Fist AlsaLoop model playing music (work in progress)

1 files changed, 80 insertions, 0 deletions

diff --git a/plugins/alsa/alsa-capture.c b/plugins/alsa/alsa-capture.c
new file mode 100644
index 0000000..992f731
--- /dev/null
+++ b/plugins/alsa/alsa-capture.c
@@ -0,0 +1,80 @@
+/*
+ * 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.
+ *
+ */
+
+#define _GNU_SOURCE  // needed for vasprintf
+
+#include "alsa-softmixer.h"
+
+PUBLIC snd_pcm_t* AlsaCreateCapture(CtlSourceT *source, const char* sndDevPath, unsigned int deviceIdx, unsigned int subpcmNamex, unsigned int channelCount) {
+    char pcmName[32];
+    int error;
+    snd_pcm_t *pcmHandle;
+    snd_pcm_hw_params_t *pcmParams;
+    
+    AFB_ApiNotice(source->api, "AlsaCreateCapture: start ");
+    
+        // get card info from /dev/snd/xxx
+    snd_ctl_card_info_t *cardInfo = AlsaByPathInfo(source, sndDevPath);
+    
+    if (!cardInfo) {
+        AFB_ApiError(source->api,"AlsaCreateCapture: fail to find sndcard by path= %s", sndDevPath);
+        goto OnErrorExit;        
+    }
+
+    // extract useful info from cardInfo handle
+    int cardIdx = snd_ctl_card_info_get_card(cardInfo);
+    const char *cardName = snd_ctl_card_info_get_name(cardInfo);
+
+
+    // build a valid name and open sndcard
+    snprintf(pcmName, sizeof (pcmName), "hw:%i,%i,%i", cardIdx, deviceIdx, subpcmNamex);
+    error= snd_pcm_open(&pcmHandle, pcmName, SND_PCM_STREAM_CAPTURE, SND_PCM_ASYNC);
+    if (error) {
+        AFB_ApiError(source->api,"AlsaCreateCapture: fail openpcm (hw:%d -> %s pcmNamex=%i subpcmNamex=%d): %s"
+                , cardIdx, cardName, deviceIdx, subpcmNamex, snd_strerror(error));
+        goto OnErrorExit;
+    }
+
+    // set default to param object
+    snd_pcm_hw_params_alloca(&pcmParams);
+    snd_pcm_hw_params_any(pcmHandle, pcmParams);
+    
+    
+    error= snd_pcm_hw_params_set_channels (pcmHandle, pcmParams, channelCount);
+    if (error) {
+        AFB_ApiError(source->api,"lsaCreateCapture: fail set channel count (hw:%d -> %s pcmNamex=%i subpcmNamex=%d channelCount=%d): %s"
+                , cardIdx, cardName, deviceIdx, subpcmNamex, channelCount, snd_strerror(error));
+        goto OnErrorExit;
+    }
+    
+    // push selected params to PCM
+    error= snd_pcm_hw_params(pcmHandle, pcmParams);
+    if (error) {
+        AFB_ApiError(source->api,"lsaCreateCapture: fail pushing params (hw:%d -> %s pcmNamex=%i subpcmNamex=%d): %s"
+                , cardIdx, cardName, deviceIdx, subpcmNamex, snd_strerror(error));
+        goto OnErrorExit;
+    }
+
+    AFB_ApiNotice(source->api, "AlsaCreateCapture: done");
+    free (cardInfo);
+    return NULL;
+
+OnErrorExit:
+    AFB_ApiNotice(source->api, "AlsaCreateCapture: OnErrorExit");
+    return NULL;
+}
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