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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 /** size of probe buffer, for guessing file type from file contents */
30 #define PROBE_BUF_MIN 2048
31 #define PROBE_BUF_MAX (1<<20)
32 
33 #ifdef DEBUG
34 # define hex_dump_debug(class, buf, size) av_hex_dump_log(class, AV_LOG_DEBUG, buf, size)
35 #else
36 # define hex_dump_debug(class, buf, size)
37 #endif
38 
39 typedef struct AVCodecTag {
40  enum AVCodecID id;
41  unsigned int tag;
42 } AVCodecTag;
43 
44 typedef struct CodecMime{
45  char str[32];
46  enum AVCodecID id;
47 } CodecMime;
48 
49 #ifdef __GNUC__
50 #define dynarray_add(tab, nb_ptr, elem)\
51 do {\
52  __typeof__(tab) _tab = (tab);\
53  __typeof__(elem) _elem = (elem);\
54  (void)sizeof(**_tab == _elem); /* check that types are compatible */\
55  av_dynarray_add(_tab, nb_ptr, _elem);\
56 } while(0)
57 #else
58 #define dynarray_add(tab, nb_ptr, elem)\
59 do {\
60  av_dynarray_add((tab), nb_ptr, (elem));\
61 } while(0)
62 #endif
63 
64 struct tm *ff_brktimegm(time_t secs, struct tm *tm);
65 
66 char *ff_data_to_hex(char *buf, const uint8_t *src, int size, int lowercase);
67 
68 /**
69  * Parse a string of hexadecimal strings. Any space between the hexadecimal
70  * digits is ignored.
71  *
72  * @param data if non-null, the parsed data is written to this pointer
73  * @param p the string to parse
74  * @return the number of bytes written (or to be written, if data is null)
75  */
76 int ff_hex_to_data(uint8_t *data, const char *p);
77 
78 void ff_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
79 
80 /**
81  * Add packet to AVFormatContext->packet_buffer list, determining its
82  * interleaved position using compare() function argument.
83  * @return 0, or < 0 on error
84  */
86  int (*compare)(AVFormatContext *, AVPacket *, AVPacket *));
87 
89 
90 #define NTP_OFFSET 2208988800ULL
91 #define NTP_OFFSET_US (NTP_OFFSET * 1000000ULL)
92 
93 /** Get the current time since NTP epoch in microseconds. */
94 uint64_t ff_ntp_time(void);
95 
96 /**
97  * Append the media-specific SDP fragment for the media stream c
98  * to the buffer buff.
99  *
100  * Note, the buffer needs to be initialized, since it is appended to
101  * existing content.
102  *
103  * @param buff the buffer to append the SDP fragment to
104  * @param size the size of the buff buffer
105  * @param st the AVStream of the media to describe
106  * @param idx the global stream index
107  * @param dest_addr the destination address of the media stream, may be NULL
108  * @param dest_type the destination address type, may be NULL
109  * @param port the destination port of the media stream, 0 if unknown
110  * @param ttl the time to live of the stream, 0 if not multicast
111  * @param fmt the AVFormatContext, which might contain options modifying
112  * the generated SDP
113  */
114 void ff_sdp_write_media(char *buff, int size, AVStream *st, int idx,
115  const char *dest_addr, const char *dest_type,
116  int port, int ttl, AVFormatContext *fmt);
117 
118 /**
119  * Write a packet to another muxer than the one the user originally
120  * intended. Useful when chaining muxers, where one muxer internally
121  * writes a received packet to another muxer.
122  *
123  * @param dst the muxer to write the packet to
124  * @param dst_stream the stream index within dst to write the packet to
125  * @param pkt the packet to be written
126  * @param src the muxer the packet originally was intended for
127  * @return the value av_write_frame returned
128  */
129 int ff_write_chained(AVFormatContext *dst, int dst_stream, AVPacket *pkt,
131 
132 /**
133  * Get the length in bytes which is needed to store val as v.
134  */
135 int ff_get_v_length(uint64_t val);
136 
137 /**
138  * Put val using a variable number of bytes.
139  */
140 void ff_put_v(AVIOContext *bc, uint64_t val);
141 
142 /**
143  * Read a whole line of text from AVIOContext. Stop reading after reaching
144  * either a \\n, a \\0 or EOF. The returned string is always \\0-terminated,
145  * and may be truncated if the buffer is too small.
146  *
147  * @param s the read-only AVIOContext
148  * @param buf buffer to store the read line
149  * @param maxlen size of the buffer
150  * @return the length of the string written in the buffer, not including the
151  * final \\0
152  */
153 int ff_get_line(AVIOContext *s, char *buf, int maxlen);
154 
155 #define SPACE_CHARS " \t\r\n"
156 
157 /**
158  * Callback function type for ff_parse_key_value.
159  *
160  * @param key a pointer to the key
161  * @param key_len the number of bytes that belong to the key, including the '='
162  * char
163  * @param dest return the destination pointer for the value in *dest, may
164  * be null to ignore the value
165  * @param dest_len the length of the *dest buffer
166  */
167 typedef void (*ff_parse_key_val_cb)(void *context, const char *key,
168  int key_len, char **dest, int *dest_len);
169 /**
170  * Parse a string with comma-separated key=value pairs. The value strings
171  * may be quoted and may contain escaped characters within quoted strings.
172  *
173  * @param str the string to parse
174  * @param callback_get_buf function that returns where to store the
175  * unescaped value string.
176  * @param context the opaque context pointer to pass to callback_get_buf
177  */
178 void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf,
179  void *context);
180 
181 /**
182  * Find stream index based on format-specific stream ID
183  * @return stream index, or < 0 on error
184  */
185 int ff_find_stream_index(AVFormatContext *s, int id);
186 
187 /**
188  * Internal version of av_index_search_timestamp
189  */
190 int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
191  int64_t wanted_timestamp, int flags);
192 
193 /**
194  * Internal version of av_add_index_entry
195  */
196 int ff_add_index_entry(AVIndexEntry **index_entries,
197  int *nb_index_entries,
198  unsigned int *index_entries_allocated_size,
199  int64_t pos, int64_t timestamp, int size, int distance, int flags);
200 
201 /**
202  * Add a new chapter.
203  *
204  * @param s media file handle
205  * @param id unique ID for this chapter
206  * @param start chapter start time in time_base units
207  * @param end chapter end time in time_base units
208  * @param title chapter title
209  *
210  * @return AVChapter or NULL on error
211  */
213  int64_t start, int64_t end, const char *title);
214 
215 /**
216  * Ensure the index uses less memory than the maximum specified in
217  * AVFormatContext.max_index_size by discarding entries if it grows
218  * too large.
219  */
220 void ff_reduce_index(AVFormatContext *s, int stream_index);
221 
222 enum AVCodecID ff_guess_image2_codec(const char *filename);
223 
224 /**
225  * Convert a date string in ISO8601 format to Unix timestamp.
226  */
227 int64_t ff_iso8601_to_unix_time(const char *datestr);
228 
229 /**
230  * Perform a binary search using av_index_search_timestamp() and
231  * AVInputFormat.read_timestamp().
232  *
233  * @param target_ts target timestamp in the time base of the given stream
234  * @param stream_index stream number
235  */
236 int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
237  int64_t target_ts, int flags);
238 
239 /**
240  * Update cur_dts of all streams based on the given timestamp and AVStream.
241  *
242  * Stream ref_st unchanged, others set cur_dts in their native time base.
243  * Only needed for timestamp wrapping or if (dts not set and pts!=dts).
244  * @param timestamp new dts expressed in time_base of param ref_st
245  * @param ref_st reference stream giving time_base of param timestamp
246  */
247 void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
248 
249 int ff_find_last_ts(AVFormatContext *s, int stream_index, int64_t *ts, int64_t *pos,
250  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
251 
252 /**
253  * Perform a binary search using read_timestamp().
254  *
255  * @param target_ts target timestamp in the time base of the given stream
256  * @param stream_index stream number
257  */
258 int64_t ff_gen_search(AVFormatContext *s, int stream_index,
259  int64_t target_ts, int64_t pos_min,
260  int64_t pos_max, int64_t pos_limit,
261  int64_t ts_min, int64_t ts_max,
262  int flags, int64_t *ts_ret,
263  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
264 
265 /**
266  * Set the time base and wrapping info for a given stream. This will be used
267  * to interpret the stream's timestamps. If the new time base is invalid
268  * (numerator or denominator are non-positive), it leaves the stream
269  * unchanged.
270  *
271  * @param s stream
272  * @param pts_wrap_bits number of bits effectively used by the pts
273  * (used for wrap control)
274  * @param pts_num time base numerator
275  * @param pts_den time base denominator
276  */
277 void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits,
278  unsigned int pts_num, unsigned int pts_den);
279 
280 /**
281  * Add side data to a packet for changing parameters to the given values.
282  * Parameters set to 0 aren't included in the change.
283  */
284 int ff_add_param_change(AVPacket *pkt, int32_t channels,
285  uint64_t channel_layout, int32_t sample_rate,
287 
288 /**
289  * Set the timebase for each stream from the corresponding codec timebase and
290  * print it.
291  */
293 
294 /**
295  * Read a transport packet from a media file.
296  *
297  * @param s media file handle
298  * @param pkt is filled
299  * @return 0 if OK, AVERROR_xxx on error
300  */
302 
303 /**
304  * Interleave a packet per dts in an output media file.
305  *
306  * Packets with pkt->destruct == av_destruct_packet will be freed inside this
307  * function, so they cannot be used after it. Note that calling av_free_packet()
308  * on them is still safe.
309  *
310  * @param s media file handle
311  * @param out the interleaved packet will be output here
312  * @param pkt the input packet
313  * @param flush 1 if no further packets are available as input and all
314  * remaining packets should be output
315  * @return 1 if a packet was output, 0 if no packet could be output,
316  * < 0 if an error occurred
317  */
319  AVPacket *pkt, int flush);
320 
322 
323 /**
324  * Return the frame duration in seconds. Return 0 if not available.
325  */
326 void ff_compute_frame_duration(int *pnum, int *pden, AVStream *st,
327  AVCodecParserContext *pc, AVPacket *pkt);
328 
329 int ff_get_audio_frame_size(AVCodecContext *enc, int size, int mux);
330 
331 unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id);
332 
333 enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag);
334 
335 /**
336  * Select a PCM codec based on the given parameters.
337  *
338  * @param bps bits-per-sample
339  * @param flt floating-point
340  * @param be big-endian
341  * @param sflags signed flags. each bit corresponds to one byte of bit depth.
342  * e.g. the 1st bit indicates if 8-bit should be signed or
343  * unsigned, the 2nd bit indicates if 16-bit should be signed or
344  * unsigned, etc... This is useful for formats such as WAVE where
345  * only 8-bit is unsigned and all other bit depths are signed.
346  * @return a PCM codec id or AV_CODEC_ID_NONE
347  */
348 enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
349 
350 /**
351  * Chooses a timebase for muxing the specified stream.
352  *
353  * The choosen timebase allows sample accurate timestamps based
354  * on the framerate or sample rate for audio streams. It also is
355  * at least as precisse as 1/min_precission would be.
356  */
357 AVRational ff_choose_timebase(AVFormatContext *s, AVStream *st, int min_precission);
358 
359 /**
360  * Generate standard extradata for AVC-Intra based on width/height and field order.
361  */
363 
364 /**
365  * Allocate extradata with additional FF_INPUT_BUFFER_PADDING_SIZE at end
366  * which is always set to 0.
367  *
368  * @param size size of extradata
369  * @return 0 if OK, AVERROR_xxx on error
370  */
371 int ff_alloc_extradata(AVCodecContext *avctx, int size);
372 
373 #endif /* AVFORMAT_INTERNAL_H */