xref: /third_party/ffmpeg/libavcodec/defs.h (revision cabdff1a) 
1/*
2 *
3 * This file is part of FFmpeg.
4 *
5 * FFmpeg is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * FFmpeg is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with FFmpeg; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20#ifndef AVCODEC_DEFS_H
21#define AVCODEC_DEFS_H
22
23/**
24 * @file
25 * @ingroup libavc
26 * Misc types and constants that do not belong anywhere else.
27 */
28
29#include <stdint.h>
30#include <stdlib.h>
31
32/**
33 * @ingroup lavc_decoding
34 * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
35 * This is mainly needed because some optimized bitstream readers read
36 * 32 or 64 bit at once and could read over the end.<br>
37 * Note: If the first 23 bits of the additional bytes are not 0, then damaged
38 * MPEG bitstreams could cause overread and segfault.
39 */
40#define AV_INPUT_BUFFER_PADDING_SIZE 64
41
42/**
43 * @ingroup lavc_decoding
44 */
45enum AVDiscard{
46    /* We leave some space between them for extensions (drop some
47     * keyframes for intra-only or drop just some bidir frames). */
48    AVDISCARD_NONE    =-16, ///< discard nothing
49    AVDISCARD_DEFAULT =  0, ///< discard useless packets like 0 size packets in avi
50    AVDISCARD_NONREF  =  8, ///< discard all non reference
51    AVDISCARD_BIDIR   = 16, ///< discard all bidirectional frames
52    AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
53    AVDISCARD_NONKEY  = 32, ///< discard all frames except keyframes
54    AVDISCARD_ALL     = 48, ///< discard all
55};
56
57enum AVAudioServiceType {
58    AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
59    AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
60    AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
61    AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
62    AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
63    AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
64    AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
65    AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
66    AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
67    AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
68};
69
70/**
71 * Pan Scan area.
72 * This specifies the area which should be displayed.
73 * Note there may be multiple such areas for one frame.
74 */
75typedef struct AVPanScan {
76    /**
77     * id
78     * - encoding: Set by user.
79     * - decoding: Set by libavcodec.
80     */
81    int id;
82
83    /**
84     * width and height in 1/16 pel
85     * - encoding: Set by user.
86     * - decoding: Set by libavcodec.
87     */
88    int width;
89    int height;
90
91    /**
92     * position of the top left corner in 1/16 pel for up to 3 fields/frames
93     * - encoding: Set by user.
94     * - decoding: Set by libavcodec.
95     */
96    int16_t position[3][2];
97} AVPanScan;
98
99/**
100 * This structure describes the bitrate properties of an encoded bitstream. It
101 * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
102 * parameters for H.264/HEVC.
103 */
104typedef struct AVCPBProperties {
105    /**
106     * Maximum bitrate of the stream, in bits per second.
107     * Zero if unknown or unspecified.
108     */
109    int64_t max_bitrate;
110    /**
111     * Minimum bitrate of the stream, in bits per second.
112     * Zero if unknown or unspecified.
113     */
114    int64_t min_bitrate;
115    /**
116     * Average bitrate of the stream, in bits per second.
117     * Zero if unknown or unspecified.
118     */
119    int64_t avg_bitrate;
120
121    /**
122     * The size of the buffer to which the ratecontrol is applied, in bits.
123     * Zero if unknown or unspecified.
124     */
125    int64_t buffer_size;
126
127    /**
128     * The delay between the time the packet this structure is associated with
129     * is received and the time when it should be decoded, in periods of a 27MHz
130     * clock.
131     *
132     * UINT64_MAX when unknown or unspecified.
133     */
134    uint64_t vbv_delay;
135} AVCPBProperties;
136
137/**
138 * Allocate a CPB properties structure and initialize its fields to default
139 * values.
140 *
141 * @param size if non-NULL, the size of the allocated struct will be written
142 *             here. This is useful for embedding it in side data.
143 *
144 * @return the newly allocated struct or NULL on failure
145 */
146AVCPBProperties *av_cpb_properties_alloc(size_t *size);
147
148/**
149 * This structure supplies correlation between a packet timestamp and a wall clock
150 * production time. The definition follows the Producer Reference Time ('prft')
151 * as defined in ISO/IEC 14496-12
152 */
153typedef struct AVProducerReferenceTime {
154    /**
155     * A UTC timestamp, in microseconds, since Unix epoch (e.g, av_gettime()).
156     */
157    int64_t wallclock;
158    int flags;
159} AVProducerReferenceTime;
160
161/**
162 * Encode extradata length to a buffer. Used by xiph codecs.
163 *
164 * @param s buffer to write to; must be at least (v/255+1) bytes long
165 * @param v size of extradata in bytes
166 * @return number of bytes written to the buffer.
167 */
168unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
169
170#endif // AVCODEC_DEFS_H
171