commit 97d61f751899d3d68f53fb14d0025766bf1be3f7
author Chia-chi Yeh <chiachi@android.com> Tue Jun 22 08:01:13 2010 +0800
committer Chia-chi Yeh <chiachi@android.com> Wed Jun 23 08:01:04 2010 +0800
tree d51681169ac25ab1014a96396f56c5d1ba7d16f9
parent ef8f96a717554a85aa63a60f8c61be2afbd12a5c

media: add AudioRecord::getMinFrameCount().

Change-Id: I952071ab10aa49aa96b727d157b68470d69fff3d

include/media/AudioRecord.h

diff --git a/include/media/AudioRecord.h b/include/media/AudioRecord.h
index d956882..38e3d44 100644
--- a/include/media/AudioRecord.h
+++ b/include/media/AudioRecord.h
@@ -100,6 +100,19 @@
 
     typedef void (*callback_t)(int event, void* user, void *info);
 
+    /* Returns the minimum frame count required for the successful creation of
+     * an AudioRecord object.
+     * Returned status (from utils/Errors.h) can be:
+     *  - NO_ERROR: successful operation
+     *  - NO_INIT: audio server or audio hardware not initialized
+     *  - BAD_VALUE: unsupported configuration
+     */
+
+     static status_t getMinFrameCount(int* frameCount,
+                                      uint32_t sampleRate,
+                                      int format,
+                                      int channelCount);
+
     /* Constructs an uninitialized AudioRecord. No connection with
      * AudioFlinger takes place.
      */

media/libmedia/AudioRecord.cpp

diff --git a/media/libmedia/AudioRecord.cpp b/media/libmedia/AudioRecord.cpp
index a2436ab..a6c515c 100644
--- a/media/libmedia/AudioRecord.cpp
+++ b/media/libmedia/AudioRecord.cpp
@@ -41,6 +41,38 @@
 #define UNLIKELY( exp )     (__builtin_expect( (exp) != 0, false ))
 
 namespace android {
+// ---------------------------------------------------------------------------
+
+// static
+status_t AudioRecord::getMinFrameCount(
+        int* frameCount,
+        uint32_t sampleRate,
+        int format,
+        int channelCount)
+{
+    size_t size = 0;
+    if (AudioSystem::getInputBufferSize(sampleRate, format, channelCount, &size)
+            != NO_ERROR) {
+        LOGE("AudioSystem could not query the input buffer size.");
+        return NO_INIT;
+    }
+
+    if (size == 0) {
+        LOGE("Unsupported configuration: sampleRate %d, format %d, channelCount %d",
+            sampleRate, format, channelCount);
+        return BAD_VALUE;
+    }
+
+    // We double the size of input buffer for ping pong use of record buffer.
+    size <<= 1;
+
+    if (AudioSystem::isLinearPCM(format)) {
+        size /= channelCount * (format == AudioSystem::PCM_16_BIT ? 2 : 1);
+    }
+
+    *frameCount = size;
+    return NO_ERROR;
+}
 
 // ---------------------------------------------------------------------------
 
@@ -132,29 +164,11 @@
     }
 
     // validate framecount
-    size_t inputBuffSizeInBytes = -1;
-    if (AudioSystem::getInputBufferSize(sampleRate, format, channelCount, &inputBuffSizeInBytes)
-            != NO_ERROR) {
-        LOGE("AudioSystem could not query the input buffer size.");
-        return NO_INIT;
+    int minFrameCount = 0;
+    status_t status = getMinFrameCount(&minFrameCount, sampleRate, format, channelCount);
+    if (status != NO_ERROR) {
+        return status;
     }
-
-    if (inputBuffSizeInBytes == 0) {
-        LOGE("Recording parameters are not supported: sampleRate %d, channelCount %d, format %d",
-            sampleRate, channelCount, format);
-        return BAD_VALUE;
-    }
-
-    int frameSizeInBytes = channelCount * (format == AudioSystem::PCM_16_BIT ? 2 : 1);
-    if (AudioSystem::isLinearPCM(format)) {
-        frameSizeInBytes = channelCount * (format == AudioSystem::PCM_16_BIT ? sizeof(int16_t) : sizeof(int8_t));
-    } else {
-        frameSizeInBytes = sizeof(int8_t);
-    }
-
-
-    // We use 2* size of input buffer for ping pong use of record buffer.
-    int minFrameCount = 2 * inputBuffSizeInBytes / frameSizeInBytes;
     LOGV("AudioRecord::set() minFrameCount = %d", minFrameCount);
 
     if (frameCount == 0) {
@@ -170,9 +184,8 @@
     mSessionId = sessionId;
 
     // create the IAudioRecord
-    status_t status = openRecord(sampleRate, format, channelCount,
-                                 frameCount, flags, input);
-
+    status = openRecord(sampleRate, format, channelCount,
+                        frameCount, flags, input);
     if (status != NO_ERROR) {
         return status;
     }