1 // Copyright 2019 The libgav1 Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "examples/ivf_parser.h"
16
17 #include <cstdio>
18 #include <cstring>
19
20 #include "examples/file_reader_constants.h"
21 #include "examples/logging.h"
22
23 namespace libgav1 {
24 namespace {
25
ReadLittleEndian16(const uint8_t * const buffer)26 size_t ReadLittleEndian16(const uint8_t* const buffer) {
27 size_t value = buffer[1] << 8;
28 value |= buffer[0];
29 return value;
30 }
31
ReadLittleEndian32(const uint8_t * const buffer)32 size_t ReadLittleEndian32(const uint8_t* const buffer) {
33 size_t value = buffer[3] << 24;
34 value |= buffer[2] << 16;
35 value |= buffer[1] << 8;
36 value |= buffer[0];
37 return value;
38 }
39
40 } // namespace
41
ParseIvfFileHeader(const uint8_t * const header_buffer,IvfFileHeader * const ivf_file_header)42 bool ParseIvfFileHeader(const uint8_t* const header_buffer,
43 IvfFileHeader* const ivf_file_header) {
44 if (header_buffer == nullptr || ivf_file_header == nullptr) return false;
45
46 if (memcmp(kIvfSignature, header_buffer, 4) != 0) {
47 return false;
48 }
49
50 // Verify header version and length.
51 const size_t ivf_header_version = ReadLittleEndian16(&header_buffer[4]);
52 if (ivf_header_version != kIvfHeaderVersion) {
53 LIBGAV1_EXAMPLES_LOG_ERROR("Unexpected IVF version");
54 }
55
56 const size_t ivf_header_size = ReadLittleEndian16(&header_buffer[6]);
57 if (ivf_header_size != kIvfFileHeaderSize) {
58 LIBGAV1_EXAMPLES_LOG_ERROR("Invalid IVF file header size");
59 return false;
60 }
61
62 if (memcmp(kAv1FourCcLower, &header_buffer[8], 4) != 0 &&
63 memcmp(kAv1FourCcUpper, &header_buffer[8], 4) != 0) {
64 LIBGAV1_EXAMPLES_LOG_ERROR("Unsupported codec 4CC");
65 return false;
66 }
67
68 ivf_file_header->width = ReadLittleEndian16(&header_buffer[12]);
69 ivf_file_header->height = ReadLittleEndian16(&header_buffer[14]);
70 ivf_file_header->frame_rate_numerator =
71 ReadLittleEndian32(&header_buffer[16]);
72 ivf_file_header->frame_rate_denominator =
73 ReadLittleEndian32(&header_buffer[20]);
74
75 return true;
76 }
77
ParseIvfFrameHeader(const uint8_t * const header_buffer,IvfFrameHeader * const ivf_frame_header)78 bool ParseIvfFrameHeader(const uint8_t* const header_buffer,
79 IvfFrameHeader* const ivf_frame_header) {
80 if (header_buffer == nullptr || ivf_frame_header == nullptr) return false;
81
82 ivf_frame_header->frame_size = ReadLittleEndian32(header_buffer);
83 if (ivf_frame_header->frame_size > kMaxTemporalUnitSize) {
84 LIBGAV1_EXAMPLES_LOG_ERROR("Temporal Unit size exceeds maximum");
85 return false;
86 }
87
88 ivf_frame_header->timestamp = ReadLittleEndian32(&header_buffer[4]);
89 const uint64_t timestamp_hi =
90 static_cast<uint64_t>(ReadLittleEndian32(&header_buffer[8])) << 32;
91 ivf_frame_header->timestamp |= timestamp_hi;
92
93 return true;
94 }
95
96 } // namespace libgav1
97