1 /*
2 **
3 ** Copyright 2007, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 ** http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17
18 #define LOG_TAG "ResampleInputStream"
19 #include "utils/Log.h"
20
21 #include <media/mediarecorder.h>
22 #include <stdio.h>
23 #include <assert.h>
24 #include <limits.h>
25 #include <unistd.h>
26 #include <fcntl.h>
27 #include <utils/threads.h>
28
29 #include "jni.h"
30 #include "JNIHelp.h"
31 #include "android_runtime/AndroidRuntime.h"
32
33
34 // ----------------------------------------------------------------------------
35
36 using namespace android;
37
38
39 //
40 // helper function to throw an exception
41 //
throwException(JNIEnv * env,const char * ex,const char * fmt,int data)42 static void throwException(JNIEnv *env, const char* ex, const char* fmt, int data) {
43 if (jclass cls = env->FindClass(ex)) {
44 char msg[1000];
45 sprintf(msg, fmt, data);
46 env->ThrowNew(cls, msg);
47 env->DeleteLocalRef(cls);
48 }
49 }
50
51
52 #define FIR_COEF(coef) (short)(0x10000 * coef)
53 static const short fir21[] = {
54 FIR_COEF(-0.006965742326),
55 FIR_COEF(-0.008428945737),
56 FIR_COEF( 0.004241280174),
57 FIR_COEF( 0.022141096893),
58 FIR_COEF( 0.018765669437),
59 FIR_COEF(-0.009871891152),
60 FIR_COEF(-0.024842433247),
61 FIR_COEF( 0.006121772058),
62 FIR_COEF( 0.045890841611),
63 FIR_COEF( 0.021573503509),
64 FIR_COEF(-0.059681984668),
65 FIR_COEF(-0.076036275138),
66 FIR_COEF( 0.072405390275),
67 FIR_COEF( 0.308255674582),
68 FIR_COEF( 0.424321210495),
69 FIR_COEF( 0.308255674582),
70 FIR_COEF( 0.072405390275),
71 FIR_COEF(-0.076036275138),
72 FIR_COEF(-0.059681984668),
73 FIR_COEF( 0.021573503509),
74 FIR_COEF( 0.045890841611),
75 FIR_COEF( 0.006121772058),
76 FIR_COEF(-0.024842433247),
77 FIR_COEF(-0.009871891152),
78 FIR_COEF( 0.018765669437),
79 FIR_COEF( 0.022141096893),
80 FIR_COEF( 0.004241280174),
81 FIR_COEF(-0.008428945737),
82 FIR_COEF(-0.006965742326)
83 };
84 static const int nFir21 = sizeof(fir21) / sizeof(fir21[0]);
85
86 static const int BUF_SIZE = 2048;
87
88
android_media_ResampleInputStream_fir21(JNIEnv * env,jclass clazz,jbyteArray jIn,jint jInOffset,jbyteArray jOut,jint jOutOffset,jint jNpoints)89 static void android_media_ResampleInputStream_fir21(JNIEnv *env, jclass clazz,
90 jbyteArray jIn, jint jInOffset,
91 jbyteArray jOut, jint jOutOffset,
92 jint jNpoints) {
93
94 // safety first!
95 if (nFir21 + jNpoints > BUF_SIZE) {
96 throwException(env, "java/lang/IllegalArgumentException",
97 "FIR+data too long %d", nFir21 + jNpoints);
98 return;
99 }
100
101 // get input data
102 short in[BUF_SIZE];
103 env->GetByteArrayRegion(jIn, jInOffset, (jNpoints * 2 + nFir21 - 1) * 2, (jbyte*)in);
104
105 // compute filter
106 short out[BUF_SIZE];
107 for (int i = 0; i < jNpoints; i++) {
108 long sum = 0;
109 const short* firp = &fir21[0];
110 const short* inp = &in[i * 2];
111 for (int n = nFir21; --n >= 0; ) {
112 sum += ((long)*firp++) * ((long)*inp++);
113 }
114 out[i] = (short)(sum >> 16);
115 }
116
117 // save new values
118 env->SetByteArrayRegion(jOut, jOutOffset, jNpoints * 2, (jbyte*)out);
119 }
120
121 // ----------------------------------------------------------------------------
122
123 static JNINativeMethod gMethods[] = {
124 {"fir21", "([BI[BII)V", (void*)android_media_ResampleInputStream_fir21},
125 };
126
127
register_android_media_ResampleInputStream(JNIEnv * env)128 int register_android_media_ResampleInputStream(JNIEnv *env)
129 {
130 const char* const kClassPathName = "android/media/ResampleInputStream";
131
132 return AndroidRuntime::registerNativeMethods(env,
133 kClassPathName, gMethods, NELEM(gMethods));
134 }
135
136
137