Ticket #12222: alsas24.2.diff

mythtv/libs/libmyth/audio/audiooutputalsa.cpp

@@ -34 +34 @@
     m_pbufsize(-1),
     m_card(-1),
     m_device(-1),
-    m_subdevice(-1)
+    m_subdevice(-1),
+    m_s24_3bytes(false)
 {
     m_mixer.handle = NULL;
     m_mixer.elem = NULL;
@@ -382 +383 @@
             default:         continue;
         }
         if (snd_pcm_hw_params_test_format(pcm_handle, params, afmt) >= 0)
+        {
             settings->AddSupportedFormat(fmt);
+            m_s24_3bytes = true;
+        }
+        else if (fmt == FORMAT_S24LSB)
+        {
+#if HAVE_BIGENDIAN
+            afmt = SND_PCM_FORMAT_S24_3BE;
+#else
+            afmt = SND_PCM_FORMAT_S24_3LE;
+#endif
+            if (snd_pcm_hw_params_test_format(pcm_handle, params, afmt) >= 0)
+            {
+                settings->AddSupportedFormat(fmt);
+                m_s24_3bytes = true;
+                VBAUDIO("S24 3 bytes format supported");
+            }
+            else
+            {
+                m_s24_3bytes = false;
+            }
+        }
     }
 
     for (uint channels = CHANNELS_MIN; channels <= CHANNELS_MAX; channels++)
@@ -470 +492 @@
     {
         case FORMAT_U8:     format = SND_PCM_FORMAT_U8;    break;
         case FORMAT_S16:    format = SND_PCM_FORMAT_S16;   break;
-        case FORMAT_S24LSB: format = SND_PCM_FORMAT_S24;   break;
+        case FORMAT_S24LSB:
+            if (m_s24_3bytes)
+            {
+#if HAVE_BIGENDIAN
+                format = SND_PCM_FORMAT_S24_3BE;
+#else
+                format = SND_PCM_FORMAT_S24_3LE;
+#endif
+            }
+            else
+            {
+                format = SND_PCM_FORMAT_S24;
+            }
+            break;
         case FORMAT_S24:    format = SND_PCM_FORMAT_S32;   break;
         case FORMAT_S32:    format = SND_PCM_FORMAT_S32;   break;
         case FORMAT_FLT:    format = SND_PCM_FORMAT_FLOAT; break;
@@ -543 +578 @@
     }
 }
 
+static inline void ConvertS24To3Bytes(uchar *buf, uint samples)
+{
+    int *bufi = (int *)buf;
+
+    for (uint i = 0; i < samples; i++)
+    {
+        int *tmpi = (int *)buf;
+
+        *tmpi = *bufi;
+        bufi++;
+        buf += 3;
+    }
+}
+
 void AudioOutputALSA::WriteAudio(uchar *aubuf, int size)
 {
     uchar *tmpbuf = aubuf;
     uint frames = size / output_bytes_per_frame;
     int err, lw = 0;
+    bool s243bytes = false;
 
     if (pcm_handle == NULL)
     {
@@ -561 +611 @@
         ReorderSmpteToAlsa(aubuf, frames, output_format, channels - 6);
     }
 
+    if (output_format == FORMAT_S24LSB && m_s24_3bytes)
+    {
+        // Handle special format where ALSA expects
+        s243bytes = true;
+        ConvertS24To3Bytes(aubuf, frames * channels);
+    }
+
     LOG(VB_AUDIO | VB_TIMESTAMP, LOG_INFO,
             QString("WriteAudio: Preparing %1 bytes (%2 frames)")
             .arg(size).arg(frames));
@@ -576 +633 @@
                         .arg(lw * output_bytes_per_frame));
 
             frames -= lw;
-            tmpbuf += lw * output_bytes_per_frame; // bytes
+            tmpbuf +=
+                lw * (s243bytes ? channels * 3 : output_bytes_per_frame); // bytes
             continue;
         }
 

mythtv/libs/libmyth/audio/audiooutputalsa.h

@@ -58 +58 @@
         long               volrange;
     } m_mixer;
 
+    bool         m_s24_3bytes;
 };
 #endif