FFmpeg
h2645_parse.h
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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  const uint8_t *data;
36  int size;
37 
38  /**
39  * Size, in bits, of just the data, excluding the stop bit and any trailing
40  * padding. I.e. what HEVC calls SODB.
41  */
42  int size_bits;
43 
44  int raw_size;
45  const uint8_t *raw_data;
46 
48 
49  /**
50  * NAL unit type
51  */
52  int type;
53 
54  /**
55  * H.264 only, nal_ref_idc
56  */
57  int ref_idc;
58 
59  /**
60  * HEVC only, nuh_temporal_id_plus_1 - 1
61  */
63 
64  /*
65  * HEVC only, identifier of layer to which nal unit belongs
66  */
68 
72 } H2645NAL;
73 
74 typedef struct H2645RBSP {
75  uint8_t *rbsp_buffer;
79 } H2645RBSP;
80 
81 /* an input packet split into unescaped NAL units */
82 typedef struct H2645Packet {
85  int nb_nals;
87  unsigned nal_buffer_size;
88 } H2645Packet;
89 
90 /**
91  * Extract the raw (unescaped) bitstream.
92  */
93 int ff_h2645_extract_rbsp(const uint8_t *src, int length, H2645RBSP *rbsp,
94  H2645NAL *nal, int small_padding);
95 
96 /**
97  * Split an input packet into NAL units.
98  *
99  * If data == raw_data holds true for a NAL unit of the returned pkt, then
100  * said NAL unit does not contain any emulation_prevention_three_byte and
101  * the data is contained in the input buffer pointed to by buf.
102  * Otherwise, the unescaped data is part of the rbsp_buffer described by the
103  * packet's H2645RBSP.
104  *
105  * If the packet's rbsp_buffer_ref is not NULL, the underlying AVBuffer must
106  * own rbsp_buffer. If not and rbsp_buffer is not NULL, use_ref must be 0.
107  * If use_ref is set, rbsp_buffer will be reference-counted and owned by
108  * the underlying AVBuffer of rbsp_buffer_ref.
109  */
110 int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
111  void *logctx, int is_nalff, int nal_length_size,
112  enum AVCodecID codec_id, int small_padding, int use_ref);
113 
114 /**
115  * Free all the allocated memory in the packet.
116  */
118 
119 static inline int get_nalsize(int nal_length_size, const uint8_t *buf,
120  int buf_size, int *buf_index, void *logctx)
121 {
122  int i, nalsize = 0;
123 
124  if (*buf_index >= buf_size - nal_length_size) {
125  // the end of the buffer is reached, refill it
126  return AVERROR_INVALIDDATA;
127  }
128 
129  for (i = 0; i < nal_length_size; i++)
130  nalsize = ((unsigned)nalsize << 8) | buf[(*buf_index)++];
131  if (nalsize <= 0 || nalsize > buf_size - *buf_index) {
132  av_log(logctx, AV_LOG_ERROR,
133  "Invalid NAL unit size (%d > %d).\n", nalsize, buf_size - *buf_index);
134  return AVERROR_INVALIDDATA;
135  }
136  return nalsize;
137 }
138 
139 #endif /* AVCODEC_H2645_PARSE_H */
H2645NAL::ref_idc
int ref_idc
H.264 only, nal_ref_idc.
Definition: h2645_parse.h:57
H2645NAL::nuh_layer_id
int nuh_layer_id
Definition: h2645_parse.h:67
H2645Packet::nals_allocated
int nals_allocated
Definition: h2645_parse.h:86
H2645NAL::skipped_bytes_pos_size
int skipped_bytes_pos_size
Definition: h2645_parse.h:70
H2645NAL::temporal_id
int temporal_id
HEVC only, nuh_temporal_id_plus_1 - 1.
Definition: h2645_parse.h:62
H2645Packet::nb_nals
int nb_nals
Definition: h2645_parse.h:85
H2645NAL::size_bits
int size_bits
Size, in bits, of just the data, excluding the stop bit and any trailing padding.
Definition: h2645_parse.h:42
ff_h2645_packet_split
int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length, void *logctx, int is_nalff, int nal_length_size, enum AVCodecID codec_id, int small_padding, int use_ref)
Split an input packet into NAL units.
Definition: h2645_parse.c:464
GetBitContext
Definition: get_bits.h:108
ff_h2645_packet_uninit
void ff_h2645_packet_uninit(H2645Packet *pkt)
Free all the allocated memory in the packet.
Definition: h2645_parse.c:598
H2645Packet::rbsp
H2645RBSP rbsp
Definition: h2645_parse.h:84
pkt
AVPacket * pkt
Definition: movenc.c:60
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
codec_id.h
H2645NAL::size
int size
Definition: h2645_parse.h:36
get_bits.h
H2645NAL::data
const uint8_t * data
Definition: h2645_parse.h:35
H2645NAL::skipped_bytes_pos
int * skipped_bytes_pos
Definition: h2645_parse.h:71
codec_id
enum AVCodecID codec_id
Definition: vaapi_decode.c:392
H2645NAL::type
int type
NAL unit type.
Definition: h2645_parse.h:52
H2645NAL::raw_size
int raw_size
Definition: h2645_parse.h:44
error.h
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:49
H2645NAL::skipped_bytes
int skipped_bytes
Definition: h2645_parse.h:69
H2645RBSP::rbsp_buffer
uint8_t * rbsp_buffer
Definition: h2645_parse.h:75
H2645NAL::gb
GetBitContext gb
Definition: h2645_parse.h:47
H2645NAL
Definition: h2645_parse.h:34
H2645RBSP::rbsp_buffer_size
int rbsp_buffer_size
Definition: h2645_parse.h:78
buffer.h
H2645Packet::nal_buffer_size
unsigned nal_buffer_size
Definition: h2645_parse.h:87
H2645Packet::nals
H2645NAL * nals
Definition: h2645_parse.h:83
log.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
H2645RBSP::rbsp_buffer_ref
AVBufferRef * rbsp_buffer_ref
Definition: h2645_parse.h:76
H2645RBSP::rbsp_buffer_alloc_size
int rbsp_buffer_alloc_size
Definition: h2645_parse.h:77
H2645NAL::raw_data
const uint8_t * raw_data
Definition: h2645_parse.h:45
AVBufferRef
A reference to a data buffer.
Definition: buffer.h:82
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
get_nalsize
static int get_nalsize(int nal_length_size, const uint8_t *buf, int buf_size, int *buf_index, void *logctx)
Definition: h2645_parse.h:119
ff_h2645_extract_rbsp
int ff_h2645_extract_rbsp(const uint8_t *src, int length, H2645RBSP *rbsp, H2645NAL *nal, int small_padding)
Extract the raw (unescaped) bitstream.
Definition: h2645_parse.c:35
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
H2645Packet
Definition: h2645_parse.h:82
H2645RBSP
Definition: h2645_parse.h:74