Libav
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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "libavutil/avassert.h"
30 #include "libavutil/mem.h"
31 #include "libavutil/opt.h"
32 #include <float.h> /* FLT_MIN, FLT_MAX */
33 #include <string.h>
34 
35 #include "options_table.h"
36 
37 static const char* context_to_name(void* ptr) {
38  AVCodecContext *avc= ptr;
39 
40  if(avc && avc->codec && avc->codec->name)
41  return avc->codec->name;
42  else
43  return "NULL";
44 }
45 
46 static void *codec_child_next(void *obj, void *prev)
47 {
48  AVCodecContext *s = obj;
49  if (!prev && s->codec && s->codec->priv_class && s->priv_data)
50  return s->priv_data;
51  return NULL;
52 }
53 
54 static const AVClass *codec_child_class_next(const AVClass *prev)
55 {
56  AVCodec *c = NULL;
57 
58  /* find the codec that corresponds to prev */
59  while (prev && (c = av_codec_next(c)))
60  if (c->priv_class == prev)
61  break;
62 
63  /* find next codec with priv options */
64  while (c = av_codec_next(c))
65  if (c->priv_class)
66  return c->priv_class;
67  return NULL;
68 }
69 
71  .class_name = "AVCodecContext",
72  .item_name = context_to_name,
73  .option = avcodec_options,
74  .version = LIBAVUTIL_VERSION_INT,
75  .log_level_offset_offset = offsetof(AVCodecContext, log_level_offset),
76  .child_next = codec_child_next,
77  .child_class_next = codec_child_class_next,
78 };
79 
81 {
82  memset(s, 0, sizeof(AVCodecContext));
83 
85 
86  s->codec_type = codec ? codec->type : AVMEDIA_TYPE_UNKNOWN;
87  s->codec = codec;
89 
90  s->time_base = (AVRational){0,1};
95  s->sample_aspect_ratio = (AVRational){0,1};
98 
100  if(codec && codec->priv_data_size){
101  if(!s->priv_data){
102  s->priv_data= av_mallocz(codec->priv_data_size);
103  if (!s->priv_data) {
104  return AVERROR(ENOMEM);
105  }
106  }
107  if(codec->priv_class){
108  *(const AVClass**)s->priv_data = codec->priv_class;
110  }
111  }
112  if (codec && codec->defaults) {
113  int ret;
114  const AVCodecDefault *d = codec->defaults;
115  while (d->key) {
116  ret = av_opt_set(s, d->key, d->value, 0);
117  av_assert0(ret >= 0);
118  d++;
119  }
120  }
121  return 0;
122 }
123 
125 {
126  AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
127 
128  if(avctx==NULL) return NULL;
129 
130  if(avcodec_get_context_defaults3(avctx, codec) < 0){
131  av_free(avctx);
132  return NULL;
133  }
134 
135  return avctx;
136 }
137 
139 {
140  if (avcodec_is_open(dest)) { // check that the dest context is uninitialized
141  av_log(dest, AV_LOG_ERROR,
142  "Tried to copy AVCodecContext %p into already-initialized %p\n",
143  src, dest);
144  return AVERROR(EINVAL);
145  }
146  memcpy(dest, src, sizeof(*dest));
147 
148  /* set values specific to opened codecs back to their default state */
149  dest->priv_data = NULL;
150  dest->codec = NULL;
151  dest->slice_offset = NULL;
152  dest->hwaccel = NULL;
153  dest->internal = NULL;
154 
155  /* reallocate values that should be allocated separately */
156  dest->rc_eq = NULL;
157  dest->extradata = NULL;
158  dest->intra_matrix = NULL;
159  dest->inter_matrix = NULL;
160  dest->rc_override = NULL;
161  if (src->rc_eq) {
162  dest->rc_eq = av_strdup(src->rc_eq);
163  if (!dest->rc_eq)
164  return AVERROR(ENOMEM);
165  }
166 
167 #define alloc_and_copy_or_fail(obj, size, pad) \
168  if (src->obj && size > 0) { \
169  dest->obj = av_malloc(size + pad); \
170  if (!dest->obj) \
171  goto fail; \
172  memcpy(dest->obj, src->obj, size); \
173  if (pad) \
174  memset(((uint8_t *) dest->obj) + size, 0, pad); \
175  }
176  alloc_and_copy_or_fail(extradata, src->extradata_size,
178  alloc_and_copy_or_fail(intra_matrix, 64 * sizeof(int16_t), 0);
179  alloc_and_copy_or_fail(inter_matrix, 64 * sizeof(int16_t), 0);
180  alloc_and_copy_or_fail(rc_override, src->rc_override_count * sizeof(*src->rc_override), 0);
181 #undef alloc_and_copy_or_fail
182 
183  return 0;
184 
185 fail:
186  av_freep(&dest->rc_override);
187  av_freep(&dest->intra_matrix);
188  av_freep(&dest->inter_matrix);
189  av_freep(&dest->extradata);
190  av_freep(&dest->rc_eq);
191  return AVERROR(ENOMEM);
192 }
193 
195 {
196  return &av_codec_context_class;
197 }