/
NalUnitUtil.java
890 lines (834 loc) · 35.8 KB
/
NalUnitUtil.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.android.exoplayer2.util;
import static java.lang.Math.min;
import androidx.annotation.Nullable;
import com.google.android.exoplayer2.C;
import java.nio.ByteBuffer;
import java.util.Arrays;
/** Utility methods for handling H.264/AVC and H.265/HEVC NAL units. */
public final class NalUnitUtil {
private static final String TAG = "NalUnitUtil";
/** Coded slice of a non-IDR picture. */
public static final int NAL_UNIT_TYPE_NON_IDR = 1;
/** Coded slice data partition A. */
public static final int NAL_UNIT_TYPE_PARTITION_A = 2;
/** Coded slice of an IDR picture. */
public static final int NAL_UNIT_TYPE_IDR = 5;
/** Supplemental enhancement information. */
public static final int NAL_UNIT_TYPE_SEI = 6;
/** Sequence parameter set. */
public static final int NAL_UNIT_TYPE_SPS = 7;
/** Picture parameter set. */
public static final int NAL_UNIT_TYPE_PPS = 8;
/** Access unit delimiter. */
public static final int NAL_UNIT_TYPE_AUD = 9;
/** Holds data parsed from a H.264 sequence parameter set NAL unit. */
public static final class SpsData {
public final int profileIdc;
public final int constraintsFlagsAndReservedZero2Bits;
public final int levelIdc;
public final int seqParameterSetId;
public final int maxNumRefFrames;
public final int width;
public final int height;
public final float pixelWidthHeightRatio;
public final boolean separateColorPlaneFlag;
public final boolean frameMbsOnlyFlag;
public final int frameNumLength;
public final int picOrderCountType;
public final int picOrderCntLsbLength;
public final boolean deltaPicOrderAlwaysZeroFlag;
public SpsData(
int profileIdc,
int constraintsFlagsAndReservedZero2Bits,
int levelIdc,
int seqParameterSetId,
int maxNumRefFrames,
int width,
int height,
float pixelWidthHeightRatio,
boolean separateColorPlaneFlag,
boolean frameMbsOnlyFlag,
int frameNumLength,
int picOrderCountType,
int picOrderCntLsbLength,
boolean deltaPicOrderAlwaysZeroFlag) {
this.profileIdc = profileIdc;
this.constraintsFlagsAndReservedZero2Bits = constraintsFlagsAndReservedZero2Bits;
this.levelIdc = levelIdc;
this.seqParameterSetId = seqParameterSetId;
this.maxNumRefFrames = maxNumRefFrames;
this.width = width;
this.height = height;
this.pixelWidthHeightRatio = pixelWidthHeightRatio;
this.separateColorPlaneFlag = separateColorPlaneFlag;
this.frameMbsOnlyFlag = frameMbsOnlyFlag;
this.frameNumLength = frameNumLength;
this.picOrderCountType = picOrderCountType;
this.picOrderCntLsbLength = picOrderCntLsbLength;
this.deltaPicOrderAlwaysZeroFlag = deltaPicOrderAlwaysZeroFlag;
}
}
/** Holds data parsed from a H.265 sequence parameter set NAL unit. */
public static final class H265SpsData {
public final int generalProfileSpace;
public final boolean generalTierFlag;
public final int generalProfileIdc;
public final int generalProfileCompatibilityFlags;
public final int[] constraintBytes;
public final int generalLevelIdc;
public final int seqParameterSetId;
public final int width;
public final int height;
public final float pixelWidthHeightRatio;
public H265SpsData(
int generalProfileSpace,
boolean generalTierFlag,
int generalProfileIdc,
int generalProfileCompatibilityFlags,
int[] constraintBytes,
int generalLevelIdc,
int seqParameterSetId,
int width,
int height,
float pixelWidthHeightRatio) {
this.generalProfileSpace = generalProfileSpace;
this.generalTierFlag = generalTierFlag;
this.generalProfileIdc = generalProfileIdc;
this.generalProfileCompatibilityFlags = generalProfileCompatibilityFlags;
this.constraintBytes = constraintBytes;
this.generalLevelIdc = generalLevelIdc;
this.seqParameterSetId = seqParameterSetId;
this.width = width;
this.height = height;
this.pixelWidthHeightRatio = pixelWidthHeightRatio;
}
}
/** Holds data parsed from a picture parameter set NAL unit. */
public static final class PpsData {
public final int picParameterSetId;
public final int seqParameterSetId;
public final boolean bottomFieldPicOrderInFramePresentFlag;
public PpsData(
int picParameterSetId,
int seqParameterSetId,
boolean bottomFieldPicOrderInFramePresentFlag) {
this.picParameterSetId = picParameterSetId;
this.seqParameterSetId = seqParameterSetId;
this.bottomFieldPicOrderInFramePresentFlag = bottomFieldPicOrderInFramePresentFlag;
}
}
/** Four initial bytes that must prefix NAL units for decoding. */
public static final byte[] NAL_START_CODE = new byte[] {0, 0, 0, 1};
/** Value for aspect_ratio_idc indicating an extended aspect ratio, in H.264 and H.265 SPSs. */
public static final int EXTENDED_SAR = 0xFF;
/** Aspect ratios indexed by aspect_ratio_idc, in H.264 and H.265 SPSs. */
public static final float[] ASPECT_RATIO_IDC_VALUES =
new float[] {
1f /* Unspecified. Assume square */,
1f,
12f / 11f,
10f / 11f,
16f / 11f,
40f / 33f,
24f / 11f,
20f / 11f,
32f / 11f,
80f / 33f,
18f / 11f,
15f / 11f,
64f / 33f,
160f / 99f,
4f / 3f,
3f / 2f,
2f
};
private static final int H264_NAL_UNIT_TYPE_SEI = 6; // Supplemental enhancement information
private static final int H264_NAL_UNIT_TYPE_SPS = 7; // Sequence parameter set
private static final int H265_NAL_UNIT_TYPE_PREFIX_SEI = 39;
private static final Object scratchEscapePositionsLock = new Object();
/**
* Temporary store for positions of escape codes in {@link #unescapeStream(byte[], int)}. Guarded
* by {@link #scratchEscapePositionsLock}.
*/
private static int[] scratchEscapePositions = new int[10];
/**
* Unescapes {@code data} up to the specified limit, replacing occurrences of [0, 0, 3] with [0,
* 0]. The unescaped data is returned in-place, with the return value indicating its length.
*
* <p>Executions of this method are mutually exclusive, so it should not be called with very large
* buffers.
*
* @param data The data to unescape.
* @param limit The limit (exclusive) of the data to unescape.
* @return The length of the unescaped data.
*/
public static int unescapeStream(byte[] data, int limit) {
synchronized (scratchEscapePositionsLock) {
int position = 0;
int scratchEscapeCount = 0;
while (position < limit) {
position = findNextUnescapeIndex(data, position, limit);
if (position < limit) {
if (scratchEscapePositions.length <= scratchEscapeCount) {
// Grow scratchEscapePositions to hold a larger number of positions.
scratchEscapePositions =
Arrays.copyOf(scratchEscapePositions, scratchEscapePositions.length * 2);
}
scratchEscapePositions[scratchEscapeCount++] = position;
position += 3;
}
}
int unescapedLength = limit - scratchEscapeCount;
int escapedPosition = 0; // The position being read from.
int unescapedPosition = 0; // The position being written to.
for (int i = 0; i < scratchEscapeCount; i++) {
int nextEscapePosition = scratchEscapePositions[i];
int copyLength = nextEscapePosition - escapedPosition;
System.arraycopy(data, escapedPosition, data, unescapedPosition, copyLength);
unescapedPosition += copyLength;
data[unescapedPosition++] = 0;
data[unescapedPosition++] = 0;
escapedPosition += copyLength + 3;
}
int remainingLength = unescapedLength - unescapedPosition;
System.arraycopy(data, escapedPosition, data, unescapedPosition, remainingLength);
return unescapedLength;
}
}
/**
* Discards data from the buffer up to the first SPS, where {@code data.position()} is interpreted
* as the length of the buffer.
*
* <p>When the method returns, {@code data.position()} will contain the new length of the buffer.
* If the buffer is not empty it is guaranteed to start with an SPS.
*
* @param data Buffer containing start code delimited NAL units.
*/
public static void discardToSps(ByteBuffer data) {
int length = data.position();
int consecutiveZeros = 0;
int offset = 0;
while (offset + 1 < length) {
int value = data.get(offset) & 0xFF;
if (consecutiveZeros == 3) {
if (value == 1 && (data.get(offset + 1) & 0x1F) == H264_NAL_UNIT_TYPE_SPS) {
// Copy from this NAL unit onwards to the start of the buffer.
ByteBuffer offsetData = data.duplicate();
offsetData.position(offset - 3);
offsetData.limit(length);
data.position(0);
data.put(offsetData);
return;
}
} else if (value == 0) {
consecutiveZeros++;
}
if (value != 0) {
consecutiveZeros = 0;
}
offset++;
}
// Empty the buffer if the SPS NAL unit was not found.
data.clear();
}
/**
* Returns whether the NAL unit with the specified header contains supplemental enhancement
* information.
*
* @param mimeType The sample MIME type, or {@code null} if unknown.
* @param nalUnitHeaderFirstByte The first byte of nal_unit().
* @return Whether the NAL unit with the specified header is an SEI NAL unit. False is returned if
* the {@code MimeType} is {@code null}.
*/
public static boolean isNalUnitSei(@Nullable String mimeType, byte nalUnitHeaderFirstByte) {
return (MimeTypes.VIDEO_H264.equals(mimeType)
&& (nalUnitHeaderFirstByte & 0x1F) == H264_NAL_UNIT_TYPE_SEI)
|| (MimeTypes.VIDEO_H265.equals(mimeType)
&& ((nalUnitHeaderFirstByte & 0x7E) >> 1) == H265_NAL_UNIT_TYPE_PREFIX_SEI);
}
/**
* Returns the type of the NAL unit in {@code data} that starts at {@code offset}.
*
* @param data The data to search.
* @param offset The start offset of a NAL unit. Must lie between {@code -3} (inclusive) and
* {@code data.length - 3} (exclusive).
* @return The type of the unit.
*/
public static int getNalUnitType(byte[] data, int offset) {
return data[offset + 3] & 0x1F;
}
/**
* Returns the type of the H.265 NAL unit in {@code data} that starts at {@code offset}.
*
* @param data The data to search.
* @param offset The start offset of a NAL unit. Must lie between {@code -3} (inclusive) and
* {@code data.length - 3} (exclusive).
* @return The type of the unit.
*/
public static int getH265NalUnitType(byte[] data, int offset) {
return (data[offset + 3] & 0x7E) >> 1;
}
/**
* Parses a SPS NAL unit using the syntax defined in ITU-T Recommendation H.264 (2013) subsection
* 7.3.2.1.1.
*
* @param nalData A buffer containing escaped SPS data.
* @param nalOffset The offset of the NAL unit header in {@code nalData}.
* @param nalLimit The limit of the NAL unit in {@code nalData}.
* @return A parsed representation of the SPS data.
*/
public static SpsData parseSpsNalUnit(byte[] nalData, int nalOffset, int nalLimit) {
return parseSpsNalUnitPayload(nalData, nalOffset + 1, nalLimit);
}
/**
* Parses a SPS NAL unit payload (excluding the NAL unit header) using the syntax defined in ITU-T
* Recommendation H.264 (2013) subsection 7.3.2.1.1.
*
* @param nalData A buffer containing escaped SPS data.
* @param nalOffset The offset of the NAL unit payload in {@code nalData}.
* @param nalLimit The limit of the NAL unit in {@code nalData}.
* @return A parsed representation of the SPS data.
*/
public static SpsData parseSpsNalUnitPayload(byte[] nalData, int nalOffset, int nalLimit) {
ParsableNalUnitBitArray data = new ParsableNalUnitBitArray(nalData, nalOffset, nalLimit);
int profileIdc = data.readBits(8);
int constraintsFlagsAndReservedZero2Bits = data.readBits(8);
int levelIdc = data.readBits(8);
int seqParameterSetId = data.readUnsignedExpGolombCodedInt();
int chromaFormatIdc = 1; // Default is 4:2:0
boolean separateColorPlaneFlag = false;
if (profileIdc == 100
|| profileIdc == 110
|| profileIdc == 122
|| profileIdc == 244
|| profileIdc == 44
|| profileIdc == 83
|| profileIdc == 86
|| profileIdc == 118
|| profileIdc == 128
|| profileIdc == 138) {
chromaFormatIdc = data.readUnsignedExpGolombCodedInt();
if (chromaFormatIdc == 3) {
separateColorPlaneFlag = data.readBit();
}
data.readUnsignedExpGolombCodedInt(); // bit_depth_luma_minus8
data.readUnsignedExpGolombCodedInt(); // bit_depth_chroma_minus8
data.skipBit(); // qpprime_y_zero_transform_bypass_flag
boolean seqScalingMatrixPresentFlag = data.readBit();
if (seqScalingMatrixPresentFlag) {
int limit = (chromaFormatIdc != 3) ? 8 : 12;
for (int i = 0; i < limit; i++) {
boolean seqScalingListPresentFlag = data.readBit();
if (seqScalingListPresentFlag) {
skipScalingList(data, i < 6 ? 16 : 64);
}
}
}
}
int frameNumLength = data.readUnsignedExpGolombCodedInt() + 4; // log2_max_frame_num_minus4 + 4
int picOrderCntType = data.readUnsignedExpGolombCodedInt();
int picOrderCntLsbLength = 0;
boolean deltaPicOrderAlwaysZeroFlag = false;
if (picOrderCntType == 0) {
// log2_max_pic_order_cnt_lsb_minus4 + 4
picOrderCntLsbLength = data.readUnsignedExpGolombCodedInt() + 4;
} else if (picOrderCntType == 1) {
deltaPicOrderAlwaysZeroFlag = data.readBit(); // delta_pic_order_always_zero_flag
data.readSignedExpGolombCodedInt(); // offset_for_non_ref_pic
data.readSignedExpGolombCodedInt(); // offset_for_top_to_bottom_field
long numRefFramesInPicOrderCntCycle = data.readUnsignedExpGolombCodedInt();
for (int i = 0; i < numRefFramesInPicOrderCntCycle; i++) {
data.readUnsignedExpGolombCodedInt(); // offset_for_ref_frame[i]
}
}
int maxNumRefFrames = data.readUnsignedExpGolombCodedInt(); // max_num_ref_frames
data.skipBit(); // gaps_in_frame_num_value_allowed_flag
int picWidthInMbs = data.readUnsignedExpGolombCodedInt() + 1;
int picHeightInMapUnits = data.readUnsignedExpGolombCodedInt() + 1;
boolean frameMbsOnlyFlag = data.readBit();
int frameHeightInMbs = (2 - (frameMbsOnlyFlag ? 1 : 0)) * picHeightInMapUnits;
if (!frameMbsOnlyFlag) {
data.skipBit(); // mb_adaptive_frame_field_flag
}
data.skipBit(); // direct_8x8_inference_flag
int frameWidth = picWidthInMbs * 16;
int frameHeight = frameHeightInMbs * 16;
boolean frameCroppingFlag = data.readBit();
if (frameCroppingFlag) {
int frameCropLeftOffset = data.readUnsignedExpGolombCodedInt();
int frameCropRightOffset = data.readUnsignedExpGolombCodedInt();
int frameCropTopOffset = data.readUnsignedExpGolombCodedInt();
int frameCropBottomOffset = data.readUnsignedExpGolombCodedInt();
int cropUnitX;
int cropUnitY;
if (chromaFormatIdc == 0) {
cropUnitX = 1;
cropUnitY = 2 - (frameMbsOnlyFlag ? 1 : 0);
} else {
int subWidthC = (chromaFormatIdc == 3) ? 1 : 2;
int subHeightC = (chromaFormatIdc == 1) ? 2 : 1;
cropUnitX = subWidthC;
cropUnitY = subHeightC * (2 - (frameMbsOnlyFlag ? 1 : 0));
}
frameWidth -= (frameCropLeftOffset + frameCropRightOffset) * cropUnitX;
frameHeight -= (frameCropTopOffset + frameCropBottomOffset) * cropUnitY;
}
float pixelWidthHeightRatio = 1;
boolean vuiParametersPresentFlag = data.readBit();
if (vuiParametersPresentFlag) {
boolean aspectRatioInfoPresentFlag = data.readBit();
if (aspectRatioInfoPresentFlag) {
int aspectRatioIdc = data.readBits(8);
if (aspectRatioIdc == NalUnitUtil.EXTENDED_SAR) {
int sarWidth = data.readBits(16);
int sarHeight = data.readBits(16);
if (sarWidth != 0 && sarHeight != 0) {
pixelWidthHeightRatio = (float) sarWidth / sarHeight;
}
} else if (aspectRatioIdc < NalUnitUtil.ASPECT_RATIO_IDC_VALUES.length) {
pixelWidthHeightRatio = NalUnitUtil.ASPECT_RATIO_IDC_VALUES[aspectRatioIdc];
} else {
Log.w(TAG, "Unexpected aspect_ratio_idc value: " + aspectRatioIdc);
}
}
}
return new SpsData(
profileIdc,
constraintsFlagsAndReservedZero2Bits,
levelIdc,
seqParameterSetId,
maxNumRefFrames,
frameWidth,
frameHeight,
pixelWidthHeightRatio,
separateColorPlaneFlag,
frameMbsOnlyFlag,
frameNumLength,
picOrderCntType,
picOrderCntLsbLength,
deltaPicOrderAlwaysZeroFlag);
}
/**
* Parses a H.265 SPS NAL unit using the syntax defined in ITU-T Recommendation H.265 (2019)
* subsection 7.3.2.2.1.
*
* @param nalData A buffer containing escaped SPS data.
* @param nalOffset The offset of the NAL unit header in {@code nalData}.
* @param nalLimit The limit of the NAL unit in {@code nalData}.
* @return A parsed representation of the SPS data.
*/
public static H265SpsData parseH265SpsNalUnit(byte[] nalData, int nalOffset, int nalLimit) {
return parseH265SpsNalUnitPayload(nalData, nalOffset + 2, nalLimit);
}
/**
* Parses a H.265 SPS NAL unit payload (excluding the NAL unit header) using the syntax defined in
* ITU-T Recommendation H.265 (2019) subsection 7.3.2.2.1.
*
* @param nalData A buffer containing escaped SPS data.
* @param nalOffset The offset of the NAL unit payload in {@code nalData}.
* @param nalLimit The limit of the NAL unit in {@code nalData}.
* @return A parsed representation of the SPS data.
*/
public static H265SpsData parseH265SpsNalUnitPayload(
byte[] nalData, int nalOffset, int nalLimit) {
ParsableNalUnitBitArray data = new ParsableNalUnitBitArray(nalData, nalOffset, nalLimit);
data.skipBits(4); // sps_video_parameter_set_id
int maxSubLayersMinus1 = data.readBits(3);
data.skipBit(); // sps_temporal_id_nesting_flag
int generalProfileSpace = data.readBits(2);
boolean generalTierFlag = data.readBit();
int generalProfileIdc = data.readBits(5);
int generalProfileCompatibilityFlags = 0;
for (int i = 0; i < 32; i++) {
if (data.readBit()) {
generalProfileCompatibilityFlags |= (1 << i);
}
}
int[] constraintBytes = new int[6];
for (int i = 0; i < constraintBytes.length; ++i) {
constraintBytes[i] = data.readBits(8);
}
int generalLevelIdc = data.readBits(8);
int toSkip = 0;
for (int i = 0; i < maxSubLayersMinus1; i++) {
if (data.readBit()) { // sub_layer_profile_present_flag[i]
toSkip += 89;
}
if (data.readBit()) { // sub_layer_level_present_flag[i]
toSkip += 8;
}
}
data.skipBits(toSkip);
if (maxSubLayersMinus1 > 0) {
data.skipBits(2 * (8 - maxSubLayersMinus1));
}
int seqParameterSetId = data.readUnsignedExpGolombCodedInt();
int chromaFormatIdc = data.readUnsignedExpGolombCodedInt();
if (chromaFormatIdc == 3) {
data.skipBit(); // separate_colour_plane_flag
}
int frameWidth = data.readUnsignedExpGolombCodedInt();
int frameHeight = data.readUnsignedExpGolombCodedInt();
if (data.readBit()) { // conformance_window_flag
int confWinLeftOffset = data.readUnsignedExpGolombCodedInt();
int confWinRightOffset = data.readUnsignedExpGolombCodedInt();
int confWinTopOffset = data.readUnsignedExpGolombCodedInt();
int confWinBottomOffset = data.readUnsignedExpGolombCodedInt();
// H.265/HEVC (2014) Table 6-1
int subWidthC = chromaFormatIdc == 1 || chromaFormatIdc == 2 ? 2 : 1;
int subHeightC = chromaFormatIdc == 1 ? 2 : 1;
frameWidth -= subWidthC * (confWinLeftOffset + confWinRightOffset);
frameHeight -= subHeightC * (confWinTopOffset + confWinBottomOffset);
}
data.readUnsignedExpGolombCodedInt(); // bit_depth_luma_minus8
data.readUnsignedExpGolombCodedInt(); // bit_depth_chroma_minus8
int log2MaxPicOrderCntLsbMinus4 = data.readUnsignedExpGolombCodedInt();
// for (i = sps_sub_layer_ordering_info_present_flag ? 0 : sps_max_sub_layers_minus1; ...)
for (int i = data.readBit() ? 0 : maxSubLayersMinus1; i <= maxSubLayersMinus1; i++) {
data.readUnsignedExpGolombCodedInt(); // sps_max_dec_pic_buffering_minus1[i]
data.readUnsignedExpGolombCodedInt(); // sps_max_num_reorder_pics[i]
data.readUnsignedExpGolombCodedInt(); // sps_max_latency_increase_plus1[i]
}
data.readUnsignedExpGolombCodedInt(); // log2_min_luma_coding_block_size_minus3
data.readUnsignedExpGolombCodedInt(); // log2_diff_max_min_luma_coding_block_size
data.readUnsignedExpGolombCodedInt(); // log2_min_luma_transform_block_size_minus2
data.readUnsignedExpGolombCodedInt(); // log2_diff_max_min_luma_transform_block_size
data.readUnsignedExpGolombCodedInt(); // max_transform_hierarchy_depth_inter
data.readUnsignedExpGolombCodedInt(); // max_transform_hierarchy_depth_intra
// if (scaling_list_enabled_flag) { if (sps_scaling_list_data_present_flag) {...}}
boolean scalingListEnabled = data.readBit();
if (scalingListEnabled && data.readBit()) {
skipH265ScalingList(data);
}
data.skipBits(2); // amp_enabled_flag (1), sample_adaptive_offset_enabled_flag (1)
if (data.readBit()) { // pcm_enabled_flag
// pcm_sample_bit_depth_luma_minus1 (4), pcm_sample_bit_depth_chroma_minus1 (4)
data.skipBits(8);
data.readUnsignedExpGolombCodedInt(); // log2_min_pcm_luma_coding_block_size_minus3
data.readUnsignedExpGolombCodedInt(); // log2_diff_max_min_pcm_luma_coding_block_size
data.skipBit(); // pcm_loop_filter_disabled_flag
}
skipShortTermReferencePictureSets(data);
if (data.readBit()) { // long_term_ref_pics_present_flag
// num_long_term_ref_pics_sps
for (int i = 0; i < data.readUnsignedExpGolombCodedInt(); i++) {
int ltRefPicPocLsbSpsLength = log2MaxPicOrderCntLsbMinus4 + 4;
// lt_ref_pic_poc_lsb_sps[i], used_by_curr_pic_lt_sps_flag[i]
data.skipBits(ltRefPicPocLsbSpsLength + 1);
}
}
data.skipBits(2); // sps_temporal_mvp_enabled_flag, strong_intra_smoothing_enabled_flag
float pixelWidthHeightRatio = 1;
if (data.readBit()) { // vui_parameters_present_flag
if (data.readBit()) { // aspect_ratio_info_present_flag
int aspectRatioIdc = data.readBits(8);
if (aspectRatioIdc == NalUnitUtil.EXTENDED_SAR) {
int sarWidth = data.readBits(16);
int sarHeight = data.readBits(16);
if (sarWidth != 0 && sarHeight != 0) {
pixelWidthHeightRatio = (float) sarWidth / sarHeight;
}
} else if (aspectRatioIdc < NalUnitUtil.ASPECT_RATIO_IDC_VALUES.length) {
pixelWidthHeightRatio = NalUnitUtil.ASPECT_RATIO_IDC_VALUES[aspectRatioIdc];
} else {
Log.w(TAG, "Unexpected aspect_ratio_idc value: " + aspectRatioIdc);
}
}
if (data.readBit()) { // overscan_info_present_flag
data.skipBit(); // overscan_appropriate_flag
}
if (data.readBit()) { // video_signal_type_present_flag
data.skipBits(4); // video_format, video_full_range_flag
if (data.readBit()) { // colour_description_present_flag
// colour_primaries, transfer_characteristics, matrix_coeffs
data.skipBits(24);
}
}
if (data.readBit()) { // chroma_loc_info_present_flag
data.readUnsignedExpGolombCodedInt(); // chroma_sample_loc_type_top_field
data.readUnsignedExpGolombCodedInt(); // chroma_sample_loc_type_bottom_field
}
data.skipBit(); // neutral_chroma_indication_flag
if (data.readBit()) { // field_seq_flag
// field_seq_flag equal to 1 indicates that the coded video sequence conveys pictures that
// represent fields, which means that frame height is double the picture height.
frameHeight *= 2;
}
}
return new H265SpsData(
generalProfileSpace,
generalTierFlag,
generalProfileIdc,
generalProfileCompatibilityFlags,
constraintBytes,
generalLevelIdc,
seqParameterSetId,
frameWidth,
frameHeight,
pixelWidthHeightRatio);
}
/**
* Parses a PPS NAL unit using the syntax defined in ITU-T Recommendation H.264 (2013) subsection
* 7.3.2.2.
*
* @param nalData A buffer containing escaped PPS data.
* @param nalOffset The offset of the NAL unit header in {@code nalData}.
* @param nalLimit The limit of the NAL unit in {@code nalData}.
* @return A parsed representation of the PPS data.
*/
public static PpsData parsePpsNalUnit(byte[] nalData, int nalOffset, int nalLimit) {
return parsePpsNalUnitPayload(nalData, nalOffset + 1, nalLimit);
}
/**
* Parses a PPS NAL unit payload (excluding the NAL unit header) using the syntax defined in ITU-T
* Recommendation H.264 (2013) subsection 7.3.2.2.
*
* @param nalData A buffer containing escaped PPS data.
* @param nalOffset The offset of the NAL unit payload in {@code nalData}.
* @param nalLimit The limit of the NAL unit in {@code nalData}.
* @return A parsed representation of the PPS data.
*/
public static PpsData parsePpsNalUnitPayload(byte[] nalData, int nalOffset, int nalLimit) {
ParsableNalUnitBitArray data = new ParsableNalUnitBitArray(nalData, nalOffset, nalLimit);
int picParameterSetId = data.readUnsignedExpGolombCodedInt();
int seqParameterSetId = data.readUnsignedExpGolombCodedInt();
data.skipBit(); // entropy_coding_mode_flag
boolean bottomFieldPicOrderInFramePresentFlag = data.readBit();
return new PpsData(picParameterSetId, seqParameterSetId, bottomFieldPicOrderInFramePresentFlag);
}
/**
* Finds the first NAL unit in {@code data}.
*
* <p>If {@code prefixFlags} is null then the first three bytes of a NAL unit must be entirely
* contained within the part of the array being searched in order for it to be found.
*
* <p>When {@code prefixFlags} is non-null, this method supports finding NAL units whose first
* four bytes span {@code data} arrays passed to successive calls. To use this feature, pass the
* same {@code prefixFlags} parameter to successive calls. State maintained in this parameter
* enables the detection of such NAL units. Note that when using this feature, the return value
* may be 3, 2 or 1 less than {@code startOffset}, to indicate a NAL unit starting 3, 2 or 1 bytes
* before the first byte in the current array.
*
* @param data The data to search.
* @param startOffset The offset (inclusive) in the data to start the search.
* @param endOffset The offset (exclusive) in the data to end the search.
* @param prefixFlags A boolean array whose first three elements are used to store the state
* required to detect NAL units where the NAL unit prefix spans array boundaries. The array
* must be at least 3 elements long.
* @return The offset of the NAL unit, or {@code endOffset} if a NAL unit was not found.
*/
public static int findNalUnit(
byte[] data, int startOffset, int endOffset, boolean[] prefixFlags) {
int length = endOffset - startOffset;
Assertions.checkState(length >= 0);
if (length == 0) {
return endOffset;
}
if (prefixFlags[0]) {
clearPrefixFlags(prefixFlags);
return startOffset - 3;
} else if (length > 1 && prefixFlags[1] && data[startOffset] == 1) {
clearPrefixFlags(prefixFlags);
return startOffset - 2;
} else if (length > 2
&& prefixFlags[2]
&& data[startOffset] == 0
&& data[startOffset + 1] == 1) {
clearPrefixFlags(prefixFlags);
return startOffset - 1;
}
int limit = endOffset - 1;
// We're looking for the NAL unit start code prefix 0x000001. The value of i tracks the index of
// the third byte.
for (int i = startOffset + 2; i < limit; i += 3) {
if ((data[i] & 0xFE) != 0) {
// There isn't a NAL prefix here, or at the next two positions. Do nothing and let the
// loop advance the index by three.
} else if (data[i - 2] == 0 && data[i - 1] == 0 && data[i] == 1) {
clearPrefixFlags(prefixFlags);
return i - 2;
} else {
// There isn't a NAL prefix here, but there might be at the next position. We should
// only skip forward by one. The loop will skip forward by three, so subtract two here.
i -= 2;
}
}
// True if the last three bytes in the data seen so far are {0,0,1}.
prefixFlags[0] =
length > 2
? (data[endOffset - 3] == 0 && data[endOffset - 2] == 0 && data[endOffset - 1] == 1)
: length == 2
? (prefixFlags[2] && data[endOffset - 2] == 0 && data[endOffset - 1] == 1)
: (prefixFlags[1] && data[endOffset - 1] == 1);
// True if the last two bytes in the data seen so far are {0,0}.
prefixFlags[1] =
length > 1
? data[endOffset - 2] == 0 && data[endOffset - 1] == 0
: prefixFlags[2] && data[endOffset - 1] == 0;
// True if the last byte in the data seen so far is {0}.
prefixFlags[2] = data[endOffset - 1] == 0;
return endOffset;
}
/**
* Clears prefix flags, as used by {@link #findNalUnit(byte[], int, int, boolean[])}.
*
* @param prefixFlags The flags to clear.
*/
public static void clearPrefixFlags(boolean[] prefixFlags) {
prefixFlags[0] = false;
prefixFlags[1] = false;
prefixFlags[2] = false;
}
private static int findNextUnescapeIndex(byte[] bytes, int offset, int limit) {
for (int i = offset; i < limit - 2; i++) {
if (bytes[i] == 0x00 && bytes[i + 1] == 0x00 && bytes[i + 2] == 0x03) {
return i;
}
}
return limit;
}
private static void skipScalingList(ParsableNalUnitBitArray bitArray, int size) {
int lastScale = 8;
int nextScale = 8;
for (int i = 0; i < size; i++) {
if (nextScale != 0) {
int deltaScale = bitArray.readSignedExpGolombCodedInt();
nextScale = (lastScale + deltaScale + 256) % 256;
}
lastScale = (nextScale == 0) ? lastScale : nextScale;
}
}
private static void skipH265ScalingList(ParsableNalUnitBitArray bitArray) {
for (int sizeId = 0; sizeId < 4; sizeId++) {
for (int matrixId = 0; matrixId < 6; matrixId += sizeId == 3 ? 3 : 1) {
if (!bitArray.readBit()) { // scaling_list_pred_mode_flag[sizeId][matrixId]
// scaling_list_pred_matrix_id_delta[sizeId][matrixId]
bitArray.readUnsignedExpGolombCodedInt();
} else {
int coefNum = min(64, 1 << (4 + (sizeId << 1)));
if (sizeId > 1) {
// scaling_list_dc_coef_minus8[sizeId - 2][matrixId]
bitArray.readSignedExpGolombCodedInt();
}
for (int i = 0; i < coefNum; i++) {
bitArray.readSignedExpGolombCodedInt(); // scaling_list_delta_coef
}
}
}
}
}
/**
* Skips any short term reference picture sets contained in a SPS.
*
* <p>Note: The st_ref_pic_set parsing in this method is simplified for the case where they're
* contained in a SPS, and would need generalizing for use elsewhere.
*/
private static void skipShortTermReferencePictureSets(ParsableNalUnitBitArray bitArray) {
int numShortTermRefPicSets = bitArray.readUnsignedExpGolombCodedInt();
// As this method applies in a SPS, each short term reference picture set only accesses data
// from the previous one. This is because RefRpsIdx = stRpsIdx - (delta_idx_minus1 + 1), and
// delta_idx_minus1 is always zero in a SPS. Hence we just keep track of variables from the
// previous one as we iterate.
int previousNumNegativePics = C.INDEX_UNSET;
int previousNumPositivePics = C.INDEX_UNSET;
int[] previousDeltaPocS0 = new int[0];
int[] previousDeltaPocS1 = new int[0];
for (int stRpsIdx = 0; stRpsIdx < numShortTermRefPicSets; stRpsIdx++) {
int numNegativePics;
int numPositivePics;
int[] deltaPocS0;
int[] deltaPocS1;
boolean interRefPicSetPredictionFlag = stRpsIdx != 0 && bitArray.readBit();
if (interRefPicSetPredictionFlag) {
int previousNumDeltaPocs = previousNumNegativePics + previousNumPositivePics;
int deltaRpsSign = bitArray.readBit() ? 1 : 0;
int absDeltaRps = bitArray.readUnsignedExpGolombCodedInt() + 1;
int deltaRps = (1 - 2 * deltaRpsSign) * absDeltaRps;
boolean[] useDeltaFlags = new boolean[previousNumDeltaPocs + 1];
for (int j = 0; j <= previousNumDeltaPocs; j++) {
if (!bitArray.readBit()) { // used_by_curr_pic_flag[j]
useDeltaFlags[j] = bitArray.readBit();
} else {
// When use_delta_flag[j] is not present, its value is 1.
useDeltaFlags[j] = true;
}
}
// Derive numNegativePics, numPositivePics, deltaPocS0 and deltaPocS1 as per Rec. ITU-T
// H.265 v6 (06/2019) Section 7.4.8
int i = 0;
deltaPocS0 = new int[previousNumDeltaPocs + 1];
deltaPocS1 = new int[previousNumDeltaPocs + 1];
for (int j = previousNumPositivePics - 1; j >= 0; j--) {
int dPoc = previousDeltaPocS1[j] + deltaRps;
if (dPoc < 0 && useDeltaFlags[previousNumNegativePics + j]) {
deltaPocS0[i++] = dPoc;
}
}
if (deltaRps < 0 && useDeltaFlags[previousNumDeltaPocs]) {
deltaPocS0[i++] = deltaRps;
}
for (int j = 0; j < previousNumNegativePics; j++) {
int dPoc = previousDeltaPocS0[j] + deltaRps;
if (dPoc < 0 && useDeltaFlags[j]) {
deltaPocS0[i++] = dPoc;
}
}
numNegativePics = i;
deltaPocS0 = Arrays.copyOf(deltaPocS0, numNegativePics);
i = 0;
for (int j = previousNumNegativePics - 1; j >= 0; j--) {
int dPoc = previousDeltaPocS0[j] + deltaRps;
if (dPoc > 0 && useDeltaFlags[j]) {
deltaPocS1[i++] = dPoc;
}
}
if (deltaRps > 0 && useDeltaFlags[previousNumDeltaPocs]) {
deltaPocS1[i++] = deltaRps;
}
for (int j = 0; j < previousNumPositivePics; j++) {
int dPoc = previousDeltaPocS1[j] + deltaRps;
if (dPoc > 0 && useDeltaFlags[previousNumNegativePics + j]) {
deltaPocS1[i++] = dPoc;
}
}
numPositivePics = i;
deltaPocS1 = Arrays.copyOf(deltaPocS1, numPositivePics);
} else {
numNegativePics = bitArray.readUnsignedExpGolombCodedInt();
numPositivePics = bitArray.readUnsignedExpGolombCodedInt();
deltaPocS0 = new int[numNegativePics];
for (int i = 0; i < numNegativePics; i++) {
deltaPocS0[i] = bitArray.readUnsignedExpGolombCodedInt() + 1;
bitArray.skipBit(); // used_by_curr_pic_s0_flag[i]
}
deltaPocS1 = new int[numPositivePics];
for (int i = 0; i < numPositivePics; i++) {
deltaPocS1[i] = bitArray.readUnsignedExpGolombCodedInt() + 1;
bitArray.skipBit(); // used_by_curr_pic_s1_flag[i]
}
}
previousNumNegativePics = numNegativePics;
previousNumPositivePics = numPositivePics;
previousDeltaPocS0 = deltaPocS0;
previousDeltaPocS1 = deltaPocS1;
}
}
private NalUnitUtil() {
// Prevent instantiation.
}
}