commit 6146c08f0c3dd8b9e5788063aa433f304a810602
author Andy Hung <hunga@google.com> Tue Mar 18 11:56:15 2014 -0700
committer Andy Hung <hunga@google.com> Wed Jun 25 13:02:15 2014 -0700
tree 26c9854fb01a0f9a7f3daf31cbbed99105cc88c3
parent 3a227969f604d7c6a24a795661a13f70a5f37e1f

Add enabling variable for extended precision audio

Set AudioFlinger::kEnableExtendedPrecision = true to enable
extended precision. Enabling will be required for devices (such as
USB) which report 24 bit or 32 bit sink formats.

Change-Id: I0dc1d7a4f7607086d7b536ea0e43aef0e696f2ee

services/audioflinger/AudioFlinger.cpp

diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 527fd65..11a01cc 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -1621,6 +1621,19 @@
     mHardwareStatus = AUDIO_HW_OUTPUT_OPEN;
 
     audio_stream_out_t *outStream = NULL;
+
+    // FOR TESTING ONLY:
+    // Enable increased sink precision for mixing mode if kEnableExtendedPrecision is true.
+    if (kEnableExtendedPrecision &&  // Check only for Normal Mixing mode
+            !(flags & (AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD | AUDIO_OUTPUT_FLAG_DIRECT))) {
+        // Update format
+        //config.format = AUDIO_FORMAT_PCM_FLOAT;
+        //config.format = AUDIO_FORMAT_PCM_24_BIT_PACKED;
+        //config.format = AUDIO_FORMAT_PCM_32_BIT;
+        //config.format = AUDIO_FORMAT_PCM_8_24_BIT;
+        // ALOGV("openOutput() upgrading format to %#08x", config.format);
+    }
+
     status_t status = hwDevHal->open_output_stream(hwDevHal,
                                           id,
                                           *pDevices,
@@ -1644,9 +1657,9 @@
         if (flags & AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD) {
             thread = new OffloadThread(this, output, id, *pDevices);
             ALOGV("openOutput() created offload output: ID %d thread %p", id, thread);
-        } else if ((flags & AUDIO_OUTPUT_FLAG_DIRECT) ||
-            (config.format != AUDIO_FORMAT_PCM_16_BIT) ||
-            (config.channel_mask != AUDIO_CHANNEL_OUT_STEREO)) {
+        } else if ((flags & AUDIO_OUTPUT_FLAG_DIRECT)
+                || !isValidPcmSinkFormat(config.format)
+                || (config.channel_mask != AUDIO_CHANNEL_OUT_STEREO)) {
             thread = new DirectOutputThread(this, output, id, *pDevices);
             ALOGV("openOutput() created direct output: ID %d thread %p", id, thread);
         } else {