1 /*
2  * Copyright (c) 2011, Luca Barbato
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 /**
22  * @file generic segmenter
23  * M3U8 specification can be find here:
24  * @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}
25  */
26 
27 #include "config_components.h"
28 
29 #include <time.h>
30 
31 #include "avformat.h"
32 #include "internal.h"
33 #include "mux.h"
34 
35 #include "libavutil/avassert.h"
36 #include "libavutil/internal.h"
37 #include "libavutil/log.h"
38 #include "libavutil/opt.h"
39 #include "libavutil/avstring.h"
40 #include "libavutil/parseutils.h"
41 #include "libavutil/mathematics.h"
42 #include "libavutil/time.h"
43 #include "libavutil/timecode.h"
44 #include "libavutil/time_internal.h"
45 #include "libavutil/timestamp.h"
46 
47 typedef struct SegmentListEntry {
48     int index;
49     double start_time, end_time;
50     int64_t start_pts;
51     int64_t offset_pts;
52     char *filename;
53     struct SegmentListEntry *next;
54     int64_t last_duration;
55 } SegmentListEntry;
56 
57 typedef enum {
58     LIST_TYPE_UNDEFINED = -1,
59     LIST_TYPE_FLAT = 0,
60     LIST_TYPE_CSV,
61     LIST_TYPE_M3U8,
62     LIST_TYPE_EXT, ///< deprecated
63     LIST_TYPE_FFCONCAT,
64     LIST_TYPE_NB,
65 } ListType;
66 
67 #define SEGMENT_LIST_FLAG_CACHE 1
68 #define SEGMENT_LIST_FLAG_LIVE  2
69 
70 typedef struct SegmentContext {
71     const AVClass *class;  /**< Class for private options. */
72     int segment_idx;       ///< index of the segment file to write, starting from 0
73     int segment_idx_wrap;  ///< number after which the index wraps
74     int segment_idx_wrap_nb;  ///< number of time the index has wraped
75     int segment_count;     ///< number of segment files already written
76     const AVOutputFormat *oformat;
77     AVFormatContext *avf;
78     char *format;              ///< format to use for output segment files
79     AVDictionary *format_options;
80     char *list;            ///< filename for the segment list file
81     int   list_flags;      ///< flags affecting list generation
82     int   list_size;       ///< number of entries for the segment list file
83 
84     int is_nullctx;       ///< whether avf->pb is a nullctx
85     int use_clocktime;    ///< flag to cut segments at regular clock time
86     int64_t clocktime_offset; //< clock offset for cutting the segments at regular clock time
87     int64_t clocktime_wrap_duration; //< wrapping duration considered for starting a new segment
88     int64_t last_val;      ///< remember last time for wrap around detection
89     int cut_pending;
90     int header_written;    ///< whether we've already called avformat_write_header
91 
92     char *entry_prefix;    ///< prefix to add to list entry filenames
93     int list_type;         ///< set the list type
94     AVIOContext *list_pb;  ///< list file put-byte context
95     int64_t time;          ///< segment duration
96     int use_strftime;      ///< flag to expand filename with strftime
97     int increment_tc;      ///< flag to increment timecode if found
98 
99     char *times_str;       ///< segment times specification string
100     int64_t *times;        ///< list of segment interval specification
101     int nb_times;          ///< number of elments in the times array
102 
103     char *frames_str;      ///< segment frame numbers specification string
104     int *frames;           ///< list of frame number specification
105     int nb_frames;         ///< number of elments in the frames array
106     int frame_count;       ///< total number of reference frames
107     int segment_frame_count; ///< number of reference frames in the segment
108 
109     int64_t time_delta;
110     int  individual_header_trailer; /**< Set by a private option. */
111     int  write_header_trailer; /**< Set by a private option. */
112     char *header_filename;  ///< filename to write the output header to
113 
114     int reset_timestamps;  ///< reset timestamps at the beginning of each segment
115     int64_t initial_offset;    ///< initial timestamps offset, expressed in microseconds
116     char *reference_stream_specifier; ///< reference stream specifier
117     int   reference_stream_index;
118     int   break_non_keyframes;
119     int   write_empty;
120 
121     int use_rename;
122     char temp_list_filename[1024];
123 
124     SegmentListEntry cur_entry;
125     SegmentListEntry *segment_list_entries;
126     SegmentListEntry *segment_list_entries_end;
127 } SegmentContext;
128 
print_csv_escaped_str(AVIOContext *ctx, const char *str)129 static void print_csv_escaped_str(AVIOContext *ctx, const char *str)
130 {
131     int needs_quoting = !!str[strcspn(str, "\",\n\r")];
132 
133     if (needs_quoting)
134         avio_w8(ctx, '"');
135 
136     for (; *str; str++) {
137         if (*str == '"')
138             avio_w8(ctx, '"');
139         avio_w8(ctx, *str);
140     }
141     if (needs_quoting)
142         avio_w8(ctx, '"');
143 }
144 
segment_mux_init(AVFormatContext *s)145 static int segment_mux_init(AVFormatContext *s)
146 {
147     SegmentContext *seg = s->priv_data;
148     AVFormatContext *oc;
149     int i;
150     int ret;
151 
152     ret = avformat_alloc_output_context2(&seg->avf, seg->oformat, NULL, NULL);
153     if (ret < 0)
154         return ret;
155     oc = seg->avf;
156 
157     oc->interrupt_callback = s->interrupt_callback;
158     oc->max_delay          = s->max_delay;
159     av_dict_copy(&oc->metadata, s->metadata, 0);
160     oc->opaque             = s->opaque;
161     oc->io_close           = s->io_close;
162     oc->io_close2          = s->io_close2;
163     oc->io_open            = s->io_open;
164     oc->flags              = s->flags;
165 
166     for (i = 0; i < s->nb_streams; i++) {
167         AVStream *st, *ist = s->streams[i];
168         AVCodecParameters *ipar = ist->codecpar, *opar;
169 
170         if (!(st = avformat_new_stream(oc, NULL)))
171             return AVERROR(ENOMEM);
172         ret = ff_stream_encode_params_copy(st, ist);
173         if (ret < 0)
174             return ret;
175         opar = st->codecpar;
176         if (!oc->oformat->codec_tag ||
177             av_codec_get_id (oc->oformat->codec_tag, ipar->codec_tag) == opar->codec_id ||
178             av_codec_get_tag(oc->oformat->codec_tag, ipar->codec_id) <= 0) {
179             opar->codec_tag = ipar->codec_tag;
180         } else {
181             opar->codec_tag = 0;
182         }
183     }
184 
185     return 0;
186 }
187 
set_segment_filename(AVFormatContext *s)188 static int set_segment_filename(AVFormatContext *s)
189 {
190     SegmentContext *seg = s->priv_data;
191     AVFormatContext *oc = seg->avf;
192     size_t size;
193     int ret;
194     char buf[1024];
195     char *new_name;
196 
197     if (seg->segment_idx_wrap)
198         seg->segment_idx %= seg->segment_idx_wrap;
199     if (seg->use_strftime) {
200         time_t now0;
201         struct tm *tm, tmpbuf;
202         time(&now0);
203         tm = localtime_r(&now0, &tmpbuf);
204         if (!strftime(buf, sizeof(buf), s->url, tm)) {
205             av_log(oc, AV_LOG_ERROR, "Could not get segment filename with strftime\n");
206             return AVERROR(EINVAL);
207         }
208     } else if (av_get_frame_filename(buf, sizeof(buf),
209                                      s->url, seg->segment_idx) < 0) {
210         av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", s->url);
211         return AVERROR(EINVAL);
212     }
213     new_name = av_strdup(buf);
214     if (!new_name)
215         return AVERROR(ENOMEM);
216     ff_format_set_url(oc, new_name);
217 
218     /* copy modified name in list entry */
219     size = strlen(av_basename(oc->url)) + 1;
220     if (seg->entry_prefix)
221         size += strlen(seg->entry_prefix);
222 
223     if ((ret = av_reallocp(&seg->cur_entry.filename, size)) < 0)
224         return ret;
225     snprintf(seg->cur_entry.filename, size, "%s%s",
226              seg->entry_prefix ? seg->entry_prefix : "",
227              av_basename(oc->url));
228 
229     return 0;
230 }
231 
segment_start(AVFormatContext *s, int write_header)232 static int segment_start(AVFormatContext *s, int write_header)
233 {
234     SegmentContext *seg = s->priv_data;
235     AVFormatContext *oc = seg->avf;
236     int err = 0;
237 
238     if (write_header) {
239         avformat_free_context(oc);
240         seg->avf = NULL;
241         if ((err = segment_mux_init(s)) < 0)
242             return err;
243         oc = seg->avf;
244     }
245 
246     seg->segment_idx++;
247     if ((seg->segment_idx_wrap) && (seg->segment_idx % seg->segment_idx_wrap == 0))
248         seg->segment_idx_wrap_nb++;
249 
250     if ((err = set_segment_filename(s)) < 0)
251         return err;
252 
253     if ((err = s->io_open(s, &oc->pb, oc->url, AVIO_FLAG_WRITE, NULL)) < 0) {
254         av_log(s, AV_LOG_ERROR, "Failed to open segment '%s'\n", oc->url);
255         return err;
256     }
257     if (!seg->individual_header_trailer)
258         oc->pb->seekable = 0;
259 
260     if (oc->oformat->priv_class && oc->priv_data)
261         av_opt_set(oc->priv_data, "mpegts_flags", "+resend_headers", 0);
262 
263     if (write_header) {
264         AVDictionary *options = NULL;
265         av_dict_copy(&options, seg->format_options, 0);
266         av_dict_set(&options, "fflags", "-autobsf", 0);
267         err = avformat_write_header(oc, &options);
268         av_dict_free(&options);
269         if (err < 0)
270             return err;
271     }
272 
273     seg->segment_frame_count = 0;
274     return 0;
275 }
276 
segment_list_open(AVFormatContext *s)277 static int segment_list_open(AVFormatContext *s)
278 {
279     SegmentContext *seg = s->priv_data;
280     int ret;
281 
282     snprintf(seg->temp_list_filename, sizeof(seg->temp_list_filename), seg->use_rename ? "%s.tmp" : "%s", seg->list);
283     ret = s->io_open(s, &seg->list_pb, seg->temp_list_filename, AVIO_FLAG_WRITE, NULL);
284     if (ret < 0) {
285         av_log(s, AV_LOG_ERROR, "Failed to open segment list '%s'\n", seg->list);
286         return ret;
287     }
288 
289     if (seg->list_type == LIST_TYPE_M3U8 && seg->segment_list_entries) {
290         SegmentListEntry *entry;
291         double max_duration = 0;
292 
293         avio_printf(seg->list_pb, "#EXTM3U\n");
294         avio_printf(seg->list_pb, "#EXT-X-VERSION:3\n");
295         avio_printf(seg->list_pb, "#EXT-X-MEDIA-SEQUENCE:%d\n", seg->segment_list_entries->index);
296         avio_printf(seg->list_pb, "#EXT-X-ALLOW-CACHE:%s\n",
297                     seg->list_flags & SEGMENT_LIST_FLAG_CACHE ? "YES" : "NO");
298 
299         av_log(s, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%d\n",
300                seg->segment_list_entries->index);
301 
302         for (entry = seg->segment_list_entries; entry; entry = entry->next)
303             max_duration = FFMAX(max_duration, entry->end_time - entry->start_time);
304         avio_printf(seg->list_pb, "#EXT-X-TARGETDURATION:%"PRId64"\n", (int64_t)ceil(max_duration));
305     } else if (seg->list_type == LIST_TYPE_FFCONCAT) {
306         avio_printf(seg->list_pb, "ffconcat version 1.0\n");
307     }
308 
309     return ret;
310 }
311 
segment_list_print_entry(AVIOContext *list_ioctx, ListType list_type, const SegmentListEntry *list_entry, void *log_ctx)312 static void segment_list_print_entry(AVIOContext      *list_ioctx,
313                                      ListType          list_type,
314                                      const SegmentListEntry *list_entry,
315                                      void *log_ctx)
316 {
317     switch (list_type) {
318     case LIST_TYPE_FLAT:
319         avio_printf(list_ioctx, "%s\n", list_entry->filename);
320         break;
321     case LIST_TYPE_CSV:
322     case LIST_TYPE_EXT:
323         print_csv_escaped_str(list_ioctx, list_entry->filename);
324         avio_printf(list_ioctx, ",%f,%f\n", list_entry->start_time, list_entry->end_time);
325         break;
326     case LIST_TYPE_M3U8:
327         avio_printf(list_ioctx, "#EXTINF:%f,\n%s\n",
328                     list_entry->end_time - list_entry->start_time, list_entry->filename);
329         break;
330     case LIST_TYPE_FFCONCAT:
331     {
332         char *buf;
333         if (av_escape(&buf, list_entry->filename, NULL, AV_ESCAPE_MODE_AUTO, AV_ESCAPE_FLAG_WHITESPACE) < 0) {
334             av_log(log_ctx, AV_LOG_WARNING,
335                    "Error writing list entry '%s' in list file\n", list_entry->filename);
336             return;
337         }
338         avio_printf(list_ioctx, "file %s\n", buf);
339         av_free(buf);
340         break;
341     }
342     default:
343         av_assert0(!"Invalid list type");
344     }
345 }
346 
segment_end(AVFormatContext *s, int write_trailer, int is_last)347 static int segment_end(AVFormatContext *s, int write_trailer, int is_last)
348 {
349     SegmentContext *seg = s->priv_data;
350     AVFormatContext *oc = seg->avf;
351     int ret = 0;
352     AVTimecode tc;
353     AVRational rate;
354     AVDictionaryEntry *tcr;
355     char buf[AV_TIMECODE_STR_SIZE];
356     int i;
357     int err;
358 
359     if (!oc || !oc->pb)
360         return AVERROR(EINVAL);
361 
362     av_write_frame(oc, NULL); /* Flush any buffered data (fragmented mp4) */
363     if (write_trailer)
364         ret = av_write_trailer(oc);
365 
366     if (ret < 0)
367         av_log(s, AV_LOG_ERROR, "Failure occurred when ending segment '%s'\n",
368                oc->url);
369 
370     if (seg->list) {
371         if (seg->list_size || seg->list_type == LIST_TYPE_M3U8) {
372             SegmentListEntry *entry = av_mallocz(sizeof(*entry));
373             if (!entry) {
374                 ret = AVERROR(ENOMEM);
375                 goto end;
376             }
377 
378             /* append new element */
379             memcpy(entry, &seg->cur_entry, sizeof(*entry));
380             entry->filename = av_strdup(entry->filename);
381             if (!seg->segment_list_entries)
382                 seg->segment_list_entries = seg->segment_list_entries_end = entry;
383             else
384                 seg->segment_list_entries_end->next = entry;
385             seg->segment_list_entries_end = entry;
386 
387             /* drop first item */
388             if (seg->list_size && seg->segment_count >= seg->list_size) {
389                 entry = seg->segment_list_entries;
390                 seg->segment_list_entries = seg->segment_list_entries->next;
391                 av_freep(&entry->filename);
392                 av_freep(&entry);
393             }
394 
395             if ((ret = segment_list_open(s)) < 0)
396                 goto end;
397             for (entry = seg->segment_list_entries; entry; entry = entry->next)
398                 segment_list_print_entry(seg->list_pb, seg->list_type, entry, s);
399             if (seg->list_type == LIST_TYPE_M3U8 && is_last)
400                 avio_printf(seg->list_pb, "#EXT-X-ENDLIST\n");
401             ff_format_io_close(s, &seg->list_pb);
402             if (seg->use_rename)
403                 ff_rename(seg->temp_list_filename, seg->list, s);
404         } else {
405             segment_list_print_entry(seg->list_pb, seg->list_type, &seg->cur_entry, s);
406             avio_flush(seg->list_pb);
407         }
408     }
409 
410     av_log(s, AV_LOG_VERBOSE, "segment:'%s' count:%d ended\n",
411            seg->avf->url, seg->segment_count);
412     seg->segment_count++;
413 
414     if (seg->increment_tc) {
415         tcr = av_dict_get(s->metadata, "timecode", NULL, 0);
416         if (tcr) {
417             /* search the first video stream */
418             for (i = 0; i < s->nb_streams; i++) {
419                 if (s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
420                     rate = s->streams[i]->avg_frame_rate;/* Get fps from the video stream */
421                     err = av_timecode_init_from_string(&tc, rate, tcr->value, s);
422                     if (err < 0) {
423                         av_log(s, AV_LOG_WARNING, "Could not increment global timecode, error occurred during timecode creation.\n");
424                         break;
425                     }
426                     tc.start += (int)((seg->cur_entry.end_time - seg->cur_entry.start_time) * av_q2d(rate));/* increment timecode */
427                     av_dict_set(&s->metadata, "timecode",
428                                 av_timecode_make_string(&tc, buf, 0), 0);
429                     break;
430                 }
431             }
432         } else {
433             av_log(s, AV_LOG_WARNING, "Could not increment global timecode, no global timecode metadata found.\n");
434         }
435         for (i = 0; i < s->nb_streams; i++) {
436             if (s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
437                 char st_buf[AV_TIMECODE_STR_SIZE];
438                 AVTimecode st_tc;
439                 AVRational st_rate = s->streams[i]->avg_frame_rate;
440                 AVDictionaryEntry *st_tcr = av_dict_get(s->streams[i]->metadata, "timecode", NULL, 0);
441                 if (st_tcr) {
442                     if ((av_timecode_init_from_string(&st_tc, st_rate, st_tcr->value, s) < 0)) {
443                         av_log(s, AV_LOG_WARNING, "Could not increment stream %d timecode, error occurred during timecode creation.\n", i);
444                         continue;
445                     }
446                 st_tc.start += (int)((seg->cur_entry.end_time - seg->cur_entry.start_time) * av_q2d(st_rate));    // increment timecode
447                 av_dict_set(&s->streams[i]->metadata, "timecode", av_timecode_make_string(&st_tc, st_buf, 0), 0);
448                 }
449             }
450         }
451     }
452 
453 end:
454     ff_format_io_close(oc, &oc->pb);
455 
456     return ret;
457 }
458 
parse_times(void *log_ctx, int64_t **times, int *nb_times, const char *times_str)459 static int parse_times(void *log_ctx, int64_t **times, int *nb_times,
460                        const char *times_str)
461 {
462     char *p;
463     int i, ret = 0;
464     char *times_str1 = av_strdup(times_str);
465     char *saveptr = NULL;
466 
467     if (!times_str1)
468         return AVERROR(ENOMEM);
469 
470 #define FAIL(err) ret = err; goto end
471 
472     *nb_times = 1;
473     for (p = times_str1; *p; p++)
474         if (*p == ',')
475             (*nb_times)++;
476 
477     *times = av_malloc_array(*nb_times, sizeof(**times));
478     if (!*times) {
479         av_log(log_ctx, AV_LOG_ERROR, "Could not allocate forced times array\n");
480         FAIL(AVERROR(ENOMEM));
481     }
482 
483     p = times_str1;
484     for (i = 0; i < *nb_times; i++) {
485         int64_t t;
486         char *tstr = av_strtok(p, ",", &saveptr);
487         p = NULL;
488 
489         if (!tstr || !tstr[0]) {
490             av_log(log_ctx, AV_LOG_ERROR, "Empty time specification in times list %s\n",
491                    times_str);
492             FAIL(AVERROR(EINVAL));
493         }
494 
495         ret = av_parse_time(&t, tstr, 1);
496         if (ret < 0) {
497             av_log(log_ctx, AV_LOG_ERROR,
498                    "Invalid time duration specification '%s' in times list %s\n", tstr, times_str);
499             FAIL(AVERROR(EINVAL));
500         }
501         (*times)[i] = t;
502 
503         /* check on monotonicity */
504         if (i && (*times)[i-1] > (*times)[i]) {
505             av_log(log_ctx, AV_LOG_ERROR,
506                    "Specified time %f is smaller than the last time %f\n",
507                    (float)((*times)[i])/1000000, (float)((*times)[i-1])/1000000);
508             FAIL(AVERROR(EINVAL));
509         }
510     }
511 
512 end:
513     av_free(times_str1);
514     return ret;
515 }
516 
parse_frames(void *log_ctx, int **frames, int *nb_frames, const char *frames_str)517 static int parse_frames(void *log_ctx, int **frames, int *nb_frames,
518                         const char *frames_str)
519 {
520     const char *p;
521     int i;
522 
523     *nb_frames = 1;
524     for (p = frames_str; *p; p++)
525         if (*p == ',')
526             (*nb_frames)++;
527 
528     *frames = av_malloc_array(*nb_frames, sizeof(**frames));
529     if (!*frames) {
530         av_log(log_ctx, AV_LOG_ERROR, "Could not allocate forced frames array\n");
531         return AVERROR(ENOMEM);
532     }
533 
534     p = frames_str;
535     for (i = 0; i < *nb_frames; i++) {
536         long int f;
537         char *tailptr;
538 
539         if (*p == '\0' || *p == ',') {
540             av_log(log_ctx, AV_LOG_ERROR, "Empty frame specification in frame list %s\n",
541                    frames_str);
542             return AVERROR(EINVAL);
543         }
544         f = strtol(p, &tailptr, 10);
545         if (*tailptr != '\0' && *tailptr != ',' || f <= 0 || f >= INT_MAX) {
546             av_log(log_ctx, AV_LOG_ERROR,
547                    "Invalid argument '%s', must be a positive integer < INT_MAX\n",
548                    p);
549             return AVERROR(EINVAL);
550         }
551         if (*tailptr == ',')
552             tailptr++;
553         p = tailptr;
554         (*frames)[i] = f;
555 
556         /* check on monotonicity */
557         if (i && (*frames)[i-1] > (*frames)[i]) {
558             av_log(log_ctx, AV_LOG_ERROR,
559                    "Specified frame %d is smaller than the last frame %d\n",
560                    (*frames)[i], (*frames)[i-1]);
561             return AVERROR(EINVAL);
562         }
563     }
564 
565     return 0;
566 }
567 
open_null_ctx(AVIOContext **ctx)568 static int open_null_ctx(AVIOContext **ctx)
569 {
570     int buf_size = 32768;
571     uint8_t *buf = av_malloc(buf_size);
572     if (!buf)
573         return AVERROR(ENOMEM);
574     *ctx = avio_alloc_context(buf, buf_size, 1, NULL, NULL, NULL, NULL);
575     if (!*ctx) {
576         av_free(buf);
577         return AVERROR(ENOMEM);
578     }
579     return 0;
580 }
581 
close_null_ctxp(AVIOContext **pb)582 static void close_null_ctxp(AVIOContext **pb)
583 {
584     av_freep(&(*pb)->buffer);
585     avio_context_free(pb);
586 }
587 
select_reference_stream(AVFormatContext *s)588 static int select_reference_stream(AVFormatContext *s)
589 {
590     SegmentContext *seg = s->priv_data;
591     int ret, i;
592 
593     seg->reference_stream_index = -1;
594     if (!strcmp(seg->reference_stream_specifier, "auto")) {
595         /* select first index of type with highest priority */
596         int type_index_map[AVMEDIA_TYPE_NB];
597         static const enum AVMediaType type_priority_list[] = {
598             AVMEDIA_TYPE_VIDEO,
599             AVMEDIA_TYPE_AUDIO,
600             AVMEDIA_TYPE_SUBTITLE,
601             AVMEDIA_TYPE_DATA,
602             AVMEDIA_TYPE_ATTACHMENT
603         };
604         enum AVMediaType type;
605 
606         for (i = 0; i < AVMEDIA_TYPE_NB; i++)
607             type_index_map[i] = -1;
608 
609         /* select first index for each type */
610         for (i = 0; i < s->nb_streams; i++) {
611             type = s->streams[i]->codecpar->codec_type;
612             if ((unsigned)type < AVMEDIA_TYPE_NB && type_index_map[type] == -1
613                 /* ignore attached pictures/cover art streams */
614                 && !(s->streams[i]->disposition & AV_DISPOSITION_ATTACHED_PIC))
615                 type_index_map[type] = i;
616         }
617 
618         for (i = 0; i < FF_ARRAY_ELEMS(type_priority_list); i++) {
619             type = type_priority_list[i];
620             if ((seg->reference_stream_index = type_index_map[type]) >= 0)
621                 break;
622         }
623     } else {
624         for (i = 0; i < s->nb_streams; i++) {
625             ret = avformat_match_stream_specifier(s, s->streams[i],
626                                                   seg->reference_stream_specifier);
627             if (ret < 0)
628                 return ret;
629             if (ret > 0) {
630                 seg->reference_stream_index = i;
631                 break;
632             }
633         }
634     }
635 
636     if (seg->reference_stream_index < 0) {
637         av_log(s, AV_LOG_ERROR, "Could not select stream matching identifier '%s'\n",
638                seg->reference_stream_specifier);
639         return AVERROR(EINVAL);
640     }
641 
642     return 0;
643 }
644 
seg_free(AVFormatContext *s)645 static void seg_free(AVFormatContext *s)
646 {
647     SegmentContext *seg = s->priv_data;
648     SegmentListEntry *cur;
649 
650     ff_format_io_close(s, &seg->list_pb);
651     if (seg->avf) {
652         if (seg->is_nullctx)
653             close_null_ctxp(&seg->avf->pb);
654         else
655             ff_format_io_close(s, &seg->avf->pb);
656         avformat_free_context(seg->avf);
657         seg->avf = NULL;
658     }
659     av_freep(&seg->times);
660     av_freep(&seg->frames);
661     av_freep(&seg->cur_entry.filename);
662 
663     cur = seg->segment_list_entries;
664     while (cur) {
665         SegmentListEntry *next = cur->next;
666         av_freep(&cur->filename);
667         av_free(cur);
668         cur = next;
669     }
670 }
671 
seg_init(AVFormatContext *s)672 static int seg_init(AVFormatContext *s)
673 {
674     SegmentContext *seg = s->priv_data;
675     AVFormatContext *oc = seg->avf;
676     AVDictionary *options = NULL;
677     int ret;
678     int i;
679 
680     seg->segment_count = 0;
681     if (!seg->write_header_trailer)
682         seg->individual_header_trailer = 0;
683 
684     if (seg->header_filename) {
685         seg->write_header_trailer = 1;
686         seg->individual_header_trailer = 0;
687     }
688 
689     if (seg->initial_offset > 0) {
690         av_log(s, AV_LOG_WARNING, "NOTE: the option initial_offset is deprecated,"
691                "you can use output_ts_offset instead of it\n");
692     }
693 
694     if ((seg->time != 2000000) + !!seg->times_str + !!seg->frames_str > 1) {
695         av_log(s, AV_LOG_ERROR,
696                "segment_time, segment_times, and segment_frames options "
697                "are mutually exclusive, select just one of them\n");
698         return AVERROR(EINVAL);
699     }
700 
701     if (seg->times_str) {
702         if ((ret = parse_times(s, &seg->times, &seg->nb_times, seg->times_str)) < 0)
703             return ret;
704     } else if (seg->frames_str) {
705         if ((ret = parse_frames(s, &seg->frames, &seg->nb_frames, seg->frames_str)) < 0)
706             return ret;
707     } else {
708         if (seg->use_clocktime) {
709             if (seg->time <= 0) {
710                 av_log(s, AV_LOG_ERROR, "Invalid negative segment_time with segment_atclocktime option set\n");
711                 return AVERROR(EINVAL);
712             }
713             seg->clocktime_offset = seg->time - (seg->clocktime_offset % seg->time);
714         }
715     }
716 
717     if (seg->list) {
718         if (seg->list_type == LIST_TYPE_UNDEFINED) {
719             if      (av_match_ext(seg->list, "csv" )) seg->list_type = LIST_TYPE_CSV;
720             else if (av_match_ext(seg->list, "ext" )) seg->list_type = LIST_TYPE_EXT;
721             else if (av_match_ext(seg->list, "m3u8")) seg->list_type = LIST_TYPE_M3U8;
722             else if (av_match_ext(seg->list, "ffcat,ffconcat")) seg->list_type = LIST_TYPE_FFCONCAT;
723             else                                      seg->list_type = LIST_TYPE_FLAT;
724         }
725         if (!seg->list_size && seg->list_type != LIST_TYPE_M3U8) {
726             if ((ret = segment_list_open(s)) < 0)
727                 return ret;
728         } else {
729             const char *proto = avio_find_protocol_name(seg->list);
730             seg->use_rename = proto && !strcmp(proto, "file");
731         }
732     }
733 
734     if (seg->list_type == LIST_TYPE_EXT)
735         av_log(s, AV_LOG_WARNING, "'ext' list type option is deprecated in favor of 'csv'\n");
736 
737     if ((ret = select_reference_stream(s)) < 0)
738         return ret;
739     av_log(s, AV_LOG_VERBOSE, "Selected stream id:%d type:%s\n",
740            seg->reference_stream_index,
741            av_get_media_type_string(s->streams[seg->reference_stream_index]->codecpar->codec_type));
742 
743     seg->oformat = av_guess_format(seg->format, s->url, NULL);
744 
745     if (!seg->oformat)
746         return AVERROR_MUXER_NOT_FOUND;
747     if (seg->oformat->flags & AVFMT_NOFILE) {
748         av_log(s, AV_LOG_ERROR, "format %s not supported.\n",
749                seg->oformat->name);
750         return AVERROR(EINVAL);
751     }
752 
753     if ((ret = segment_mux_init(s)) < 0)
754         return ret;
755 
756     if ((ret = set_segment_filename(s)) < 0)
757         return ret;
758     oc = seg->avf;
759 
760     if (seg->write_header_trailer) {
761         if ((ret = s->io_open(s, &oc->pb,
762                               seg->header_filename ? seg->header_filename : oc->url,
763                               AVIO_FLAG_WRITE, NULL)) < 0) {
764             av_log(s, AV_LOG_ERROR, "Failed to open segment '%s'\n", oc->url);
765             return ret;
766         }
767         if (!seg->individual_header_trailer)
768             oc->pb->seekable = 0;
769     } else {
770         if ((ret = open_null_ctx(&oc->pb)) < 0)
771             return ret;
772         seg->is_nullctx = 1;
773     }
774 
775     av_dict_copy(&options, seg->format_options, 0);
776     av_dict_set(&options, "fflags", "-autobsf", 0);
777     ret = avformat_init_output(oc, &options);
778     if (av_dict_count(options)) {
779         av_log(s, AV_LOG_ERROR,
780                "Some of the provided format options are not recognized\n");
781         av_dict_free(&options);
782         return AVERROR(EINVAL);
783     }
784     av_dict_free(&options);
785 
786     if (ret < 0) {
787         return ret;
788     }
789     seg->segment_frame_count = 0;
790 
791     av_assert0(s->nb_streams == oc->nb_streams);
792     if (ret == AVSTREAM_INIT_IN_WRITE_HEADER) {
793         ret = avformat_write_header(oc, NULL);
794         if (ret < 0)
795             return ret;
796         seg->header_written = 1;
797     }
798 
799     for (i = 0; i < s->nb_streams; i++) {
800         AVStream *inner_st  = oc->streams[i];
801         AVStream *outer_st = s->streams[i];
802         avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits, inner_st->time_base.num, inner_st->time_base.den);
803     }
804 
805     if (oc->avoid_negative_ts > 0 && s->avoid_negative_ts < 0)
806         s->avoid_negative_ts = 1;
807 
808     return ret;
809 }
810 
seg_write_header(AVFormatContext *s)811 static int seg_write_header(AVFormatContext *s)
812 {
813     SegmentContext *seg = s->priv_data;
814     AVFormatContext *oc = seg->avf;
815     int ret;
816 
817     if (!seg->header_written) {
818         ret = avformat_write_header(oc, NULL);
819         if (ret < 0)
820             return ret;
821     }
822 
823     if (!seg->write_header_trailer || seg->header_filename) {
824         if (seg->header_filename) {
825             av_write_frame(oc, NULL);
826             ff_format_io_close(oc, &oc->pb);
827         } else {
828             close_null_ctxp(&oc->pb);
829             seg->is_nullctx = 0;
830         }
831         if ((ret = oc->io_open(oc, &oc->pb, oc->url, AVIO_FLAG_WRITE, NULL)) < 0)
832             return ret;
833         if (!seg->individual_header_trailer)
834             oc->pb->seekable = 0;
835     }
836 
837     return 0;
838 }
839 
seg_write_packet(AVFormatContext *s, AVPacket *pkt)840 static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
841 {
842     SegmentContext *seg = s->priv_data;
843     AVStream *st = s->streams[pkt->stream_index];
844     int64_t end_pts = INT64_MAX, offset;
845     int start_frame = INT_MAX;
846     int ret;
847     struct tm ti;
848     int64_t usecs;
849     int64_t wrapped_val;
850 
851     if (!seg->avf || !seg->avf->pb)
852         return AVERROR(EINVAL);
853 
854     if (!st->codecpar->extradata_size) {
855         size_t pkt_extradata_size;
856         uint8_t *pkt_extradata = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &pkt_extradata_size);
857         if (pkt_extradata && pkt_extradata_size > 0) {
858             ret = ff_alloc_extradata(st->codecpar, pkt_extradata_size);
859             if (ret < 0) {
860                 av_log(s, AV_LOG_WARNING, "Unable to add extradata to stream. Output segments may be invalid.\n");
861                 goto calc_times;
862             }
863             memcpy(st->codecpar->extradata, pkt_extradata, pkt_extradata_size);
864         }
865     }
866 
867 calc_times:
868     if (seg->times) {
869         end_pts = seg->segment_count < seg->nb_times ?
870             seg->times[seg->segment_count] : INT64_MAX;
871     } else if (seg->frames) {
872         start_frame = seg->segment_count < seg->nb_frames ?
873             seg->frames[seg->segment_count] : INT_MAX;
874     } else {
875         if (seg->use_clocktime) {
876             int64_t avgt = av_gettime();
877             time_t sec = avgt / 1000000;
878             localtime_r(&sec, &ti);
879             usecs = (int64_t)(ti.tm_hour * 3600 + ti.tm_min * 60 + ti.tm_sec) * 1000000 + (avgt % 1000000);
880             wrapped_val = (usecs + seg->clocktime_offset) % seg->time;
881             if (wrapped_val < seg->last_val && wrapped_val < seg->clocktime_wrap_duration)
882                 seg->cut_pending = 1;
883             seg->last_val = wrapped_val;
884         } else {
885             end_pts = seg->time * (seg->segment_count + 1);
886         }
887     }
888 
889     ff_dlog(s, "packet stream:%d pts:%s pts_time:%s duration_time:%s is_key:%d frame:%d\n",
890             pkt->stream_index, av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),
891             av_ts2timestr(pkt->duration, &st->time_base),
892             pkt->flags & AV_PKT_FLAG_KEY,
893             pkt->stream_index == seg->reference_stream_index ? seg->frame_count : -1);
894 
895     if (pkt->stream_index == seg->reference_stream_index &&
896         (pkt->flags & AV_PKT_FLAG_KEY || seg->break_non_keyframes) &&
897         (seg->segment_frame_count > 0 || seg->write_empty) &&
898         (seg->cut_pending || seg->frame_count >= start_frame ||
899          (pkt->pts != AV_NOPTS_VALUE &&
900           av_compare_ts(pkt->pts, st->time_base,
901                         end_pts - seg->time_delta, AV_TIME_BASE_Q) >= 0))) {
902         /* sanitize end time in case last packet didn't have a defined duration */
903         if (seg->cur_entry.last_duration == 0)
904             seg->cur_entry.end_time = (double)pkt->pts * av_q2d(st->time_base);
905 
906         if ((ret = segment_end(s, seg->individual_header_trailer, 0)) < 0)
907             goto fail;
908 
909         if ((ret = segment_start(s, seg->individual_header_trailer)) < 0)
910             goto fail;
911 
912         seg->cut_pending = 0;
913         seg->cur_entry.index = seg->segment_idx + seg->segment_idx_wrap * seg->segment_idx_wrap_nb;
914         seg->cur_entry.start_time = (double)pkt->pts * av_q2d(st->time_base);
915         seg->cur_entry.start_pts = av_rescale_q(pkt->pts, st->time_base, AV_TIME_BASE_Q);
916         seg->cur_entry.end_time = seg->cur_entry.start_time;
917 
918         if (seg->times || (!seg->frames && !seg->use_clocktime) && seg->write_empty)
919             goto calc_times;
920     }
921 
922     if (pkt->stream_index == seg->reference_stream_index) {
923         if (pkt->pts != AV_NOPTS_VALUE)
924             seg->cur_entry.end_time =
925                 FFMAX(seg->cur_entry.end_time, (double)(pkt->pts + pkt->duration) * av_q2d(st->time_base));
926         seg->cur_entry.last_duration = pkt->duration;
927     }
928 
929     if (seg->segment_frame_count == 0) {
930         av_log(s, AV_LOG_VERBOSE, "segment:'%s' starts with packet stream:%d pts:%s pts_time:%s frame:%d\n",
931                seg->avf->url, pkt->stream_index,
932                av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base), seg->frame_count);
933     }
934 
935     av_log(s, AV_LOG_DEBUG, "stream:%d start_pts_time:%s pts:%s pts_time:%s dts:%s dts_time:%s",
936            pkt->stream_index,
937            av_ts2timestr(seg->cur_entry.start_pts, &AV_TIME_BASE_Q),
938            av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),
939            av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &st->time_base));
940 
941     /* compute new timestamps */
942     offset = av_rescale_q(seg->initial_offset - (seg->reset_timestamps ? seg->cur_entry.start_pts : 0),
943                           AV_TIME_BASE_Q, st->time_base);
944     if (pkt->pts != AV_NOPTS_VALUE)
945         pkt->pts += offset;
946     if (pkt->dts != AV_NOPTS_VALUE)
947         pkt->dts += offset;
948 
949     av_log(s, AV_LOG_DEBUG, " -> pts:%s pts_time:%s dts:%s dts_time:%s\n",
950            av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),
951            av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &st->time_base));
952 
953     ret = ff_write_chained(seg->avf, pkt->stream_index, pkt, s,
954                            seg->initial_offset || seg->reset_timestamps || seg->avf->oformat->interleave_packet);
955 
956 fail:
957     /* Use st->index here as the packet returned from ff_write_chained()
958      * is blank if interleaving has been used. */
959     if (st->index == seg->reference_stream_index) {
960         seg->frame_count++;
961         seg->segment_frame_count++;
962     }
963 
964     return ret;
965 }
966 
seg_write_trailer(struct AVFormatContext *s)967 static int seg_write_trailer(struct AVFormatContext *s)
968 {
969     SegmentContext *seg = s->priv_data;
970     AVFormatContext *oc = seg->avf;
971     int ret;
972 
973     if (!oc)
974         return 0;
975 
976     if (!seg->write_header_trailer) {
977         if ((ret = segment_end(s, 0, 1)) < 0)
978             return ret;
979         if ((ret = open_null_ctx(&oc->pb)) < 0)
980             return ret;
981         seg->is_nullctx = 1;
982         ret = av_write_trailer(oc);
983     } else {
984         ret = segment_end(s, 1, 1);
985     }
986     return ret;
987 }
988 
seg_check_bitstream(AVFormatContext *s, AVStream *st, const AVPacket *pkt)989 static int seg_check_bitstream(AVFormatContext *s, AVStream *st,
990                                const AVPacket *pkt)
991 {
992     SegmentContext *seg = s->priv_data;
993     AVFormatContext *oc = seg->avf;
994     if (oc->oformat->check_bitstream) {
995         AVStream *const ost = oc->streams[st->index];
996         int ret = oc->oformat->check_bitstream(oc, ost, pkt);
997         if (ret == 1) {
998             FFStream *const  sti = ffstream(st);
999             FFStream *const osti = ffstream(ost);
1000              sti->bsfc = osti->bsfc;
1001             osti->bsfc = NULL;
1002         }
1003         return ret;
1004     }
1005     return 1;
1006 }
1007 
1008 #define OFFSET(x) offsetof(SegmentContext, x)
1009 #define E AV_OPT_FLAG_ENCODING_PARAM
1010 static const AVOption options[] = {
1011     { "reference_stream",  "set reference stream", OFFSET(reference_stream_specifier), AV_OPT_TYPE_STRING, {.str = "auto"}, 0, 0, E },
1012     { "segment_format",    "set container format used for the segments", OFFSET(format),  AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
1013     { "segment_format_options", "set list of options for the container format used for the segments", OFFSET(format_options), AV_OPT_TYPE_DICT, {.str = NULL}, 0, 0, E },
1014     { "segment_list",      "set the segment list filename",              OFFSET(list),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
1015     { "segment_header_filename", "write a single file containing the header", OFFSET(header_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
1016 
1017     { "segment_list_flags","set flags affecting segment list generation", OFFSET(list_flags), AV_OPT_TYPE_FLAGS, {.i64 = SEGMENT_LIST_FLAG_CACHE }, 0, UINT_MAX, E, "list_flags"},
1018     { "cache",             "allow list caching",                                    0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_LIST_FLAG_CACHE }, INT_MIN, INT_MAX,   E, "list_flags"},
1019     { "live",              "enable live-friendly list generation (useful for HLS)", 0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_LIST_FLAG_LIVE }, INT_MIN, INT_MAX,    E, "list_flags"},
1020 
1021     { "segment_list_size", "set the maximum number of playlist entries", OFFSET(list_size), AV_OPT_TYPE_INT,  {.i64 = 0},     0, INT_MAX, E },
1022 
1023     { "segment_list_type", "set the segment list type",                  OFFSET(list_type), AV_OPT_TYPE_INT,  {.i64 = LIST_TYPE_UNDEFINED}, -1, LIST_TYPE_NB-1, E, "list_type" },
1024     { "flat", "flat format",     0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_FLAT }, INT_MIN, INT_MAX, E, "list_type" },
1025     { "csv",  "csv format",      0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_CSV  }, INT_MIN, INT_MAX, E, "list_type" },
1026     { "ext",  "extended format", 0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_EXT  }, INT_MIN, INT_MAX, E, "list_type" },
1027     { "ffconcat", "ffconcat format", 0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_FFCONCAT }, INT_MIN, INT_MAX, E, "list_type" },
1028     { "m3u8", "M3U8 format",     0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_M3U8 }, INT_MIN, INT_MAX, E, "list_type" },
1029     { "hls", "Apple HTTP Live Streaming compatible", 0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_M3U8 }, INT_MIN, INT_MAX, E, "list_type" },
1030 
1031     { "segment_atclocktime",      "set segment to be cut at clocktime",  OFFSET(use_clocktime), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E},
1032     { "segment_clocktime_offset", "set segment clocktime offset",        OFFSET(clocktime_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, 86400000000LL, E},
1033     { "segment_clocktime_wrap_duration", "set segment clocktime wrapping duration", OFFSET(clocktime_wrap_duration), AV_OPT_TYPE_DURATION, {.i64 = INT64_MAX}, 0, INT64_MAX, E},
1034     { "segment_time",      "set segment duration",                       OFFSET(time),AV_OPT_TYPE_DURATION, {.i64 = 2000000}, INT64_MIN, INT64_MAX,       E },
1035     { "segment_time_delta","set approximation value used for the segment times", OFFSET(time_delta), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, E },
1036     { "segment_times",     "set segment split time points",              OFFSET(times_str),AV_OPT_TYPE_STRING,{.str = NULL},  0, 0,       E },
1037     { "segment_frames",    "set segment split frame numbers",            OFFSET(frames_str),AV_OPT_TYPE_STRING,{.str = NULL},  0, 0,       E },
1038     { "segment_wrap",      "set number after which the index wraps",     OFFSET(segment_idx_wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
1039     { "segment_list_entry_prefix", "set base url prefix for segments", OFFSET(entry_prefix), AV_OPT_TYPE_STRING,  {.str = NULL}, 0, 0, E },
1040     { "segment_start_number", "set the sequence number of the first segment", OFFSET(segment_idx), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
1041     { "segment_wrap_number", "set the number of wrap before the first segment", OFFSET(segment_idx_wrap_nb), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
1042     { "strftime",          "set filename expansion with strftime at segment creation", OFFSET(use_strftime), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
1043     { "increment_tc", "increment timecode between each segment", OFFSET(increment_tc), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
1044     { "break_non_keyframes", "allow breaking segments on non-keyframes", OFFSET(break_non_keyframes), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
1045 
1046     { "individual_header_trailer", "write header/trailer to each segment", OFFSET(individual_header_trailer), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, E },
1047     { "write_header_trailer", "write a header to the first segment and a trailer to the last one", OFFSET(write_header_trailer), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, E },
1048     { "reset_timestamps", "reset timestamps at the beginning of each segment", OFFSET(reset_timestamps), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
1049     { "initial_offset", "set initial timestamp offset", OFFSET(initial_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, -INT64_MAX, INT64_MAX, E },
1050     { "write_empty_segments", "allow writing empty 'filler' segments", OFFSET(write_empty), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
1051     { NULL },
1052 };
1053 
1054 static const AVClass seg_class = {
1055     .class_name = "(stream) segment muxer",
1056     .item_name  = av_default_item_name,
1057     .option     = options,
1058     .version    = LIBAVUTIL_VERSION_INT,
1059 };
1060 
1061 #if CONFIG_SEGMENT_MUXER
1062 const AVOutputFormat ff_segment_muxer = {
1063     .name           = "segment",
1064     .long_name      = NULL_IF_CONFIG_SMALL("segment"),
1065     .priv_data_size = sizeof(SegmentContext),
1066     .flags          = AVFMT_NOFILE|AVFMT_GLOBALHEADER,
1067     .init           = seg_init,
1068     .write_header   = seg_write_header,
1069     .write_packet   = seg_write_packet,
1070     .write_trailer  = seg_write_trailer,
1071     .deinit         = seg_free,
1072     .check_bitstream = seg_check_bitstream,
1073     .priv_class     = &seg_class,
1074 };
1075 #endif
1076 
1077 #if CONFIG_STREAM_SEGMENT_MUXER
1078 const AVOutputFormat ff_stream_segment_muxer = {
1079     .name           = "stream_segment,ssegment",
1080     .long_name      = NULL_IF_CONFIG_SMALL("streaming segment muxer"),
1081     .priv_data_size = sizeof(SegmentContext),
1082     .flags          = AVFMT_NOFILE,
1083     .init           = seg_init,
1084     .write_header   = seg_write_header,
1085     .write_packet   = seg_write_packet,
1086     .write_trailer  = seg_write_trailer,
1087     .deinit         = seg_free,
1088     .check_bitstream = seg_check_bitstream,
1089     .priv_class     = &seg_class,
1090 };
1091 #endif
1092