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/*
**
** 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 * 2 > 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";
return AndroidRuntime::registerNativeMethods(env,
kClassPathName, gMethods, NELEM(gMethods));
}
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