From: dmitrykos <dmitrykos@0f58301d-fd10-0410-b4af-bbb618454e57>
Date: Mon, 2 Aug 2010 10:37:18 +0000 (+0000)
Subject: alsa:
X-Git-Tag: pa_stable_v19_20110326_r1647~97
X-Git-Url: https://andrewgundersen.net/repos?a=commitdiff_plain;h=2b8866cd3d42b21e1abcda66673fc1b261f812f0;p=portaudio

alsa:
 - trying to fix specific case of stream failing to open when min/max period is specifying fixed value with +/-1 difference, we try choosing middle then which seems to be aligned to 2
---

diff --git a/src/hostapi/alsa/pa_linux_alsa.c b/src/hostapi/alsa/pa_linux_alsa.c
index 90bf7a0..df77877 100644
--- a/src/hostapi/alsa/pa_linux_alsa.c
+++ b/src/hostapi/alsa/pa_linux_alsa.c
@@ -1696,20 +1696,21 @@ static PaError PaAlsaStreamComponent_DetermineFramesPerBuffer( PaAlsaStreamCompo
 
     {
         /* Get min/max period sizes and adjust our chosen */
-        snd_pcm_uframes_t min = 0, max = 0;
+        snd_pcm_uframes_t min = 0, max = 0, minmax_diff;
         ENSURE_( snd_pcm_hw_params_get_period_size_min( hwParams, &min, NULL ), paUnanticipatedHostError );
         ENSURE_( snd_pcm_hw_params_get_period_size_max( hwParams, &max, NULL ), paUnanticipatedHostError );
+        minmax_diff = max - min;
 
         if( framesPerHostBuffer < min )
         {
             PA_DEBUG(( "%s: The determined period size (%lu) is less than minimum (%lu)\n", __FUNCTION__, framesPerHostBuffer, min ));
-            framesPerHostBuffer = min;
+            framesPerHostBuffer = ((minmax_diff == 2) ? min + 1 : min);
         }
         else 
         if( framesPerHostBuffer > max )
         {
             PA_DEBUG(( "%s: The determined period size (%lu) is greater than maximum (%lu)\n", __FUNCTION__, framesPerHostBuffer, max ));
-            framesPerHostBuffer = max;
+            framesPerHostBuffer = ((minmax_diff == 2) ? max - 1 : max);
         }
 
 		PA_DEBUG(( "%s: device period minimum          = %lu\n", __FUNCTION__, min ));
@@ -1717,7 +1718,7 @@ static PaError PaAlsaStreamComponent_DetermineFramesPerBuffer( PaAlsaStreamCompo
 		PA_DEBUG(( "%s: host buffer period             = %lu\n", __FUNCTION__, framesPerHostBuffer ));
 		PA_DEBUG(( "%s: host buffer period latency     = %f\n", __FUNCTION__, (double)(framesPerHostBuffer / sampleRate) ));
 
-        /* Try set period size */
+        /* Try setting period size */
         dir = 0;
         ENSURE_( snd_pcm_hw_params_set_period_size_near( self->pcm, hwParams, &framesPerHostBuffer, &dir ), paUnanticipatedHostError );
         if( dir != 0 )