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1 // Copyright 2014 The Chromium Authors. All rights reserved. | 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 | 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 <stddef.h> | 5 #include <stddef.h> |
6 | 6 |
7 #include <algorithm> | 7 #include <algorithm> |
8 | 8 |
9 #include "base/logging.h" | 9 #include "base/logging.h" |
10 #include "base/macros.h" | 10 #include "base/macros.h" |
11 #include "media/filters/h264_parser.h" | 11 #include "media/filters/h264_parser.h" |
12 #include "media/video/h264_poc.h" | 12 #include "media/video/h264_poc.h" |
13 | 13 |
14 namespace media { | 14 namespace media { |
15 | 15 |
16 H264POC::H264POC() { | 16 namespace { |
17 Reset(); | |
18 } | |
19 | |
20 H264POC::~H264POC() { | |
21 } | |
22 | |
23 void H264POC::Reset() { | |
24 // It shouldn't be necessary to reset these values, but doing so will improve | |
25 // reproducibility for buggy streams. | |
26 ref_pic_order_cnt_msb_ = 0; | |
27 ref_pic_order_cnt_lsb_ = 0; | |
28 prev_frame_num_ = 0; | |
29 prev_frame_num_offset_ = 0; | |
30 } | |
31 | 17 |
32 // Check if a slice includes memory management control operation 5, which | 18 // Check if a slice includes memory management control operation 5, which |
33 // results in some |pic_order_cnt| state being cleared. | 19 // results in some |pic_order_cnt| state being cleared. |
34 static bool HasMMCO5(const media::H264SliceHeader& slice_hdr) { | 20 bool HasMMCO5(const media::H264SliceHeader& slice_hdr) { |
35 // Require that the frame actually has memory management control operations. | 21 // Require that the frame actually has memory management control operations. |
36 if (slice_hdr.nal_ref_idc == 0 || | 22 if (slice_hdr.nal_ref_idc == 0 || |
37 slice_hdr.idr_pic_flag || | 23 slice_hdr.idr_pic_flag || |
38 !slice_hdr.adaptive_ref_pic_marking_mode_flag) { | 24 !slice_hdr.adaptive_ref_pic_marking_mode_flag) { |
39 return false; | 25 return false; |
40 } | 26 } |
41 | 27 |
42 for (size_t i = 0; i < arraysize(slice_hdr.ref_pic_marking); i++) { | 28 for (size_t i = 0; i < arraysize(slice_hdr.ref_pic_marking); i++) { |
43 int32_t op = slice_hdr.ref_pic_marking[i].memory_mgmnt_control_operation; | 29 int32_t op = slice_hdr.ref_pic_marking[i].memory_mgmnt_control_operation; |
44 if (op == 5) | 30 if (op == 5) |
45 return true; | 31 return true; |
46 | 32 |
47 // Stop at the end of the list. | 33 // Stop at the end of the list. |
48 if (op == 0) | 34 if (op == 0) |
49 return false; | 35 return false; |
50 } | 36 } |
51 | 37 |
52 // Should not get here, the list is always zero terminated. | 38 // Should not get here, the list is always zero terminated. |
53 return false; | 39 return false; |
54 } | 40 } |
55 | 41 |
| 42 } // namespace |
| 43 |
| 44 H264POC::H264POC() { |
| 45 Reset(); |
| 46 } |
| 47 |
| 48 H264POC::~H264POC() {} |
| 49 |
| 50 void H264POC::Reset() { |
| 51 // It shouldn't be necessary to reset these values, but doing so will improve |
| 52 // reproducibility for buggy streams. |
| 53 ref_pic_order_cnt_msb_ = 0; |
| 54 ref_pic_order_cnt_lsb_ = 0; |
| 55 prev_frame_num_ = 0; |
| 56 prev_frame_num_offset_ = 0; |
| 57 pending_mmco5_ = false; |
| 58 } |
| 59 |
56 bool H264POC::ComputePicOrderCnt( | 60 bool H264POC::ComputePicOrderCnt( |
57 const H264SPS* sps, | 61 const H264SPS* sps, |
58 const H264SliceHeader& slice_hdr, | 62 const H264SliceHeader& slice_hdr, |
59 int32_t *pic_order_cnt) { | 63 int32_t *pic_order_cnt) { |
60 if (slice_hdr.field_pic_flag) { | 64 if (slice_hdr.field_pic_flag) { |
61 DLOG(ERROR) << "Interlaced frames are not supported"; | 65 DLOG(ERROR) << "Interlaced frames are not supported"; |
62 return false; | 66 return false; |
63 } | 67 } |
64 | 68 |
65 bool mmco5 = HasMMCO5(slice_hdr); | 69 bool mmco5 = HasMMCO5(slice_hdr); |
66 int32_t max_frame_num = 1 << (sps->log2_max_frame_num_minus4 + 4); | 70 int32_t max_frame_num = 1 << (sps->log2_max_frame_num_minus4 + 4); |
67 int32_t max_pic_order_cnt_lsb = | 71 int32_t max_pic_order_cnt_lsb = |
68 1 << (sps->log2_max_pic_order_cnt_lsb_minus4 + 4); | 72 1 << (sps->log2_max_pic_order_cnt_lsb_minus4 + 4); |
69 | 73 |
70 // Note: Duplicate frame numbers are ignored. They occur in many videos | |
71 // despite appearing to be invalid according to the spec. | |
72 // TODO(sandersd): Check if these videos are using slices or have redundant | |
73 // streams. | |
74 | |
75 // Note: Gaps in frame numbers are also ignored. They do not affect POC | |
76 // computation. | |
77 | |
78 // Based on T-REC-H.264 8.2.1, "Decoding process for picture order | 74 // Based on T-REC-H.264 8.2.1, "Decoding process for picture order |
79 // count", available from http://www.itu.int/rec/T-REC-H.264. | 75 // count", available from http://www.itu.int/rec/T-REC-H.264. |
80 // | 76 // |
81 // Reorganized slightly from spec pseudocode to handle MMCO5 when storing | 77 // Reorganized slightly from spec pseudocode to handle MMCO5 when storing |
82 // state instead of when loading it. | 78 // state instead of when loading it. |
| 79 // |
| 80 // Note: Gaps in frame numbers are ignored. They do not affect POC |
| 81 // computation. |
83 switch (sps->pic_order_cnt_type) { | 82 switch (sps->pic_order_cnt_type) { |
84 case 0: { | 83 case 0: { |
85 int32_t prev_pic_order_cnt_msb = ref_pic_order_cnt_msb_; | 84 int32_t prev_pic_order_cnt_msb = ref_pic_order_cnt_msb_; |
86 int32_t prev_pic_order_cnt_lsb = ref_pic_order_cnt_lsb_; | 85 int32_t prev_pic_order_cnt_lsb = ref_pic_order_cnt_lsb_; |
87 | 86 |
88 // For an IDR picture, clear the state. | 87 // For an IDR picture, clear the state. |
89 if (slice_hdr.idr_pic_flag) { | 88 if (slice_hdr.idr_pic_flag) { |
90 prev_pic_order_cnt_msb = 0; | 89 prev_pic_order_cnt_msb = 0; |
91 prev_pic_order_cnt_lsb = 0; | 90 prev_pic_order_cnt_lsb = 0; |
92 } | 91 } |
(...skipping 11 matching lines...) Expand all Loading... |
104 max_pic_order_cnt_lsb / 2)) { | 103 max_pic_order_cnt_lsb / 2)) { |
105 pic_order_cnt_msb = prev_pic_order_cnt_msb - max_pic_order_cnt_lsb; | 104 pic_order_cnt_msb = prev_pic_order_cnt_msb - max_pic_order_cnt_lsb; |
106 } else { | 105 } else { |
107 pic_order_cnt_msb = prev_pic_order_cnt_msb; | 106 pic_order_cnt_msb = prev_pic_order_cnt_msb; |
108 } | 107 } |
109 | 108 |
110 // 8-4, 8-5. Derive |top_field_order_count| and |bottom_field_order_cnt| | 109 // 8-4, 8-5. Derive |top_field_order_count| and |bottom_field_order_cnt| |
111 // (assuming no interlacing). | 110 // (assuming no interlacing). |
112 int32_t top_foc = pic_order_cnt_msb + slice_hdr.pic_order_cnt_lsb; | 111 int32_t top_foc = pic_order_cnt_msb + slice_hdr.pic_order_cnt_lsb; |
113 int32_t bottom_foc = top_foc + slice_hdr.delta_pic_order_cnt_bottom; | 112 int32_t bottom_foc = top_foc + slice_hdr.delta_pic_order_cnt_bottom; |
114 *pic_order_cnt = std::min(top_foc, bottom_foc); | 113 |
| 114 // Compute POC. |
| 115 // |
| 116 // MMCO5, like IDR, starts a new reordering group. The POC is specified to |
| 117 // change to 0 after decoding; we change it immediately and set the |
| 118 // |pending_mmco5_| flag. |
| 119 if (mmco5) |
| 120 *pic_order_cnt = 0; |
| 121 else |
| 122 *pic_order_cnt = std::min(top_foc, bottom_foc); |
115 | 123 |
116 // Store state. | 124 // Store state. |
| 125 pending_mmco5_ = mmco5; |
117 prev_frame_num_ = slice_hdr.frame_num; | 126 prev_frame_num_ = slice_hdr.frame_num; |
118 if (slice_hdr.nal_ref_idc != 0) { | 127 if (slice_hdr.nal_ref_idc != 0) { |
119 if (mmco5) { | 128 if (mmco5) { |
120 ref_pic_order_cnt_msb_ = 0; | 129 ref_pic_order_cnt_msb_ = 0; |
121 ref_pic_order_cnt_lsb_ = top_foc; | 130 ref_pic_order_cnt_lsb_ = top_foc; |
122 } else { | 131 } else { |
123 ref_pic_order_cnt_msb_ = pic_order_cnt_msb; | 132 ref_pic_order_cnt_msb_ = pic_order_cnt_msb; |
124 ref_pic_order_cnt_lsb_ = slice_hdr.pic_order_cnt_lsb; | 133 ref_pic_order_cnt_lsb_ = slice_hdr.pic_order_cnt_lsb; |
125 } | 134 } |
126 } | 135 } |
(...skipping 46 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
173 expected_pic_order_cnt += sps->offset_for_ref_frame[i]; | 182 expected_pic_order_cnt += sps->offset_for_ref_frame[i]; |
174 } | 183 } |
175 if (slice_hdr.nal_ref_idc == 0) | 184 if (slice_hdr.nal_ref_idc == 0) |
176 expected_pic_order_cnt += sps->offset_for_non_ref_pic; | 185 expected_pic_order_cnt += sps->offset_for_non_ref_pic; |
177 | 186 |
178 // 8-10. Derive |top_field_order_cnt| and |bottom_field_order_cnt| | 187 // 8-10. Derive |top_field_order_cnt| and |bottom_field_order_cnt| |
179 // (assuming no interlacing). | 188 // (assuming no interlacing). |
180 int32_t top_foc = expected_pic_order_cnt + slice_hdr.delta_pic_order_cnt0; | 189 int32_t top_foc = expected_pic_order_cnt + slice_hdr.delta_pic_order_cnt0; |
181 int32_t bottom_foc = top_foc + sps->offset_for_top_to_bottom_field + | 190 int32_t bottom_foc = top_foc + sps->offset_for_top_to_bottom_field + |
182 slice_hdr.delta_pic_order_cnt1; | 191 slice_hdr.delta_pic_order_cnt1; |
183 *pic_order_cnt = std::min(top_foc, bottom_foc); | 192 |
| 193 // Compute POC. MMCO5 handling is the same as |pic_order_cnt_type| == 0. |
| 194 if (mmco5) |
| 195 *pic_order_cnt = 0; |
| 196 else |
| 197 *pic_order_cnt = std::min(top_foc, bottom_foc); |
184 | 198 |
185 // Store state. | 199 // Store state. |
| 200 pending_mmco5_ = mmco5; |
186 prev_frame_num_ = slice_hdr.frame_num; | 201 prev_frame_num_ = slice_hdr.frame_num; |
187 prev_frame_num_offset_ = frame_num_offset; | |
188 if (mmco5) | 202 if (mmco5) |
189 prev_frame_num_offset_ = 0; | 203 prev_frame_num_offset_ = 0; |
| 204 else |
| 205 prev_frame_num_offset_ = frame_num_offset; |
190 | 206 |
191 break; | 207 break; |
192 } | 208 } |
193 | 209 |
194 case 2: { | 210 case 2: { |
195 // 8-11. Derive |frame_num_offset|. | 211 // 8-11. Derive |frame_num_offset|. |
196 int32_t frame_num_offset; | 212 int32_t frame_num_offset; |
197 if (slice_hdr.idr_pic_flag) | 213 if (slice_hdr.idr_pic_flag) |
198 frame_num_offset = 0; | 214 frame_num_offset = 0; |
199 else if (prev_frame_num_ > slice_hdr.frame_num) | 215 else if (prev_frame_num_ > slice_hdr.frame_num) |
200 frame_num_offset = prev_frame_num_offset_ + max_frame_num; | 216 frame_num_offset = prev_frame_num_offset_ + max_frame_num; |
201 else | 217 else |
202 frame_num_offset = prev_frame_num_offset_; | 218 frame_num_offset = prev_frame_num_offset_; |
203 | 219 |
204 // 8-12, 8-13. Derive |temp_pic_order_count| (it's always the | 220 // 8-12, 8-13. Derive |temp_pic_order_count| (it's always the |
205 // |pic_order_cnt|, regardless of interlacing). | 221 // |pic_order_cnt|, regardless of interlacing). |
| 222 int32_t temp_pic_order_count; |
206 if (slice_hdr.idr_pic_flag) | 223 if (slice_hdr.idr_pic_flag) |
| 224 temp_pic_order_count = 0; |
| 225 else if (slice_hdr.nal_ref_idc == 0) |
| 226 temp_pic_order_count = 2 * (frame_num_offset + slice_hdr.frame_num) - 1; |
| 227 else |
| 228 temp_pic_order_count = 2 * (frame_num_offset + slice_hdr.frame_num); |
| 229 |
| 230 // Compute POC. MMCO5 handling is the same as |pic_order_cnt_type| == 0. |
| 231 if (mmco5) |
207 *pic_order_cnt = 0; | 232 *pic_order_cnt = 0; |
208 else if (slice_hdr.nal_ref_idc == 0) | |
209 *pic_order_cnt = 2 * (frame_num_offset + slice_hdr.frame_num) - 1; | |
210 else | 233 else |
211 *pic_order_cnt = 2 * (frame_num_offset + slice_hdr.frame_num); | 234 *pic_order_cnt = temp_pic_order_count; |
212 | 235 |
213 // Store state. | 236 // Store state. |
| 237 pending_mmco5_ = mmco5; |
214 prev_frame_num_ = slice_hdr.frame_num; | 238 prev_frame_num_ = slice_hdr.frame_num; |
215 prev_frame_num_offset_ = frame_num_offset; | |
216 if (mmco5) | 239 if (mmco5) |
217 prev_frame_num_offset_ = 0; | 240 prev_frame_num_offset_ = 0; |
| 241 else |
| 242 prev_frame_num_offset_ = frame_num_offset; |
218 | 243 |
219 break; | 244 break; |
220 } | 245 } |
221 | 246 |
222 default: | 247 default: |
223 DLOG(ERROR) << "Invalid pic_order_cnt_type: " << sps->pic_order_cnt_type; | 248 DLOG(ERROR) << "Invalid pic_order_cnt_type: " << sps->pic_order_cnt_type; |
224 return false; | 249 return false; |
225 } | 250 } |
226 | 251 |
227 return true; | 252 return true; |
228 } | 253 } |
229 | 254 |
230 } // namespace media | 255 } // namespace media |
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