FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/h2645_parse.h
Date: 2021-09-26 18:22:30
Exec Total Coverage
Lines: 11 11 100.0%
Branches: 7 8 87.5%

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1 /*
2 * H.264/HEVC common parsing code
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #ifndef AVCODEC_H2645_PARSE_H
22 #define AVCODEC_H2645_PARSE_H
23
24 #include <stdint.h>
25
26 #include "libavutil/buffer.h"
27 #include "libavutil/error.h"
28 #include "libavutil/log.h"
29 #include "codec_id.h"
30 #include "get_bits.h"
31
32 #define MAX_MBPAIR_SIZE (256*1024) // a tighter bound could be calculated if someone cares about a few bytes
33
34 typedef struct H2645NAL {
35 uint8_t *rbsp_buffer;
36
37 int size;
38 const uint8_t *data;
39
40 /**
41 * Size, in bits, of just the data, excluding the stop bit and any trailing
42 * padding. I.e. what HEVC calls SODB.
43 */
44 int size_bits;
45
46 int raw_size;
47 const uint8_t *raw_data;
48
49 GetBitContext gb;
50
51 /**
52 * NAL unit type
53 */
54 int type;
55
56 /**
57 * HEVC only, nuh_temporal_id_plus_1 - 1
58 */
59 int temporal_id;
60
61 /*
62 * HEVC only, identifier of layer to which nal unit belongs
63 */
64 int nuh_layer_id;
65
66 int skipped_bytes;
67 int skipped_bytes_pos_size;
68 int *skipped_bytes_pos;
69 /**
70 * H.264 only, nal_ref_idc
71 */
72 int ref_idc;
73 } H2645NAL;
74
75 typedef struct H2645RBSP {
76 uint8_t *rbsp_buffer;
77 AVBufferRef *rbsp_buffer_ref;
78 int rbsp_buffer_alloc_size;
79 int rbsp_buffer_size;
80 } H2645RBSP;
81
82 /* an input packet split into unescaped NAL units */
83 typedef struct H2645Packet {
84 H2645NAL *nals;
85 H2645RBSP rbsp;
86 int nb_nals;
87 int nals_allocated;
88 unsigned nal_buffer_size;
89 } H2645Packet;
90
91 /**
92 * Extract the raw (unescaped) bitstream.
93 */
94 int ff_h2645_extract_rbsp(const uint8_t *src, int length, H2645RBSP *rbsp,
95 H2645NAL *nal, int small_padding);
96
97 /**
98 * Split an input packet into NAL units.
99 *
100 * If data == raw_data holds true for a NAL unit of the returned pkt, then
101 * said NAL unit does not contain any emulation_prevention_three_byte and
102 * the data is contained in the input buffer pointed to by buf.
103 * Otherwise, the unescaped data is part of the rbsp_buffer described by the
104 * packet's H2645RBSP.
105 *
106 * If the packet's rbsp_buffer_ref is not NULL, the underlying AVBuffer must
107 * own rbsp_buffer. If not and rbsp_buffer is not NULL, use_ref must be 0.
108 * If use_ref is set, rbsp_buffer will be reference-counted and owned by
109 * the underlying AVBuffer of rbsp_buffer_ref.
110 */
111 int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
112 void *logctx, int is_nalff, int nal_length_size,
113 enum AVCodecID codec_id, int small_padding, int use_ref);
114
115 /**
116 * Free all the allocated memory in the packet.
117 */
118 void ff_h2645_packet_uninit(H2645Packet *pkt);
119
120 14322 static inline int get_nalsize(int nal_length_size, const uint8_t *buf,
121 int buf_size, int *buf_index, void *logctx)
122 {
123 14322 int i, nalsize = 0;
124
125
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14322 if (*buf_index >= buf_size - nal_length_size) {
126 // the end of the buffer is reached, refill it
127 331 return AVERROR(EAGAIN);
128 }
129
130
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68683 for (i = 0; i < nal_length_size; i++)
131 54692 nalsize = ((unsigned)nalsize << 8) | buf[(*buf_index)++];
132
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13991 if (nalsize <= 0 || nalsize > buf_size - *buf_index) {
133 2 av_log(logctx, AV_LOG_ERROR,
134 2 "Invalid NAL unit size (%d > %d).\n", nalsize, buf_size - *buf_index);
135 2 return AVERROR_INVALIDDATA;
136 }
137 13989 return nalsize;
138 }
139
140 #endif /* AVCODEC_H2645_PARSE_H */
141