From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Victor Toso <victortoso@redhat.com>

Date: Fri, 6 Mar 2015 18:14:21 +0100

Subject: [PATCH] audio: add functions to set volume/mute with alsa

This patch includes the vdagent-audio.[ch] files in order to

communicate with backend audio server.

The two functions provide a way to set volume and mute in the guest

by connecting to default mixer control in alsa which is 'Master' for

playback and 'Capture' for record.

---

 Makefile.am         |  12 +++-

 configure.ac        |   1 +

 src/vdagent-audio.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++++

 src/vdagent-audio.h |  27 +++++++++

 4 files changed, 205 insertions(+), 3 deletions(-)

 create mode 100644 src/vdagent-audio.c

 create mode 100644 src/vdagent-audio.h

diff --git a/Makefile.am b/Makefile.am

index a06a259..2effe4e 100644

--- a/Makefile.am

+++ b/Makefile.am

@@ -4,9 +4,14 @@ NULL =

 bin_PROGRAMS = src/spice-vdagent

 sbin_PROGRAMS = src/spice-vdagentd

-src_spice_vdagent_CFLAGS = $(X_CFLAGS) $(SPICE_CFLAGS) $(GLIB2_CFLAGS)

-src_spice_vdagent_LDADD = $(X_LIBS) $(SPICE_LIBS) $(GLIB2_LIBS)

-src_spice_vdagent_SOURCES = src/vdagent.c src/vdagent-x11.c src/vdagent-x11-randr.c src/vdagent-file-xfers.c src/udscs.c

+src_spice_vdagent_CFLAGS = $(X_CFLAGS) $(SPICE_CFLAGS) $(GLIB2_CFLAGS) $(ALSA_CFLAGS)

+src_spice_vdagent_LDADD = $(X_LIBS) $(SPICE_LIBS) $(GLIB2_LIBS) $(ALSA_LIBS)

+src_spice_vdagent_SOURCES = src/vdagent.c \

+                            src/vdagent-x11.c \

+                            src/vdagent-x11-randr.c \

+                            src/vdagent-file-xfers.c \

+                            src/vdagent-audio.c \

+                            src/udscs.c

 src_spice_vdagentd_CFLAGS = $(DBUS_CFLAGS) $(LIBSYSTEMD_LOGIN_CFLAGS) \

   $(PCIACCESS_CFLAGS) $(SPICE_CFLAGS) $(GLIB2_CFLAGS) $(PIE_CFLAGS)

@@ -30,6 +35,7 @@ endif

 noinst_HEADERS = src/glib-compat.h \

                  src/session-info.h \

                  src/udscs.h \

+                 src/vdagent-audio.h \

                  src/vdagent-file-xfers.h \

                  src/vdagent-virtio-port.h \

                  src/vdagent-x11.h \

diff --git a/configure.ac b/configure.ac

index a1ce6c0..377fc74 100644

--- a/configure.ac

+++ b/configure.ac

@@ -79,6 +79,7 @@ AC_ARG_ENABLE([static-uinput],

 PKG_CHECK_MODULES([GLIB2], [glib-2.0 >= 2.12])

 PKG_CHECK_MODULES(X, [xfixes xrandr >= 1.3 xinerama x11])

 PKG_CHECK_MODULES(SPICE, [spice-protocol >= 0.12.5])

+PKG_CHECK_MODULES(ALSA, [alsa >= 1.0.22])

 if test "$with_session_info" = "auto" || test "$with_session_info" = "systemd"; then

     PKG_CHECK_MODULES([LIBSYSTEMD_LOGIN],

diff --git a/src/vdagent-audio.c b/src/vdagent-audio.c

new file mode 100644

index 0000000..6b11cd8

--- /dev/null

+++ b/src/vdagent-audio.c

@@ -0,0 +1,168 @@

+/*  vdagent-audio.c vdagentd audio handling code

+

+    Copyright 2015 Red Hat, Inc.

+

+    This program is free software: you can redistribute it and/or modify

+    it under the terms of the GNU General Public License as published by

+    the Free Software Foundation, either version 3 of the License, or

+    (at your option) any later version.

+

+    This program 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 General Public License for more details.

+

+    You should have received a copy of the GNU General Public License

+    along with this program.  If not, see <http://www.gnu.org/licenses/>.

+*/

+

+#ifdef HAVE_CONFIG_H

+#include <config.h>

+#endif

+

+#include <glib.h>

+#include <syslog.h>

+#include <stdbool.h>

+#include <alsa/asoundlib.h>

+#include <alsa/mixer.h>

+#include <alsa/error.h>

+#include "vdagent-audio.h"

+

+#define ALSA_MUTE   0

+#define ALSA_UNMUTE 1

+

+static snd_mixer_elem_t *

+get_alsa_default_mixer_by_name(snd_mixer_t **handle, const char *name)

+{

+    snd_mixer_selem_id_t *sid;

+    int err = 0;

+

+    if ((err = snd_mixer_open(handle, 0)) < 0)

+        goto fail;

+

+    if ((err = snd_mixer_attach(*handle, "default")) < 0)

+        goto fail;

+

+    if ((err = snd_mixer_selem_register(*handle, NULL, NULL)) < 0)

+        goto fail;

+

+    if ((err = snd_mixer_load(*handle)) < 0)

+        goto fail;

+

+    snd_mixer_selem_id_alloca(&sid;;

+    snd_mixer_selem_id_set_index(sid, 0);

+    snd_mixer_selem_id_set_name(sid, name);

+    return snd_mixer_find_selem(*handle, sid);

+

+fail:

+    syslog(LOG_WARNING, "%s fail: %s", __func__, snd_strerror(err));

+    return NULL;

+}

+

+static bool set_alsa_capture(uint8_t mute, uint8_t nchannels, uint16_t *volume)

+{

+    snd_mixer_t *handle = NULL;

+    snd_mixer_elem_t *e;

+    long min, max, vol;

+    bool ret = true;

+    int alsa_mute;

+

+    e = get_alsa_default_mixer_by_name (&handle, "Capture");

+    if (e == NULL) {

+        syslog(LOG_WARNING, "vdagent-audio: can't get default alsa mixer");

+        ret = false;

+        goto end;

+    }

+

+    alsa_mute = (mute) ? ALSA_MUTE : ALSA_UNMUTE;

+    snd_mixer_selem_set_capture_switch_all(e, alsa_mute);

+

+    snd_mixer_selem_get_capture_volume_range(e, &min, &max;;

+    switch (nchannels) {

+    case 1: /* MONO */

+        vol = CLAMP(volume[0], min, max);

+        snd_mixer_selem_set_capture_volume(e, SND_MIXER_SCHN_MONO, vol);

+        syslog(LOG_DEBUG, "vdagent-audio: (capture-mono) %lu (%%%0.2f)",

+               vol, (float) (100*vol/max));

+        break;

+    case 2: /* LEFT-RIGHT */

+        vol = CLAMP(volume[0], min, max);

+        snd_mixer_selem_set_capture_volume(e, SND_MIXER_SCHN_FRONT_LEFT, vol);

+        syslog(LOG_DEBUG, "vdagent-audio: (capture-left) %lu (%%%0.2f)",

+               vol, (float) (100*vol/max));

+        vol = CLAMP(volume[1], min, max);

+        snd_mixer_selem_set_capture_volume(e, SND_MIXER_SCHN_FRONT_RIGHT, vol);

+        syslog(LOG_DEBUG, "vdagent-audio: (capture-right) %lu (%%%0.2f)",

+               vol, (float) (100*vol/max));

+        break;

+    default:

+        syslog(LOG_WARNING, "vdagent-audio: number of channels not supported");

+        ret = false;

+    }

+end:

+    if (handle != NULL)

+        snd_mixer_close(handle);

+    return ret;

+}

+

+static bool set_alsa_playback (uint8_t mute, uint8_t nchannels, uint16_t *volume)

+{

+    snd_mixer_t *handle = NULL;

+    snd_mixer_elem_t* e;

+    long min, max, vol;

+    bool ret = true;

+    int alsa_mute;

+

+    e = get_alsa_default_mixer_by_name (&handle, "Master");

+    if (e == NULL) {

+        syslog(LOG_WARNING, "vdagent-audio: can't get default alsa mixer");

+        ret = false;

+        goto end;

+    }

+

+    alsa_mute = (mute) ? ALSA_MUTE : ALSA_UNMUTE;

+    snd_mixer_selem_set_playback_switch_all(e, alsa_mute);

+

+    snd_mixer_selem_get_playback_volume_range(e, &min, &max;;

+    switch (nchannels) {

+    case 1: /* MONO */

+        vol = CLAMP(volume[0], min, max);

+        snd_mixer_selem_set_playback_volume(e, SND_MIXER_SCHN_MONO, vol);

+        syslog(LOG_DEBUG, "vdagent-audio: (playback-mono) %lu (%%%0.2f)",

+               vol, (float) (100*vol/max));

+        break;

+    case 2: /* LEFT-RIGHT */

+        vol = CLAMP(volume[0], min, max);

+        snd_mixer_selem_set_playback_volume(e, SND_MIXER_SCHN_FRONT_LEFT, vol);

+        syslog(LOG_DEBUG, "vdagent-audio: (playback-left) %lu (%%%0.2f)",

+               vol, (float) (100*vol/max));

+        vol = CLAMP(volume[1], min, max);

+        snd_mixer_selem_set_playback_volume(e, SND_MIXER_SCHN_FRONT_RIGHT, vol);

+        syslog(LOG_DEBUG, "vdagent-audio: (playback-right) %lu (%%%0.2f)",

+               vol, (float) (100*vol/max));

+        break;

+    default:

+        syslog(LOG_WARNING, "vdagent-audio: number of channels not supported");

+        ret = false;

+    }

+end:

+    if (handle != NULL)

+        snd_mixer_close(handle);

+    return ret;

+}

+

+void vdagent_audio_playback_sync(uint8_t mute, uint8_t nchannels, uint16_t *volume)

+{

+    syslog(LOG_DEBUG, "%s mute=%s nchannels=%u",

+           __func__, (mute) ? "yes" : "no", nchannels);

+    if (set_alsa_playback (mute, nchannels, volume) == false)

+        syslog(LOG_WARNING, "Fail to sync playback volume");

+}

+

+void vdagent_audio_record_sync(uint8_t mute, uint8_t nchannels, uint16_t *volume)

+{

+    syslog(LOG_DEBUG, "%s mute=%s nchannels=%u",

+           __func__, (mute) ? "yes" : "no", nchannels);

+    if (set_alsa_capture (mute, nchannels, volume) == false)

+        syslog(LOG_WARNING, "Fail to sync record volume");

+}

diff --git a/src/vdagent-audio.h b/src/vdagent-audio.h

new file mode 100644

index 0000000..6f29d4b

--- /dev/null

+++ b/src/vdagent-audio.h

@@ -0,0 +1,27 @@

+/*  vdagent-audio.h vdagentd audio handling header

+

+    Copyright 2015 Red Hat, Inc.

+

+    This program is free software: you can redistribute it and/or modify

+    it under the terms of the GNU General Public License as published by

+    the Free Software Foundation, either version 3 of the License, or

+    (at your option) any later version.

+

+    This program 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 General Public License for more details.

+

+    You should have received a copy of the GNU General Public License

+    along with this program.  If not, see <http://www.gnu.org/licenses/>.

+*/

+#ifndef __VDAGENT_AUDIO_H

+#define __VDAGENT_AUDIO_H

+

+#include <stdio.h>

+#include <stdint.h>

+

+void vdagent_audio_playback_sync(uint8_t mute, uint8_t nchannels, uint16_t *volume);

+void vdagent_audio_record_sync(uint8_t mute, uint8_t nchannels, uint16_t *volume);

+

+#endif