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 "AmrInputStream"
19 #include "utils/Log.h"
20
21 #include "jni.h"
22 #include "JNIHelp.h"
23 #include "android_runtime/AndroidRuntime.h"
24 #include "gsmamr_enc.h"
25
26 // ----------------------------------------------------------------------------
27
28 using namespace android;
29
30 // Corresponds to max bit rate of 12.2 kbps.
31 static const int MAX_OUTPUT_BUFFER_SIZE = 32;
32 static const int FRAME_DURATION_MS = 20;
33 static const int SAMPLING_RATE_HZ = 8000;
34 static const int SAMPLES_PER_FRAME = ((SAMPLING_RATE_HZ * FRAME_DURATION_MS) / 1000);
35 static const int BYTES_PER_SAMPLE = 2; // Assume 16-bit PCM samples
36 static const int BYTES_PER_FRAME = (SAMPLES_PER_FRAME * BYTES_PER_SAMPLE);
37
38 struct GsmAmrEncoderState {
GsmAmrEncoderStateGsmAmrEncoderState39 GsmAmrEncoderState()
40 : mEncState(NULL),
41 mSidState(NULL),
42 mLastModeUsed(0) {
43 }
44
~GsmAmrEncoderStateGsmAmrEncoderState45 ~GsmAmrEncoderState() {}
46
47 void* mEncState;
48 void* mSidState;
49 int32_t mLastModeUsed;
50 };
51
android_media_AmrInputStream_GsmAmrEncoderNew(JNIEnv * env,jclass)52 static jlong android_media_AmrInputStream_GsmAmrEncoderNew
53 (JNIEnv *env, jclass /* clazz */) {
54 GsmAmrEncoderState* gae = new GsmAmrEncoderState();
55 if (gae == NULL) {
56 jniThrowRuntimeException(env, "Out of memory");
57 }
58 return (jlong)gae;
59 }
60
android_media_AmrInputStream_GsmAmrEncoderInitialize(JNIEnv * env,jclass,jlong gae)61 static void android_media_AmrInputStream_GsmAmrEncoderInitialize
62 (JNIEnv *env, jclass /* clazz */, jlong gae) {
63 GsmAmrEncoderState *state = (GsmAmrEncoderState *) gae;
64 int32_t nResult = AMREncodeInit(&state->mEncState, &state->mSidState, false);
65 if (nResult != OK) {
66 jniThrowExceptionFmt(env, "java/lang/IllegalArgumentException",
67 "GsmAmrEncoder initialization failed %d", nResult);
68 }
69 }
70
android_media_AmrInputStream_GsmAmrEncoderEncode(JNIEnv * env,jclass,jlong gae,jbyteArray pcm,jint pcmOffset,jbyteArray amr,jint amrOffset)71 static jint android_media_AmrInputStream_GsmAmrEncoderEncode
72 (JNIEnv *env, jclass /* clazz */,
73 jlong gae, jbyteArray pcm, jint pcmOffset, jbyteArray amr, jint amrOffset) {
74
75 jbyte inBuf[BYTES_PER_FRAME];
76 jbyte outBuf[MAX_OUTPUT_BUFFER_SIZE];
77
78 env->GetByteArrayRegion(pcm, pcmOffset, sizeof(inBuf), inBuf);
79 GsmAmrEncoderState *state = (GsmAmrEncoderState *) gae;
80 int32_t length = AMREncode(state->mEncState, state->mSidState,
81 (Mode) MR122,
82 (int16_t *) inBuf,
83 (unsigned char *) outBuf,
84 (Frame_Type_3GPP*) &state->mLastModeUsed,
85 AMR_TX_WMF);
86 if (length < 0) {
87 jniThrowExceptionFmt(env, "java/io/IOException",
88 "Failed to encode a frame with error code: %d", length);
89 return (jint)-1;
90 }
91
92 // The 1st byte of PV AMR frames are WMF (Wireless Multimedia Forum)
93 // bitpacked, i.e.;
94 // [P(4) + FT(4)]. Q=1 for good frame, P=padding bit, 0
95 // Here we are converting the header to be as specified in Section 5.3 of
96 // RFC 3267 (AMR storage format) i.e.
97 // [P(1) + FT(4) + Q(1) + P(2)].
98 if (length > 0) {
99 outBuf[0] = (outBuf[0] << 3) | 0x4;
100 }
101
102 env->SetByteArrayRegion(amr, amrOffset, length, outBuf);
103
104 return (jint)length;
105 }
106
android_media_AmrInputStream_GsmAmrEncoderCleanup(JNIEnv *,jclass,jlong gae)107 static void android_media_AmrInputStream_GsmAmrEncoderCleanup
108 (JNIEnv* /* env */, jclass /* clazz */, jlong gae) {
109 GsmAmrEncoderState *state = (GsmAmrEncoderState *) gae;
110 AMREncodeExit(&state->mEncState, &state->mSidState);
111 state->mEncState = NULL;
112 state->mSidState = NULL;
113 }
114
android_media_AmrInputStream_GsmAmrEncoderDelete(JNIEnv *,jclass,jlong gae)115 static void android_media_AmrInputStream_GsmAmrEncoderDelete
116 (JNIEnv* /* env */, jclass /* clazz */, jlong gae) {
117 delete (GsmAmrEncoderState*)gae;
118 }
119
120 // ----------------------------------------------------------------------------
121
122 static JNINativeMethod gMethods[] = {
123 {"GsmAmrEncoderNew", "()J", (void*)android_media_AmrInputStream_GsmAmrEncoderNew},
124 {"GsmAmrEncoderInitialize", "(J)V", (void*)android_media_AmrInputStream_GsmAmrEncoderInitialize},
125 {"GsmAmrEncoderEncode", "(J[BI[BI)I", (void*)android_media_AmrInputStream_GsmAmrEncoderEncode},
126 {"GsmAmrEncoderCleanup", "(J)V", (void*)android_media_AmrInputStream_GsmAmrEncoderCleanup},
127 {"GsmAmrEncoderDelete", "(J)V", (void*)android_media_AmrInputStream_GsmAmrEncoderDelete},
128 };
129
130
register_android_media_AmrInputStream(JNIEnv * env)131 int register_android_media_AmrInputStream(JNIEnv *env)
132 {
133 const char* const kClassPathName = "android/media/AmrInputStream";
134
135 return AndroidRuntime::registerNativeMethods(env,
136 kClassPathName, gMethods, NELEM(gMethods));
137 }
138