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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  * Append the media-specific SDP fragment for the media stream c
94  * to the buffer buff.
95  *
96  * Note, the buffer needs to be initialized, since it is appended to
97  * existing content.
98  *
99  * @param buff the buffer to append the SDP fragment to
100  * @param size the size of the buff buffer
101  * @param st the AVStream of the media to describe
102  * @param idx the global stream index
103  * @param dest_addr the destination address of the media stream, may be NULL
104  * @param dest_type the destination address type, may be NULL
105  * @param port the destination port of the media stream, 0 if unknown
106  * @param ttl the time to live of the stream, 0 if not multicast
107  * @param fmt the AVFormatContext, which might contain options modifying
108  * the generated SDP
109  */
110 void ff_sdp_write_media(char *buff, int size, AVStream *st, int idx,
111  const char *dest_addr, const char *dest_type,
112  int port, int ttl, AVFormatContext *fmt);
113 
114 /**
115  * Write a packet to another muxer than the one the user originally
116  * intended. Useful when chaining muxers, where one muxer internally
117  * writes a received packet to another muxer.
118  *
119  * @param dst the muxer to write the packet to
120  * @param dst_stream the stream index within dst to write the packet to
121  * @param pkt the packet to be written
122  * @param src the muxer the packet originally was intended for
123  * @return the value av_write_frame returned
124  */
125 int ff_write_chained(AVFormatContext *dst, int dst_stream, AVPacket *pkt,
127 
128 /**
129  * Get the length in bytes which is needed to store val as v.
130  */
131 int ff_get_v_length(uint64_t val);
132 
133 /**
134  * Put val using a variable number of bytes.
135  */
136 void ff_put_v(AVIOContext *bc, uint64_t val);
137 
138 /**
139  * Read a whole line of text from AVIOContext. Stop reading after reaching
140  * either a \\n, a \\0 or EOF. The returned string is always \\0-terminated,
141  * and may be truncated if the buffer is too small.
142  *
143  * @param s the read-only AVIOContext
144  * @param buf buffer to store the read line
145  * @param maxlen size of the buffer
146  * @return the length of the string written in the buffer, not including the
147  * final \\0
148  */
149 int ff_get_line(AVIOContext *s, char *buf, int maxlen);
150 
151 #define SPACE_CHARS " \t\r\n"
152 
153 /**
154  * Callback function type for ff_parse_key_value.
155  *
156  * @param key a pointer to the key
157  * @param key_len the number of bytes that belong to the key, including the '='
158  * char
159  * @param dest return the destination pointer for the value in *dest, may
160  * be null to ignore the value
161  * @param dest_len the length of the *dest buffer
162  */
163 typedef void (*ff_parse_key_val_cb)(void *context, const char *key,
164  int key_len, char **dest, int *dest_len);
165 /**
166  * Parse a string with comma-separated key=value pairs. The value strings
167  * may be quoted and may contain escaped characters within quoted strings.
168  *
169  * @param str the string to parse
170  * @param callback_get_buf function that returns where to store the
171  * unescaped value string.
172  * @param context the opaque context pointer to pass to callback_get_buf
173  */
174 void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf,
175  void *context);
176 
177 /**
178  * Find stream index based on format-specific stream ID
179  * @return stream index, or < 0 on error
180  */
181 int ff_find_stream_index(AVFormatContext *s, int id);
182 
183 /**
184  * Internal version of av_index_search_timestamp
185  */
186 int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
187  int64_t wanted_timestamp, int flags);
188 
189 /**
190  * Internal version of av_add_index_entry
191  */
192 int ff_add_index_entry(AVIndexEntry **index_entries,
193  int *nb_index_entries,
194  unsigned int *index_entries_allocated_size,
195  int64_t pos, int64_t timestamp, int size, int distance, int flags);
196 
197 /**
198  * Add a new chapter.
199  *
200  * @param s media file handle
201  * @param id unique ID for this chapter
202  * @param start chapter start time in time_base units
203  * @param end chapter end time in time_base units
204  * @param title chapter title
205  *
206  * @return AVChapter or NULL on error
207  */
209  int64_t start, int64_t end, const char *title);
210 
211 /**
212  * Ensure the index uses less memory than the maximum specified in
213  * AVFormatContext.max_index_size by discarding entries if it grows
214  * too large.
215  */
216 void ff_reduce_index(AVFormatContext *s, int stream_index);
217 
218 enum AVCodecID ff_guess_image2_codec(const char *filename);
219 
220 /**
221  * Convert a date string in ISO8601 format to Unix timestamp.
222  */
223 int64_t ff_iso8601_to_unix_time(const char *datestr);
224 
225 /**
226  * Perform a binary search using av_index_search_timestamp() and
227  * AVInputFormat.read_timestamp().
228  *
229  * @param target_ts target timestamp in the time base of the given stream
230  * @param stream_index stream number
231  */
232 int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
233  int64_t target_ts, int flags);
234 
235 /**
236  * Update cur_dts of all streams based on the given timestamp and AVStream.
237  *
238  * Stream ref_st unchanged, others set cur_dts in their native time base.
239  * Only needed for timestamp wrapping or if (dts not set and pts!=dts).
240  * @param timestamp new dts expressed in time_base of param ref_st
241  * @param ref_st reference stream giving time_base of param timestamp
242  */
243 void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
244 
245 int ff_find_last_ts(AVFormatContext *s, int stream_index, int64_t *ts, int64_t *pos,
246  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
247 
248 /**
249  * Perform a binary search using read_timestamp().
250  *
251  * @param target_ts target timestamp in the time base of the given stream
252  * @param stream_index stream number
253  */
254 int64_t ff_gen_search(AVFormatContext *s, int stream_index,
255  int64_t target_ts, int64_t pos_min,
256  int64_t pos_max, int64_t pos_limit,
257  int64_t ts_min, int64_t ts_max,
258  int flags, int64_t *ts_ret,
259  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
260 
261 /**
262  * Set the time base and wrapping info for a given stream. This will be used
263  * to interpret the stream's timestamps. If the new time base is invalid
264  * (numerator or denominator are non-positive), it leaves the stream
265  * unchanged.
266  *
267  * @param s stream
268  * @param pts_wrap_bits number of bits effectively used by the pts
269  * (used for wrap control)
270  * @param pts_num time base numerator
271  * @param pts_den time base denominator
272  */
273 void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits,
274  unsigned int pts_num, unsigned int pts_den);
275 
276 /**
277  * Add side data to a packet for changing parameters to the given values.
278  * Parameters set to 0 aren't included in the change.
279  */
280 int ff_add_param_change(AVPacket *pkt, int32_t channels,
281  uint64_t channel_layout, int32_t sample_rate,
283 
284 /**
285  * Set the timebase for each stream from the corresponding codec timebase and
286  * print it.
287  */
289 
290 /**
291  * Read a transport packet from a media file.
292  *
293  * @param s media file handle
294  * @param pkt is filled
295  * @return 0 if OK, AVERROR_xxx on error
296  */
298 
299 /**
300  * Interleave a packet per dts in an output media file.
301  *
302  * Packets with pkt->destruct == av_destruct_packet will be freed inside this
303  * function, so they cannot be used after it. Note that calling av_free_packet()
304  * on them is still safe.
305  *
306  * @param s media file handle
307  * @param out the interleaved packet will be output here
308  * @param pkt the input packet
309  * @param flush 1 if no further packets are available as input and all
310  * remaining packets should be output
311  * @return 1 if a packet was output, 0 if no packet could be output,
312  * < 0 if an error occurred
313  */
315  AVPacket *pkt, int flush);
316 
318 
319 /**
320  * Return the frame duration in seconds. Return 0 if not available.
321  */
322 void ff_compute_frame_duration(int *pnum, int *pden, AVStream *st,
323  AVCodecParserContext *pc, AVPacket *pkt);
324 
325 int ff_get_audio_frame_size(AVCodecContext *enc, int size, int mux);
326 
327 unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id);
328 
329 enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag);
330 
331 /**
332  * Select a PCM codec based on the given parameters.
333  *
334  * @param bps bits-per-sample
335  * @param flt floating-point
336  * @param be big-endian
337  * @param sflags signed flags. each bit corresponds to one byte of bit depth.
338  * e.g. the 1st bit indicates if 8-bit should be signed or
339  * unsigned, the 2nd bit indicates if 16-bit should be signed or
340  * unsigned, etc... This is useful for formats such as WAVE where
341  * only 8-bit is unsigned and all other bit depths are signed.
342  * @return a PCM codec id or AV_CODEC_ID_NONE
343  */
344 enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
345 
346 /**
347  * Chooses a timebase for muxing the specified stream.
348  *
349  * The choosen timebase allows sample accurate timestamps based
350  * on the framerate or sample rate for audio streams. It also is
351  * at least as precisse as 1/min_precission would be.
352  */
353 AVRational ff_choose_timebase(AVFormatContext *s, AVStream *st, int min_precission);
354 
355 /**
356  * Generate standard extradata for AVC-Intra based on width/height and field order.
357  */
359 
360 #endif /* AVFORMAT_INTERNAL_H */