1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "media/formats/mp4/avc.h"
6
7 #include <algorithm>
8 #include <vector>
9
10 #include "base/logging.h"
11 #include "media/base/decrypt_config.h"
12 #include "media/filters/h264_parser.h"
13 #include "media/formats/mp4/box_definitions.h"
14 #include "media/formats/mp4/box_reader.h"
15
16 namespace media {
17 namespace mp4 {
18
19 static const uint8 kAnnexBStartCode[] = {0, 0, 0, 1};
20 static const int kAnnexBStartCodeSize = 4;
21
ConvertAVCToAnnexBInPlaceForLengthSize4(std::vector<uint8> * buf)22 static bool ConvertAVCToAnnexBInPlaceForLengthSize4(std::vector<uint8>* buf) {
23 const int kLengthSize = 4;
24 size_t pos = 0;
25 while (pos + kLengthSize < buf->size()) {
26 uint32 nal_size = (*buf)[pos];
27 nal_size = (nal_size << 8) + (*buf)[pos+1];
28 nal_size = (nal_size << 8) + (*buf)[pos+2];
29 nal_size = (nal_size << 8) + (*buf)[pos+3];
30
31 if (nal_size == 0) {
32 DVLOG(1) << "nal_size is 0";
33 return false;
34 }
35
36 std::copy(kAnnexBStartCode, kAnnexBStartCode + kAnnexBStartCodeSize,
37 buf->begin() + pos);
38 pos += kLengthSize + nal_size;
39 }
40 return pos == buf->size();
41 }
42
43 // static
ConvertFrameToAnnexB(int length_size,std::vector<uint8> * buffer)44 bool AVC::ConvertFrameToAnnexB(int length_size, std::vector<uint8>* buffer) {
45 RCHECK(length_size == 1 || length_size == 2 || length_size == 4);
46
47 if (length_size == 4)
48 return ConvertAVCToAnnexBInPlaceForLengthSize4(buffer);
49
50 std::vector<uint8> temp;
51 temp.swap(*buffer);
52 buffer->reserve(temp.size() + 32);
53
54 size_t pos = 0;
55 while (pos + length_size < temp.size()) {
56 int nal_size = temp[pos];
57 if (length_size == 2) nal_size = (nal_size << 8) + temp[pos+1];
58 pos += length_size;
59
60 if (nal_size == 0) {
61 DVLOG(1) << "nal_size is 0";
62 return false;
63 }
64
65 RCHECK(pos + nal_size <= temp.size());
66 buffer->insert(buffer->end(), kAnnexBStartCode,
67 kAnnexBStartCode + kAnnexBStartCodeSize);
68 buffer->insert(buffer->end(), temp.begin() + pos,
69 temp.begin() + pos + nal_size);
70 pos += nal_size;
71 }
72 return pos == temp.size();
73 }
74
75 // static
InsertParamSetsAnnexB(const AVCDecoderConfigurationRecord & avc_config,std::vector<uint8> * buffer,std::vector<SubsampleEntry> * subsamples)76 bool AVC::InsertParamSetsAnnexB(const AVCDecoderConfigurationRecord& avc_config,
77 std::vector<uint8>* buffer,
78 std::vector<SubsampleEntry>* subsamples) {
79 DCHECK(AVC::IsValidAnnexB(*buffer));
80
81 scoped_ptr<H264Parser> parser(new H264Parser());
82 const uint8* start = &(*buffer)[0];
83 parser->SetStream(start, buffer->size());
84
85 H264NALU nalu;
86 if (parser->AdvanceToNextNALU(&nalu) != H264Parser::kOk)
87 return false;
88
89 std::vector<uint8>::iterator config_insert_point = buffer->begin();
90 std::vector<SubsampleEntry>::iterator subsamples_insert_point =
91 subsamples->begin();
92
93 if (nalu.nal_unit_type == H264NALU::kAUD) {
94 // Move insert point to just after the AUD.
95 config_insert_point += (nalu.data + nalu.size) - start;
96
97 if (!subsamples->empty()) {
98 int64 first_subsample_size =
99 (*subsamples)[0].clear_bytes + (*subsamples)[0].cypher_bytes;
100
101 if (first_subsample_size != (config_insert_point - buffer->begin()))
102 return false;
103
104 subsamples_insert_point++;
105 }
106
107 }
108
109 // Clear |parser| and |start| since they aren't needed anymore and
110 // will hold stale pointers once the insert happens.
111 parser.reset();
112 start = NULL;
113
114 std::vector<uint8> param_sets;
115 std::vector<SubsampleEntry> config_subsamples;
116 RCHECK(AVC::ConvertConfigToAnnexB(avc_config,
117 ¶m_sets,
118 &config_subsamples));
119
120 if (!subsamples->empty()) {
121 subsamples->insert(subsamples_insert_point,
122 config_subsamples.begin(),
123 config_subsamples.end());
124 }
125
126 buffer->insert(config_insert_point,
127 param_sets.begin(), param_sets.end());
128
129 DCHECK(AVC::IsValidAnnexB(*buffer));
130 return true;
131 }
132
133 // static
ConvertConfigToAnnexB(const AVCDecoderConfigurationRecord & avc_config,std::vector<uint8> * buffer,std::vector<SubsampleEntry> * subsamples)134 bool AVC::ConvertConfigToAnnexB(
135 const AVCDecoderConfigurationRecord& avc_config,
136 std::vector<uint8>* buffer,
137 std::vector<SubsampleEntry>* subsamples) {
138 DCHECK(buffer->empty());
139 buffer->clear();
140 int total_size = 0;
141 for (size_t i = 0; i < avc_config.sps_list.size(); i++)
142 total_size += avc_config.sps_list[i].size() + kAnnexBStartCodeSize;
143 for (size_t i = 0; i < avc_config.pps_list.size(); i++)
144 total_size += avc_config.pps_list[i].size() + kAnnexBStartCodeSize;
145 buffer->reserve(total_size);
146
147 for (size_t i = 0; i < avc_config.sps_list.size(); i++) {
148 buffer->insert(buffer->end(), kAnnexBStartCode,
149 kAnnexBStartCode + kAnnexBStartCodeSize);
150 buffer->insert(buffer->end(), avc_config.sps_list[i].begin(),
151 avc_config.sps_list[i].end());
152
153 SubsampleEntry entry;
154 entry.clear_bytes = kAnnexBStartCodeSize + avc_config.sps_list[i].size();
155 entry.cypher_bytes = 0;
156 subsamples->push_back(entry);
157 }
158
159 for (size_t i = 0; i < avc_config.pps_list.size(); i++) {
160 buffer->insert(buffer->end(), kAnnexBStartCode,
161 kAnnexBStartCode + kAnnexBStartCodeSize);
162 buffer->insert(buffer->end(), avc_config.pps_list[i].begin(),
163 avc_config.pps_list[i].end());
164
165 SubsampleEntry entry;
166 entry.clear_bytes = kAnnexBStartCodeSize + avc_config.pps_list[i].size();
167 entry.cypher_bytes = 0;
168 subsamples->push_back(entry);
169 }
170 return true;
171 }
172
173 // Verifies AnnexB NALU order according to ISO/IEC 14496-10 Section 7.4.1.2.3
IsValidAnnexB(const std::vector<uint8> & buffer)174 bool AVC::IsValidAnnexB(const std::vector<uint8>& buffer) {
175 return IsValidAnnexB(&buffer[0], buffer.size());
176 }
177
IsValidAnnexB(const uint8 * buffer,size_t size)178 bool AVC::IsValidAnnexB(const uint8* buffer, size_t size) {
179 DVLOG(1) << __FUNCTION__;
180 DCHECK(buffer);
181
182 if (size == 0)
183 return true;
184
185 H264Parser parser;
186 parser.SetStream(buffer, size);
187
188 typedef enum {
189 kAUDAllowed,
190 kBeforeFirstVCL, // VCL == nal_unit_types 1-5
191 kAfterFirstVCL,
192 kEOStreamAllowed,
193 kNoMoreDataAllowed,
194 } NALUOrderState;
195
196 H264NALU nalu;
197 NALUOrderState order_state = kAUDAllowed;
198 int last_nalu_type = H264NALU::kUnspecified;
199 bool done = false;
200 while (!done) {
201 switch (parser.AdvanceToNextNALU(&nalu)) {
202 case H264Parser::kOk:
203 DVLOG(1) << "nal_unit_type " << nalu.nal_unit_type;
204
205 switch (nalu.nal_unit_type) {
206 case H264NALU::kAUD:
207 if (order_state > kAUDAllowed) {
208 DVLOG(1) << "Unexpected AUD in order_state " << order_state;
209 return false;
210 }
211 order_state = kBeforeFirstVCL;
212 break;
213
214 case H264NALU::kSEIMessage:
215 case H264NALU::kReserved14:
216 case H264NALU::kReserved15:
217 case H264NALU::kReserved16:
218 case H264NALU::kReserved17:
219 case H264NALU::kReserved18:
220 case H264NALU::kPPS:
221 case H264NALU::kSPS:
222 if (order_state > kBeforeFirstVCL) {
223 DVLOG(1) << "Unexpected NALU type " << nalu.nal_unit_type
224 << " in order_state " << order_state;
225 return false;
226 }
227 order_state = kBeforeFirstVCL;
228 break;
229
230 case H264NALU::kSPSExt:
231 if (last_nalu_type != H264NALU::kSPS) {
232 DVLOG(1) << "SPS extension does not follow an SPS.";
233 return false;
234 }
235 break;
236
237 case H264NALU::kNonIDRSlice:
238 case H264NALU::kSliceDataA:
239 case H264NALU::kSliceDataB:
240 case H264NALU::kSliceDataC:
241 case H264NALU::kIDRSlice:
242 if (order_state > kAfterFirstVCL) {
243 DVLOG(1) << "Unexpected VCL in order_state " << order_state;
244 return false;
245 }
246 order_state = kAfterFirstVCL;
247 break;
248
249 case H264NALU::kCodedSliceAux:
250 if (order_state != kAfterFirstVCL) {
251 DVLOG(1) << "Unexpected extension in order_state " << order_state;
252 return false;
253 }
254 break;
255
256 case H264NALU::kEOSeq:
257 if (order_state != kAfterFirstVCL) {
258 DVLOG(1) << "Unexpected EOSeq in order_state " << order_state;
259 return false;
260 }
261 order_state = kEOStreamAllowed;
262 break;
263
264 case H264NALU::kEOStream:
265 if (order_state < kAfterFirstVCL) {
266 DVLOG(1) << "Unexpected EOStream in order_state " << order_state;
267 return false;
268 }
269 order_state = kNoMoreDataAllowed;
270 break;
271
272 case H264NALU::kFiller:
273 case H264NALU::kUnspecified:
274 if (!(order_state >= kAfterFirstVCL &&
275 order_state < kEOStreamAllowed)) {
276 DVLOG(1) << "Unexpected NALU type " << nalu.nal_unit_type
277 << " in order_state " << order_state;
278 return false;
279 }
280 break;
281
282 default:
283 DCHECK_GE(nalu.nal_unit_type, 20);
284 if (nalu.nal_unit_type >= 20 && nalu.nal_unit_type <= 31 &&
285 order_state != kAfterFirstVCL) {
286 DVLOG(1) << "Unexpected NALU type " << nalu.nal_unit_type
287 << " in order_state " << order_state;
288 return false;
289 }
290 }
291 last_nalu_type = nalu.nal_unit_type;
292 break;
293
294 case H264Parser::kInvalidStream:
295 return false;
296
297 case H264Parser::kUnsupportedStream:
298 NOTREACHED() << "AdvanceToNextNALU() returned kUnsupportedStream!";
299 return false;
300
301 case H264Parser::kEOStream:
302 done = true;
303 }
304 }
305
306 return order_state >= kAfterFirstVCL;
307 }
308
309 } // namespace mp4
310 } // namespace media
311