MediaCodec解码aac,播放

来源：互联网发布：unity3d游戏开发pdf 编辑：程序博客网时间：2024/05/22 17:36

版权声明：本文为博主原创文章，未经博主允许不得转载。

自己写了个小测试：
对本地的aac文件用MediaCodec解码出来，就是pcm编码的音频数据了，然后直接将pcm数据写进AudioTrack进行播放。

public class AudioDecoder {    private static final String TAG = "AudioDecoder";    public static final int KEY_CHANNEL_COUNT = 0;    private Worker mWorker;    private String path;//aac文件的路径。    public AudioDecoder(String filename) {        this.path = filename;    }    public void start() {        if (mWorker == null) {            mWorker = new Worker();            mWorker.setRunning(true);            mWorker.start();        }    }    public void stop() {        if (mWorker != null) {            mWorker.setRunning(false);            mWorker = null;        }    }    private class Worker extends Thread {        private static final int KEY_SAMPLE_RATE = 0;        private boolean isRunning = false;        private AudioTrack mPlayer;        private MediaCodec mDecoder;        private MediaExtractor extractor;        public void setRunning(boolean run) {            isRunning = run;        }        @Override        public void run() {            super.run();            if (!prepare()) {                isRunning = false;                Log.d(TAG, "音频解码器初始化失败");            }            while (isRunning) {                decode();            }            release();        }        /**         * 等待客户端连接，初始化解码器         *          * @return 初始化失败返回false，成功返回true         */        public boolean prepare() {            // 等待客户端            mPlayer = new AudioTrack(AudioManager.STREAM_MUSIC, 8000, AudioFormat.CHANNEL_OUT_STEREO,                    AudioFormat.ENCODING_PCM_16BIT, 2048, AudioTrack.MODE_STREAM);//            mPlayer.play();            try {                mDecoder = MediaCodec.createDecoderByType("audio/mp4a-latm");                final String encodeFile = path;                extractor = new MediaExtractor();                extractor.setDataSource(encodeFile);                MediaFormat mediaFormat = null;                for (int i = 0; i < extractor.getTrackCount(); i++) {                    MediaFormat format = extractor.getTrackFormat(i);                    String mime = format.getString(MediaFormat.KEY_MIME);                    if (mime.startsWith("audio/")) {                        extractor.selectTrack(i);                        mediaFormat = format;                        break;                    }                }                mediaFormat.setString(MediaFormat.KEY_MIME, "audio/mp4a-latm");                mediaFormat.setInteger(MediaFormat.KEY_CHANNEL_COUNT, KEY_CHANNEL_COUNT);                mediaFormat.setInteger(MediaFormat.KEY_SAMPLE_RATE, KEY_SAMPLE_RATE);                mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, 24000);                mediaFormat.setInteger(MediaFormat.KEY_IS_ADTS, 1);                mediaFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, 0);                mDecoder.configure(mediaFormat, null, null, 0);            } catch (IOException e) {                e.printStackTrace();                return false;            }            if (mDecoder == null) {                Log.e(TAG, "create mediaDecode failed");                return false;            }            mDecoder.start();            return true;        }        /**         * aac解码+播放         */        public void decode() {            ByteBuffer[] codecInputBuffers = mDecoder.getInputBuffers();            ByteBuffer[] codecOutputBuffers = mDecoder.getOutputBuffers();            final long kTimeOutUs = 5000;            MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();            boolean sawInputEOS = false;            boolean sawOutputEOS = false;            int totalRawSize = 0;            try {                while (!sawOutputEOS) {                    if (!sawInputEOS) {                        int inputBufIndex = mDecoder.dequeueInputBuffer(kTimeOutUs);                        if (inputBufIndex >= 0) {                            ByteBuffer dstBuf = codecInputBuffers[inputBufIndex];                            int sampleSize = extractor.readSampleData(dstBuf, 0);                            if (sampleSize < 0) {                                Log.i("TAG", "saw input EOS.");                                sawInputEOS = true;                                mDecoder.queueInputBuffer(inputBufIndex, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);                            } else {                                long presentationTimeUs = extractor.getSampleTime();                                mDecoder.queueInputBuffer(inputBufIndex, 0, sampleSize, presentationTimeUs, 0);                                extractor.advance();                            }                        }                    }                    int res = mDecoder.dequeueOutputBuffer(info, kTimeOutUs);                    if (res >= 0) {                        int outputBufIndex = res;                        // Simply ignore codec config buffers.                        if ((info.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {                            Log.i("TAG", "audio encoder: codec config buffer");                            mDecoder.releaseOutputBuffer(outputBufIndex, false);                            continue;                        }                        if (info.size != 0) {                            ByteBuffer outBuf = codecOutputBuffers[outputBufIndex];                            outBuf.position(info.offset);                            outBuf.limit(info.offset + info.size);                            byte[] data = new byte[info.size];                            outBuf.get(data);                            totalRawSize += data.length;                            // fosDecoder.write(data);                            // 播放音乐                            mPlayer.write(data, 0, info.size);                        }                        mDecoder.releaseOutputBuffer(outputBufIndex, false);                        if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {                            Log.i("TAG", "saw output EOS.");                            sawOutputEOS = true;                        }                    } else if (res == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {                        codecOutputBuffers = mDecoder.getOutputBuffers();                        Log.i("TAG", "output buffers have changed.");                    } else if (res == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {                        MediaFormat oformat = mDecoder.getOutputFormat();                        Log.i("TAG", "output format has changed to " + oformat);                    }                }            } finally {                // fosDecoder.close();                extractor.release();            }        }        /**         * 释放资源         */        private void release() {            if (mDecoder != null) {                mDecoder.stop();                mDecoder.release();            }            if (mPlayer != null) {                mPlayer.stop();                mPlayer.release();                mPlayer = null;            }            if (extractor != null) {                extractor.release();                extractor = null;            }        }    }}1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195

使用的时候就传aac文件的路径，然后直接开启线程就可以了：

    String fielPath = (Environment.getExternalStorageDirectory().getPath() + "/audio.aac");        AudioDecoder audioDecoder = new AudioDecoder(fielPath);        audioDecoder.start();

0 0