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 FF_API_REORDERED_OPAQUE
130  s->reordered_opaque = AV_NOPTS_VALUE;
132 #endif
133  if(codec && codec2->priv_data_size){
134  s->priv_data = av_mallocz(codec2->priv_data_size);
135  if (!s->priv_data)
136  return AVERROR(ENOMEM);
137  if(codec->priv_class){
138  *(const AVClass**)s->priv_data = codec->priv_class;
139  av_opt_set_defaults(s->priv_data);
140  }
141  }
142  if (codec && codec2->defaults) {
143  int ret;
144  const FFCodecDefault *d = codec2->defaults;
145  while (d->key) {
146  ret = av_opt_set(s, d->key, d->value, 0);
147  av_assert0(ret >= 0);
148  d++;
149  }
150  }
151  return 0;
152 }
153 
155 {
156  AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
157 
158  if (!avctx)
159  return NULL;
160 
161  if (init_context_defaults(avctx, codec) < 0) {
162  av_free(avctx);
163  return NULL;
164  }
165 
166  return avctx;
167 }
168 
170 {
171  AVCodecContext *avctx = *pavctx;
172 
173  if (!avctx)
174  return;
175 
176  ff_codec_close(avctx);
177 
178  av_freep(&avctx->extradata);
179  av_freep(&avctx->subtitle_header);
180  av_freep(&avctx->intra_matrix);
181  av_freep(&avctx->inter_matrix);
182  av_freep(&avctx->rc_override);
184 
185  av_freep(pavctx);
186 }
187 
189 {
190  return &av_codec_context_class;
191 }
192 
193 #define SROFFSET(x) offsetof(AVSubtitleRect,x)
194 
196 {"x", "", SROFFSET(x), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
197 {"y", "", SROFFSET(y), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
198 {"w", "", SROFFSET(w), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
199 {"h", "", SROFFSET(h), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
200 {"type", "", SROFFSET(type), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
201 {"flags", "", SROFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, 1, 0, .unit = "flags"},
202 {"forced", "", SROFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, 1, 0},
203 {NULL},
204 };
205 
207  .class_name = "AVSubtitleRect",
208  .item_name = NULL,
209  .option = subtitle_rect_options,
210  .version = LIBAVUTIL_VERSION_INT,
211 };
212 
214 {
215  return &av_subtitle_rect_class;
216 }
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:168
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:1435
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:219
AVCodecContext::intra_matrix
uint16_t * intra_matrix
custom intra quantization matrix Must be allocated with the av_malloc() family of functions,...
Definition: avcodec.h:941
w
uint8_t w
Definition: llviddspenc.c:38
AVOption
AVOption.
Definition: opt.h:294
FFCodec
Definition: codec_internal.h:127
AVCodecContext::subtitle_header
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:1780
avcodec_default_get_format
enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
Definition: decode.c:1045
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
FFCodec::priv_data_size
int priv_data_size
Definition: codec_internal.h:145
FFCodecDefault
Definition: codec_internal.h:97
AVCodecContext::codec
const struct AVCodec * codec
Definition: avcodec.h:454
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2111
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:497
AV_OPT_FLAG_AUDIO_PARAM
#define AV_OPT_FLAG_AUDIO_PARAM
Definition: opt.h:256
subtitle_rect_options
static const AVOption subtitle_rect_options[]
Definition: options.c:195
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:154
av_subtitle_rect_class
static const AVClass av_subtitle_rect_class
Definition: options.c:206
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:188
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:169
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:213
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:1281
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
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
ffcodec
static const av_always_inline FFCodec * ffcodec(const AVCodec *codec)
Definition: codec_internal.h:325
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:57
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:260
SROFFSET
#define SROFFSET(x)
Definition: options.c:193
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:71
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:546
internal.h
AV_OPT_FLAG_SUBTITLE_PARAM
#define AV_OPT_FLAG_SUBTITLE_PARAM
Definition: opt.h:258
AV_OPT_FLAG_VIDEO_PARAM
#define AV_OPT_FLAG_VIDEO_PARAM
Definition: opt.h:257
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:254
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:932
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:225
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:662
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:1440
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:435
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:83
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:950
d
d
Definition: ffmpeg_filter.c:424
AV_OPT_TYPE_FLAGS
@ AV_OPT_TYPE_FLAGS
Definition: opt.h:224
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
avcodec_options
static const AVOption avcodec_options[]
Definition: options_table.h:47
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