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1 /* | |
2 * Copyright (c) 2015 The WebRTC project authors. All Rights Reserved. | |
3 * | |
4 * Use of this source code is governed by a BSD-style license | |
5 * that can be found in the LICENSE file in the root of the source | |
6 * tree. An additional intellectual property rights grant can be found | |
7 * in the file PATENTS. All contributing project authors may | |
8 * be found in the AUTHORS file in the root of the source tree. | |
9 * | |
10 */ | |
11 | |
12 #include "webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.h" | |
13 | |
14 #include <CoreFoundation/CoreFoundation.h> | |
15 #include <memory> | |
16 #include <vector> | |
17 | |
18 #include "webrtc/base/checks.h" | |
19 #include "webrtc/base/logging.h" | |
20 | |
21 namespace webrtc { | |
22 | |
23 using H264::kAud; | |
24 using H264::kSps; | |
25 using H264::NaluIndex; | |
26 using H264::NaluType; | |
27 using H264::ParseNaluType; | |
28 | |
29 const char kAnnexBHeaderBytes[4] = {0, 0, 0, 1}; | |
30 const size_t kAvccHeaderByteSize = sizeof(uint32_t); | |
31 | |
32 bool H264CMSampleBufferToAnnexBBuffer( | |
33 CMSampleBufferRef avcc_sample_buffer, | |
34 bool is_keyframe, | |
35 rtc::Buffer* annexb_buffer, | |
36 webrtc::RTPFragmentationHeader** out_header) { | |
37 RTC_DCHECK(avcc_sample_buffer); | |
38 RTC_DCHECK(out_header); | |
39 *out_header = nullptr; | |
40 | |
41 // Get format description from the sample buffer. | |
42 CMVideoFormatDescriptionRef description = | |
43 CMSampleBufferGetFormatDescription(avcc_sample_buffer); | |
44 if (description == nullptr) { | |
45 LOG(LS_ERROR) << "Failed to get sample buffer's description."; | |
46 return false; | |
47 } | |
48 | |
49 // Get parameter set information. | |
50 int nalu_header_size = 0; | |
51 size_t param_set_count = 0; | |
52 OSStatus status = CMVideoFormatDescriptionGetH264ParameterSetAtIndex( | |
53 description, 0, nullptr, nullptr, ¶m_set_count, &nalu_header_size); | |
54 if (status != noErr) { | |
55 LOG(LS_ERROR) << "Failed to get parameter set."; | |
56 return false; | |
57 } | |
58 RTC_CHECK_EQ(nalu_header_size, kAvccHeaderByteSize); | |
59 RTC_DCHECK_EQ(param_set_count, 2); | |
60 | |
61 // Truncate any previous data in the buffer without changing its capacity. | |
62 annexb_buffer->SetSize(0); | |
63 | |
64 size_t nalu_offset = 0; | |
65 std::vector<size_t> frag_offsets; | |
66 std::vector<size_t> frag_lengths; | |
67 | |
68 // Place all parameter sets at the front of buffer. | |
69 if (is_keyframe) { | |
70 size_t param_set_size = 0; | |
71 const uint8_t* param_set = nullptr; | |
72 for (size_t i = 0; i < param_set_count; ++i) { | |
73 status = CMVideoFormatDescriptionGetH264ParameterSetAtIndex( | |
74 description, i, ¶m_set, ¶m_set_size, nullptr, nullptr); | |
75 if (status != noErr) { | |
76 LOG(LS_ERROR) << "Failed to get parameter set."; | |
77 return false; | |
78 } | |
79 // Update buffer. | |
80 annexb_buffer->AppendData(kAnnexBHeaderBytes, sizeof(kAnnexBHeaderBytes)); | |
81 annexb_buffer->AppendData(reinterpret_cast<const char*>(param_set), | |
82 param_set_size); | |
83 // Update fragmentation. | |
84 frag_offsets.push_back(nalu_offset + sizeof(kAnnexBHeaderBytes)); | |
85 frag_lengths.push_back(param_set_size); | |
86 nalu_offset += sizeof(kAnnexBHeaderBytes) + param_set_size; | |
87 } | |
88 } | |
89 | |
90 // Get block buffer from the sample buffer. | |
91 CMBlockBufferRef block_buffer = | |
92 CMSampleBufferGetDataBuffer(avcc_sample_buffer); | |
93 if (block_buffer == nullptr) { | |
94 LOG(LS_ERROR) << "Failed to get sample buffer's block buffer."; | |
95 return false; | |
96 } | |
97 CMBlockBufferRef contiguous_buffer = nullptr; | |
98 // Make sure block buffer is contiguous. | |
99 if (!CMBlockBufferIsRangeContiguous(block_buffer, 0, 0)) { | |
100 status = CMBlockBufferCreateContiguous( | |
101 nullptr, block_buffer, nullptr, nullptr, 0, 0, 0, &contiguous_buffer); | |
102 if (status != noErr) { | |
103 LOG(LS_ERROR) << "Failed to flatten non-contiguous block buffer: " | |
104 << status; | |
105 return false; | |
106 } | |
107 } else { | |
108 contiguous_buffer = block_buffer; | |
109 // Retain to make cleanup easier. | |
110 CFRetain(contiguous_buffer); | |
111 block_buffer = nullptr; | |
112 } | |
113 | |
114 // Now copy the actual data. | |
115 char* data_ptr = nullptr; | |
116 size_t block_buffer_size = CMBlockBufferGetDataLength(contiguous_buffer); | |
117 status = CMBlockBufferGetDataPointer(contiguous_buffer, 0, nullptr, nullptr, | |
118 &data_ptr); | |
119 if (status != noErr) { | |
120 LOG(LS_ERROR) << "Failed to get block buffer data."; | |
121 CFRelease(contiguous_buffer); | |
122 return false; | |
123 } | |
124 size_t bytes_remaining = block_buffer_size; | |
125 while (bytes_remaining > 0) { | |
126 // The size type here must match |nalu_header_size|, we expect 4 bytes. | |
127 // Read the length of the next packet of data. Must convert from big endian | |
128 // to host endian. | |
129 RTC_DCHECK_GE(bytes_remaining, (size_t)nalu_header_size); | |
130 uint32_t* uint32_data_ptr = reinterpret_cast<uint32_t*>(data_ptr); | |
131 uint32_t packet_size = CFSwapInt32BigToHost(*uint32_data_ptr); | |
132 // Update buffer. | |
133 annexb_buffer->AppendData(kAnnexBHeaderBytes, sizeof(kAnnexBHeaderBytes)); | |
134 annexb_buffer->AppendData(data_ptr + nalu_header_size, packet_size); | |
135 // Update fragmentation. | |
136 frag_offsets.push_back(nalu_offset + sizeof(kAnnexBHeaderBytes)); | |
137 frag_lengths.push_back(packet_size); | |
138 nalu_offset += sizeof(kAnnexBHeaderBytes) + packet_size; | |
139 | |
140 size_t bytes_written = packet_size + sizeof(kAnnexBHeaderBytes); | |
141 bytes_remaining -= bytes_written; | |
142 data_ptr += bytes_written; | |
143 } | |
144 RTC_DCHECK_EQ(bytes_remaining, (size_t)0); | |
145 | |
146 std::unique_ptr<webrtc::RTPFragmentationHeader> header; | |
147 header.reset(new webrtc::RTPFragmentationHeader()); | |
148 header->VerifyAndAllocateFragmentationHeader(frag_offsets.size()); | |
149 RTC_DCHECK_EQ(frag_lengths.size(), frag_offsets.size()); | |
150 for (size_t i = 0; i < frag_offsets.size(); ++i) { | |
151 header->fragmentationOffset[i] = frag_offsets[i]; | |
152 header->fragmentationLength[i] = frag_lengths[i]; | |
153 header->fragmentationPlType[i] = 0; | |
154 header->fragmentationTimeDiff[i] = 0; | |
155 } | |
156 *out_header = header.release(); | |
157 CFRelease(contiguous_buffer); | |
158 return true; | |
159 } | |
160 | |
161 bool H264AnnexBBufferToCMSampleBuffer(const uint8_t* annexb_buffer, | |
162 size_t annexb_buffer_size, | |
163 CMVideoFormatDescriptionRef video_format, | |
164 CMSampleBufferRef* out_sample_buffer) { | |
165 RTC_DCHECK(annexb_buffer); | |
166 RTC_DCHECK(out_sample_buffer); | |
167 RTC_DCHECK(video_format); | |
168 *out_sample_buffer = nullptr; | |
169 | |
170 AnnexBBufferReader reader(annexb_buffer, annexb_buffer_size); | |
171 if (H264AnnexBBufferHasVideoFormatDescription(annexb_buffer, | |
172 annexb_buffer_size)) { | |
173 // Advance past the SPS and PPS. | |
174 const uint8_t* data = nullptr; | |
175 size_t data_len = 0; | |
176 if (!reader.ReadNalu(&data, &data_len)) { | |
177 LOG(LS_ERROR) << "Failed to read SPS"; | |
178 return false; | |
179 } | |
180 if (!reader.ReadNalu(&data, &data_len)) { | |
181 LOG(LS_ERROR) << "Failed to read PPS"; | |
182 return false; | |
183 } | |
184 } | |
185 | |
186 // Allocate memory as a block buffer. | |
187 // TODO(tkchin): figure out how to use a pool. | |
188 CMBlockBufferRef block_buffer = nullptr; | |
189 OSStatus status = CMBlockBufferCreateWithMemoryBlock( | |
190 nullptr, nullptr, reader.BytesRemaining(), nullptr, nullptr, 0, | |
191 reader.BytesRemaining(), kCMBlockBufferAssureMemoryNowFlag, | |
192 &block_buffer); | |
193 if (status != kCMBlockBufferNoErr) { | |
194 LOG(LS_ERROR) << "Failed to create block buffer."; | |
195 return false; | |
196 } | |
197 | |
198 // Make sure block buffer is contiguous. | |
199 CMBlockBufferRef contiguous_buffer = nullptr; | |
200 if (!CMBlockBufferIsRangeContiguous(block_buffer, 0, 0)) { | |
201 status = CMBlockBufferCreateContiguous( | |
202 nullptr, block_buffer, nullptr, nullptr, 0, 0, 0, &contiguous_buffer); | |
203 if (status != noErr) { | |
204 LOG(LS_ERROR) << "Failed to flatten non-contiguous block buffer: " | |
205 << status; | |
206 CFRelease(block_buffer); | |
207 return false; | |
208 } | |
209 } else { | |
210 contiguous_buffer = block_buffer; | |
211 block_buffer = nullptr; | |
212 } | |
213 | |
214 // Get a raw pointer into allocated memory. | |
215 size_t block_buffer_size = 0; | |
216 char* data_ptr = nullptr; | |
217 status = CMBlockBufferGetDataPointer(contiguous_buffer, 0, nullptr, | |
218 &block_buffer_size, &data_ptr); | |
219 if (status != kCMBlockBufferNoErr) { | |
220 LOG(LS_ERROR) << "Failed to get block buffer data pointer."; | |
221 CFRelease(contiguous_buffer); | |
222 return false; | |
223 } | |
224 RTC_DCHECK(block_buffer_size == reader.BytesRemaining()); | |
225 | |
226 // Write Avcc NALUs into block buffer memory. | |
227 AvccBufferWriter writer(reinterpret_cast<uint8_t*>(data_ptr), | |
228 block_buffer_size); | |
229 while (reader.BytesRemaining() > 0) { | |
230 const uint8_t* nalu_data_ptr = nullptr; | |
231 size_t nalu_data_size = 0; | |
232 if (reader.ReadNalu(&nalu_data_ptr, &nalu_data_size)) { | |
233 writer.WriteNalu(nalu_data_ptr, nalu_data_size); | |
234 } | |
235 } | |
236 | |
237 // Create sample buffer. | |
238 status = CMSampleBufferCreate(nullptr, contiguous_buffer, true, nullptr, | |
239 nullptr, video_format, 1, 0, nullptr, 0, | |
240 nullptr, out_sample_buffer); | |
241 if (status != noErr) { | |
242 LOG(LS_ERROR) << "Failed to create sample buffer."; | |
243 CFRelease(contiguous_buffer); | |
244 return false; | |
245 } | |
246 CFRelease(contiguous_buffer); | |
247 return true; | |
248 } | |
249 | |
250 bool H264AnnexBBufferHasVideoFormatDescription(const uint8_t* annexb_buffer, | |
251 size_t annexb_buffer_size) { | |
252 RTC_DCHECK(annexb_buffer); | |
253 RTC_DCHECK_GT(annexb_buffer_size, 4); | |
254 | |
255 // The buffer we receive via RTP has 00 00 00 01 start code artifically | |
256 // embedded by the RTP depacketizer. Extract NALU information. | |
257 // TODO(tkchin): handle potential case where sps and pps are delivered | |
258 // separately. | |
259 NaluType first_nalu_type = ParseNaluType(annexb_buffer[4]); | |
260 bool is_first_nalu_type_sps = first_nalu_type == kSps; | |
261 if (is_first_nalu_type_sps) | |
262 return true; | |
263 bool is_first_nalu_type_aud = first_nalu_type == kAud; | |
264 // Start code + access unit delimiter + start code = 4 + 2 + 4 = 10. | |
265 if (!is_first_nalu_type_aud || annexb_buffer_size <= 10u) | |
266 return false; | |
267 NaluType second_nalu_type = ParseNaluType(annexb_buffer[10]); | |
268 bool is_second_nalu_type_sps = second_nalu_type == kSps; | |
269 return is_second_nalu_type_sps; | |
270 } | |
271 | |
272 CMVideoFormatDescriptionRef CreateVideoFormatDescription( | |
273 const uint8_t* annexb_buffer, | |
274 size_t annexb_buffer_size) { | |
275 if (!H264AnnexBBufferHasVideoFormatDescription(annexb_buffer, | |
276 annexb_buffer_size)) { | |
277 return nullptr; | |
278 } | |
279 AnnexBBufferReader reader(annexb_buffer, annexb_buffer_size); | |
280 CMVideoFormatDescriptionRef description = nullptr; | |
281 OSStatus status = noErr; | |
282 // Parse the SPS and PPS into a CMVideoFormatDescription. | |
283 const uint8_t* param_set_ptrs[2] = {}; | |
284 size_t param_set_sizes[2] = {}; | |
285 // Skip AUD. | |
286 if (ParseNaluType(annexb_buffer[4]) == kAud) { | |
287 if (!reader.ReadNalu(¶m_set_ptrs[0], ¶m_set_sizes[0])) { | |
288 LOG(LS_ERROR) << "Failed to read AUD"; | |
289 return nullptr; | |
290 } | |
291 } | |
292 if (!reader.ReadNalu(¶m_set_ptrs[0], ¶m_set_sizes[0])) { | |
293 LOG(LS_ERROR) << "Failed to read SPS"; | |
294 return nullptr; | |
295 } | |
296 if (!reader.ReadNalu(¶m_set_ptrs[1], ¶m_set_sizes[1])) { | |
297 LOG(LS_ERROR) << "Failed to read PPS"; | |
298 return nullptr; | |
299 } | |
300 status = CMVideoFormatDescriptionCreateFromH264ParameterSets( | |
301 kCFAllocatorDefault, 2, param_set_ptrs, param_set_sizes, 4, | |
302 &description); | |
303 if (status != noErr) { | |
304 LOG(LS_ERROR) << "Failed to create video format description."; | |
305 return nullptr; | |
306 } | |
307 return description; | |
308 } | |
309 | |
310 AnnexBBufferReader::AnnexBBufferReader(const uint8_t* annexb_buffer, | |
311 size_t length) | |
312 : start_(annexb_buffer), length_(length) { | |
313 RTC_DCHECK(annexb_buffer); | |
314 offsets_ = H264::FindNaluIndices(annexb_buffer, length); | |
315 offset_ = offsets_.begin(); | |
316 } | |
317 | |
318 bool AnnexBBufferReader::ReadNalu(const uint8_t** out_nalu, | |
319 size_t* out_length) { | |
320 RTC_DCHECK(out_nalu); | |
321 RTC_DCHECK(out_length); | |
322 *out_nalu = nullptr; | |
323 *out_length = 0; | |
324 | |
325 if (offset_ == offsets_.end()) { | |
326 return false; | |
327 } | |
328 *out_nalu = start_ + offset_->payload_start_offset; | |
329 *out_length = offset_->payload_size; | |
330 ++offset_; | |
331 return true; | |
332 } | |
333 | |
334 size_t AnnexBBufferReader::BytesRemaining() const { | |
335 if (offset_ == offsets_.end()) { | |
336 return 0; | |
337 } | |
338 return length_ - offset_->start_offset; | |
339 } | |
340 | |
341 AvccBufferWriter::AvccBufferWriter(uint8_t* const avcc_buffer, size_t length) | |
342 : start_(avcc_buffer), offset_(0), length_(length) { | |
343 RTC_DCHECK(avcc_buffer); | |
344 } | |
345 | |
346 bool AvccBufferWriter::WriteNalu(const uint8_t* data, size_t data_size) { | |
347 // Check if we can write this length of data. | |
348 if (data_size + kAvccHeaderByteSize > BytesRemaining()) { | |
349 return false; | |
350 } | |
351 // Write length header, which needs to be big endian. | |
352 uint32_t big_endian_length = CFSwapInt32HostToBig(data_size); | |
353 memcpy(start_ + offset_, &big_endian_length, sizeof(big_endian_length)); | |
354 offset_ += sizeof(big_endian_length); | |
355 // Write data. | |
356 memcpy(start_ + offset_, data, data_size); | |
357 offset_ += data_size; | |
358 return true; | |
359 } | |
360 | |
361 size_t AvccBufferWriter::BytesRemaining() const { | |
362 return length_ - offset_; | |
363 } | |
364 | |
365 } // namespace webrtc | |
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