1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package com.google.android.exoplayer2.decoder;
17 
18 import androidx.annotation.IntDef;
19 import androidx.annotation.Nullable;
20 import com.google.android.exoplayer2.C;
21 import java.lang.annotation.Documented;
22 import java.lang.annotation.Retention;
23 import java.lang.annotation.RetentionPolicy;
24 import java.nio.ByteBuffer;
25 import org.checkerframework.checker.nullness.qual.EnsuresNonNull;
26 
27 /**
28  * Holds input for a decoder.
29  */
30 public class DecoderInputBuffer extends Buffer {
31 
32   /**
33    * The buffer replacement mode, which may disable replacement. One of {@link
34    * #BUFFER_REPLACEMENT_MODE_DISABLED}, {@link #BUFFER_REPLACEMENT_MODE_NORMAL} or {@link
35    * #BUFFER_REPLACEMENT_MODE_DIRECT}.
36    */
37   @Documented
38   @Retention(RetentionPolicy.SOURCE)
39   @IntDef({
40     BUFFER_REPLACEMENT_MODE_DISABLED,
41     BUFFER_REPLACEMENT_MODE_NORMAL,
42     BUFFER_REPLACEMENT_MODE_DIRECT
43   })
44   public @interface BufferReplacementMode {}
45   /**
46    * Disallows buffer replacement.
47    */
48   public static final int BUFFER_REPLACEMENT_MODE_DISABLED = 0;
49   /**
50    * Allows buffer replacement using {@link ByteBuffer#allocate(int)}.
51    */
52   public static final int BUFFER_REPLACEMENT_MODE_NORMAL = 1;
53   /**
54    * Allows buffer replacement using {@link ByteBuffer#allocateDirect(int)}.
55    */
56   public static final int BUFFER_REPLACEMENT_MODE_DIRECT = 2;
57 
58   /**
59    * {@link CryptoInfo} for encrypted data.
60    */
61   public final CryptoInfo cryptoInfo;
62 
63   /** The buffer's data, or {@code null} if no data has been set. */
64   @Nullable public ByteBuffer data;
65 
66   // TODO: Remove this temporary signaling once end-of-stream propagation for clips using content
67   // protection is fixed. See [Internal: b/153326944] for details.
68   /**
69    * Whether the last attempt to read a sample into this buffer failed due to not yet having the DRM
70    * keys associated with the next sample.
71    */
72   public boolean waitingForKeys;
73 
74   /**
75    * The time at which the sample should be presented.
76    */
77   public long timeUs;
78 
79   /**
80    * Supplemental data related to the buffer, if {@link #hasSupplementalData()} returns true. If
81    * present, the buffer is populated with supplemental data from position 0 to its limit.
82    */
83   @Nullable public ByteBuffer supplementalData;
84 
85   @BufferReplacementMode private final int bufferReplacementMode;
86 
87   /**
88    * Creates a new instance for which {@link #isFlagsOnly()} will return true.
89    *
90    * @return A new flags only input buffer.
91    */
newFlagsOnlyInstance()92   public static DecoderInputBuffer newFlagsOnlyInstance() {
93     return new DecoderInputBuffer(BUFFER_REPLACEMENT_MODE_DISABLED);
94   }
95 
96   /**
97    * @param bufferReplacementMode Determines the behavior of {@link #ensureSpaceForWrite(int)}. One
98    *     of {@link #BUFFER_REPLACEMENT_MODE_DISABLED}, {@link #BUFFER_REPLACEMENT_MODE_NORMAL} and
99    *     {@link #BUFFER_REPLACEMENT_MODE_DIRECT}.
100    */
DecoderInputBuffer(@ufferReplacementMode int bufferReplacementMode)101   public DecoderInputBuffer(@BufferReplacementMode int bufferReplacementMode) {
102     this.cryptoInfo = new CryptoInfo();
103     this.bufferReplacementMode = bufferReplacementMode;
104   }
105 
106   /**
107    * Clears {@link #supplementalData} and ensures that it's large enough to accommodate {@code
108    * length} bytes.
109    *
110    * @param length The length of the supplemental data that must be accommodated, in bytes.
111    */
112   @EnsuresNonNull("supplementalData")
resetSupplementalData(int length)113   public void resetSupplementalData(int length) {
114     if (supplementalData == null || supplementalData.capacity() < length) {
115       supplementalData = ByteBuffer.allocate(length);
116     } else {
117       supplementalData.clear();
118     }
119   }
120 
121   /**
122    * Ensures that {@link #data} is large enough to accommodate a write of a given length at its
123    * current position.
124    *
125    * <p>If the capacity of {@link #data} is sufficient this method does nothing. If the capacity is
126    * insufficient then an attempt is made to replace {@link #data} with a new {@link ByteBuffer}
127    * whose capacity is sufficient. Data up to the current position is copied to the new buffer.
128    *
129    * @param length The length of the write that must be accommodated, in bytes.
130    * @throws IllegalStateException If there is insufficient capacity to accommodate the write and
131    *     the buffer replacement mode of the holder is {@link #BUFFER_REPLACEMENT_MODE_DISABLED}.
132    */
133   @EnsuresNonNull("data")
ensureSpaceForWrite(int length)134   public void ensureSpaceForWrite(int length) {
135     if (data == null) {
136       data = createReplacementByteBuffer(length);
137       return;
138     }
139     // Check whether the current buffer is sufficient.
140     int capacity = data.capacity();
141     int position = data.position();
142     int requiredCapacity = position + length;
143     if (capacity >= requiredCapacity) {
144       return;
145     }
146     // Instantiate a new buffer if possible.
147     ByteBuffer newData = createReplacementByteBuffer(requiredCapacity);
148     newData.order(data.order());
149     // Copy data up to the current position from the old buffer to the new one.
150     if (position > 0) {
151       data.flip();
152       newData.put(data);
153     }
154     // Set the new buffer.
155     data = newData;
156   }
157 
158   /**
159    * Returns whether the buffer is only able to hold flags, meaning {@link #data} is null and
160    * its replacement mode is {@link #BUFFER_REPLACEMENT_MODE_DISABLED}.
161    */
isFlagsOnly()162   public final boolean isFlagsOnly() {
163     return data == null && bufferReplacementMode == BUFFER_REPLACEMENT_MODE_DISABLED;
164   }
165 
166   /**
167    * Returns whether the {@link C#BUFFER_FLAG_ENCRYPTED} flag is set.
168    */
isEncrypted()169   public final boolean isEncrypted() {
170     return getFlag(C.BUFFER_FLAG_ENCRYPTED);
171   }
172 
173   /**
174    * Flips {@link #data} and {@link #supplementalData} in preparation for being queued to a decoder.
175    *
176    * @see java.nio.Buffer#flip()
177    */
flip()178   public final void flip() {
179     data.flip();
180     if (supplementalData != null) {
181       supplementalData.flip();
182     }
183   }
184 
185   @Override
clear()186   public void clear() {
187     super.clear();
188     if (data != null) {
189       data.clear();
190     }
191     if (supplementalData != null) {
192       supplementalData.clear();
193     }
194     waitingForKeys = false;
195   }
196 
createReplacementByteBuffer(int requiredCapacity)197   private ByteBuffer createReplacementByteBuffer(int requiredCapacity) {
198     if (bufferReplacementMode == BUFFER_REPLACEMENT_MODE_NORMAL) {
199       return ByteBuffer.allocate(requiredCapacity);
200     } else if (bufferReplacementMode == BUFFER_REPLACEMENT_MODE_DIRECT) {
201       return ByteBuffer.allocateDirect(requiredCapacity);
202     } else {
203       int currentCapacity = data == null ? 0 : data.capacity();
204       throw new IllegalStateException("Buffer too small (" + currentCapacity + " < "
205           + requiredCapacity + ")");
206     }
207   }
208 
209 }
210