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/*
* Copyright(C) 2018 "IoT.bzh"
* Author Fulup Ar Foll <fulup@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http : //www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License
for the specific language governing permissions and
* limitations under the License.
*
* reference :
* https://github.com/zonque/simple-alsa-loop/blob/master/loop.c
* https://www.alsa-project.org/alsa-doc/alsa-lib/_2test_2pcm_8c-example.html#a31
*
*/
#define _GNU_SOURCE // needed for vasprintf
#include <pthread.h>
#include <sys/syscall.h>
#include "alsa-softmixer.h"
typedef struct {
const char *uid;
long current;
long target;
int numid;
AlsaSndCtlT *sndcard;
AlsaVolRampT *ramp;
sd_event_source *evtsrc;
SoftMixerT *mixer;
sd_event *sdLoop;
} VolRampHandleT;
STATIC int VolRampTimerCB(sd_event_source* source, uint64_t timer, void* handle) {
VolRampHandleT *rHandle = (VolRampHandleT*)handle;
int error;
uint64_t usec;
// RampDown
if (rHandle->current > rHandle->target) {
rHandle->current = rHandle->current - rHandle->ramp->stepDown;
if (rHandle->current < rHandle->target) rHandle->current = rHandle->target;
}
// RampUp
if (rHandle->current < rHandle->target) {
rHandle->current = rHandle->current + rHandle->ramp->stepUp;
if (rHandle->current > rHandle->target) rHandle->current = rHandle->target;
}
error = AlsaCtlNumidSetLong(rHandle->mixer, rHandle->sndcard, rHandle->numid, rHandle->current);
if (error) goto OnErrorExit;
// we reach target stop volram event
if (rHandle->current == rHandle->target) {
sd_event_source_unref(rHandle->evtsrc);
free(rHandle);
} else {
// otherwise validate timer for a new run
sd_event_now(rHandle->sdLoop, CLOCK_MONOTONIC, &usec);
sd_event_source_set_enabled(rHandle->evtsrc, SD_EVENT_ONESHOT);
error = sd_event_source_set_time(rHandle->evtsrc, usec + rHandle->ramp->delay);
}
return 0;
OnErrorExit:
AFB_ApiWarning(rHandle->mixer->api, "VolRampTimerCB stream=%s numid=%d value=%ld", rHandle->uid, rHandle->numid, rHandle->current);
sd_event_source_unref(source); // abandon volRamp
return -1;
}
PUBLIC int AlsaVolRampApply(SoftMixerT *mixer, AlsaSndCtlT *sndcard, AlsaStreamAudioT *stream, json_object *rampJ) {
long curvol, newvol;
const char *uid, *volS;
json_object *volJ;
int error, index;
uint64_t usec;
int count = 0;
error = wrap_json_unpack(rampJ, "{ss so !}"
, "uid", &uid
, "vol", &volJ
);
if (error) {
AFB_ApiError(mixer->api, "AlsaVolRampApply:mixer=%s stream=%s invalid-json should {uid:ramp, vol:[+,-,=]value} ramp=%s", mixer->uid, stream->uid, json_object_get_string(rampJ));
goto OnErrorExit;
}
switch (json_object_get_type(volJ)) {
case json_type_string:
volS = json_object_get_string(volJ);
switch (volS[0]) {
case '+':
count= sscanf(&volS[1], "%ld", &newvol);
newvol = curvol + newvol;
break;
case '-':
count= sscanf(&volS[1], "%ld", &newvol);
newvol = curvol - newvol;
break;
case '=':
count= sscanf(&volS[1], "%ld", &newvol);
break;
default:
// hope for int as a string and force it as relative
sscanf(&volS[0], "%ld", &newvol);
if (newvol < 0) newvol = curvol - newvol;
else newvol = curvol + newvol;
}
if (count != 1) {
AFB_ApiError(mixer->api, "AlsaVolRampApply:mixer=%s stream=%s invalid-numeric expect {uid:%s, vol:[+,-,=]value} get vol:%s", mixer->uid, stream->uid, uid, json_object_get_string(volJ));
goto OnErrorExit;
}
break;
case json_type_int:
newvol = json_object_get_int(volJ);
break;
default:
AFB_ApiError(mixer->api, "AlsaVolRampApply:mixer=%s stream=%s invalid-type expect {uid:%s, vol:[+,-,=]value} get vol:%s", mixer->uid, stream->uid, uid, json_object_get_string(volJ));
goto OnErrorExit;
}
error = AlsaCtlNumidGetLong(mixer, sndcard, stream->volume, &curvol);
if (error) {
AFB_ApiError(mixer->api, "AlsaVolRampApply:mixer=%s stream=%s ramp=%s Fail to get volume from numid=%d", mixer->uid, stream->uid, uid, stream->volume);
goto OnErrorExit;
}
// search for ramp uid in mixer
for (index=0; index<= mixer->max.ramps; index++) {
if (!strcasecmp(mixer->ramps[index]->uid, uid)) {
break;
}
}
if (index == mixer->max.ramps) {
AFB_ApiError(mixer->api, "AlsaVolRampApply:mixer=%s stream=%s ramp=%s does not exit", mixer->uid, stream->uid, uid);
goto OnErrorExit;
}
VolRampHandleT *rHandle = calloc(1, sizeof (VolRampHandleT));
rHandle->uid = stream->uid;
rHandle->numid = stream->volume;
rHandle->sndcard = sndcard;
rHandle->mixer = mixer;
rHandle->ramp = mixer->ramps[index];
rHandle->target = newvol;
rHandle->current = curvol;
rHandle->sdLoop = mixer->sdLoop;
// set a timer with ~250us accuracy
sd_event_now(rHandle->sdLoop, CLOCK_MONOTONIC, &usec);
(void) sd_event_add_time(rHandle->sdLoop, &rHandle->evtsrc, CLOCK_MONOTONIC, usec + 100, 250, VolRampTimerCB, rHandle);
return 0;
OnErrorExit:
return -1;
}
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