FFmpeg
options.c
Go to the documentation of this file.
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 "avcodec.h"
28 #include "internal.h"
29 #include "libavutil/avassert.h"
30 #include "libavutil/internal.h"
31 #include "libavutil/mem.h"
32 #include "libavutil/opt.h"
33 #include <string.h>
34 
36 #include "options_table.h"
38 
39 static const char* context_to_name(void* ptr) {
40  AVCodecContext *avc= ptr;
41 
42  if(avc && avc->codec && avc->codec->name)
43  return avc->codec->name;
44  else
45  return "NULL";
46 }
47 
48 static void *codec_child_next(void *obj, void *prev)
49 {
50  AVCodecContext *s = obj;
51  if (!prev && s->codec && s->codec->priv_class && s->priv_data)
52  return s->priv_data;
53  return NULL;
54 }
55 
56 static const AVClass *codec_child_class_next(const AVClass *prev)
57 {
58  AVCodec *c = NULL;
59 
60  /* find the codec that corresponds to prev */
61  while (prev && (c = av_codec_next(c)))
62  if (c->priv_class == prev)
63  break;
64 
65  /* find next codec with priv options */
66  while (c = av_codec_next(c))
67  if (c->priv_class)
68  return c->priv_class;
69  return NULL;
70 }
71 
72 static AVClassCategory get_category(void *ptr)
73 {
74  AVCodecContext* avctx = ptr;
75  if(avctx->codec && avctx->codec->decode) return AV_CLASS_CATEGORY_DECODER;
76  else return AV_CLASS_CATEGORY_ENCODER;
77 }
78 
80  .class_name = "AVCodecContext",
81  .item_name = context_to_name,
82  .option = avcodec_options,
83  .version = LIBAVUTIL_VERSION_INT,
84  .log_level_offset_offset = offsetof(AVCodecContext, log_level_offset),
85  .child_next = codec_child_next,
86  .child_class_next = codec_child_class_next,
88  .get_category = get_category,
89 };
90 
91 static int init_context_defaults(AVCodecContext *s, const AVCodec *codec)
92 {
93  int flags=0;
94  memset(s, 0, sizeof(AVCodecContext));
95 
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 
106  else if(s->codec_type == AVMEDIA_TYPE_VIDEO)
108  else if(s->codec_type == AVMEDIA_TYPE_SUBTITLE)
110  av_opt_set_defaults2(s, flags, flags);
111 
112  s->time_base = (AVRational){0,1};
113  s->framerate = (AVRational){ 0, 1 };
114  s->pkt_timebase = (AVRational){ 0, 1 };
119  s->sample_aspect_ratio = (AVRational){0,1};
123 
125  if(codec && codec->priv_data_size){
126  if(!s->priv_data){
127  s->priv_data= av_mallocz(codec->priv_data_size);
128  if (!s->priv_data) {
129  return AVERROR(ENOMEM);
130  }
131  }
132  if(codec->priv_class){
133  *(const AVClass**)s->priv_data = codec->priv_class;
135  }
136  }
137  if (codec && codec->defaults) {
138  int ret;
139  const AVCodecDefault *d = codec->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 
149 #if FF_API_GET_CONTEXT_DEFAULTS
151 {
152  return init_context_defaults(s, codec);
153 }
154 #endif
155 
157 {
158  AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
159 
160  if (!avctx)
161  return NULL;
162 
163  if (init_context_defaults(avctx, codec) < 0) {
164  av_free(avctx);
165  return NULL;
166  }
167 
168  return avctx;
169 }
170 
172 {
173  AVCodecContext *avctx = *pavctx;
174 
175  if (!avctx)
176  return;
177 
178  avcodec_close(avctx);
179 
180  av_freep(&avctx->extradata);
181  av_freep(&avctx->subtitle_header);
182  av_freep(&avctx->intra_matrix);
183  av_freep(&avctx->inter_matrix);
184  av_freep(&avctx->rc_override);
185 
186  av_freep(pavctx);
187 }
188 
189 #if FF_API_COPY_CONTEXT
191 {
192  int i;
193 
194  av_opt_free(avctx);
195 #if FF_API_CODED_FRAME
197  av_frame_free(&avctx->coded_frame);
199 #endif
200  av_freep(&avctx->rc_override);
201  av_freep(&avctx->intra_matrix);
202  av_freep(&avctx->inter_matrix);
203  av_freep(&avctx->extradata);
204  av_freep(&avctx->subtitle_header);
207  for (i = 0; i < avctx->nb_coded_side_data; i++)
208  av_freep(&avctx->coded_side_data[i].data);
209  av_freep(&avctx->coded_side_data);
210  avctx->subtitle_header_size = 0;
211  avctx->nb_coded_side_data = 0;
212  avctx->extradata_size = 0;
213 }
214 
216 {
217  const AVCodec *orig_codec = dest->codec;
218  uint8_t *orig_priv_data = dest->priv_data;
219 
220  if (avcodec_is_open(dest)) { // check that the dest context is uninitialized
221  av_log(dest, AV_LOG_ERROR,
222  "Tried to copy AVCodecContext %p into already-initialized %p\n",
223  src, dest);
224  return AVERROR(EINVAL);
225  }
226 
227  copy_context_reset(dest);
228 
229  memcpy(dest, src, sizeof(*dest));
230  av_opt_copy(dest, src);
231 
232  dest->priv_data = orig_priv_data;
233  dest->codec = orig_codec;
234 
235  if (orig_priv_data && src->codec && src->codec->priv_class &&
236  dest->codec && dest->codec->priv_class)
237  av_opt_copy(orig_priv_data, src->priv_data);
238 
239 
240  /* set values specific to opened codecs back to their default state */
241  dest->slice_offset = NULL;
242  dest->hwaccel = NULL;
243  dest->internal = NULL;
244 #if FF_API_CODED_FRAME
246  dest->coded_frame = NULL;
248 #endif
249 
250  /* reallocate values that should be allocated separately */
251  dest->extradata = NULL;
252  dest->coded_side_data = NULL;
253  dest->intra_matrix = NULL;
254  dest->inter_matrix = NULL;
255  dest->rc_override = NULL;
256  dest->subtitle_header = NULL;
257  dest->hw_frames_ctx = NULL;
258  dest->hw_device_ctx = NULL;
259  dest->nb_coded_side_data = 0;
260 
261 #define alloc_and_copy_or_fail(obj, size, pad) \
262  if (src->obj && size > 0) { \
263  dest->obj = av_malloc(size + pad); \
264  if (!dest->obj) \
265  goto fail; \
266  memcpy(dest->obj, src->obj, size); \
267  if (pad) \
268  memset(((uint8_t *) dest->obj) + size, 0, pad); \
269  }
270  alloc_and_copy_or_fail(extradata, src->extradata_size,
272  dest->extradata_size = src->extradata_size;
273  alloc_and_copy_or_fail(intra_matrix, 64 * sizeof(int16_t), 0);
274  alloc_and_copy_or_fail(inter_matrix, 64 * sizeof(int16_t), 0);
275  alloc_and_copy_or_fail(rc_override, src->rc_override_count * sizeof(*src->rc_override), 0);
276  alloc_and_copy_or_fail(subtitle_header, src->subtitle_header_size, 1);
278 #undef alloc_and_copy_or_fail
279 
280  if (src->hw_frames_ctx) {
282  if (!dest->hw_frames_ctx)
283  goto fail;
284  }
285 
286  return 0;
287 
288 fail:
289  copy_context_reset(dest);
290  return AVERROR(ENOMEM);
291 }
292 #endif
293 
295 {
296  return &av_codec_context_class;
297 }
298 
299 #define FOFFSET(x) offsetof(AVFrame,x)
300 
301 static const AVOption frame_options[]={
302 {"best_effort_timestamp", "", FOFFSET(best_effort_timestamp), AV_OPT_TYPE_INT64, {.i64 = AV_NOPTS_VALUE }, INT64_MIN, INT64_MAX, 0},
303 {"pkt_pos", "", FOFFSET(pkt_pos), AV_OPT_TYPE_INT64, {.i64 = -1 }, INT64_MIN, INT64_MAX, 0},
304 {"pkt_size", "", FOFFSET(pkt_size), AV_OPT_TYPE_INT64, {.i64 = -1 }, INT64_MIN, INT64_MAX, 0},
305 {"sample_aspect_ratio", "", FOFFSET(sample_aspect_ratio), AV_OPT_TYPE_RATIONAL, {.dbl = 0 }, 0, INT_MAX, 0},
306 {"width", "", FOFFSET(width), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
307 {"height", "", FOFFSET(height), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
308 {"format", "", FOFFSET(format), AV_OPT_TYPE_INT, {.i64 = -1 }, 0, INT_MAX, 0},
309 {"channel_layout", "", FOFFSET(channel_layout), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, 0},
310 {"sample_rate", "", FOFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
311 {NULL},
312 };
313 
314 static const AVClass av_frame_class = {
315  .class_name = "AVFrame",
316  .item_name = NULL,
317  .option = frame_options,
318  .version = LIBAVUTIL_VERSION_INT,
319 };
320 
322 {
323  return &av_frame_class;
324 }
325 
326 #define SROFFSET(x) offsetof(AVSubtitleRect,x)
327 
329 {"x", "", SROFFSET(x), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
330 {"y", "", SROFFSET(y), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
331 {"w", "", SROFFSET(w), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
332 {"h", "", SROFFSET(h), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
333 {"type", "", SROFFSET(type), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
334 {"flags", "", SROFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, 1, 0, "flags"},
335 {"forced", "", SROFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, 1, 0},
336 {NULL},
337 };
338 
340  .class_name = "AVSubtitleRect",
341  .item_name = NULL,
342  .option = subtitle_rect_options,
343  .version = LIBAVUTIL_VERSION_INT,
344 };
345 
347 {
348  return &av_subtitle_rect_class;
349 }
enum AVPixelFormat(* get_format)(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
callback to negotiate the pixelFormat
Definition: avcodec.h:1822
#define NULL
Definition: coverity.c:32
const struct AVCodec * codec
Definition: avcodec.h:1579
AVRational framerate
Definition: avcodec.h:3110
void av_buffer_unref(AVBufferRef **buf)
Free a given reference and automatically free the buffer if there are no more references to it...
Definition: buffer.c:125
int avcodec_default_execute2(AVCodecContext *c, int(*func)(AVCodecContext *c2, void *arg2, int, int), void *arg, int *ret, int count)
AVOption.
Definition: opt.h:246
#define AV_OPT_FLAG_SUBTITLE_PARAM
Definition: opt.h:280
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
Memory handling functions.
AVCodec * av_codec_next(const AVCodec *c)
If c is NULL, returns the first registered codec, if c is non-NULL, returns the next registered codec...
Definition: allcodecs.c:846
void av_opt_set_defaults(void *s)
Set the values of all AVOption fields to their default values.
Definition: opt.c:1328
#define AV_OPT_FLAG_AUDIO_PARAM
Definition: opt.h:278
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel...
Definition: avcodec.h:1949
static const AVOption avcodec_options[]
Definition: options_table.h:44
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1780
GLint GLenum type
Definition: opengl_enc.c:104
enum AVMediaType type
Definition: avcodec.h:3507
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
const struct AVHWAccel * hwaccel
Hardware accelerator in use.
Definition: avcodec.h:2734
#define src
Definition: vp8dsp.c:254
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 format(the sample packing is implied by the sample format) and sample rate.The lists are not just lists
AVCodec.
Definition: avcodec.h:3494
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avcodec.h:1693
static void copy_context_reset(AVCodecContext *avctx)
Definition: options.c:190
const AVClass * avcodec_get_class(void)
Get the AVClass for AVCodecContext.
Definition: options.c:294
static const AVClass av_codec_context_class
Definition: options.c:79
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:72
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
static int init_context_defaults(AVCodecContext *s, const AVCodec *codec)
Definition: options.c:91
enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
Definition: decode.c:1158
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2238
uint8_t
#define av_malloc(s)
static const AVOption subtitle_rect_options[]
Definition: options.c:328
AVOptions.
int subtitle_header_size
Definition: avcodec.h:3056
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
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1671
const AVClass * av_class
information on struct for av_log
Definition: avcodec.h:1575
static const AVClass av_subtitle_rect_class
Definition: options.c:339
#define height
uint8_t * data
Definition: avcodec.h:1426
const AVClass * avcodec_get_frame_class(void)
Get the AVClass for AVFrame.
Definition: options.c:321
#define av_log(a,...)
int avcodec_close(AVCodecContext *avctx)
Close a given AVCodecContext and free all the data associated with it (but not the AVCodecContext its...
Definition: utils.c:1100
AVRational pkt_timebase
Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
Definition: avcodec.h:3124
enum AVCodecID id
Definition: avcodec.h:3508
const AVCodecDefault * defaults
Private codec-specific defaults.
Definition: avcodec.h:3567
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
int avcodec_is_open(AVCodecContext *s)
Definition: utils.c:1898
static void * codec_child_next(void *obj, void *prev)
Definition: options.c:48
simple assert() macros that are a bit more flexible than ISO C assert().
const char * name
Name of the codec implementation.
Definition: avcodec.h:3501
AVClassCategory category
Category used for visualization (like color) This is only set if the category is equal for all object...
Definition: log.h:130
#define fail()
Definition: checkasm.h:122
common internal API header
int rc_override_count
ratecontrol override, see RcOverride
Definition: avcodec.h:2440
AVPacketSideData * coded_side_data
Additional data associated with the entire coded stream.
Definition: avcodec.h:3242
int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src)
Copy the settings of the source AVCodecContext into the destination AVCodecContext.
Definition: options.c:215
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
Definition: options.c:156
#define width
uint8_t w
Definition: llviddspenc.c:38
AVBufferRef * hw_frames_ctx
A reference to the AVHWFramesContext describing the input (for encoding) or output (decoding) frames...
Definition: avcodec.h:3267
int priv_data_size
Definition: avcodec.h:3542
static const AVClass * codec_child_class_next(const AVClass *prev)
Definition: options.c:56
const AVClass * avcodec_get_subtitle_rect_class(void)
Get the AVClass for AVSubtitleRect.
Definition: options.c:346
#define s(width, name)
Definition: cbs_vp9.c:257
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:1333
int64_t reordered_opaque
opaque 64-bit number (generally a PTS) that will be reordered and output in AVFrame.reordered_opaque
Definition: avcodec.h:2727
Usually treated as AVMEDIA_TYPE_DATA.
Definition: avutil.h:200
RcOverride * rc_override
Definition: avcodec.h:2441
int(* execute2)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count)
The codec may call this to execute several independent things.
Definition: avcodec.h:2889
sample_rate
int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags)
The default callback for AVCodecContext.get_buffer2().
Definition: decode.c:1701
#define SROFFSET(x)
Definition: options.c:326
Libavcodec external API header.
enum AVMediaType codec_type
Definition: avcodec.h:1578
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:171
enum AVCodecID codec_id
Definition: avcodec.h:1580
#define AV_OPT_FLAG_VIDEO_PARAM
Definition: opt.h:279
main external API structure.
Definition: avcodec.h:1570
int extradata_size
Definition: avcodec.h:1672
uint16_t * intra_matrix
custom intra quantization matrix Must be allocated with the av_malloc() family of functions...
Definition: avcodec.h:2070
int nb_coded_side_data
Definition: avcodec.h:3243
Describe the class of an AVClass context structure.
Definition: log.h:67
int(* get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags)
This callback is called at the beginning of each frame to get data buffer(s) for it.
Definition: avcodec.h:2385
Rational number (pair of numerator and denominator).
Definition: rational.h:58
uint16_t * inter_matrix
custom inter quantization matrix Must be allocated with the av_malloc() family of functions...
Definition: avcodec.h:2079
#define flags(name, subs,...)
Definition: cbs_av1.c:561
const AVClass * priv_class
AVClass for the private context.
Definition: avcodec.h:3520
const uint8_t * key
Definition: internal.h:232
const uint8_t * value
Definition: internal.h:233
void av_opt_free(void *obj)
Free all allocated objects in obj.
Definition: opt.c:1581
static const AVOption frame_options[]
Definition: options.c:301
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:84
int(* decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt)
Definition: avcodec.h:3592
common internal api header.
AVBufferRef * av_buffer_ref(AVBufferRef *buf)
Create a new reference to an AVBuffer.
Definition: buffer.c:93
int av_opt_copy(void *dst, const void *src)
Copy options from src object into dest object.
Definition: opt.c:1739
static AVClassCategory get_category(void *ptr)
Definition: options.c:72
attribute_deprecated AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:2820
static const AVClass av_frame_class
Definition: options.c:314
int avcodec_get_context_defaults3(AVCodecContext *s, const AVCodec *codec)
Definition: options.c:150
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:795
void * priv_data
Definition: avcodec.h:1597
#define av_free(p)
AVClassCategory
Definition: log.h:29
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:85
#define alloc_and_copy_or_fail(obj, size, pad)
struct AVCodecInternal * internal
Private context used for internal data.
Definition: avcodec.h:1605
FF_DISABLE_DEPRECATION_WARNINGS static FF_ENABLE_DEPRECATION_WARNINGS const char * context_to_name(void *ptr)
Definition: options.c:39
int * slice_offset
slice offsets in the frame in bytes
Definition: avcodec.h:1940
#define av_freep(p)
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
AVBufferRef * hw_device_ctx
A reference to the AVHWDeviceContext describing the device which will be used by a hardware encoder/d...
Definition: avcodec.h:3319
int(* execute)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size)
The codec may call this to execute several independent things.
Definition: avcodec.h:2869
int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
Definition: opt.c:449
enum AVPixelFormat sw_pix_fmt
Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:3117
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
#define FOFFSET(x)
Definition: options.c:299
int avcodec_default_execute(AVCodecContext *c, int(*func)(AVCodecContext *c2, void *arg2), void *arg, int *ret, int count, int size)
Definition: utils.c:441
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:3055