FFmpeg
options.c
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1 /*
2  * Copyright (c) 2001 Fabrice Bellard
3  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Options definition for AVCodecContext.
25  */
26 
27 #include "config_components.h"
28 
29 #include "avcodec.h"
30 #include "avcodec_internal.h"
31 #include "codec_internal.h"
32 #include "libavutil/avassert.h"
33 #include "libavutil/internal.h"
34 #include "libavutil/mem.h"
35 #include "libavutil/opt.h"
36 #include <string.h>
37 
39 #include "options_table.h"
41 
42 static const char* context_to_name(void* ptr) {
43  AVCodecContext *avc= ptr;
44 
45  if (avc && avc->codec)
46  return avc->codec->name;
47  else
48  return "NULL";
49 }
50 
51 static void *codec_child_next(void *obj, void *prev)
52 {
53  AVCodecContext *s = obj;
54  if (!prev && s->codec && s->codec->priv_class && s->priv_data)
55  return s->priv_data;
56  return NULL;
57 }
58 
59 static const AVClass *codec_child_class_iterate(void **iter)
60 {
61  const AVCodec *c;
62  /* find next codec with priv options */
63  while (c = av_codec_iterate(iter))
64  if (c->priv_class)
65  return c->priv_class;
66  return NULL;
67 }
68 
69 static AVClassCategory get_category(void *ptr)
70 {
71  AVCodecContext* avctx = ptr;
72  if (avctx->codec && av_codec_is_decoder(avctx->codec))
74  else
76 }
77 
79  .class_name = "AVCodecContext",
80  .item_name = context_to_name,
81  .option = avcodec_options,
82  .version = LIBAVUTIL_VERSION_INT,
83  .log_level_offset_offset = offsetof(AVCodecContext, log_level_offset),
84  .child_next = codec_child_next,
85  .child_class_iterate = codec_child_class_iterate,
87  .get_category = get_category,
88 };
89 
90 static int init_context_defaults(AVCodecContext *s, const AVCodec *codec)
91 {
92  const FFCodec *const codec2 = ffcodec(codec);
93  int flags=0;
94  memset(s, 0, sizeof(AVCodecContext));
95 
96  s->av_class = &av_codec_context_class;
97 
98  s->codec_type = codec ? codec->type : AVMEDIA_TYPE_UNKNOWN;
99  if (codec) {
100  s->codec = codec;
101  s->codec_id = codec->id;
102  }
103 
104  if(s->codec_type == AVMEDIA_TYPE_AUDIO)
106  else if(s->codec_type == AVMEDIA_TYPE_VIDEO)
108  else if(s->codec_type == AVMEDIA_TYPE_SUBTITLE)
111 
112  av_channel_layout_uninit(&s->ch_layout);
113 
114  s->time_base = (AVRational){0,1};
115  s->framerate = (AVRational){ 0, 1 };
116  s->pkt_timebase = (AVRational){ 0, 1 };
117  s->get_buffer2 = avcodec_default_get_buffer2;
118  s->get_format = avcodec_default_get_format;
119  s->get_encode_buffer = avcodec_default_get_encode_buffer;
120  s->execute = avcodec_default_execute;
121  s->execute2 = avcodec_default_execute2;
122  s->sample_aspect_ratio = (AVRational){0,1};
123  s->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
124  s->pix_fmt = AV_PIX_FMT_NONE;
125  s->sw_pix_fmt = AV_PIX_FMT_NONE;
126  s->sample_fmt = AV_SAMPLE_FMT_NONE;
127 
128  if(codec && codec2->priv_data_size){
129  s->priv_data = av_mallocz(codec2->priv_data_size);
130  if (!s->priv_data)
131  return AVERROR(ENOMEM);
132  if(codec->priv_class){
133  *(const AVClass**)s->priv_data = codec->priv_class;
134  av_opt_set_defaults(s->priv_data);
135  }
136  }
137  if (codec && codec2->defaults) {
138  int ret;
139  const FFCodecDefault *d = codec2->defaults;
140  while (d->key) {
141  ret = av_opt_set(s, d->key, d->value, 0);
142  av_assert0(ret >= 0);
143  d++;
144  }
145  }
146  return 0;
147 }
148 
150 {
151  AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
152 
153  if (!avctx)
154  return NULL;
155 
156  if (init_context_defaults(avctx, codec) < 0) {
157  av_free(avctx);
158  return NULL;
159  }
160 
161  return avctx;
162 }
163 
165 {
166  AVCodecContext *avctx = *pavctx;
167 
168  if (!avctx)
169  return;
170 
171  ff_codec_close(avctx);
172 
173  av_freep(&avctx->extradata);
174  av_freep(&avctx->subtitle_header);
175  av_freep(&avctx->intra_matrix);
176  av_freep(&avctx->chroma_intra_matrix);
177  av_freep(&avctx->inter_matrix);
178  av_freep(&avctx->rc_override);
180 
181  av_freep(pavctx);
182 }
183 
185 {
186  return &av_codec_context_class;
187 }
188 
189 #define SROFFSET(x) offsetof(AVSubtitleRect,x)
190 
192 {"x", "", SROFFSET(x), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
193 {"y", "", SROFFSET(y), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
194 {"w", "", SROFFSET(w), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
195 {"h", "", SROFFSET(h), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
196 {"type", "", SROFFSET(type), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
197 {"flags", "", SROFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, 1, 0, .unit = "flags"},
198 {"forced", "", SROFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, 1, 0},
199 {NULL},
200 };
201 
203  .class_name = "AVSubtitleRect",
204  .item_name = NULL,
205  .option = subtitle_rect_options,
206  .version = LIBAVUTIL_VERSION_INT,
207 };
208 
210 {
211  return &av_subtitle_rect_class;
212 }
AVCodec
AVCodec.
Definition: codec.h:187
FF_ENABLE_DEPRECATION_WARNINGS
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:73
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
FFCodec::defaults
const FFCodecDefault * defaults
Private codec-specific defaults.
Definition: codec_internal.h:167
av_opt_set_defaults
void av_opt_set_defaults(void *s)
Set the values of all AVOption fields to their default values.
Definition: opt.c:1654
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
AV_CLASS_CATEGORY_DECODER
@ AV_CLASS_CATEGORY_DECODER
Definition: log.h:35
options_table.h
AVCodec::priv_class
const AVClass * priv_class
AVClass for the private context.
Definition: codec.h:212
AVCodecContext::intra_matrix
uint16_t * intra_matrix
custom intra quantization matrix Must be allocated with the av_malloc() family of functions,...
Definition: avcodec.h:974
w
uint8_t w
Definition: llviddspenc.c:38
AVOption
AVOption.
Definition: opt.h:357
FFCodec
Definition: codec_internal.h:126
AVCodecContext::subtitle_header
uint8_t * subtitle_header
Definition: avcodec.h:1892
avcodec_default_get_format
enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
Definition: decode.c:1022
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
FFCodec::priv_data_size
int priv_data_size
Definition: codec_internal.h:144
FFCodecDefault
Definition: codec_internal.h:96
AVCodecContext::codec
const struct AVCodec * codec
Definition: avcodec.h:454
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:1065
av_codec_context_class
static const AVClass av_codec_context_class
Definition: options.c:78
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
init_context_defaults
static int init_context_defaults(AVCodecContext *s, const AVCodec *codec)
Definition: options.c:90
av_opt_set
int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
Definition: opt.c:747
AV_OPT_FLAG_AUDIO_PARAM
#define AV_OPT_FLAG_AUDIO_PARAM
Definition: opt.h:285
subtitle_rect_options
static const AVOption subtitle_rect_options[]
Definition: options.c:191
avassert.h
avcodec_alloc_context3
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
Definition: options.c:149
av_subtitle_rect_class
static const AVClass av_subtitle_rect_class
Definition: options.c:202
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AV_CHANNEL_ORDER_UNSPEC
@ AV_CHANNEL_ORDER_UNSPEC
Only the channel count is specified, without any further information about the channel order.
Definition: channel_layout.h:112
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:40
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
avcodec_get_class
const AVClass * avcodec_get_class(void)
Get the AVClass for AVCodecContext.
Definition: options.c:184
NULL
#define NULL
Definition: coverity.c:32
AVCodec::type
enum AVMediaType type
Definition: codec.h:200
avcodec_free_context
void avcodec_free_context(AVCodecContext **pavctx)
Free the codec context and everything associated with it and write NULL to the provided pointer.
Definition: options.c:164
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
codec_child_next
static void * codec_child_next(void *obj, void *prev)
Definition: options.c:51
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
avcodec_get_subtitle_rect_class
const AVClass * avcodec_get_subtitle_rect_class(void)
Get the AVClass for AVSubtitleRect.
Definition: options.c:209
av_codec_is_decoder
int av_codec_is_decoder(const AVCodec *codec)
Definition: utils.c:86
AVCodecContext::rc_override
RcOverride * rc_override
Definition: avcodec.h:1285
codec_internal.h
codec_child_class_iterate
static const AVClass * codec_child_class_iterate(void **iter)
Definition: options.c:59
AVClass::category
AVClassCategory category
Category used for visualization (like color) This is only set if the category is equal for all object...
Definition: log.h:114
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:56
ffcodec
static const av_always_inline FFCodec * ffcodec(const AVCodec *codec)
Definition: codec_internal.h:305
AVCodecContext::chroma_intra_matrix
uint16_t * chroma_intra_matrix
custom intra quantization matrix
Definition: avcodec.h:990
AVMEDIA_TYPE_UNKNOWN
@ AVMEDIA_TYPE_UNKNOWN
Usually treated as AVMEDIA_TYPE_DATA.
Definition: avutil.h:200
avcodec_default_execute
int avcodec_default_execute(AVCodecContext *c, int(*func)(AVCodecContext *c2, void *arg2), void *arg, int *ret, int count, int size)
Definition: avcodec.c:71
AVCodec::id
enum AVCodecID id
Definition: codec.h:201
avcodec_default_get_buffer2
int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags)
The default callback for AVCodecContext.get_buffer2().
Definition: get_buffer.c:254
SROFFSET
#define SROFFSET(x)
Definition: options.c:189
AVClassCategory
AVClassCategory
Definition: log.h:28
avcodec_default_execute2
int avcodec_default_execute2(AVCodecContext *c, int(*func)(AVCodecContext *c2, void *arg2, int jobnr, int threadnr), void *arg, int *ret, int count)
Definition: avcodec.c:85
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:523
internal.h
AV_OPT_FLAG_SUBTITLE_PARAM
#define AV_OPT_FLAG_SUBTITLE_PARAM
Definition: opt.h:287
AV_OPT_FLAG_VIDEO_PARAM
#define AV_OPT_FLAG_VIDEO_PARAM
Definition: opt.h:286
av_mallocz
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:256
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
av_codec_iterate
const AVCodec * av_codec_iterate(void **opaque)
Iterate over all registered codecs.
Definition: allcodecs.c:915
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
get_category
static AVClassCategory get_category(void *ptr)
Definition: options.c:69
AVCodecContext
main external API structure.
Definition: avcodec.h:445
avcodec_internal.h
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:72
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:245
av_channel_layout_uninit
void av_channel_layout_uninit(AVChannelLayout *channel_layout)
Free any allocated data in the channel layout and reset the channel count to 0.
Definition: channel_layout.c:433
av_opt_set_defaults2
void av_opt_set_defaults2(void *s, int mask, int flags)
Set the values of all AVOption fields to their default values.
Definition: opt.c:1659
FF_DISABLE_DEPRECATION_WARNINGS
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:72
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
ff_codec_close
av_cold void ff_codec_close(AVCodecContext *avctx)
Definition: avcodec.c:415
av_free
#define av_free(p)
Definition: tableprint_vlc.h:33
avcodec_default_get_encode_buffer
int avcodec_default_get_encode_buffer(AVCodecContext *s, AVPacket *pkt, int flags)
The default callback for AVCodecContext.get_encode_buffer().
Definition: encode.c:84
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
AVCodecContext::inter_matrix
uint16_t * inter_matrix
custom inter quantization matrix Must be allocated with the av_malloc() family of functions,...
Definition: avcodec.h:983
d
d
Definition: ffmpeg_filter.c:424
AV_OPT_TYPE_FLAGS
@ AV_OPT_TYPE_FLAGS
Definition: opt.h:244
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
avcodec_options
static const AVOption avcodec_options[]
Definition: options_table.h:49
AV_CLASS_CATEGORY_ENCODER
@ AV_CLASS_CATEGORY_ENCODER
Definition: log.h:34
h
h
Definition: vp9dsp_template.c:2038
context_to_name
FF_DISABLE_DEPRECATION_WARNINGS static const FF_ENABLE_DEPRECATION_WARNINGS char * context_to_name(void *ptr)
Definition: options.c:42