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1 /*
2  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 #include "avformat.h"
21 #include "avio_internal.h"
22 #include "demux.h"
23 #include "internal.h"
24 
25 #include "libavcodec/avcodec.h"
26 #include "libavcodec/codec_par.h"
27 
28 #include "libavutil/avassert.h"
29 #include "libavutil/internal.h"
30 #include "libavutil/intmath.h"
31 #include "libavutil/opt.h"
32 
33 /**
34  * @file
35  * Options definition for AVFormatContext.
36  */
37 
38 FF_DISABLE_DEPRECATION_WARNINGS
39 #include "options_table.h"
40 FF_ENABLE_DEPRECATION_WARNINGS
41 
format_to_name(void * ptr)42 static const char* format_to_name(void* ptr)
43 {
44     AVFormatContext* fc = (AVFormatContext*) ptr;
45     if(fc->iformat) return fc->iformat->name;
46     else if(fc->oformat) return fc->oformat->name;
47     else return "NULL";
48 }
49 
format_child_next(void * obj,void * prev)50 static void *format_child_next(void *obj, void *prev)
51 {
52     AVFormatContext *s = obj;
53     if (!prev && s->priv_data &&
54         ((s->iformat && s->iformat->priv_class) ||
55           s->oformat && s->oformat->priv_class))
56         return s->priv_data;
57     if (s->pb && s->pb->av_class && prev != s->pb)
58         return s->pb;
59     return NULL;
60 }
61 
62 enum {
63     CHILD_CLASS_ITER_AVIO = 0,
64     CHILD_CLASS_ITER_MUX,
65     CHILD_CLASS_ITER_DEMUX,
66     CHILD_CLASS_ITER_DONE,
67 
68 };
69 
70 #define ITER_STATE_SHIFT 16
71 
format_child_class_iterate(void ** iter)72 static const AVClass *format_child_class_iterate(void **iter)
73 {
74     // we use the low 16 bits of iter as the value to be passed to
75     // av_(de)muxer_iterate()
76     void *val = (void*)(((uintptr_t)*iter) & ((1 << ITER_STATE_SHIFT) - 1));
77     unsigned int state = ((uintptr_t)*iter) >> ITER_STATE_SHIFT;
78     const AVClass *ret = NULL;
79 
80     if (state == CHILD_CLASS_ITER_AVIO) {
81         ret = &ff_avio_class;
82         state++;
83         goto finish;
84     }
85 
86     if (state == CHILD_CLASS_ITER_MUX) {
87         const AVOutputFormat *ofmt;
88 
89         while ((ofmt = av_muxer_iterate(&val))) {
90             ret = ofmt->priv_class;
91             if (ret)
92                 goto finish;
93         }
94 
95         val = NULL;
96         state++;
97     }
98 
99     if (state == CHILD_CLASS_ITER_DEMUX) {
100         const AVInputFormat *ifmt;
101 
102         while ((ifmt = av_demuxer_iterate(&val))) {
103             ret = ifmt->priv_class;
104             if (ret)
105                 goto finish;
106         }
107         val = NULL;
108         state++;
109     }
110 
111 finish:
112     // make sure none av_(de)muxer_iterate does not set the high bits of val
113     av_assert0(!((uintptr_t)val >> ITER_STATE_SHIFT));
114     *iter = (void*)((uintptr_t)val | (state << ITER_STATE_SHIFT));
115     return ret;
116 }
117 
get_category(void * ptr)118 static AVClassCategory get_category(void *ptr)
119 {
120     AVFormatContext* s = ptr;
121     if(s->iformat) return AV_CLASS_CATEGORY_DEMUXER;
122     else           return AV_CLASS_CATEGORY_MUXER;
123 }
124 
125 static const AVClass av_format_context_class = {
126     .class_name     = "AVFormatContext",
127     .item_name      = format_to_name,
128     .option         = avformat_options,
129     .version        = LIBAVUTIL_VERSION_INT,
130     .child_next     = format_child_next,
131     .child_class_iterate = format_child_class_iterate,
132     .category       = AV_CLASS_CATEGORY_MUXER,
133     .get_category   = get_category,
134 };
135 
io_open_default(AVFormatContext * s,AVIOContext ** pb,const char * url,int flags,AVDictionary ** options)136 static int io_open_default(AVFormatContext *s, AVIOContext **pb,
137                            const char *url, int flags, AVDictionary **options)
138 {
139     int loglevel;
140 
141     if (!strcmp(url, s->url) ||
142         s->iformat && !strcmp(s->iformat->name, "image2") ||
143         s->oformat && !strcmp(s->oformat->name, "image2")
144     ) {
145         loglevel = AV_LOG_DEBUG;
146     } else
147         loglevel = AV_LOG_INFO;
148 
149     av_log(s, loglevel, "Opening \'%s\' for %s\n", url, flags & AVIO_FLAG_WRITE ? "writing" : "reading");
150 
151     return ffio_open_whitelist(pb, url, flags, &s->interrupt_callback, options, s->protocol_whitelist, s->protocol_blacklist);
152 }
153 
ff_format_io_close_default(AVFormatContext * s,AVIOContext * pb)154 void ff_format_io_close_default(AVFormatContext *s, AVIOContext *pb)
155 {
156     avio_close(pb);
157 }
158 
io_close2_default(AVFormatContext * s,AVIOContext * pb)159 static int io_close2_default(AVFormatContext *s, AVIOContext *pb)
160 {
161     return avio_close(pb);
162 }
163 
avformat_alloc_context(void)164 AVFormatContext *avformat_alloc_context(void)
165 {
166     FFFormatContext *const si = av_mallocz(sizeof(*si));
167     AVFormatContext *s;
168 
169     if (!si)
170         return NULL;
171 
172     s = &si->pub;
173     s->av_class = &av_format_context_class;
174     s->io_open  = io_open_default;
175     s->io_close = ff_format_io_close_default;
176     s->io_close2= io_close2_default;
177 
178     av_opt_set_defaults(s);
179 
180     si->pkt = av_packet_alloc();
181     si->parse_pkt = av_packet_alloc();
182     if (!si->pkt || !si->parse_pkt) {
183         avformat_free_context(s);
184         return NULL;
185     }
186 
187     si->shortest_end = AV_NOPTS_VALUE;
188 
189     return s;
190 }
191 
av_fmt_ctx_get_duration_estimation_method(const AVFormatContext * ctx)192 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx)
193 {
194     return ctx->duration_estimation_method;
195 }
196 
avformat_get_class(void)197 const AVClass *avformat_get_class(void)
198 {
199     return &av_format_context_class;
200 }
201 
202 static const AVOption stream_options[] = {
203     { "disposition", NULL, offsetof(AVStream, disposition), AV_OPT_TYPE_FLAGS, { .i64 = 0 },
204         .flags = AV_OPT_FLAG_ENCODING_PARAM, .unit = "disposition" },
205         { "default",            .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_DEFAULT           },    .unit = "disposition" },
206         { "dub",                .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_DUB               },    .unit = "disposition" },
207         { "original",           .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_ORIGINAL          },    .unit = "disposition" },
208         { "comment",            .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_COMMENT           },    .unit = "disposition" },
209         { "lyrics",             .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_LYRICS            },    .unit = "disposition" },
210         { "karaoke",            .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_KARAOKE           },    .unit = "disposition" },
211         { "forced",             .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_FORCED            },    .unit = "disposition" },
212         { "hearing_impaired",   .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_HEARING_IMPAIRED  },    .unit = "disposition" },
213         { "visual_impaired",    .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_VISUAL_IMPAIRED   },    .unit = "disposition" },
214         { "clean_effects",      .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_CLEAN_EFFECTS     },    .unit = "disposition" },
215         { "attached_pic",       .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_ATTACHED_PIC      },    .unit = "disposition" },
216         { "timed_thumbnails",   .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_TIMED_THUMBNAILS  },    .unit = "disposition" },
217         { "captions",           .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_CAPTIONS          },    .unit = "disposition" },
218         { "descriptions",       .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_DESCRIPTIONS      },    .unit = "disposition" },
219         { "metadata",           .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_METADATA          },    .unit = "disposition" },
220         { "dependent",          .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_DEPENDENT         },    .unit = "disposition" },
221         { "still_image",        .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_STILL_IMAGE       },    .unit = "disposition" },
222     { NULL }
223 };
224 
225 static const AVClass stream_class = {
226     .class_name     = "AVStream",
227     .item_name      = av_default_item_name,
228     .version        = LIBAVUTIL_VERSION_INT,
229     .option         = stream_options,
230 };
231 
av_stream_get_class(void)232 const AVClass *av_stream_get_class(void)
233 {
234     return &stream_class;
235 }
236 
avformat_new_stream(AVFormatContext * s,const AVCodec * c)237 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c)
238 {
239     FFFormatContext *const si = ffformatcontext(s);
240     FFStream *sti;
241     AVStream *st;
242     AVStream **streams;
243 
244     if (s->nb_streams >= s->max_streams) {
245         av_log(s, AV_LOG_ERROR, "Number of streams exceeds max_streams parameter"
246                " (%d), see the documentation if you wish to increase it\n",
247                s->max_streams);
248         return NULL;
249     }
250     streams = av_realloc_array(s->streams, s->nb_streams + 1, sizeof(*streams));
251     if (!streams)
252         return NULL;
253     s->streams = streams;
254 
255     sti = av_mallocz(sizeof(*sti));
256     if (!sti)
257         return NULL;
258     st = &sti->pub;
259 
260 #if FF_API_AVSTREAM_CLASS
261     st->av_class = &stream_class;
262 #endif
263 
264     st->codecpar = avcodec_parameters_alloc();
265     if (!st->codecpar)
266         goto fail;
267 
268     sti->avctx = avcodec_alloc_context3(NULL);
269     if (!sti->avctx)
270         goto fail;
271 
272     if (s->iformat) {
273         sti->info = av_mallocz(sizeof(*sti->info));
274         if (!sti->info)
275             goto fail;
276 
277 #if FF_API_R_FRAME_RATE
278         sti->info->last_dts      = AV_NOPTS_VALUE;
279 #endif
280         sti->info->fps_first_dts = AV_NOPTS_VALUE;
281         sti->info->fps_last_dts  = AV_NOPTS_VALUE;
282 
283         /* default pts setting is MPEG-like */
284         avpriv_set_pts_info(st, 33, 1, 90000);
285         /* we set the current DTS to 0 so that formats without any timestamps
286          * but durations get some timestamps, formats with some unknown
287          * timestamps have their first few packets buffered and the
288          * timestamps corrected before they are returned to the user */
289         sti->cur_dts = RELATIVE_TS_BASE;
290     } else {
291         sti->cur_dts = AV_NOPTS_VALUE;
292     }
293 
294     st->index      = s->nb_streams;
295     st->start_time = AV_NOPTS_VALUE;
296     st->duration   = AV_NOPTS_VALUE;
297     sti->first_dts     = AV_NOPTS_VALUE;
298     sti->probe_packets = s->max_probe_packets;
299     sti->pts_wrap_reference = AV_NOPTS_VALUE;
300     sti->pts_wrap_behavior  = AV_PTS_WRAP_IGNORE;
301 
302     sti->last_IP_pts = AV_NOPTS_VALUE;
303     sti->last_dts_for_order_check = AV_NOPTS_VALUE;
304     for (int i = 0; i < MAX_REORDER_DELAY + 1; i++)
305         sti->pts_buffer[i] = AV_NOPTS_VALUE;
306 
307     st->sample_aspect_ratio = (AVRational) { 0, 1 };
308 
309     sti->inject_global_side_data = si->inject_global_side_data;
310 
311     sti->need_context_update = 1;
312 
313     s->streams[s->nb_streams++] = st;
314     return st;
315 fail:
316     ff_free_stream(&st);
317     return NULL;
318 }
319 
option_is_disposition(const AVOption * opt)320 static int option_is_disposition(const AVOption *opt)
321 {
322     return opt->type == AV_OPT_TYPE_CONST &&
323            opt->unit && !strcmp(opt->unit, "disposition");
324 }
325 
av_disposition_from_string(const char * disp)326 int av_disposition_from_string(const char *disp)
327 {
328     for (const AVOption *opt = stream_options; opt->name; opt++)
329         if (option_is_disposition(opt) && !strcmp(disp, opt->name))
330             return opt->default_val.i64;
331     return AVERROR(EINVAL);
332 }
333 
av_disposition_to_string(int disposition)334 const char *av_disposition_to_string(int disposition)
335 {
336     int val;
337 
338     if (disposition <= 0)
339         return NULL;
340 
341     val = 1 << ff_ctz(disposition);
342     for (const AVOption *opt = stream_options; opt->name; opt++)
343         if (option_is_disposition(opt) && opt->default_val.i64 == val)
344             return opt->name;
345 
346     return NULL;
347 }
348