Fist AlsaLoop model playing music (work in progress)

1 files changed, 380 insertions, 0 deletions

diff --git a/plugins/alsa/alsa-pcm.c b/plugins/alsa/alsa-pcm.c
new file mode 100644
index 0000000..f342888
--- /dev/null
+++ b/plugins/alsa/alsa-pcm.c
@@ -0,0 +1,380 @@
+/*
+ * 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 "alsa-softmixer.h"
+#include <pthread.h>
+#include <sys/syscall.h>
+
+
+
+#define BUFFER_FRAME_COUNT 1024
+
+
+typedef struct {
+    snd_pcm_t *pcmIn;
+    snd_pcm_t *pcmOut;
+    AFB_ApiT api;
+    sd_event_source* evtsrc;
+    void* buffer;
+    size_t frameSize;
+    unsigned int frameCount; 
+    unsigned int channels;
+    sd_event *sdLoop;
+    pthread_t thread;
+    int tid;
+    char* info;
+} AlsaPcmCopyHandleT;
+
+static int defaultPcmRate = 48000;
+static int defaultPcmChannels = 2;
+static snd_pcm_format_t defaultPcmFormat = SND_PCM_FORMAT_S16_LE;
+static snd_pcm_access_t defaultPcmAccess = SND_PCM_ACCESS_RW_INTERLEAVED;
+
+STATIC int AlsaPeriodSize(snd_pcm_format_t pcmFormat) {
+    int pcmSampleSize;
+
+    switch (pcmFormat) {
+
+        case SND_PCM_FORMAT_S8:
+        case SND_PCM_FORMAT_U8:
+            pcmSampleSize = 1;
+            break;
+
+        case SND_PCM_FORMAT_U16_LE:
+        case SND_PCM_FORMAT_U16_BE:
+        case SND_PCM_FORMAT_S16_LE:
+        case SND_PCM_FORMAT_S16_BE:
+            pcmSampleSize = 2;
+            break;
+
+        case SND_PCM_FORMAT_U32_LE:
+        case SND_PCM_FORMAT_U32_BE:
+        case SND_PCM_FORMAT_S32_LE:
+        case SND_PCM_FORMAT_S32_BE:
+            pcmSampleSize = 4;
+            break;
+
+        default:
+            pcmSampleSize = 0;
+    }
+
+    return pcmSampleSize;
+}
+
+
+PUBLIC int AlsaPcmConf(CtlSourceT *source, snd_pcm_t *pcmHandle, snd_pcm_format_t pcmFormat, unsigned int pcmRate, unsigned int pcmChannels, AlsaPcmHwInfoT *pcmHwInfo) {
+    char string[32];
+    int error;
+    snd_pcm_hw_params_t *pxmHwParams;
+    snd_pcm_sw_params_t *pxmSwParams;
+
+    // retrieve hadware config from PCM
+    snd_pcm_hw_params_alloca(&pxmHwParams);
+    snd_pcm_hw_params_any(pcmHandle, pxmHwParams);
+
+    error = snd_pcm_hw_params_set_access(pcmHandle, pxmHwParams, defaultPcmAccess);
+    if (error) {
+        AFB_ApiError(source->api, "AlsaPcmConf: Fail PCM=%s Set_Interleave=%d mode error=%s", AlsaPcmUID(pcmHandle, string), defaultPcmAccess, snd_strerror(error));
+        goto OnErrorExit;
+    };
+
+    if (pcmFormat == ALSA_PCM_DEFAULT_FORMAT) pcmFormat = defaultPcmFormat;
+    if (pcmFormat != SND_PCM_FORMAT_UNKNOWN) {
+        if ((error = snd_pcm_hw_params_set_format(pcmHandle, pxmHwParams, pcmFormat)) < 0) {
+            AFB_ApiError(source->api, "AlsaPcmConf: Fail PCM=%s Set_Format=%d error=%s", AlsaPcmUID(pcmHandle, string), pcmFormat, snd_strerror(error));
+            AlsaDumpFormats(source, pcmHandle);
+            goto OnErrorExit;
+        }
+    }
+
+    if (pcmRate == ALSA_PCM_DEFAULT_RATE) pcmRate = defaultPcmRate;
+    pcmHwInfo->rate = pcmRate;
+    if ((error = snd_pcm_hw_params_set_rate_near(pcmHandle, pxmHwParams, &pcmHwInfo->rate, 0)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmConf: Fail PCM=%s Set_Rate=%d error=%s", AlsaPcmUID(pcmHandle, string), pcmRate, snd_strerror(error));
+        goto OnErrorExit;
+    }
+
+    // check we got requested rate
+    if (pcmHwInfo->rate != pcmRate) {
+        AFB_ApiError(source->api, "AlsaPcmConf: Fail PCM=%s Set_Rate ask=%dHz get=%dHz", AlsaPcmUID(pcmHandle, string), pcmRate, pcmHwInfo->rate);
+        goto OnErrorExit;
+    }
+
+    if (pcmChannels == ALSA_PCM_DEFAULT_CHANNELS) pcmChannels = defaultPcmChannels;
+    if ((error = snd_pcm_hw_params_set_channels(pcmHandle, pxmHwParams, pcmChannels)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmConf: Fail PCM=%s Set_Channels=%d current=%d mode error=%s", AlsaPcmUID(pcmHandle, string), pcmChannels, pcmHwInfo->channels, snd_strerror(error));
+        goto OnErrorExit;
+    };
+
+    // store selected values
+    if ((error = snd_pcm_hw_params(pcmHandle, pxmHwParams)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmConf: Fail PCM=%s apply hwparams error=%s", AlsaPcmUID(pcmHandle, string), snd_strerror(error));
+        goto OnErrorExit;
+    }
+
+    // check we effective hw params after optional format change
+    snd_pcm_hw_params_get_channels(pxmHwParams, &pcmHwInfo->channels);
+    snd_pcm_hw_params_get_format(pxmHwParams, &pcmHwInfo->format);
+    snd_pcm_hw_params_get_rate(pxmHwParams, &pcmHwInfo->rate, 0);
+    pcmHwInfo->sampleSize = AlsaPeriodSize(pcmHwInfo->format);
+    if (pcmHwInfo->sampleSize == 0) {
+        AFB_ApiError(source->api, "AlsaPcmConf: Fail PCM=%s unsupported format format=%d", AlsaPcmUID(pcmHandle, string), pcmFormat);
+        goto OnErrorExit;
+    }
+
+    // retrieve software config from PCM
+    snd_pcm_sw_params_alloca(&pxmSwParams);
+    snd_pcm_sw_params_current(pcmHandle, pxmSwParams);
+
+    if ((error = snd_pcm_sw_params_set_avail_min(pcmHandle, pxmSwParams, 16)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmConf: Fail to PCM=%s set_buffersize error=%s", AlsaPcmUID(pcmHandle, string), snd_strerror(error));
+        goto OnErrorExit;
+    };
+
+    // push software params into PCM
+    if ((error = snd_pcm_sw_params(pcmHandle, pxmSwParams)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmConf: Fail to push software=%s params error=%s", AlsaPcmUID(pcmHandle, string), snd_strerror(error));
+        goto OnErrorExit;
+    };
+
+
+    AFB_ApiNotice(source->api, "AlsaPcmConf: PCM=%s done", AlsaPcmUID(pcmHandle, string));
+    return 0;
+
+OnErrorExit:
+    return -1;
+}
+
+STATIC int AlsaPcmReadCB(sd_event_source* src, int fd, uint32_t revents, void* userData) {
+    char string[32];
+    int error;
+    snd_pcm_sframes_t framesIn, framesOut, availIn, availOut;
+    AlsaPcmCopyHandleT *pcmCopyHandle = (AlsaPcmCopyHandleT*) userData;
+
+
+    // PCM has was closed
+    if ((revents & EPOLLHUP) != 0) {
+        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s hanghup/disconnected", AlsaPcmUID(pcmCopyHandle->pcmIn, string));
+        goto ExitOnSuccess;
+    }
+
+    // ignore any non input events
+    if ((revents & EPOLLIN) == 0) {
+        goto ExitOnSuccess;
+    }
+
+    // Fulup this should be optimised to limit CPU usage when idle
+    snd_pcm_state_t pcmState = snd_pcm_state(pcmCopyHandle->pcmIn);
+    if (pcmState == SND_PCM_STATE_PAUSED) {
+        sleep(1);
+    }
+    
+    // When XRNS append try to restore PCM
+    if (pcmState == SND_PCM_STATE_XRUN) {
+        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s XRUN", AlsaPcmUID(pcmCopyHandle->pcmIn, string));
+        snd_pcm_prepare(pcmCopyHandle->pcmIn);
+    }
+   
+    // when PCM suspending loop until ready to go
+    if (pcmState == SND_PCM_STATE_SUSPENDED) {
+        while (1) {
+            if ((error = snd_pcm_resume(pcmCopyHandle->pcmIn)) < 0) {
+                AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s SUSPENDED fail to resume", AlsaPcmUID(pcmCopyHandle->pcmIn, string));
+                sleep(1); // Fulup should be replace with corresponding AFB_timer
+            } else {
+                AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s SUSPENDED success to resume", AlsaPcmUID(pcmCopyHandle->pcmIn, string));
+            }
+        }
+    }
+
+    // do we have waiting frame
+    availIn = snd_pcm_avail_update(pcmCopyHandle->pcmIn);
+    if (availIn <= 0) {
+        goto ExitOnSuccess;
+    }
+
+    // do we have space to push frame
+    availOut = snd_pcm_avail_update(pcmCopyHandle->pcmOut);
+    if (availOut <= 0) {
+        snd_pcm_prepare(pcmCopyHandle->pcmOut);
+        goto ExitOnSuccess;
+    }
+
+    // make sure we can push all input frame into output pcm without locking
+    if (availOut < availIn) availIn = availOut;
+
+    // we get too many data ignore some
+    if (availIn > pcmCopyHandle->frameCount) {
+        AFB_ApiInfo(pcmCopyHandle->api, "AlsaPcmReadCB PcmIn=%s XRUN lost=%ld", AlsaPcmUID(pcmCopyHandle->pcmIn, string), availIn - pcmCopyHandle->frameCount);
+        availIn = pcmCopyHandle->frameCount;
+    }
+
+    // effectively read pcmIn and push frame to pcmOut
+    framesIn = snd_pcm_readi(pcmCopyHandle->pcmIn, pcmCopyHandle->buffer, availIn);
+    if (framesIn < 0 || framesIn != availIn) {
+        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PcmIn=%s UNDERUN frame=%ld", AlsaPcmUID(pcmCopyHandle->pcmIn, string), framesIn);
+        goto ExitOnSuccess;
+    }
+
+    // In/Out frames transfer through buffer copy
+    framesOut = snd_pcm_writei(pcmCopyHandle->pcmOut, pcmCopyHandle->buffer, framesIn);
+    if (framesOut < 0 || framesOut != framesIn) {
+        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PcmOut=%s UNDERUN/SUSPEND frameOut=%ld", AlsaPcmUID(pcmCopyHandle->pcmOut, string), framesOut);
+        goto ExitOnSuccess;
+    }
+
+    if (framesIn != framesOut) {
+        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s Loosing frames=%ld", AlsaPcmUID(pcmCopyHandle->pcmOut, string), (framesIn - framesOut));
+        goto ExitOnSuccess;
+    }
+
+    // fprintf(stderr, ".");
+
+    return 0;
+
+    // Cannot handle error in callback
+ExitOnSuccess:
+    return 0;
+}
+
+static void *LoopInThread(void *handle) {
+    AlsaPcmCopyHandleT *pcmCopyHandle = (AlsaPcmCopyHandleT*) handle;
+    int count = 0;
+    int watchdog = MAINLOOP_WATCHDOG * 1000;
+    pcmCopyHandle->tid = (int) syscall(SYS_gettid);
+
+    AFB_ApiNotice(pcmCopyHandle->api, "LoopInThread:%s/%d Started", pcmCopyHandle->info, pcmCopyHandle->tid);
+
+
+    /* loop until end */
+    for (;;) {
+        int res = sd_event_run(pcmCopyHandle->sdLoop, watchdog);
+        if (res == 0) {
+            AFB_ApiNotice(pcmCopyHandle->api, "LoopInThread:%s/%d Idle count=%d", pcmCopyHandle->info, pcmCopyHandle->tid, count++);
+            continue;
+        }
+        if (res < 0) {
+            AFB_ApiError(pcmCopyHandle->api,"LoopInThread:%s/%d ERROR=%i Exit errno=%s.\n", pcmCopyHandle->info, pcmCopyHandle->tid, res, strerror(res));
+            break;
+        }
+    }
+    pthread_exit(0);
+}
+
+PUBLIC int AlsaPcmCopy(CtlSourceT *source, snd_pcm_t *pcmIn, snd_pcm_t *pcmOut, snd_pcm_format_t format, snd_pcm_access_t access, unsigned int rate, unsigned int channels) {
+    char string[32];
+    struct pollfd *pcmInFds;
+    int error;
+    AlsaPcmHwInfoT infoIn, infoOut;
+   
+
+    if (format == ALSA_PCM_DEFAULT_FORMAT) format = defaultPcmFormat;
+    if (rate == ALSA_PCM_DEFAULT_RATE) rate = defaultPcmRate;
+    if (access == ALSA_PCM_DEFAULT_ACCESS) access = defaultPcmAccess;
+    if (channels == ALSA_PCM_DEFAULT_CHANNELS) channels = defaultPcmChannels;
+
+    // prepare PCM for capture and replay
+    error = AlsaPcmConf(source, pcmIn, format, rate, channels, &infoIn);
+    if (error) goto OnErrorExit;
+
+    // Prepare PCM for usage
+    if ((error = snd_pcm_start(pcmIn)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmCopy: Fail to prepare PCM=%s error=%s", AlsaPcmUID(pcmIn, string), snd_strerror(error));
+        goto OnErrorExit;
+    };
+
+
+    error = AlsaPcmConf(source, pcmOut, infoIn.format, infoIn.rate, infoIn.channels, &infoOut);
+    if (error) goto OnErrorExit;
+
+    // Prepare PCM for usage
+    if ((error = snd_pcm_prepare(pcmOut)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmCopy: Fail to start PCM=%s error=%s", AlsaPcmUID(pcmOut, string), snd_strerror(error));
+        goto OnErrorExit;
+    };
+
+    if (infoIn.format != infoOut.format) {
+        AFB_ApiError(source->api, "AlsaPcmCopy: pcmIn=%s pcmOut=%s format mismatch in=%d out=%d"
+                , AlsaPcmUID(pcmIn, string), AlsaPcmUID(pcmOut, string), infoIn.format, infoOut.format);
+        goto OnErrorExit;
+    }
+
+    if (infoIn.channels != infoOut.channels) {
+        AFB_ApiError(source->api, "AlsaPcmCopy: pcmIn=%s pcmOut=%s channel count mismatch in=%d out=%d"
+                , AlsaPcmUID(pcmIn, string), AlsaPcmUID(pcmOut, string), infoIn.channels, infoOut.channels);
+        goto OnErrorExit;
+    }
+
+    AlsaPcmCopyHandleT *pcmCopyHandle = malloc(sizeof (AlsaPcmCopyHandleT));
+    pcmCopyHandle->info = "pcmCpy";
+    pcmCopyHandle->pcmIn = pcmIn;
+    pcmCopyHandle->pcmOut = pcmOut;
+    pcmCopyHandle->api = source->api;
+    pcmCopyHandle->channels = infoIn.channels;
+    pcmCopyHandle->frameSize = infoIn.channels * infoIn.sampleSize;
+    pcmCopyHandle->frameCount = BUFFER_FRAME_COUNT;
+    pcmCopyHandle->buffer = malloc(pcmCopyHandle->frameCount * pcmCopyHandle->frameSize);
+    
+    // get FD poll descriptor for capture PCM
+    int pcmInCount = snd_pcm_poll_descriptors_count(pcmCopyHandle->pcmIn);
+    if (pcmInCount <= 0) {
+        AFB_ApiError(source->api, "AlsaPcmCopy: Fail pcmIn=%s get fds count error=%s", AlsaPcmUID(pcmIn, string), snd_strerror(error));
+        goto OnErrorExit;
+    };
+
+    pcmInFds = alloca(sizeof (*pcmInFds) * pcmInCount);
+    if ((error = snd_pcm_poll_descriptors(pcmIn, pcmInFds, pcmInCount)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmCopy: Fail pcmIn=%s get pollfds error=%s", AlsaPcmUID(pcmOut, string), snd_strerror(error));
+        goto OnErrorExit;
+    };
+
+    // add poll descriptor to AGL systemd mainloop
+    if ((error = sd_event_new(&pcmCopyHandle->sdLoop)) < 0) {
+        fprintf(stderr, "LaunchCallRequest: fail pcmin=%s creating a new loop: %s\n", AlsaPcmUID(pcmOut, string), strerror(error));
+        goto OnErrorExit;
+    }
+
+    for (int idx = 0; idx < pcmInCount; idx++) {
+        if ((error = sd_event_add_io(pcmCopyHandle->sdLoop, &pcmCopyHandle->evtsrc, pcmInFds[idx].fd, EPOLLIN, AlsaPcmReadCB, pcmCopyHandle)) < 0) {
+            AFB_ApiError(source->api, "AlsaPcmCopy: Fail pcmIn=%s sd_event_add_io err=%d", AlsaPcmUID(pcmIn, string), error);
+            goto OnErrorExit;
+        }
+    }
+
+    // start a thread with a mainloop to monitor Audio-Agent
+    if ((error = pthread_create(&pcmCopyHandle->thread, NULL, &LoopInThread, pcmCopyHandle)) < 0) {
+        AFB_ApiError(source->api, "AlsaPcmCopy: Fail create waiting thread pcmIn=%s err=%d", AlsaPcmUID(pcmIn, string), error);
+        goto OnErrorExit;
+    }
+
+    return 0;
+
+OnErrorExit:
+    AFB_ApiError(source->api, "AlsaPcmCopy: Fail \n - pcmIn=%s \n - pcmOut=%s", AlsaPcmUID(pcmIn, string), AlsaPcmUID(pcmOut, string));
+
+    return -1;
+}
+