Initial Audio plugin

Signed-off-by: Manuel Bachmann <manuel.bachmann@iot.bzh>

4 files changed, 176 insertions, 18 deletions

diff --git a/plugins/audio/audio-alsa.c b/plugins/audio/audio-alsa.c
new file mode 100644
index 00000000..8c08c8db
--- /dev/null
+++ b/plugins/audio/audio-alsa.c
@@ -0,0 +1,82 @@
+#include "audio-api.h"
+#include "audio-alsa.h"
+
+PUBLIC unsigned char _alsa_init (const char *name, audioCtxHandleT *ctx) {
+
+    snd_pcm_t *dev;
+    snd_pcm_hw_params_t *params;
+    int num;
+
+    if (snd_pcm_open (&dev, name, SND_PCM_STREAM_PLAYBACK, 0) < 0)
+        return 0;
+
+    snd_pcm_hw_params_malloc (&params);
+    snd_pcm_hw_params_any (dev, params);
+    snd_pcm_hw_params_set_access (dev, params, SND_PCM_ACCESS_RW_INTERLEAVED);
+    snd_pcm_hw_params_set_format (dev, params, SND_PCM_FORMAT_S16_LE);
+    snd_pcm_hw_params_set_rate_near (dev, params, &ctx->rate, 0);
+    snd_pcm_hw_params_set_channels (dev, params, ctx->channels);
+    if (snd_pcm_hw_params (dev, params) < 0) {
+        snd_pcm_hw_params_free (params);
+        return 0;
+    }
+    snd_pcm_prepare (dev);
+    
+    /* allocate the global array if it hasn't been done */
+    if (!dev_ctx) {
+        dev_ctx = (dev_ctx_T**) malloc (sizeof(dev_ctx_T));
+        dev_ctx[0] = (dev_ctx_T*) malloc (sizeof(dev_ctx_T));
+        dev_ctx[0]->name = NULL;
+        dev_ctx[0]->dev = NULL;
+    }
+
+    /* is a card with similar name already opened ? */
+    for (num = 0; num < (sizeof(dev_ctx)/sizeof(dev_ctx_T)); num++) {
+        if (dev_ctx[num]->name &&
+           !strcmp (dev_ctx[num]->name, name))
+            return 0;
+    }
+    num++;
+
+    /* it's not... let us add it to the global array */
+    dev_ctx[num] = (dev_ctx_T*) malloc (sizeof(dev_ctx_T));
+    dev_ctx[num]->name = strdup (name);
+    dev_ctx[num]->dev = dev;
+    dev_ctx[num]->params = params;
+
+    return 1;
+}
+
+PUBLIC void _alsa_free (const char *name) {
+
+    int num;
+
+    for (num = 0; num < (sizeof(dev_ctx)/sizeof(dev_ctx_T)); num++) {
+        if (dev_ctx[num]->name &&
+           !strcmp (dev_ctx[num]->name, name)) {
+            snd_pcm_close (dev_ctx[num]->dev);
+            snd_pcm_hw_params_free (dev_ctx[num]->params);
+            free (dev_ctx[num]->name);
+            dev_ctx[num]->name = NULL;
+            dev_ctx[num]->dev = NULL;
+            free(dev_ctx[num]);
+            return;
+        }
+    }
+}
+
+PUBLIC void _alsa_play (unsigned int num, void *buf, int len) {
+
+    if (!dev_ctx || !dev_ctx[num])
+        return;
+
+    int16_t *cbuf = (int16_t *)buf;
+    int frames = len / 2;
+    int res;
+
+    if ((res = snd_pcm_writei (dev_ctx[num]->dev, cbuf, frames)) != frames) {
+        snd_pcm_recover (dev_ctx[num]->dev, res, 0);
+        snd_pcm_prepare (dev_ctx[num]->dev);
+    }
+    /* snd_pcm_drain (dev_ctx[num]->dev); */
+}
\ No newline at end of file
diff --git a/plugins/audio/audio-alsa.h b/plugins/audio/audio-alsa.h
new file mode 100644
index 00000000..a85f419d
--- /dev/null
+++ b/plugins/audio/audio-alsa.h
@@ -0,0 +1,18 @@
+#ifndef AUDIO_ALSA_H
+#define AUDIO_ALSA_H
+
+#include <alsa/asoundlib.h>
+
+#include "local-def.h"
+
+typedef struct dev_ctx dev_ctx_T;
+
+struct dev_ctx {
+  char *name;
+  snd_pcm_t *dev;
+  snd_pcm_hw_params_t *params;
+};
+
+static struct dev_ctx **dev_ctx = NULL;
+
+#endif /* AUDIO_ALSA_H */
\ No newline at end of file
diff --git a/plugins/audio/audio-api.c b/plugins/audio/audio-api.c
index 9d4f3cb6..547f97ed 100644
--- a/plugins/audio/audio-api.c
+++ b/plugins/audio/audio-api.c
@@ -16,36 +16,68 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "audio-api.h"
+#include "audio-alsa.h"
 
-#include "local-def.h"
 
-STATIC json_object* wrongApi (AFB_request *request, void* handle) {
-    int zero=0;
-    int bug=1234;
-    int impossible;
+/* ------ LOCAL HELPER FUNCTIONS --------- */
+
+/* private client context creation ; default values */
+STATIC audioCtxHandleT* initAudioCtx () {
+
+    audioCtxHandleT *ctx;
+
+    ctx = malloc (sizeof(audioCtxHandleT));
+    ctx->volume = 25;
+    ctx->rate = 22050;
+    ctx->channels = 2;
+
+    return ctx;
+}
+
+/* called when client session dies [e.g. client quits for more than 15mns] */
+STATIC json_object* freeAudio (AFB_clientCtx *client) {
+
+    //releaseAudio (client->plugin->handle, client->ctx);
+    free (client->ctx);
     
-    impossible=bug/zero;
+    return jsonNewMessage (AFB_SUCCESS, "Released radio and client context");
 }
 
 
+/* ------ PUBLIC PLUGIN FUNCTIONS --------- */
 
-STATIC struct {
-    void * somedata;
-} handle;
+STATIC json_object* init (AFB_request *request) {       /* AFB_SESSION_CREATE */
 
+    audioCtxHandleT *ctx;
+    json_object *jresp;
+
+    /* create a private client context */
+    ctx = initAudioCtx();
+    request->client->ctx = (audioCtxHandleT*)ctx;
+    
+    _alsa_init("default", ctx);
+    
+    jresp = json_object_new_object();
+    json_object_object_add (jresp, "token", json_object_new_string (request->client->token));
+}
 
-STATIC  AFB_restapi pluginApis[]= {
-  {"ping"     , AFB_SESSION_NONE, (AFB_apiCB)apiPingTest,"Ping Application Framework"},
-  {"error"    , AFB_SESSION_NONE, (AFB_apiCB)wrongApi   , "Ping Application Framework"},
+
+STATIC AFB_restapi pluginApis[]= {
+  {"init"   , AFB_SESSION_CREATE, (AFB_apiCB)init       , "Audio API - init"},
+//  {"error"  , AFB_SESSION_CHECK,   (AFB_apiCB)wrongApi   , "Ping Application Framework"},
 
   {NULL}
 };
 
-PUBLIC AFB_plugin *alsaRegister () {
-    AFB_plugin *plugin = malloc (sizeof (AFB_plugin));
-    plugin->type  = AFB_PLUGIN_JSON;
-    plugin->info  = "Application Framework Binder Service";
-    plugin->prefix= "alsa";        
-    plugin->apis  = pluginApis;
+PUBLIC AFB_plugin *audioRegister () {
+    AFB_plugin *plugin = malloc (sizeof(AFB_plugin));
+    plugin->type   = AFB_PLUGIN_JSON;
+    plugin->info   = "Application Framework Binder - Audio plugin";
+    plugin->prefix = "audio";        
+    plugin->apis   = pluginApis;
+
+    plugin->freeCtxCB = freeAudio;
+
     return (plugin);
 };
\ No newline at end of file
diff --git a/plugins/audio/audio-api.h b/plugins/audio/audio-api.h
new file mode 100644
index 00000000..0928f0fa
--- /dev/null
+++ b/plugins/audio/audio-api.h
@@ -0,0 +1,26 @@
+#ifndef AUDIO_API_H
+#define AUDIO_API_H
+
+#include "audio-alsa.h"
+
+/* global plugin handle, should store everything we may need */
+typedef struct {
+  int devCount;
+} pluginHandleT;
+  
+/* structure holding one audio card with current usage status */
+typedef struct {
+   char *name;
+   void *handle;           /* handle to implementation (ALSA, PulseAudio...) */
+ } audioDevT;
+
+/* private client context [will be destroyed when client leaves] */
+typedef struct {
+  audioDevT *radio;        /* pointer to client audio card          */
+  unsigned int volume;     /* audio volume : 0-100                  */
+  unsigned int rate;       /* audio rate (Hz)                       */
+  unsigned int channels;   /* audio channels : 1(mono)/2(stereo)... */
+} audioCtxHandleT;
+
+
+#endif /* AUDIO_API_H */
\ No newline at end of file