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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "media/base/seekable_buffer.h" | 5 #include "media/base/seekable_buffer.h" |
6 | 6 |
7 #include <algorithm> | 7 #include <algorithm> |
8 | 8 |
9 #include "base/logging.h" | 9 #include "base/logging.h" |
10 #include "media/base/data_buffer.h" | 10 #include "media/base/data_buffer.h" |
11 | 11 |
12 namespace media { | 12 namespace media { |
13 | 13 |
14 SeekableBuffer::SeekableBuffer(int backward_capacity, | 14 SeekableBuffer::SeekableBuffer(int backward_capacity, int forward_capacity) |
15 int forward_capacity) | |
16 : current_buffer_offset_(0), | 15 : current_buffer_offset_(0), |
17 backward_capacity_(backward_capacity), | 16 backward_capacity_(backward_capacity), |
18 backward_bytes_(0), | 17 backward_bytes_(0), |
19 forward_capacity_(forward_capacity), | 18 forward_capacity_(forward_capacity), |
20 forward_bytes_(0), | 19 forward_bytes_(0), |
21 current_time_(kNoTimestamp()) { | 20 current_time_(kNoTimestamp()) { |
22 current_buffer_ = buffers_.begin(); | 21 current_buffer_ = buffers_.begin(); |
23 } | 22 } |
24 | 23 |
25 SeekableBuffer::~SeekableBuffer() { | 24 SeekableBuffer::~SeekableBuffer() {} |
brettw
2013/06/24 21:18:29
I like the old way better.
| |
26 } | |
27 | 25 |
28 void SeekableBuffer::Clear() { | 26 void SeekableBuffer::Clear() { |
29 buffers_.clear(); | 27 buffers_.clear(); |
30 current_buffer_ = buffers_.begin(); | 28 current_buffer_ = buffers_.begin(); |
31 current_buffer_offset_ = 0; | 29 current_buffer_offset_ = 0; |
32 backward_bytes_ = 0; | 30 backward_bytes_ = 0; |
33 forward_bytes_ = 0; | 31 forward_bytes_ = 0; |
34 current_time_ = kNoTimestamp(); | 32 current_time_ = kNoTimestamp(); |
35 } | 33 } |
36 | 34 |
37 int SeekableBuffer::Read(uint8* data, int size) { | 35 int SeekableBuffer::Read(uint8* data, int size) { |
38 DCHECK(data); | 36 DCHECK(data); |
39 return InternalRead(data, size, true, 0); | 37 return InternalRead(data, size, true, 0); |
40 } | 38 } |
41 | 39 |
42 int SeekableBuffer::Peek(uint8* data, int size, int forward_offset) { | 40 int SeekableBuffer::Peek(uint8* data, int size, int forward_offset) { |
43 DCHECK(data); | 41 DCHECK(data); |
44 return InternalRead(data, size, false, forward_offset); | 42 return InternalRead(data, size, false, forward_offset); |
45 } | 43 } |
46 | 44 |
47 bool SeekableBuffer::GetCurrentChunk(const uint8** data, int* size) const { | 45 bool SeekableBuffer::GetCurrentChunk(const uint8** data, int* size) const { |
48 BufferQueue::iterator current_buffer = current_buffer_; | 46 BufferQueue::iterator current_buffer = current_buffer_; |
49 int current_buffer_offset = current_buffer_offset_; | 47 int current_buffer_offset = current_buffer_offset_; |
50 // Advance position if we are in the end of the current buffer. | 48 // Advance position if we are in the end of the current buffer. |
51 while (current_buffer != buffers_.end() && | 49 while (current_buffer != buffers_.end() && |
52 current_buffer_offset >= (*current_buffer)->GetDataSize()) { | 50 current_buffer_offset >= (*current_buffer)->data_size()) { |
53 ++current_buffer; | 51 ++current_buffer; |
54 current_buffer_offset = 0; | 52 current_buffer_offset = 0; |
55 } | 53 } |
56 if (current_buffer == buffers_.end()) | 54 if (current_buffer == buffers_.end()) |
57 return false; | 55 return false; |
58 *data = (*current_buffer)->GetData() + current_buffer_offset; | 56 *data = (*current_buffer)->data() + current_buffer_offset; |
59 *size = (*current_buffer)->GetDataSize() - current_buffer_offset; | 57 *size = (*current_buffer)->data_size() - current_buffer_offset; |
60 return true; | 58 return true; |
61 } | 59 } |
62 | 60 |
63 bool SeekableBuffer::Append(const scoped_refptr<DataBuffer>& buffer_in) { | 61 bool SeekableBuffer::Append(const scoped_refptr<DataBuffer>& buffer_in) { |
64 if (buffers_.empty() && buffer_in->GetTimestamp() != kNoTimestamp()) { | 62 if (buffers_.empty() && buffer_in->timestamp() != kNoTimestamp()) { |
65 current_time_ = buffer_in->GetTimestamp(); | 63 current_time_ = buffer_in->timestamp(); |
66 } | 64 } |
67 | 65 |
68 // Since the forward capacity is only used to check the criteria for buffer | 66 // Since the forward capacity is only used to check the criteria for buffer |
69 // full, we always append data to the buffer. | 67 // full, we always append data to the buffer. |
70 buffers_.push_back(buffer_in); | 68 buffers_.push_back(buffer_in); |
71 | 69 |
72 // After we have written the first buffer, update |current_buffer_| to point | 70 // After we have written the first buffer, update |current_buffer_| to point |
73 // to it. | 71 // to it. |
74 if (current_buffer_ == buffers_.end()) { | 72 if (current_buffer_ == buffers_.end()) { |
75 DCHECK_EQ(0, forward_bytes_); | 73 DCHECK_EQ(0, forward_bytes_); |
76 current_buffer_ = buffers_.begin(); | 74 current_buffer_ = buffers_.begin(); |
77 } | 75 } |
78 | 76 |
79 // Update the |forward_bytes_| counter since we have more bytes. | 77 // Update the |forward_bytes_| counter since we have more bytes. |
80 forward_bytes_ += buffer_in->GetDataSize(); | 78 forward_bytes_ += buffer_in->data_size(); |
81 | 79 |
82 // Advise the user to stop append if the amount of forward bytes exceeds | 80 // Advise the user to stop append if the amount of forward bytes exceeds |
83 // the forward capacity. A false return value means the user should stop | 81 // the forward capacity. A false return value means the user should stop |
84 // appending more data to this buffer. | 82 // appending more data to this buffer. |
85 if (forward_bytes_ >= forward_capacity_) | 83 if (forward_bytes_ >= forward_capacity_) |
86 return false; | 84 return false; |
87 return true; | 85 return true; |
88 } | 86 } |
89 | 87 |
90 bool SeekableBuffer::Append(const uint8* data, int size) { | 88 bool SeekableBuffer::Append(const uint8* data, int size) { |
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149 | 147 |
150 // The current buffer pointed by current iterator has been consumed. Move | 148 // The current buffer pointed by current iterator has been consumed. Move |
151 // the iterator backward so it points to the previous buffer. | 149 // the iterator backward so it points to the previous buffer. |
152 if (current_buffer_offset_ == 0) { | 150 if (current_buffer_offset_ == 0) { |
153 if (current_buffer_ == buffers_.begin()) | 151 if (current_buffer_ == buffers_.begin()) |
154 break; | 152 break; |
155 // Move the iterator backward. | 153 // Move the iterator backward. |
156 --current_buffer_; | 154 --current_buffer_; |
157 // Set the offset into the current buffer to be the buffer size as we | 155 // Set the offset into the current buffer to be the buffer size as we |
158 // are preparing for rewind for next iteration. | 156 // are preparing for rewind for next iteration. |
159 current_buffer_offset_ = (*current_buffer_)->GetDataSize(); | 157 current_buffer_offset_ = (*current_buffer_)->data_size(); |
160 } | 158 } |
161 } | 159 } |
162 | 160 |
163 UpdateCurrentTime(current_buffer_, current_buffer_offset_); | 161 UpdateCurrentTime(current_buffer_, current_buffer_offset_); |
164 | 162 |
165 DCHECK_EQ(taken, size); | 163 DCHECK_EQ(taken, size); |
166 return true; | 164 return true; |
167 } | 165 } |
168 | 166 |
169 void SeekableBuffer::EvictBackwardBuffers() { | 167 void SeekableBuffer::EvictBackwardBuffers() { |
170 // Advances the iterator until we hit the current pointer. | 168 // Advances the iterator until we hit the current pointer. |
171 while (backward_bytes_ > backward_capacity_) { | 169 while (backward_bytes_ > backward_capacity_) { |
172 BufferQueue::iterator i = buffers_.begin(); | 170 BufferQueue::iterator i = buffers_.begin(); |
173 if (i == current_buffer_) | 171 if (i == current_buffer_) |
174 break; | 172 break; |
175 scoped_refptr<DataBuffer> buffer = *i; | 173 scoped_refptr<DataBuffer> buffer = *i; |
176 backward_bytes_ -= buffer->GetDataSize(); | 174 backward_bytes_ -= buffer->data_size(); |
177 DCHECK_GE(backward_bytes_, 0); | 175 DCHECK_GE(backward_bytes_, 0); |
178 | 176 |
179 buffers_.erase(i); | 177 buffers_.erase(i); |
180 } | 178 } |
181 } | 179 } |
182 | 180 |
183 int SeekableBuffer::InternalRead(uint8* data, int size, | 181 int SeekableBuffer::InternalRead(uint8* data, int size, bool advance_position, |
184 bool advance_position, | |
185 int forward_offset) { | 182 int forward_offset) { |
186 // Counts how many bytes are actually read from the buffer queue. | 183 // Counts how many bytes are actually read from the buffer queue. |
187 int taken = 0; | 184 int taken = 0; |
188 | 185 |
189 BufferQueue::iterator current_buffer = current_buffer_; | 186 BufferQueue::iterator current_buffer = current_buffer_; |
190 int current_buffer_offset = current_buffer_offset_; | 187 int current_buffer_offset = current_buffer_offset_; |
191 | 188 |
192 int bytes_to_skip = forward_offset; | 189 int bytes_to_skip = forward_offset; |
193 while (taken < size) { | 190 while (taken < size) { |
194 // |current_buffer| is valid since the first time this buffer is appended | 191 // |current_buffer| is valid since the first time this buffer is appended |
195 // with data. | 192 // with data. |
196 if (current_buffer == buffers_.end()) | 193 if (current_buffer == buffers_.end()) break; |
197 break; | |
198 | 194 |
199 scoped_refptr<DataBuffer> buffer = *current_buffer; | 195 scoped_refptr<DataBuffer> buffer = *current_buffer; |
200 | 196 |
201 int remaining_bytes_in_buffer = | 197 int remaining_bytes_in_buffer = |
202 buffer->GetDataSize() - current_buffer_offset; | 198 buffer->data_size() - current_buffer_offset; |
203 | 199 |
204 if (bytes_to_skip == 0) { | 200 if (bytes_to_skip == 0) { |
205 // Find the right amount to copy from the current buffer referenced by | 201 // Find the right amount to copy from the current buffer referenced by |
206 // |buffer|. We shall copy no more than |size| bytes in total and each | 202 // |buffer|. We shall copy no more than |size| bytes in total and each |
207 // single step copied no more than the current buffer size. | 203 // single step copied no more than the current buffer size. |
208 int copied = std::min(size - taken, remaining_bytes_in_buffer); | 204 int copied = std::min(size - taken, remaining_bytes_in_buffer); |
209 | 205 |
210 // |data| is NULL if we are seeking forward, so there's no need to copy. | 206 // |data| is NULL if we are seeking forward, so there's no need to copy. |
211 if (data) | 207 if (data) |
212 memcpy(data + taken, buffer->GetData() + current_buffer_offset, copied); | 208 memcpy(data + taken, buffer->data() + current_buffer_offset, copied); |
213 | 209 |
214 // Increase total number of bytes copied, which regulates when to end this | 210 // Increase total number of bytes copied, which regulates when to end this |
215 // loop. | 211 // loop. |
216 taken += copied; | 212 taken += copied; |
217 | 213 |
218 // We have read |copied| bytes from the current buffer. Advances the | 214 // We have read |copied| bytes from the current buffer. Advances the |
219 // offset. | 215 // offset. |
220 current_buffer_offset += copied; | 216 current_buffer_offset += copied; |
221 } else { | 217 } else { |
222 int skipped = std::min(remaining_bytes_in_buffer, bytes_to_skip); | 218 int skipped = std::min(remaining_bytes_in_buffer, bytes_to_skip); |
223 current_buffer_offset += skipped; | 219 current_buffer_offset += skipped; |
224 bytes_to_skip -= skipped; | 220 bytes_to_skip -= skipped; |
225 } | 221 } |
226 | 222 |
227 // The buffer has been consumed. | 223 // The buffer has been consumed. |
228 if (current_buffer_offset == buffer->GetDataSize()) { | 224 if (current_buffer_offset == buffer->data_size()) { |
229 if (advance_position) { | 225 if (advance_position) { |
230 // Next buffer may not have timestamp, so we need to update current | 226 // Next buffer may not have timestamp, so we need to update current |
231 // timestamp before switching to the next buffer. | 227 // timestamp before switching to the next buffer. |
232 UpdateCurrentTime(current_buffer, current_buffer_offset); | 228 UpdateCurrentTime(current_buffer, current_buffer_offset); |
233 } | 229 } |
234 | 230 |
235 BufferQueue::iterator next = current_buffer; | 231 BufferQueue::iterator next = current_buffer; |
236 ++next; | 232 ++next; |
237 // If we are at the last buffer, don't advance. | 233 // If we are at the last buffer, don't advance. |
238 if (next == buffers_.end()) | 234 if (next == buffers_.end()) |
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258 UpdateCurrentTime(current_buffer_, current_buffer_offset_); | 254 UpdateCurrentTime(current_buffer_, current_buffer_offset_); |
259 EvictBackwardBuffers(); | 255 EvictBackwardBuffers(); |
260 } | 256 } |
261 | 257 |
262 return taken; | 258 return taken; |
263 } | 259 } |
264 | 260 |
265 void SeekableBuffer::UpdateCurrentTime(BufferQueue::iterator buffer, | 261 void SeekableBuffer::UpdateCurrentTime(BufferQueue::iterator buffer, |
266 int offset) { | 262 int offset) { |
267 // Garbage values are unavoidable, so this check will remain. | 263 // Garbage values are unavoidable, so this check will remain. |
268 if (buffer != buffers_.end() && (*buffer)->GetTimestamp() != kNoTimestamp()) { | 264 if (buffer != buffers_.end() && |
269 int64 time_offset = ((*buffer)->GetDuration().InMicroseconds() * | 265 (*buffer)->timestamp() != kNoTimestamp()) { |
270 offset) / (*buffer)->GetDataSize(); | 266 int64 time_offset = ((*buffer)->duration().InMicroseconds() * offset) / |
267 (*buffer)->data_size(); | |
271 | 268 |
272 current_time_ = (*buffer)->GetTimestamp() + | 269 current_time_ = (*buffer)->timestamp() + |
273 base::TimeDelta::FromMicroseconds(time_offset); | 270 base::TimeDelta::FromMicroseconds(time_offset); |
274 } | 271 } |
275 } | 272 } |
276 | 273 |
277 } // namespace media | 274 } // namespace media |
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