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1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef AVC_UTILS_H_
18 
19 #define AVC_UTILS_H_
20 
21 #include <media/stagefright/foundation/ABuffer.h>
22 #include <utils/Errors.h>
23 
24 namespace android {
25 
26 class ABitReader;
27 
28 enum {
29     kAVCProfileBaseline      = 0x42,
30     kAVCProfileMain          = 0x4d,
31     kAVCProfileExtended      = 0x58,
32     kAVCProfileHigh          = 0x64,
33     kAVCProfileHigh10        = 0x6e,
34     kAVCProfileHigh422       = 0x7a,
35     kAVCProfileHigh444       = 0xf4,
36     kAVCProfileCAVLC444Intra = 0x2c
37 };
38 
39 struct NALPosition {
40     size_t nalOffset;
41     size_t nalSize;
42 };
43 
44 // Optionally returns sample aspect ratio as well.
45 void FindAVCDimensions(
46         const sp<ABuffer> &seqParamSet,
47         int32_t *width, int32_t *height,
48         int32_t *sarWidth = NULL, int32_t *sarHeight = NULL);
49 
50 // Gets and returns an unsigned exp-golomb (ue) value from a bit reader |br|. Aborts if the value
51 // is more than 64 bits long (>=0xFFFF (!)) or the bit reader overflows.
52 unsigned parseUE(ABitReader *br);
53 
54 // Gets and returns a signed exp-golomb (se) value from a bit reader |br|. Aborts if the value is
55 // more than 64 bits long (>0x7FFF || <-0x7FFF (!)) or the bit reader overflows.
56 signed parseSE(ABitReader *br);
57 
58 // Gets an unsigned exp-golomb (ue) value from a bit reader |br|, and returns it if it was
59 // successful. Returns |fallback| if it was unsuccessful. Note: if the value was longer that 64
60 // bits, it reads past the value and still returns |fallback|.
61 unsigned parseUEWithFallback(ABitReader *br, unsigned fallback);
62 
63 // Gets a signed exp-golomb (se) value from a bit reader |br|, and returns it if it was successful.
64 // Returns |fallback| if it was unsuccessful. Note: if the value was longer that 64 bits, it reads
65 // past the value and still returns |fallback|.
66 signed parseSEWithFallback(ABitReader *br, signed fallback);
67 
68 // Skips an unsigned exp-golomb (ue) value from bit reader |br|.
skipUE(ABitReader * br)69 inline void skipUE(ABitReader *br) {
70     (void)parseUEWithFallback(br, 0U);
71 }
72 
73 // Skips a signed exp-golomb (se) value from bit reader |br|.
skipSE(ABitReader * br)74 inline void skipSE(ABitReader *br) {
75     (void)parseSEWithFallback(br, 0);
76 }
77 
78 status_t getNextNALUnit(
79         const uint8_t **_data, size_t *_size,
80         const uint8_t **nalStart, size_t *nalSize,
81         bool startCodeFollows = false);
82 
83 class MetaData;
84 sp<MetaData> MakeAVCCodecSpecificData(const sp<ABuffer> &accessUnit);
85 
86 bool IsIDR(const sp<ABuffer> &accessUnit);
87 bool IsAVCReferenceFrame(const sp<ABuffer> &accessUnit);
88 uint32_t FindAVCLayerId(const uint8_t *data, size_t size);
89 
90 const char *AVCProfileToString(uint8_t profile);
91 
92 sp<MetaData> MakeAACCodecSpecificData(
93         unsigned profile, unsigned sampling_freq_index,
94         unsigned channel_configuration);
95 
96 // Given an MPEG4 video VOL-header chunk (starting with 0x00 0x00 0x01 0x2?)
97 // parse it and fill in dimensions, returns true iff successful.
98 bool ExtractDimensionsFromVOLHeader(
99         const uint8_t *data, size_t size, int32_t *width, int32_t *height);
100 
101 bool GetMPEGAudioFrameSize(
102         uint32_t header, size_t *frame_size,
103         int *out_sampling_rate = NULL, int *out_channels = NULL,
104         int *out_bitrate = NULL, int *out_num_samples = NULL);
105 
106 }  // namespace android
107 
108 #endif  // AVC_UTILS_H_
109