1 files changed, 143 insertions, 0 deletions
diff --git a/media/jni/android_media_ResampleInputStream.cpp b/media/jni/android_media_ResampleInputStream.cpp
new file mode 100644
index 0000000..0247cdb
--- /dev/null
+++ b/media/jni/android_media_ResampleInputStream.cpp
@@ -0,0 +1,143 @@
+/*
+**
+** Copyright 2007, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#define LOG_TAG "ResampleInputStream"
+#include "utils/Log.h"
+
+#include <media/mediarecorder.h>
+#include <stdio.h>
+#include <assert.h>
+#include <limits.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <utils/threads.h>
+
+#include "jni.h"
+#include "JNIHelp.h"
+#include "android_runtime/AndroidRuntime.h"
+
+
+// ----------------------------------------------------------------------------
+
+using namespace android;
+
+
+//
+// helper function to throw an exception
+//
+static void throwException(JNIEnv *env, const char* ex, const char* fmt, int data) {
+    if (jclass cls = env->FindClass(ex)) {
+        char msg[1000];
+        sprintf(msg, fmt, data);
+        env->ThrowNew(cls, msg);
+        env->DeleteLocalRef(cls);
+    }
+}
+
+
+#define FIR_COEF(coef) (short)(0x10000 * coef)
+static const short fir21[] = {
+    FIR_COEF(-0.006965742326),
+    FIR_COEF(-0.008428945737),
+    FIR_COEF( 0.004241280174),
+    FIR_COEF( 0.022141096893),
+    FIR_COEF( 0.018765669437),
+    FIR_COEF(-0.009871891152),
+    FIR_COEF(-0.024842433247),
+    FIR_COEF( 0.006121772058),
+    FIR_COEF( 0.045890841611),
+    FIR_COEF( 0.021573503509),
+    FIR_COEF(-0.059681984668),
+    FIR_COEF(-0.076036275138),
+    FIR_COEF( 0.072405390275),
+    FIR_COEF( 0.308255674582),
+    FIR_COEF( 0.424321210495),
+    FIR_COEF( 0.308255674582),
+    FIR_COEF( 0.072405390275),
+    FIR_COEF(-0.076036275138),
+    FIR_COEF(-0.059681984668),
+    FIR_COEF( 0.021573503509),
+    FIR_COEF( 0.045890841611),
+    FIR_COEF( 0.006121772058),
+    FIR_COEF(-0.024842433247),
+    FIR_COEF(-0.009871891152),
+    FIR_COEF( 0.018765669437),
+    FIR_COEF( 0.022141096893),
+    FIR_COEF( 0.004241280174),
+    FIR_COEF(-0.008428945737),
+    FIR_COEF(-0.006965742326)
+};
+static const int nFir21 = sizeof(fir21) / sizeof(fir21[0]);
+
+static const int BUF_SIZE = 2048;
+
+
+static void android_media_ResampleInputStream_fir21(JNIEnv *env, jclass clazz,
+         jbyteArray jIn,  jint jInOffset,
+         jbyteArray jOut, jint jOutOffset,
+         jint jNpoints) {
+    
+    // safety first!
+    if (nFir21 + jNpoints > BUF_SIZE) {
+        throwException(env, "java/lang/IllegalArgumentException",
+                "FIR+data too long %d", nFir21 + jNpoints);
+        return;
+    }
+    
+    // get input data
+    short in[BUF_SIZE];
+    env->GetByteArrayRegion(jIn, jInOffset, (jNpoints * 2 + nFir21 - 1) * 2, (jbyte*)in);
+    
+    // compute filter
+    short out[BUF_SIZE];
+    for (int i = 0; i < jNpoints; i++) {
+        long sum = 0;
+        const short* firp = &fir21[0];
+        const short* inp = &in[i * 2];
+        for (int n = nFir21; --n >= 0; ) {
+            sum += ((long)*firp++) * ((long)*inp++);
+        }
+        out[i] = (short)(sum >> 16);
+    }
+
+    // save new values
+    env->SetByteArrayRegion(jOut, jOutOffset, jNpoints * 2, (jbyte*)out);
+}
+
+// ----------------------------------------------------------------------------
+
+static JNINativeMethod gMethods[] = {
+    {"fir21", "([BI[BII)V", (void*)android_media_ResampleInputStream_fir21},
+};
+
+
+int register_android_media_ResampleInputStream(JNIEnv *env)
+{
+    const char* const kClassPathName = "android/media/ResampleInputStream";
+    jclass clazz;
+
+    clazz = env->FindClass(kClassPathName);
+    if (clazz == NULL) {
+        LOGE("Can't find %s", kClassPathName);
+        return -1;
+    }
+
+    return AndroidRuntime::registerNativeMethods(env,
+            kClassPathName, gMethods, NELEM(gMethods));
+}
+
+