commit 94803b005511f8baf3281ec4e922be99f62b4186
author Taylor Holberton <taylorcholberton@gmail.com> Thu Dec 01 16:07:14 2016 -0800
committer Taylor Holberton <taylorcholberton@gmail.com> Thu Dec 01 16:07:14 2016 -0800
tree aad55e1e749f478a0293bd6482b327b53558b640
parent ba285cfbf416af5fbda1040e3c3ce74165e3e11c

Added const specifier in pcm_open

Added const specifier to the struct pcm_config argument.

Changed the way default values of the config structure are set and accessed.

They're accessed through the pointer from the argument list and set through the pointer in the pcm structure.

src/pcm.c

diff --git a/src/pcm.c b/src/pcm.c
index 73debb4..29c69a7 100644
--- a/src/pcm.c
+++ b/src/pcm.c
@@ -808,7 +808,7 @@
  * @ingroup libtinyalsa-pcm
  */
 struct pcm *pcm_open(unsigned int card, unsigned int device,
-                     unsigned int flags, struct pcm_config *config)
+                     unsigned int flags, const struct pcm_config *config)
 {
     struct pcm *pcm;
     struct snd_pcm_info info;
@@ -823,14 +823,14 @@
 
     if (config == NULL) {
         config = &pcm->config;
-        config->channels = 2;
-        config->rate = 48000;
-        config->period_size = 1024;
-        config->period_count = 4;
-        config->format = PCM_FORMAT_S16_LE;
-        config->start_threshold = config->period_count * config->period_size;
-        config->stop_threshold = config->period_count * config->period_size;
-        config->silence_threshold = 0;
+        pcm->config.channels = 2;
+        pcm->config.rate = 48000;
+        pcm->config.period_size = 1024;
+        pcm->config.period_count = 4;
+        pcm->config.format = PCM_FORMAT_S16_LE;
+        pcm->config.start_threshold = config->period_count * config->period_size;
+        pcm->config.stop_threshold = config->period_count * config->period_size;
+        pcm->config.silence_threshold = 0;
     } else {
         pcm->config = *config;
     }
@@ -890,8 +890,8 @@
     }
 
     /* get our refined hw_params */
-    config->period_size = param_get_int(&params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
-    config->period_count = param_get_int(&params, SNDRV_PCM_HW_PARAM_PERIODS);
+    pcm->config.period_size = param_get_int(&params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
+    pcm->config.period_count = param_get_int(&params, SNDRV_PCM_HW_PARAM_PERIODS);
     pcm->buffer_size = config->period_count * config->period_size;
 
     if (flags & PCM_MMAP) {