channels) > * when using an audio server (like pulseaudio) different sound card > outputs will show up as separate streams, even if we use only one > backend > > Disadvantages: > * audio capturing no longer works (wavcapture, and vnc audio extension) > * some backends only support a single playback stream or very picky > about the audio format. In this case we can't disable mixeng. > > However mixeng is not removed, only made optional, so this shouldn't be > a big concern. > > Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com> > --- > qapi/audio.json | 5 +++++ > qemu-options.hx | 6 ++++++ > 2 files changed, 11 insertions(+) > > diff --git a/qapi/audio.json b/qapi/audio.json > index 56d8ce439f..180bf207a8 100644 > --- a/qapi/audio.json > +++ b/qapi/audio.json > @@ -184,6 +184,10 @@ > # > # General audio backend options that are used for both playback and recording. > # > +# @mixeng: #optional use QEMU's mixing engine to mix all streams inside QEMU. The #optional tag is no longer necessary (the docs generator figures it out from the '*mixeng' name below). > +# When set to off, fixed-settings must be also off. Not every backend > +# compatible with the off setting (default on) Missing a '(since 4.0)' tag. > +# > # @fixed-settings: #optional use fixed settings for host input/output. When > # off, frequency, channels and format must not be specified > # (default on) > @@ -207,6 +211,7 @@ > ## > { 'struct': 'AudiodevPerDirectionOptions', > 'data': { > + '*mixeng': 'bool', > '*fixed-settings': 'bool', > '*frequency': 'int', > '*channels': 'int',
Eric Blake <eblake@redhat.com> writes: > On 12/23/18 2:52 PM, Kővágó, Zoltán wrote: >> This will allow us to disable mixeng when we use a decent backend. >> >> Disabling mixeng have a few advantages: >> * we no longer convert the audio output from one format to another, when >> the underlying audio system would just convert it to a third format. >> We no longer convert, only the underlying system, when needed. >> * the underlying system probably has better resampling and sample format >> converting methods anyway... >> * we may support formats that the mixeng currently does not support (S24 >> or float samples, more than two channels) >> * when using an audio server (like pulseaudio) different sound card >> outputs will show up as separate streams, even if we use only one >> backend >> >> Disadvantages: >> * audio capturing no longer works (wavcapture, and vnc audio extension) >> * some backends only support a single playback stream or very picky >> about the audio format. In this case we can't disable mixeng. >> >> However mixeng is not removed, only made optional, so this shouldn't be >> a big concern. >> >> Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com> >> --- >> qapi/audio.json | 5 +++++ >> qemu-options.hx | 6 ++++++ >> 2 files changed, 11 insertions(+) >> >> diff --git a/qapi/audio.json b/qapi/audio.json >> index 56d8ce439f..180bf207a8 100644 >> --- a/qapi/audio.json >> +++ b/qapi/audio.json >> @@ -184,6 +184,10 @@ >> # >> # General audio backend options that are used for both playback and recording. >> # >> +# @mixeng: #optional use QEMU's mixing engine to mix all streams inside QEMU. > > The #optional tag is no longer necessary (the docs generator figures it > out from the '*mixeng' name below). In fact, the qapi generator had special code to detect and reject #optional tags for some six months (from commit 1d8bda128d2 to 67ab1ce9263), just to ensure patches in flight don't add them. This one has been in flight for even longer. [...]
On 2019-01-10 02:43, Eric Blake wrote: > On 12/23/18 2:52 PM, Kővágó, Zoltán wrote: >> This will allow us to disable mixeng when we use a decent backend. >> >> Disabling mixeng have a few advantages: >> * we no longer convert the audio output from one format to another, when >> the underlying audio system would just convert it to a third format. >> We no longer convert, only the underlying system, when needed. >> * the underlying system probably has better resampling and sample format >> converting methods anyway... >> * we may support formats that the mixeng currently does not support (S24 >> or float samples, more than two channels) >> * when using an audio server (like pulseaudio) different sound card >> outputs will show up as separate streams, even if we use only one >> backend >> >> Disadvantages: >> * audio capturing no longer works (wavcapture, and vnc audio extension) >> * some backends only support a single playback stream or very picky >> about the audio format. In this case we can't disable mixeng. >> >> However mixeng is not removed, only made optional, so this shouldn't be >> a big concern. >> >> Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com> >> --- >> qapi/audio.json | 5 +++++ >> qemu-options.hx | 6 ++++++ >> 2 files changed, 11 insertions(+) >> >> diff --git a/qapi/audio.json b/qapi/audio.json >> index 56d8ce439f..180bf207a8 100644 >> --- a/qapi/audio.json >> +++ b/qapi/audio.json >> @@ -184,6 +184,10 @@ >> # >> # General audio backend options that are used for both playback and recording. >> # >> +# @mixeng: #optional use QEMU's mixing engine to mix all streams inside QEMU. > > The #optional tag is no longer necessary (the docs generator figures it > out from the '*mixeng' name below). Ok. >> +# When set to off, fixed-settings must be also off. Not every backend >> +# compatible with the off setting (default on) > > Missing a '(since 4.0)' tag. The whole AudiodevPerDirectionOptions struct is marked with 'Since: 4.0', so I don't think it's necessary. > >> +# >> # @fixed-settings: #optional use fixed settings for host input/output. When >> # off, frequency, channels and format must not be specified >> # (default on) >> @@ -207,6 +211,7 @@ >> ## >> { 'struct': 'AudiodevPerDirectionOptions', >> 'data': { >> + '*mixeng': 'bool', >> '*fixed-settings': 'bool', >> '*frequency': 'int', >> '*channels': 'int', > >
On 1/16/19 2:27 PM, Zoltán Kővágó wrote: >>> +++ b/qapi/audio.json >>> @@ -184,6 +184,10 @@ >>> # >>> # General audio backend options that are used for both playback and recording. >>> # >>> +# @mixeng: #optional use QEMU's mixing engine to mix all streams inside QEMU. >> >> The #optional tag is no longer necessary (the docs generator figures it >> out from the '*mixeng' name below). > > Ok. > >>> +# When set to off, fixed-settings must be also off. Not every backend >>> +# compatible with the off setting (default on) >> >> Missing a '(since 4.0)' tag. > > The whole AudiodevPerDirectionOptions struct is marked with 'Since: > 4.0', so I don't think it's necessary. Oh right. It's less common to see incremental additions to a type within a single release, but you are right that the per-member tag is only needed when an older release exposed the type you are extending.
diff --git a/qapi/audio.json b/qapi/audio.json index 56d8ce439f..180bf207a8 100644 --- a/qapi/audio.json +++ b/qapi/audio.json @@ -184,6 +184,10 @@ # # General audio backend options that are used for both playback and recording. # +# @mixeng: #optional use QEMU's mixing engine to mix all streams inside QEMU. +# When set to off, fixed-settings must be also off. Not every backend +# compatible with the off setting (default on) +# # @fixed-settings: #optional use fixed settings for host input/output. When # off, frequency, channels and format must not be specified # (default on) @@ -207,6 +211,7 @@ ## { 'struct': 'AudiodevPerDirectionOptions', 'data': { + '*mixeng': 'bool', '*fixed-settings': 'bool', '*frequency': 'int', '*channels': 'int', diff --git a/qemu-options.hx b/qemu-options.hx index 687dd23bf2..eb65b511fa 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -432,6 +432,7 @@ DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, " specifies the audio backend to use\n" " id= identifier of the backend\n" " timer-period= timer period in microseconds\n" + " in|out.mixeng= use mixeng to mix streams inside QEMU\n" " in|out.fixed-settings= use fixed settings for host audio\n" " in|out.frequency= frequency to use with fixed settings\n" " in|out.channels= number of channels to use with fixed settings\n" @@ -500,6 +501,11 @@ Identifies the audio backend. Sets the timer @var{period} used by the audio subsystem in microseconds. Default is 10000 (10 ms). +@item in|out.mixeng=on|off +Use QEMU's mixing engine to mix all streams inside QEMU. When off, +@var{fixed-settings} must be off too. Not every backend is fully +compatible with the off setting. Default is on. + @item in|out.fixed-settings=on|off Use fixed settings for host audio. When off, it will change based on how the guest opens the sound card. In this case you must not specify
This will allow us to disable mixeng when we use a decent backend. Disabling mixeng have a few advantages: * we no longer convert the audio output from one format to another, when the underlying audio system would just convert it to a third format. We no longer convert, only the underlying system, when needed. * the underlying system probably has better resampling and sample format converting methods anyway... * we may support formats that the mixeng currently does not support (S24 or float samples, more than two channels) * when using an audio server (like pulseaudio) different sound card outputs will show up as separate streams, even if we use only one backend Disadvantages: * audio capturing no longer works (wavcapture, and vnc audio extension) * some backends only support a single playback stream or very picky about the audio format. In this case we can't disable mixeng. However mixeng is not removed, only made optional, so this shouldn't be a big concern. Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com> --- qapi/audio.json | 5 +++++ qemu-options.hx | 6 ++++++ 2 files changed, 11 insertions(+)