1/*
2Copyright (c) 2011 Stanislav Vitvitskiy
3
4Permission is hereby granted, free of charge, to any person obtaining a copy of this
5software and associated documentation files (the "Software"), to deal in the Software
6without restriction, including without limitation the rights to use, copy, modify,
7merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
8permit persons to whom the Software is furnished to do so, subject to the following
9conditions:
10
11The above copyright notice and this permission notice shall be included in all copies or
12substantial portions of the Software.
13
14THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
15INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
16PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
17FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
18TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
19OR OTHER DEALINGS IN THE SOFTWARE.
20*/
21package com.googlecode.mp4parser.h264.read;
22
23
24import com.googlecode.mp4parser.h264.BTree;
25
26import java.io.IOException;
27import java.io.InputStream;
28
29import static com.googlecode.mp4parser.h264.Debug.println;
30
31
32public class CAVLCReader extends BitstreamReader {
33
34    public CAVLCReader(InputStream is) throws IOException {
35        super(is);
36    }
37
38    public long readNBit(int n, String message) throws IOException {
39        long val = readNBit(n);
40
41        trace(message, String.valueOf(val));
42
43        return val;
44    }
45
46    /**
47     * Read unsigned exp-golomb code
48     *
49     * @return
50     * @throws java.io.IOException
51     * @throws java.io.IOException
52     */
53    private int readUE() throws IOException {
54        int cnt = 0;
55        while (read1Bit() == 0)
56            cnt++;
57
58        int res = 0;
59        if (cnt > 0) {
60            long val = readNBit(cnt);
61
62            res = (int) ((1 << cnt) - 1 + val);
63        }
64
65        return res;
66    }
67
68    /*
69      * (non-Javadoc)
70      *
71      * @see
72      * ua.org.jplayer.javcodec.h264.H264BitInputStream#readUE(java.lang.String)
73      */
74    public int readUE(String message) throws IOException {
75        int res = readUE();
76
77        trace(message, String.valueOf(res));
78
79        return res;
80    }
81
82    public int readSE(String message) throws IOException {
83        int val = readUE();
84
85        int sign = ((val & 0x1) << 1) - 1;
86        val = ((val >> 1) + (val & 0x1)) * sign;
87
88        trace(message, String.valueOf(val));
89
90        return val;
91    }
92
93    public boolean readBool(String message) throws IOException {
94
95        boolean res = read1Bit() == 0 ? false : true;
96
97        trace(message, res ? "1" : "0");
98
99        return res;
100    }
101
102    public int readU(int i, String string) throws IOException {
103        return (int) readNBit(i, string);
104    }
105
106    public byte[] read(int payloadSize) throws IOException {
107        byte[] result = new byte[payloadSize];
108        for (int i = 0; i < payloadSize; i++) {
109            result[i] = (byte) readByte();
110        }
111        return result;
112    }
113
114    public boolean readAE() {
115        // TODO: do it!!
116        throw new UnsupportedOperationException("Stan");
117    }
118
119    public int readTE(int max) throws IOException {
120        if (max > 1)
121            return readUE();
122        return ~read1Bit() & 0x1;
123    }
124
125    public int readAEI() {
126        // TODO: do it!!
127        throw new UnsupportedOperationException("Stan");
128    }
129
130    public int readME(String string) throws IOException {
131        return readUE(string);
132    }
133
134    public Object readCE(BTree bt, String message) throws IOException {
135        while (true) {
136            int bit = read1Bit();
137            bt = bt.down(bit);
138            if (bt == null) {
139                throw new RuntimeException("Illegal code");
140            }
141            Object i = bt.getValue();
142            if (i != null) {
143                trace(message, i.toString());
144                return i;
145            }
146        }
147    }
148
149    public int readZeroBitCount(String message) throws IOException {
150        int count = 0;
151        while (read1Bit() == 0)
152            count++;
153
154        trace(message, String.valueOf(count));
155
156        return count;
157    }
158
159    public void readTrailingBits() throws IOException {
160        read1Bit();
161        readRemainingByte();
162    }
163
164    private void trace(String message, String val) {
165        StringBuilder traceBuilder = new StringBuilder();
166        int spaces;
167        String pos = String.valueOf(bitsRead - debugBits.length());
168        spaces = 8 - pos.length();
169
170        traceBuilder.append("@" + pos);
171
172        for (int i = 0; i < spaces; i++)
173            traceBuilder.append(' ');
174
175        traceBuilder.append(message);
176        spaces = 100 - traceBuilder.length() - debugBits.length();
177        for (int i = 0; i < spaces; i++)
178            traceBuilder.append(' ');
179        traceBuilder.append(debugBits);
180        traceBuilder.append(" (" + val + ")");
181        debugBits.clear();
182
183        println(traceBuilder.toString());
184    }
185}