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internal.h
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1 /*
2  * copyright (c) 2001 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 
21 #ifndef AVFORMAT_INTERNAL_H
22 #define AVFORMAT_INTERNAL_H
23 
24 #include <stdint.h>
25 #include "avformat.h"
26 
27 #define MAX_URL_SIZE 4096
28 
29 #ifdef DEBUG
30 # define hex_dump_debug(class, buf, size) av_hex_dump_log(class, AV_LOG_DEBUG, buf, size)
31 #else
32 # define hex_dump_debug(class, buf, size)
33 #endif
34 
35 typedef struct AVCodecTag {
36  enum AVCodecID id;
37  unsigned int tag;
38 } AVCodecTag;
39 
40 typedef struct CodecMime{
41  char str[32];
42  enum AVCodecID id;
43 } CodecMime;
44 
45 #ifdef __GNUC__
46 #define dynarray_add(tab, nb_ptr, elem)\
47 do {\
48  __typeof__(tab) _tab = (tab);\
49  __typeof__(elem) _elem = (elem);\
50  (void)sizeof(**_tab == _elem); /* check that types are compatible */\
51  av_dynarray_add(_tab, nb_ptr, _elem);\
52 } while(0)
53 #else
54 #define dynarray_add(tab, nb_ptr, elem)\
55 do {\
56  av_dynarray_add((tab), nb_ptr, (elem));\
57 } while(0)
58 #endif
59 
60 struct tm *ff_brktimegm(time_t secs, struct tm *tm);
61 
62 char *ff_data_to_hex(char *buf, const uint8_t *src, int size, int lowercase);
63 
64 /**
65  * Parse a string of hexadecimal strings. Any space between the hexadecimal
66  * digits is ignored.
67  *
68  * @param data if non-null, the parsed data is written to this pointer
69  * @param p the string to parse
70  * @return the number of bytes written (or to be written, if data is null)
71  */
72 int ff_hex_to_data(uint8_t *data, const char *p);
73 
74 void ff_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
75 
76 /**
77  * Add packet to AVFormatContext->packet_buffer list, determining its
78  * interleaved position using compare() function argument.
79  * @return 0, or < 0 on error
80  */
82  int (*compare)(AVFormatContext *, AVPacket *, AVPacket *));
83 
85 
86 #define NTP_OFFSET 2208988800ULL
87 #define NTP_OFFSET_US (NTP_OFFSET * 1000000ULL)
88 
89 /** Get the current time since NTP epoch in microseconds. */
90 uint64_t ff_ntp_time(void);
91 
92 /**
93  * Assemble a URL string from components. This is the reverse operation
94  * of av_url_split.
95  *
96  * Note, this requires networking to be initialized, so the caller must
97  * ensure ff_network_init has been called.
98  *
99  * @see av_url_split
100  *
101  * @param str the buffer to fill with the url
102  * @param size the size of the str buffer
103  * @param proto the protocol identifier, if null, the separator
104  * after the identifier is left out, too
105  * @param authorization an optional authorization string, may be null.
106  * An empty string is treated the same as a null string.
107  * @param hostname the host name string
108  * @param port the port number, left out from the string if negative
109  * @param fmt a generic format string for everything to add after the
110  * host/port, may be null
111  * @return the number of characters written to the destination buffer
112  */
113 int ff_url_join(char *str, int size, const char *proto,
114  const char *authorization, const char *hostname,
115  int port, const char *fmt, ...) av_printf_format(7, 8);
116 
117 /**
118  * Append the media-specific SDP fragment for the media stream c
119  * to the buffer buff.
120  *
121  * Note, the buffer needs to be initialized, since it is appended to
122  * existing content.
123  *
124  * @param buff the buffer to append the SDP fragment to
125  * @param size the size of the buff buffer
126  * @param st the AVStream of the media to describe
127  * @param idx the global stream index
128  * @param dest_addr the destination address of the media stream, may be NULL
129  * @param dest_type the destination address type, may be NULL
130  * @param port the destination port of the media stream, 0 if unknown
131  * @param ttl the time to live of the stream, 0 if not multicast
132  * @param fmt the AVFormatContext, which might contain options modifying
133  * the generated SDP
134  */
135 void ff_sdp_write_media(char *buff, int size, AVStream *st, int idx,
136  const char *dest_addr, const char *dest_type,
137  int port, int ttl, AVFormatContext *fmt);
138 
139 /**
140  * Write a packet to another muxer than the one the user originally
141  * intended. Useful when chaining muxers, where one muxer internally
142  * writes a received packet to another muxer.
143  *
144  * @param dst the muxer to write the packet to
145  * @param dst_stream the stream index within dst to write the packet to
146  * @param pkt the packet to be written
147  * @param src the muxer the packet originally was intended for
148  * @return the value av_write_frame returned
149  */
150 int ff_write_chained(AVFormatContext *dst, int dst_stream, AVPacket *pkt,
151  AVFormatContext *src);
152 
153 /**
154  * Get the length in bytes which is needed to store val as v.
155  */
156 int ff_get_v_length(uint64_t val);
157 
158 /**
159  * Put val using a variable number of bytes.
160  */
161 void ff_put_v(AVIOContext *bc, uint64_t val);
162 
163 /**
164  * Read a whole line of text from AVIOContext. Stop reading after reaching
165  * either a \\n, a \\0 or EOF. The returned string is always \\0-terminated,
166  * and may be truncated if the buffer is too small.
167  *
168  * @param s the read-only AVIOContext
169  * @param buf buffer to store the read line
170  * @param maxlen size of the buffer
171  * @return the length of the string written in the buffer, not including the
172  * final \\0
173  */
174 int ff_get_line(AVIOContext *s, char *buf, int maxlen);
175 
176 #define SPACE_CHARS " \t\r\n"
177 
178 /**
179  * Callback function type for ff_parse_key_value.
180  *
181  * @param key a pointer to the key
182  * @param key_len the number of bytes that belong to the key, including the '='
183  * char
184  * @param dest return the destination pointer for the value in *dest, may
185  * be null to ignore the value
186  * @param dest_len the length of the *dest buffer
187  */
188 typedef void (*ff_parse_key_val_cb)(void *context, const char *key,
189  int key_len, char **dest, int *dest_len);
190 /**
191  * Parse a string with comma-separated key=value pairs. The value strings
192  * may be quoted and may contain escaped characters within quoted strings.
193  *
194  * @param str the string to parse
195  * @param callback_get_buf function that returns where to store the
196  * unescaped value string.
197  * @param context the opaque context pointer to pass to callback_get_buf
198  */
199 void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf,
200  void *context);
201 
202 /**
203  * Find stream index based on format-specific stream ID
204  * @return stream index, or < 0 on error
205  */
206 int ff_find_stream_index(AVFormatContext *s, int id);
207 
208 /**
209  * Internal version of av_index_search_timestamp
210  */
211 int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
212  int64_t wanted_timestamp, int flags);
213 
214 /**
215  * Internal version of av_add_index_entry
216  */
217 int ff_add_index_entry(AVIndexEntry **index_entries,
218  int *nb_index_entries,
219  unsigned int *index_entries_allocated_size,
220  int64_t pos, int64_t timestamp, int size, int distance, int flags);
221 
222 /**
223  * Add a new chapter.
224  *
225  * @param s media file handle
226  * @param id unique ID for this chapter
227  * @param start chapter start time in time_base units
228  * @param end chapter end time in time_base units
229  * @param title chapter title
230  *
231  * @return AVChapter or NULL on error
232  */
234  int64_t start, int64_t end, const char *title);
235 
236 /**
237  * Ensure the index uses less memory than the maximum specified in
238  * AVFormatContext.max_index_size by discarding entries if it grows
239  * too large.
240  */
241 void ff_reduce_index(AVFormatContext *s, int stream_index);
242 
243 /**
244  * Convert a relative url into an absolute url, given a base url.
245  *
246  * @param buf the buffer where output absolute url is written
247  * @param size the size of buf
248  * @param base the base url, may be equal to buf.
249  * @param rel the new url, which is interpreted relative to base
250  */
251 void ff_make_absolute_url(char *buf, int size, const char *base,
252  const char *rel);
253 
254 enum AVCodecID ff_guess_image2_codec(const char *filename);
255 
256 /**
257  * Convert a date string in ISO8601 format to Unix timestamp.
258  */
259 int64_t ff_iso8601_to_unix_time(const char *datestr);
260 
261 /**
262  * Perform a binary search using av_index_search_timestamp() and
263  * AVInputFormat.read_timestamp().
264  *
265  * @param target_ts target timestamp in the time base of the given stream
266  * @param stream_index stream number
267  */
268 int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
269  int64_t target_ts, int flags);
270 
271 /**
272  * Update cur_dts of all streams based on the given timestamp and AVStream.
273  *
274  * Stream ref_st unchanged, others set cur_dts in their native time base.
275  * Only needed for timestamp wrapping or if (dts not set and pts!=dts).
276  * @param timestamp new dts expressed in time_base of param ref_st
277  * @param ref_st reference stream giving time_base of param timestamp
278  */
279 void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
280 
281 /**
282  * Perform a binary search using read_timestamp().
283  *
284  * @param target_ts target timestamp in the time base of the given stream
285  * @param stream_index stream number
286  */
287 int64_t ff_gen_search(AVFormatContext *s, int stream_index,
288  int64_t target_ts, int64_t pos_min,
289  int64_t pos_max, int64_t pos_limit,
290  int64_t ts_min, int64_t ts_max,
291  int flags, int64_t *ts_ret,
292  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
293 
294 /**
295  * Set the time base and wrapping info for a given stream. This will be used
296  * to interpret the stream's timestamps. If the new time base is invalid
297  * (numerator or denominator are non-positive), it leaves the stream
298  * unchanged.
299  *
300  * @param s stream
301  * @param pts_wrap_bits number of bits effectively used by the pts
302  * (used for wrap control)
303  * @param pts_num time base numerator
304  * @param pts_den time base denominator
305  */
306 void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits,
307  unsigned int pts_num, unsigned int pts_den);
308 
309 /**
310  * Add side data to a packet for changing parameters to the given values.
311  * Parameters set to 0 aren't included in the change.
312  */
313 int ff_add_param_change(AVPacket *pkt, int32_t channels,
314  uint64_t channel_layout, int32_t sample_rate,
316 
317 /**
318  * Set the timebase for each stream from the corresponding codec timebase and
319  * print it.
320  */
322 
323 /**
324  * Read a transport packet from a media file.
325  *
326  * @param s media file handle
327  * @param pkt is filled
328  * @return 0 if OK, AVERROR_xxx on error
329  */
331 
332 /**
333  * Interleave a packet per dts in an output media file.
334  *
335  * Packets with pkt->destruct == av_destruct_packet will be freed inside this
336  * function, so they cannot be used after it. Note that calling av_free_packet()
337  * on them is still safe.
338  *
339  * @param s media file handle
340  * @param out the interleaved packet will be output here
341  * @param pkt the input packet
342  * @param flush 1 if no further packets are available as input and all
343  * remaining packets should be output
344  * @return 1 if a packet was output, 0 if no packet could be output,
345  * < 0 if an error occurred
346  */
348  AVPacket *pkt, int flush);
349 
351 
352 /**
353  * Return the frame duration in seconds. Return 0 if not available.
354  */
355 void ff_compute_frame_duration(int *pnum, int *pden, AVStream *st,
356  AVCodecParserContext *pc, AVPacket *pkt);
357 
358 int ff_get_audio_frame_size(AVCodecContext *enc, int size, int mux);
359 
360 unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id);
361 
362 enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag);
363 
364 /**
365  * Select a PCM codec based on the given parameters.
366  *
367  * @param bps bits-per-sample
368  * @param flt floating-point
369  * @param be big-endian
370  * @param sflags signed flags. each bit corresponds to one byte of bit depth.
371  * e.g. the 1st bit indicates if 8-bit should be signed or
372  * unsigned, the 2nd bit indicates if 16-bit should be signed or
373  * unsigned, etc... This is useful for formats such as WAVE where
374  * only 8-bit is unsigned and all other bit depths are signed.
375  * @return a PCM codec id or AV_CODEC_ID_NONE
376  */
377 enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
378 
379 /**
380  * Chooses a timebase for muxing the specified stream.
381  *
382  * The choosen timebase allows sample accurate timestamps based
383  * on the framerate or sample rate for audio streams. It also is
384  * at least as precisse as 1/min_precission would be.
385  */
386 AVRational ff_choose_timebase(AVFormatContext *s, AVStream *st, int min_precission);
387 
388 /**
389  * Generate standard extradata for AVC-Intra based on width/height and field order.
390  */
392 
393 #endif /* AVFORMAT_INTERNAL_H */