2 * H.264/HEVC common parsing code
4 * This file is part of FFmpeg.
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.
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.
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
21 #ifndef AVCODEC_H2645_PARSE_H
22 #define AVCODEC_H2645_PARSE_H
26 #include "libavutil/buffer.h"
30 #define MAX_MBPAIR_SIZE (256*1024) // a tighter bound could be calculated if someone cares about a few bytes
32 typedef struct H2645NAL {
39 * Size, in bits, of just the data, excluding the stop bit and any trailing
40 * padding. I.e. what HEVC calls SODB.
45 const uint8_t *raw_data;
55 * HEVC only, nuh_temporal_id_plus_1 - 1
60 int skipped_bytes_pos_size;
61 int *skipped_bytes_pos;
63 * H.264 only, nal_ref_idc
68 typedef struct H2645RBSP {
70 AVBufferRef *rbsp_buffer_ref;
71 int rbsp_buffer_alloc_size;
75 /* an input packet split into unescaped NAL units */
76 typedef struct H2645Packet {
84 * Extract the raw (unescaped) bitstream.
86 int ff_h2645_extract_rbsp(const uint8_t *src, int length, H2645RBSP *rbsp,
87 H2645NAL *nal, int small_padding);
90 * Split an input packet into NAL units.
92 * If data == raw_data holds true for a NAL unit of the returned pkt, then
93 * said NAL unit does not contain any emulation_prevention_three_byte and
94 * the data is contained in the input buffer pointed to by buf.
95 * Otherwise, the unescaped data is part of the rbsp_buffer described by the
98 * If the packet's rbsp_buffer_ref is not NULL, the underlying AVBuffer must
99 * own rbsp_buffer. If not and rbsp_buffer is not NULL, use_ref must be 0.
100 * If use_ref is set, rbsp_buffer will be reference-counted and owned by
101 * the underlying AVBuffer of rbsp_buffer_ref.
103 int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
104 void *logctx, int is_nalff, int nal_length_size,
105 enum AVCodecID codec_id, int small_padding, int use_ref);
108 * Free all the allocated memory in the packet.
110 void ff_h2645_packet_uninit(H2645Packet *pkt);
112 static inline int get_nalsize(int nal_length_size, const uint8_t *buf,
113 int buf_size, int *buf_index, void *logctx)
117 if (*buf_index >= buf_size - nal_length_size) {
118 // the end of the buffer is reached, refill it
119 return AVERROR(EAGAIN);
122 for (i = 0; i < nal_length_size; i++)
123 nalsize = ((unsigned)nalsize << 8) | buf[(*buf_index)++];
124 if (nalsize <= 0 || nalsize > buf_size - *buf_index) {
125 av_log(logctx, AV_LOG_ERROR,
126 "Invalid NAL unit size (%d > %d).\n", nalsize, buf_size - *buf_index);
127 return AVERROR_INVALIDDATA;
132 #endif /* AVCODEC_H2645_PARSE_H */