| /* |
| * Copyright (C) 2008 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. |
| */ |
| |
| package android.media; |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| |
| |
| /** |
| * AmrInputStream |
| * @hide |
| */ |
| public final class AmrInputStream extends InputStream |
| { |
| static { |
| System.loadLibrary("media_jni"); |
| } |
| |
| private final static String TAG = "AmrInputStream"; |
| |
| // frame is 20 msec at 8.000 khz |
| private final static int SAMPLES_PER_FRAME = 8000 * 20 / 1000; |
| |
| // pcm input stream |
| private InputStream mInputStream; |
| |
| // native handle |
| private long mGae; |
| |
| // result amr stream |
| private final byte[] mBuf = new byte[SAMPLES_PER_FRAME * 2]; |
| private int mBufIn = 0; |
| private int mBufOut = 0; |
| |
| // helper for bytewise read() |
| private byte[] mOneByte = new byte[1]; |
| |
| /** |
| * Create a new AmrInputStream, which converts 16 bit PCM to AMR |
| * @param inputStream InputStream containing 16 bit PCM. |
| */ |
| public AmrInputStream(InputStream inputStream) { |
| mInputStream = inputStream; |
| mGae = GsmAmrEncoderNew(); |
| GsmAmrEncoderInitialize(mGae); |
| } |
| |
| @Override |
| public int read() throws IOException { |
| int rtn = read(mOneByte, 0, 1); |
| return rtn == 1 ? (0xff & mOneByte[0]) : -1; |
| } |
| |
| @Override |
| public int read(byte[] b) throws IOException { |
| return read(b, 0, b.length); |
| } |
| |
| @Override |
| public int read(byte[] b, int offset, int length) throws IOException { |
| if (mGae == 0) throw new IllegalStateException("not open"); |
| |
| // local buffer of amr encoded audio empty |
| if (mBufOut >= mBufIn) { |
| // reset the buffer |
| mBufOut = 0; |
| mBufIn = 0; |
| |
| // fetch a 20 msec frame of pcm |
| for (int i = 0; i < SAMPLES_PER_FRAME * 2; ) { |
| int n = mInputStream.read(mBuf, i, SAMPLES_PER_FRAME * 2 - i); |
| if (n == -1) return -1; |
| i += n; |
| } |
| |
| // encode it |
| mBufIn = GsmAmrEncoderEncode(mGae, mBuf, 0, mBuf, 0); |
| } |
| |
| // return encoded audio to user |
| if (length > mBufIn - mBufOut) length = mBufIn - mBufOut; |
| System.arraycopy(mBuf, mBufOut, b, offset, length); |
| mBufOut += length; |
| |
| return length; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| try { |
| if (mInputStream != null) mInputStream.close(); |
| } finally { |
| mInputStream = null; |
| try { |
| if (mGae != 0) GsmAmrEncoderCleanup(mGae); |
| } finally { |
| try { |
| if (mGae != 0) GsmAmrEncoderDelete(mGae); |
| } finally { |
| mGae = 0; |
| } |
| } |
| } |
| } |
| |
| @Override |
| protected void finalize() throws Throwable { |
| if (mGae != 0) { |
| close(); |
| throw new IllegalStateException("someone forgot to close AmrInputStream"); |
| } |
| } |
| |
| // |
| // AudioRecord JNI interface |
| // |
| private static native long GsmAmrEncoderNew(); |
| private static native void GsmAmrEncoderInitialize(long gae); |
| private static native int GsmAmrEncoderEncode(long gae, |
| byte[] pcm, int pcmOffset, byte[] amr, int amrOffset) throws IOException; |
| private static native void GsmAmrEncoderCleanup(long gae); |
| private static native void GsmAmrEncoderDelete(long gae); |
| |
| } |