1/*
2 * Apple HTTP Live Streaming demuxer
3 * Copyright (c) 2010 Martin Storsjo
4 * Copyright (c) 2013 Anssi Hannula
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23/**
24 * @file
25 * Apple HTTP Live Streaming demuxer
26 * http://tools.ietf.org/html/draft-pantos-http-live-streaming
27 */
28
29#include "libavutil/avstring.h"
30#include "libavutil/avassert.h"
31#include "libavutil/intreadwrite.h"
32#include "libavutil/mathematics.h"
33#include "libavutil/opt.h"
34#include "libavutil/dict.h"
35#include "libavutil/time.h"
36#include "avformat.h"
37#include "internal.h"
38#include "avio_internal.h"
39#include "url.h"
40#include "id3v2.h"
41
42#define INITIAL_BUFFER_SIZE 32768
43
44#define MAX_FIELD_LEN 64
45#define MAX_CHARACTERISTICS_LEN 512
46
47#define MPEG_TIME_BASE 90000
48#define MPEG_TIME_BASE_Q (AVRational){1, MPEG_TIME_BASE}
49
50/*
51 * An apple http stream consists of a playlist with media segment files,
52 * played sequentially. There may be several playlists with the same
53 * video content, in different bandwidth variants, that are played in
54 * parallel (preferably only one bandwidth variant at a time). In this case,
55 * the user supplied the url to a main playlist that only lists the variant
56 * playlists.
57 *
58 * If the main playlist doesn't point at any variants, we still create
59 * one anonymous toplevel variant for this, to maintain the structure.
60 */
61
62enum KeyType {
63    KEY_NONE,
64    KEY_AES_128,
65};
66
67struct segment {
68    int64_t duration;
69    int64_t url_offset;
70    int64_t size;
71    char *url;
72    char *key;
73    enum KeyType key_type;
74    uint8_t iv[16];
75};
76
77struct rendition;
78
79enum PlaylistType {
80    PLS_TYPE_UNSPECIFIED,
81    PLS_TYPE_EVENT,
82    PLS_TYPE_VOD
83};
84
85/*
86 * Each playlist has its own demuxer. If it currently is active,
87 * it has an open AVIOContext too, and potentially an AVPacket
88 * containing the next packet from this stream.
89 */
90struct playlist {
91    char url[MAX_URL_SIZE];
92    AVIOContext pb;
93    uint8_t* read_buffer;
94    URLContext *input;
95    AVFormatContext *parent;
96    int index;
97    AVFormatContext *ctx;
98    AVPacket pkt;
99    int stream_offset;
100
101    int finished;
102    enum PlaylistType type;
103    int64_t target_duration;
104    int start_seq_no;
105    int n_segments;
106    struct segment **segments;
107    int needed, cur_needed;
108    int cur_seq_no;
109    int64_t cur_seg_offset;
110    int64_t last_load_time;
111
112    char key_url[MAX_URL_SIZE];
113    uint8_t key[16];
114
115    /* ID3 timestamp handling (elementary audio streams have ID3 timestamps
116     * (and possibly other ID3 tags) in the beginning of each segment) */
117    int is_id3_timestamped; /* -1: not yet known */
118    int64_t id3_mpegts_timestamp; /* in mpegts tb */
119    int64_t id3_offset; /* in stream original tb */
120    uint8_t* id3_buf; /* temp buffer for id3 parsing */
121    unsigned int id3_buf_size;
122    AVDictionary *id3_initial; /* data from first id3 tag */
123    int id3_found; /* ID3 tag found at some point */
124    int id3_changed; /* ID3 tag data has changed at some point */
125    ID3v2ExtraMeta *id3_deferred_extra; /* stored here until subdemuxer is opened */
126
127    int64_t seek_timestamp;
128    int seek_flags;
129    int seek_stream_index; /* into subdemuxer stream array */
130
131    /* Renditions associated with this playlist, if any.
132     * Alternative rendition playlists have a single rendition associated
133     * with them, and variant main Media Playlists may have
134     * multiple (playlist-less) renditions associated with them. */
135    int n_renditions;
136    struct rendition **renditions;
137};
138
139/*
140 * Renditions are e.g. alternative subtitle or audio streams.
141 * The rendition may either be an external playlist or it may be
142 * contained in the main Media Playlist of the variant (in which case
143 * playlist is NULL).
144 */
145struct rendition {
146    enum AVMediaType type;
147    struct playlist *playlist;
148    char group_id[MAX_FIELD_LEN];
149    char language[MAX_FIELD_LEN];
150    char name[MAX_FIELD_LEN];
151    int disposition;
152};
153
154struct variant {
155    int bandwidth;
156
157    /* every variant contains at least the main Media Playlist in index 0 */
158    int n_playlists;
159    struct playlist **playlists;
160
161    char audio_group[MAX_FIELD_LEN];
162    char video_group[MAX_FIELD_LEN];
163    char subtitles_group[MAX_FIELD_LEN];
164};
165
166typedef struct HLSContext {
167    int n_variants;
168    struct variant **variants;
169    int n_playlists;
170    struct playlist **playlists;
171    int n_renditions;
172    struct rendition **renditions;
173
174    int cur_seq_no;
175    int first_packet;
176    int64_t first_timestamp;
177    int64_t cur_timestamp;
178    AVIOInterruptCB *interrupt_callback;
179    char *user_agent;                    ///< holds HTTP user agent set as an AVOption to the HTTP protocol context
180    char *cookies;                       ///< holds HTTP cookie values set in either the initial response or as an AVOption to the HTTP protocol context
181    char *headers;                       ///< holds HTTP headers set as an AVOption to the HTTP protocol context
182} HLSContext;
183
184static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
185{
186    int len = ff_get_line(s, buf, maxlen);
187    while (len > 0 && av_isspace(buf[len - 1]))
188        buf[--len] = '\0';
189    return len;
190}
191
192static void free_segment_list(struct playlist *pls)
193{
194    int i;
195    for (i = 0; i < pls->n_segments; i++) {
196        av_free(pls->segments[i]->key);
197        av_free(pls->segments[i]->url);
198        av_free(pls->segments[i]);
199    }
200    av_freep(&pls->segments);
201    pls->n_segments = 0;
202}
203
204static void free_playlist_list(HLSContext *c)
205{
206    int i;
207    for (i = 0; i < c->n_playlists; i++) {
208        struct playlist *pls = c->playlists[i];
209        free_segment_list(pls);
210        av_freep(&pls->renditions);
211        av_freep(&pls->id3_buf);
212        av_dict_free(&pls->id3_initial);
213        ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);
214        av_free_packet(&pls->pkt);
215        av_free(pls->pb.buffer);
216        if (pls->input)
217            ffurl_close(pls->input);
218        if (pls->ctx) {
219            pls->ctx->pb = NULL;
220            avformat_close_input(&pls->ctx);
221        }
222        av_free(pls);
223    }
224    av_freep(&c->playlists);
225    av_freep(&c->cookies);
226    av_freep(&c->user_agent);
227    c->n_playlists = 0;
228}
229
230static void free_variant_list(HLSContext *c)
231{
232    int i;
233    for (i = 0; i < c->n_variants; i++) {
234        struct variant *var = c->variants[i];
235        av_freep(&var->playlists);
236        av_free(var);
237    }
238    av_freep(&c->variants);
239    c->n_variants = 0;
240}
241
242static void free_rendition_list(HLSContext *c)
243{
244    int i;
245    for (i = 0; i < c->n_renditions; i++)
246        av_free(c->renditions[i]);
247    av_freep(&c->renditions);
248    c->n_renditions = 0;
249}
250
251/*
252 * Used to reset a statically allocated AVPacket to a clean slate,
253 * containing no data.
254 */
255static void reset_packet(AVPacket *pkt)
256{
257    av_init_packet(pkt);
258    pkt->data = NULL;
259}
260
261static struct playlist *new_playlist(HLSContext *c, const char *url,
262                                     const char *base)
263{
264    struct playlist *pls = av_mallocz(sizeof(struct playlist));
265    if (!pls)
266        return NULL;
267    reset_packet(&pls->pkt);
268    ff_make_absolute_url(pls->url, sizeof(pls->url), base, url);
269    pls->seek_timestamp = AV_NOPTS_VALUE;
270
271    pls->is_id3_timestamped = -1;
272    pls->id3_mpegts_timestamp = AV_NOPTS_VALUE;
273
274    dynarray_add(&c->playlists, &c->n_playlists, pls);
275    return pls;
276}
277
278struct variant_info {
279    char bandwidth[20];
280    /* variant group ids: */
281    char audio[MAX_FIELD_LEN];
282    char video[MAX_FIELD_LEN];
283    char subtitles[MAX_FIELD_LEN];
284};
285
286static struct variant *new_variant(HLSContext *c, struct variant_info *info,
287                                   const char *url, const char *base)
288{
289    struct variant *var;
290    struct playlist *pls;
291
292    pls = new_playlist(c, url, base);
293    if (!pls)
294        return NULL;
295
296    var = av_mallocz(sizeof(struct variant));
297    if (!var)
298        return NULL;
299
300    if (info) {
301        var->bandwidth = atoi(info->bandwidth);
302        strcpy(var->audio_group, info->audio);
303        strcpy(var->video_group, info->video);
304        strcpy(var->subtitles_group, info->subtitles);
305    }
306
307    dynarray_add(&c->variants, &c->n_variants, var);
308    dynarray_add(&var->playlists, &var->n_playlists, pls);
309    return var;
310}
311
312static void handle_variant_args(struct variant_info *info, const char *key,
313                                int key_len, char **dest, int *dest_len)
314{
315    if (!strncmp(key, "BANDWIDTH=", key_len)) {
316        *dest     =        info->bandwidth;
317        *dest_len = sizeof(info->bandwidth);
318    } else if (!strncmp(key, "AUDIO=", key_len)) {
319        *dest     =        info->audio;
320        *dest_len = sizeof(info->audio);
321    } else if (!strncmp(key, "VIDEO=", key_len)) {
322        *dest     =        info->video;
323        *dest_len = sizeof(info->video);
324    } else if (!strncmp(key, "SUBTITLES=", key_len)) {
325        *dest     =        info->subtitles;
326        *dest_len = sizeof(info->subtitles);
327    }
328}
329
330struct key_info {
331     char uri[MAX_URL_SIZE];
332     char method[10];
333     char iv[35];
334};
335
336static void handle_key_args(struct key_info *info, const char *key,
337                            int key_len, char **dest, int *dest_len)
338{
339    if (!strncmp(key, "METHOD=", key_len)) {
340        *dest     =        info->method;
341        *dest_len = sizeof(info->method);
342    } else if (!strncmp(key, "URI=", key_len)) {
343        *dest     =        info->uri;
344        *dest_len = sizeof(info->uri);
345    } else if (!strncmp(key, "IV=", key_len)) {
346        *dest     =        info->iv;
347        *dest_len = sizeof(info->iv);
348    }
349}
350
351struct rendition_info {
352    char type[16];
353    char uri[MAX_URL_SIZE];
354    char group_id[MAX_FIELD_LEN];
355    char language[MAX_FIELD_LEN];
356    char assoc_language[MAX_FIELD_LEN];
357    char name[MAX_FIELD_LEN];
358    char defaultr[4];
359    char forced[4];
360    char characteristics[MAX_CHARACTERISTICS_LEN];
361};
362
363static struct rendition *new_rendition(HLSContext *c, struct rendition_info *info,
364                                      const char *url_base)
365{
366    struct rendition *rend;
367    enum AVMediaType type = AVMEDIA_TYPE_UNKNOWN;
368    char *characteristic;
369    char *chr_ptr;
370    char *saveptr;
371
372    if (!strcmp(info->type, "AUDIO"))
373        type = AVMEDIA_TYPE_AUDIO;
374    else if (!strcmp(info->type, "VIDEO"))
375        type = AVMEDIA_TYPE_VIDEO;
376    else if (!strcmp(info->type, "SUBTITLES"))
377        type = AVMEDIA_TYPE_SUBTITLE;
378    else if (!strcmp(info->type, "CLOSED-CAPTIONS"))
379        /* CLOSED-CAPTIONS is ignored since we do not support CEA-608 CC in
380         * AVC SEI RBSP anyway */
381        return NULL;
382
383    if (type == AVMEDIA_TYPE_UNKNOWN)
384        return NULL;
385
386    /* URI is mandatory for subtitles as per spec */
387    if (type == AVMEDIA_TYPE_SUBTITLE && !info->uri[0])
388        return NULL;
389
390    /* TODO: handle subtitles (each segment has to parsed separately) */
391    if (type == AVMEDIA_TYPE_SUBTITLE)
392        return NULL;
393
394    rend = av_mallocz(sizeof(struct rendition));
395    if (!rend)
396        return NULL;
397
398    dynarray_add(&c->renditions, &c->n_renditions, rend);
399
400    rend->type = type;
401    strcpy(rend->group_id, info->group_id);
402    strcpy(rend->language, info->language);
403    strcpy(rend->name, info->name);
404
405    /* add the playlist if this is an external rendition */
406    if (info->uri[0]) {
407        rend->playlist = new_playlist(c, info->uri, url_base);
408        if (rend->playlist)
409            dynarray_add(&rend->playlist->renditions,
410                         &rend->playlist->n_renditions, rend);
411    }
412
413    if (info->assoc_language[0]) {
414        int langlen = strlen(rend->language);
415        if (langlen < sizeof(rend->language) - 3) {
416            rend->language[langlen] = ',';
417            strncpy(rend->language + langlen + 1, info->assoc_language,
418                    sizeof(rend->language) - langlen - 2);
419        }
420    }
421
422    if (!strcmp(info->defaultr, "YES"))
423        rend->disposition |= AV_DISPOSITION_DEFAULT;
424    if (!strcmp(info->forced, "YES"))
425        rend->disposition |= AV_DISPOSITION_FORCED;
426
427    chr_ptr = info->characteristics;
428    while ((characteristic = av_strtok(chr_ptr, ",", &saveptr))) {
429        if (!strcmp(characteristic, "public.accessibility.describes-music-and-sound"))
430            rend->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
431        else if (!strcmp(characteristic, "public.accessibility.describes-video"))
432            rend->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
433
434        chr_ptr = NULL;
435    }
436
437    return rend;
438}
439
440static void handle_rendition_args(struct rendition_info *info, const char *key,
441                                  int key_len, char **dest, int *dest_len)
442{
443    if (!strncmp(key, "TYPE=", key_len)) {
444        *dest     =        info->type;
445        *dest_len = sizeof(info->type);
446    } else if (!strncmp(key, "URI=", key_len)) {
447        *dest     =        info->uri;
448        *dest_len = sizeof(info->uri);
449    } else if (!strncmp(key, "GROUP-ID=", key_len)) {
450        *dest     =        info->group_id;
451        *dest_len = sizeof(info->group_id);
452    } else if (!strncmp(key, "LANGUAGE=", key_len)) {
453        *dest     =        info->language;
454        *dest_len = sizeof(info->language);
455    } else if (!strncmp(key, "ASSOC-LANGUAGE=", key_len)) {
456        *dest     =        info->assoc_language;
457        *dest_len = sizeof(info->assoc_language);
458    } else if (!strncmp(key, "NAME=", key_len)) {
459        *dest     =        info->name;
460        *dest_len = sizeof(info->name);
461    } else if (!strncmp(key, "DEFAULT=", key_len)) {
462        *dest     =        info->defaultr;
463        *dest_len = sizeof(info->defaultr);
464    } else if (!strncmp(key, "FORCED=", key_len)) {
465        *dest     =        info->forced;
466        *dest_len = sizeof(info->forced);
467    } else if (!strncmp(key, "CHARACTERISTICS=", key_len)) {
468        *dest     =        info->characteristics;
469        *dest_len = sizeof(info->characteristics);
470    }
471    /*
472     * ignored:
473     * - AUTOSELECT: client may autoselect based on e.g. system language
474     * - INSTREAM-ID: EIA-608 closed caption number ("CC1".."CC4")
475     */
476}
477
478/* used by parse_playlist to allocate a new variant+playlist when the
479 * playlist is detected to be a Media Playlist (not Master Playlist)
480 * and we have no parent Master Playlist (parsing of which would have
481 * allocated the variant and playlist already) */
482static int ensure_playlist(HLSContext *c, struct playlist **pls, const char *url)
483{
484    if (*pls)
485        return 0;
486    if (!new_variant(c, NULL, url, NULL))
487        return AVERROR(ENOMEM);
488    *pls = c->playlists[c->n_playlists - 1];
489    return 0;
490}
491
492/* pls = NULL  => Master Playlist or parentless Media Playlist
493 * pls = !NULL => parented Media Playlist, playlist+variant allocated */
494static int parse_playlist(HLSContext *c, const char *url,
495                          struct playlist *pls, AVIOContext *in)
496{
497    int ret = 0, is_segment = 0, is_variant = 0;
498    int64_t duration = 0;
499    enum KeyType key_type = KEY_NONE;
500    uint8_t iv[16] = "";
501    int has_iv = 0;
502    char key[MAX_URL_SIZE] = "";
503    char line[MAX_URL_SIZE];
504    const char *ptr;
505    int close_in = 0;
506    int64_t seg_offset = 0;
507    int64_t seg_size = -1;
508    uint8_t *new_url = NULL;
509    struct variant_info variant_info;
510    char tmp_str[MAX_URL_SIZE];
511
512    if (!in) {
513        AVDictionary *opts = NULL;
514        close_in = 1;
515        /* Some HLS servers don't like being sent the range header */
516        av_dict_set(&opts, "seekable", "0", 0);
517
518        // broker prior HTTP options that should be consistent across requests
519        av_dict_set(&opts, "user-agent", c->user_agent, 0);
520        av_dict_set(&opts, "cookies", c->cookies, 0);
521        av_dict_set(&opts, "headers", c->headers, 0);
522
523        ret = avio_open2(&in, url, AVIO_FLAG_READ,
524                         c->interrupt_callback, &opts);
525        av_dict_free(&opts);
526        if (ret < 0)
527            return ret;
528    }
529
530    if (av_opt_get(in, "location", AV_OPT_SEARCH_CHILDREN, &new_url) >= 0)
531        url = new_url;
532
533    read_chomp_line(in, line, sizeof(line));
534    if (strcmp(line, "#EXTM3U")) {
535        ret = AVERROR_INVALIDDATA;
536        goto fail;
537    }
538
539    if (pls) {
540        free_segment_list(pls);
541        pls->finished = 0;
542        pls->type = PLS_TYPE_UNSPECIFIED;
543    }
544    while (!url_feof(in)) {
545        read_chomp_line(in, line, sizeof(line));
546        if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
547            is_variant = 1;
548            memset(&variant_info, 0, sizeof(variant_info));
549            ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
550                               &variant_info);
551        } else if (av_strstart(line, "#EXT-X-KEY:", &ptr)) {
552            struct key_info info = {{0}};
553            ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_key_args,
554                               &info);
555            key_type = KEY_NONE;
556            has_iv = 0;
557            if (!strcmp(info.method, "AES-128"))
558                key_type = KEY_AES_128;
559            if (!strncmp(info.iv, "0x", 2) || !strncmp(info.iv, "0X", 2)) {
560                ff_hex_to_data(iv, info.iv + 2);
561                has_iv = 1;
562            }
563            av_strlcpy(key, info.uri, sizeof(key));
564        } else if (av_strstart(line, "#EXT-X-MEDIA:", &ptr)) {
565            struct rendition_info info = {{0}};
566            ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_rendition_args,
567                               &info);
568            new_rendition(c, &info, url);
569        } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
570            ret = ensure_playlist(c, &pls, url);
571            if (ret < 0)
572                goto fail;
573            pls->target_duration = atoi(ptr) * AV_TIME_BASE;
574        } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
575            ret = ensure_playlist(c, &pls, url);
576            if (ret < 0)
577                goto fail;
578            pls->start_seq_no = atoi(ptr);
579        } else if (av_strstart(line, "#EXT-X-PLAYLIST-TYPE:", &ptr)) {
580            ret = ensure_playlist(c, &pls, url);
581            if (ret < 0)
582                goto fail;
583            if (!strcmp(ptr, "EVENT"))
584                pls->type = PLS_TYPE_EVENT;
585            else if (!strcmp(ptr, "VOD"))
586                pls->type = PLS_TYPE_VOD;
587        } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
588            if (pls)
589                pls->finished = 1;
590        } else if (av_strstart(line, "#EXTINF:", &ptr)) {
591            is_segment = 1;
592            duration   = atof(ptr) * AV_TIME_BASE;
593        } else if (av_strstart(line, "#EXT-X-BYTERANGE:", &ptr)) {
594            seg_size = atoi(ptr);
595            ptr = strchr(ptr, '@');
596            if (ptr)
597                seg_offset = atoi(ptr+1);
598        } else if (av_strstart(line, "#", NULL)) {
599            continue;
600        } else if (line[0]) {
601            if (is_variant) {
602                if (!new_variant(c, &variant_info, line, url)) {
603                    ret = AVERROR(ENOMEM);
604                    goto fail;
605                }
606                is_variant = 0;
607            }
608            if (is_segment) {
609                struct segment *seg;
610                if (!pls) {
611                    if (!new_variant(c, 0, url, NULL)) {
612                        ret = AVERROR(ENOMEM);
613                        goto fail;
614                    }
615                    pls = c->playlists[c->n_playlists - 1];
616                }
617                seg = av_malloc(sizeof(struct segment));
618                if (!seg) {
619                    ret = AVERROR(ENOMEM);
620                    goto fail;
621                }
622                seg->duration = duration;
623                seg->key_type = key_type;
624                if (has_iv) {
625                    memcpy(seg->iv, iv, sizeof(iv));
626                } else {
627                    int seq = pls->start_seq_no + pls->n_segments;
628                    memset(seg->iv, 0, sizeof(seg->iv));
629                    AV_WB32(seg->iv + 12, seq);
630                }
631
632                if (key_type != KEY_NONE) {
633                    ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, key);
634                    seg->key = av_strdup(tmp_str);
635                    if (!seg->key) {
636                        av_free(seg);
637                        ret = AVERROR(ENOMEM);
638                        goto fail;
639                    }
640                } else {
641                    seg->key = NULL;
642                }
643
644                ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, line);
645                seg->url = av_strdup(tmp_str);
646                if (!seg->url) {
647                    av_free(seg->key);
648                    av_free(seg);
649                    ret = AVERROR(ENOMEM);
650                    goto fail;
651                }
652
653                dynarray_add(&pls->segments, &pls->n_segments, seg);
654                is_segment = 0;
655
656                seg->size = seg_size;
657                if (seg_size >= 0) {
658                    seg->url_offset = seg_offset;
659                    seg_offset += seg_size;
660                    seg_size = -1;
661                } else {
662                    seg->url_offset = 0;
663                    seg_offset = 0;
664                }
665            }
666        }
667    }
668    if (pls)
669        pls->last_load_time = av_gettime();
670
671fail:
672    av_free(new_url);
673    if (close_in)
674        avio_close(in);
675    return ret;
676}
677
678enum ReadFromURLMode {
679    READ_NORMAL,
680    READ_COMPLETE,
681};
682
683/* read from URLContext, limiting read to current segment */
684static int read_from_url(struct playlist *pls, uint8_t *buf, int buf_size,
685                         enum ReadFromURLMode mode)
686{
687    int ret;
688    struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
689
690     /* limit read if the segment was only a part of a file */
691    if (seg->size >= 0)
692        buf_size = FFMIN(buf_size, seg->size - pls->cur_seg_offset);
693
694    if (mode == READ_COMPLETE)
695        ret = ffurl_read_complete(pls->input, buf, buf_size);
696    else
697        ret = ffurl_read(pls->input, buf, buf_size);
698
699    if (ret > 0)
700        pls->cur_seg_offset += ret;
701
702    return ret;
703}
704
705/* Parse the raw ID3 data and pass contents to caller */
706static void parse_id3(AVFormatContext *s, AVIOContext *pb,
707                      AVDictionary **metadata, int64_t *dts,
708                      ID3v2ExtraMetaAPIC **apic, ID3v2ExtraMeta **extra_meta)
709{
710    static const char id3_priv_owner_ts[] = "com.apple.streaming.transportStreamTimestamp";
711    ID3v2ExtraMeta *meta;
712
713    ff_id3v2_read_dict(pb, metadata, ID3v2_DEFAULT_MAGIC, extra_meta);
714    for (meta = *extra_meta; meta; meta = meta->next) {
715        if (!strcmp(meta->tag, "PRIV")) {
716            ID3v2ExtraMetaPRIV *priv = meta->data;
717            if (priv->datasize == 8 && !strcmp(priv->owner, id3_priv_owner_ts)) {
718                /* 33-bit MPEG timestamp */
719                int64_t ts = AV_RB64(priv->data);
720                av_log(s, AV_LOG_DEBUG, "HLS ID3 audio timestamp %"PRId64"\n", ts);
721                if ((ts & ~((1ULL << 33) - 1)) == 0)
722                    *dts = ts;
723                else
724                    av_log(s, AV_LOG_ERROR, "Invalid HLS ID3 audio timestamp %"PRId64"\n", ts);
725            }
726        } else if (!strcmp(meta->tag, "APIC") && apic)
727            *apic = meta->data;
728    }
729}
730
731/* Check if the ID3 metadata contents have changed */
732static int id3_has_changed_values(struct playlist *pls, AVDictionary *metadata,
733                                  ID3v2ExtraMetaAPIC *apic)
734{
735    AVDictionaryEntry *entry = NULL;
736    AVDictionaryEntry *oldentry;
737    /* check that no keys have changed values */
738    while ((entry = av_dict_get(metadata, "", entry, AV_DICT_IGNORE_SUFFIX))) {
739        oldentry = av_dict_get(pls->id3_initial, entry->key, NULL, AV_DICT_MATCH_CASE);
740        if (!oldentry || strcmp(oldentry->value, entry->value) != 0)
741            return 1;
742    }
743
744    /* check if apic appeared */
745    if (apic && (pls->ctx->nb_streams != 2 || !pls->ctx->streams[1]->attached_pic.data))
746        return 1;
747
748    if (apic) {
749        int size = pls->ctx->streams[1]->attached_pic.size;
750        if (size != apic->buf->size - FF_INPUT_BUFFER_PADDING_SIZE)
751            return 1;
752
753        if (memcmp(apic->buf->data, pls->ctx->streams[1]->attached_pic.data, size) != 0)
754            return 1;
755    }
756
757    return 0;
758}
759
760/* Parse ID3 data and handle the found data */
761static void handle_id3(AVIOContext *pb, struct playlist *pls)
762{
763    AVDictionary *metadata = NULL;
764    ID3v2ExtraMetaAPIC *apic = NULL;
765    ID3v2ExtraMeta *extra_meta = NULL;
766    int64_t timestamp = AV_NOPTS_VALUE;
767
768    parse_id3(pls->ctx, pb, &metadata, &timestamp, &apic, &extra_meta);
769
770    if (timestamp != AV_NOPTS_VALUE) {
771        pls->id3_mpegts_timestamp = timestamp;
772        pls->id3_offset = 0;
773    }
774
775    if (!pls->id3_found) {
776        /* initial ID3 tags */
777        av_assert0(!pls->id3_deferred_extra);
778        pls->id3_found = 1;
779
780        /* get picture attachment and set text metadata */
781        if (pls->ctx->nb_streams)
782            ff_id3v2_parse_apic(pls->ctx, &extra_meta);
783        else
784            /* demuxer not yet opened, defer picture attachment */
785            pls->id3_deferred_extra = extra_meta;
786
787        av_dict_copy(&pls->ctx->metadata, metadata, 0);
788        pls->id3_initial = metadata;
789
790    } else {
791        if (!pls->id3_changed && id3_has_changed_values(pls, metadata, apic)) {
792            avpriv_report_missing_feature(pls->ctx, "Changing ID3 metadata in HLS audio elementary stream");
793            pls->id3_changed = 1;
794        }
795        av_dict_free(&metadata);
796    }
797
798    if (!pls->id3_deferred_extra)
799        ff_id3v2_free_extra_meta(&extra_meta);
800}
801
802/* Intercept and handle ID3 tags between URLContext and AVIOContext */
803static void intercept_id3(struct playlist *pls, uint8_t *buf,
804                         int buf_size, int *len)
805{
806    /* intercept id3 tags, we do not want to pass them to the raw
807     * demuxer on all segment switches */
808    int bytes;
809    int id3_buf_pos = 0;
810    int fill_buf = 0;
811
812    /* gather all the id3 tags */
813    while (1) {
814        /* see if we can retrieve enough data for ID3 header */
815        if (*len < ID3v2_HEADER_SIZE && buf_size >= ID3v2_HEADER_SIZE) {
816            bytes = read_from_url(pls, buf + *len, ID3v2_HEADER_SIZE - *len, READ_COMPLETE);
817            if (bytes > 0) {
818
819                if (bytes == ID3v2_HEADER_SIZE - *len)
820                    /* no EOF yet, so fill the caller buffer again after
821                     * we have stripped the ID3 tags */
822                    fill_buf = 1;
823
824                *len += bytes;
825
826            } else if (*len <= 0) {
827                /* error/EOF */
828                *len = bytes;
829                fill_buf = 0;
830            }
831        }
832
833        if (*len < ID3v2_HEADER_SIZE)
834            break;
835
836        if (ff_id3v2_match(buf, ID3v2_DEFAULT_MAGIC)) {
837            struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
838            int64_t maxsize = seg->size >= 0 ? seg->size : 1024*1024;
839            int taglen = ff_id3v2_tag_len(buf);
840            int tag_got_bytes = FFMIN(taglen, *len);
841            int remaining = taglen - tag_got_bytes;
842
843            if (taglen > maxsize) {
844                av_log(pls->ctx, AV_LOG_ERROR, "Too large HLS ID3 tag (%d > %"PRId64" bytes)\n",
845                       taglen, maxsize);
846                break;
847            }
848
849            /*
850             * Copy the id3 tag to our temporary id3 buffer.
851             * We could read a small id3 tag directly without memcpy, but
852             * we would still need to copy the large tags, and handling
853             * both of those cases together with the possibility for multiple
854             * tags would make the handling a bit complex.
855             */
856            pls->id3_buf = av_fast_realloc(pls->id3_buf, &pls->id3_buf_size, id3_buf_pos + taglen);
857            if (!pls->id3_buf)
858                break;
859            memcpy(pls->id3_buf + id3_buf_pos, buf, tag_got_bytes);
860            id3_buf_pos += tag_got_bytes;
861
862            /* strip the intercepted bytes */
863            *len -= tag_got_bytes;
864            memmove(buf, buf + tag_got_bytes, *len);
865            av_log(pls->ctx, AV_LOG_DEBUG, "Stripped %d HLS ID3 bytes\n", tag_got_bytes);
866
867            if (remaining > 0) {
868                /* read the rest of the tag in */
869                if (read_from_url(pls, pls->id3_buf + id3_buf_pos, remaining, READ_COMPLETE) != remaining)
870                    break;
871                id3_buf_pos += remaining;
872                av_log(pls->ctx, AV_LOG_DEBUG, "Stripped additional %d HLS ID3 bytes\n", remaining);
873            }
874
875        } else {
876            /* no more ID3 tags */
877            break;
878        }
879    }
880
881    /* re-fill buffer for the caller unless EOF */
882    if (*len >= 0 && (fill_buf || *len == 0)) {
883        bytes = read_from_url(pls, buf + *len, buf_size - *len, READ_NORMAL);
884
885        /* ignore error if we already had some data */
886        if (bytes >= 0)
887            *len += bytes;
888        else if (*len == 0)
889            *len = bytes;
890    }
891
892    if (pls->id3_buf) {
893        /* Now parse all the ID3 tags */
894        AVIOContext id3ioctx;
895        ffio_init_context(&id3ioctx, pls->id3_buf, id3_buf_pos, 0, NULL, NULL, NULL, NULL);
896        handle_id3(&id3ioctx, pls);
897    }
898
899    if (pls->is_id3_timestamped == -1)
900        pls->is_id3_timestamped = (pls->id3_mpegts_timestamp != AV_NOPTS_VALUE);
901}
902
903static int open_input(HLSContext *c, struct playlist *pls)
904{
905    AVDictionary *opts = NULL;
906    AVDictionary *opts2 = NULL;
907    int ret;
908    struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
909
910    // broker prior HTTP options that should be consistent across requests
911    av_dict_set(&opts, "user-agent", c->user_agent, 0);
912    av_dict_set(&opts, "cookies", c->cookies, 0);
913    av_dict_set(&opts, "headers", c->headers, 0);
914    av_dict_set(&opts, "seekable", "0", 0);
915
916    // Same opts for key request (ffurl_open mutilates the opts so it cannot be used twice)
917    av_dict_copy(&opts2, opts, 0);
918
919    if (seg->size >= 0) {
920        /* try to restrict the HTTP request to the part we want
921         * (if this is in fact a HTTP request) */
922        char offset[24] = { 0 };
923        char end_offset[24] = { 0 };
924        snprintf(offset, sizeof(offset) - 1, "%"PRId64,
925                 seg->url_offset);
926        snprintf(end_offset, sizeof(end_offset) - 1, "%"PRId64,
927                 seg->url_offset + seg->size);
928        av_dict_set(&opts, "offset", offset, 0);
929        av_dict_set(&opts, "end_offset", end_offset, 0);
930    }
931
932    av_log(pls->parent, AV_LOG_VERBOSE, "HLS request for url '%s', offset %"PRId64", playlist %d\n",
933           seg->url, seg->url_offset, pls->index);
934
935    if (seg->key_type == KEY_NONE) {
936        ret = ffurl_open(&pls->input, seg->url, AVIO_FLAG_READ,
937                          &pls->parent->interrupt_callback, &opts);
938
939    } else if (seg->key_type == KEY_AES_128) {
940        char iv[33], key[33], url[MAX_URL_SIZE];
941        if (strcmp(seg->key, pls->key_url)) {
942            URLContext *uc;
943            if (ffurl_open(&uc, seg->key, AVIO_FLAG_READ,
944                           &pls->parent->interrupt_callback, &opts2) == 0) {
945                if (ffurl_read_complete(uc, pls->key, sizeof(pls->key))
946                    != sizeof(pls->key)) {
947                    av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",
948                           seg->key);
949                }
950                ffurl_close(uc);
951            } else {
952                av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",
953                       seg->key);
954            }
955            av_strlcpy(pls->key_url, seg->key, sizeof(pls->key_url));
956        }
957        ff_data_to_hex(iv, seg->iv, sizeof(seg->iv), 0);
958        ff_data_to_hex(key, pls->key, sizeof(pls->key), 0);
959        iv[32] = key[32] = '\0';
960        if (strstr(seg->url, "://"))
961            snprintf(url, sizeof(url), "crypto+%s", seg->url);
962        else
963            snprintf(url, sizeof(url), "crypto:%s", seg->url);
964        if ((ret = ffurl_alloc(&pls->input, url, AVIO_FLAG_READ,
965                               &pls->parent->interrupt_callback)) < 0)
966            goto cleanup;
967        av_opt_set(pls->input->priv_data, "key", key, 0);
968        av_opt_set(pls->input->priv_data, "iv", iv, 0);
969
970        if ((ret = ffurl_connect(pls->input, &opts)) < 0) {
971            ffurl_close(pls->input);
972            pls->input = NULL;
973            goto cleanup;
974        }
975        ret = 0;
976    }
977    else
978      ret = AVERROR(ENOSYS);
979
980    /* Seek to the requested position. If this was a HTTP request, the offset
981     * should already be where want it to, but this allows e.g. local testing
982     * without a HTTP server. */
983    if (ret == 0 && seg->key_type == KEY_NONE) {
984        int seekret = ffurl_seek(pls->input, seg->url_offset, SEEK_SET);
985        if (seekret < 0) {
986            av_log(pls->parent, AV_LOG_ERROR, "Unable to seek to offset %"PRId64" of HLS segment '%s'\n", seg->url_offset, seg->url);
987            ret = seekret;
988            ffurl_close(pls->input);
989            pls->input = NULL;
990        }
991    }
992
993cleanup:
994    av_dict_free(&opts);
995    av_dict_free(&opts2);
996    pls->cur_seg_offset = 0;
997    return ret;
998}
999
1000static int64_t default_reload_interval(struct playlist *pls)
1001{
1002    return pls->n_segments > 0 ?
1003                          pls->segments[pls->n_segments - 1]->duration :
1004                          pls->target_duration;
1005}
1006
1007static int read_data(void *opaque, uint8_t *buf, int buf_size)
1008{
1009    struct playlist *v = opaque;
1010    HLSContext *c = v->parent->priv_data;
1011    int ret, i;
1012    int just_opened = 0;
1013
1014restart:
1015    if (!v->needed)
1016        return AVERROR_EOF;
1017
1018    if (!v->input) {
1019        int64_t reload_interval;
1020
1021        /* Check that the playlist is still needed before opening a new
1022         * segment. */
1023        if (v->ctx && v->ctx->nb_streams &&
1024            v->parent->nb_streams >= v->stream_offset + v->ctx->nb_streams) {
1025            v->needed = 0;
1026            for (i = v->stream_offset; i < v->stream_offset + v->ctx->nb_streams;
1027                i++) {
1028                if (v->parent->streams[i]->discard < AVDISCARD_ALL)
1029                    v->needed = 1;
1030            }
1031        }
1032        if (!v->needed) {
1033            av_log(v->parent, AV_LOG_INFO, "No longer receiving playlist %d\n",
1034                v->index);
1035            return AVERROR_EOF;
1036        }
1037
1038        /* If this is a live stream and the reload interval has elapsed since
1039         * the last playlist reload, reload the playlists now. */
1040        reload_interval = default_reload_interval(v);
1041
1042reload:
1043        if (!v->finished &&
1044            av_gettime() - v->last_load_time >= reload_interval) {
1045            if ((ret = parse_playlist(c, v->url, v, NULL)) < 0) {
1046                av_log(v->parent, AV_LOG_WARNING, "Failed to reload playlist %d\n",
1047                       v->index);
1048                return ret;
1049            }
1050            /* If we need to reload the playlist again below (if
1051             * there's still no more segments), switch to a reload
1052             * interval of half the target duration. */
1053            reload_interval = v->target_duration / 2;
1054        }
1055        if (v->cur_seq_no < v->start_seq_no) {
1056            av_log(NULL, AV_LOG_WARNING,
1057                   "skipping %d segments ahead, expired from playlists\n",
1058                   v->start_seq_no - v->cur_seq_no);
1059            v->cur_seq_no = v->start_seq_no;
1060        }
1061        if (v->cur_seq_no >= v->start_seq_no + v->n_segments) {
1062            if (v->finished)
1063                return AVERROR_EOF;
1064            while (av_gettime() - v->last_load_time < reload_interval) {
1065                if (ff_check_interrupt(c->interrupt_callback))
1066                    return AVERROR_EXIT;
1067                av_usleep(100*1000);
1068            }
1069            /* Enough time has elapsed since the last reload */
1070            goto reload;
1071        }
1072
1073        ret = open_input(c, v);
1074        if (ret < 0) {
1075            av_log(v->parent, AV_LOG_WARNING, "Failed to open segment of playlist %d\n",
1076                   v->index);
1077            return ret;
1078        }
1079        just_opened = 1;
1080    }
1081
1082    ret = read_from_url(v, buf, buf_size, READ_NORMAL);
1083    if (ret > 0) {
1084        if (just_opened && v->is_id3_timestamped != 0) {
1085            /* Intercept ID3 tags here, elementary audio streams are required
1086             * to convey timestamps using them in the beginning of each segment. */
1087            intercept_id3(v, buf, buf_size, &ret);
1088        }
1089
1090        return ret;
1091    }
1092    ffurl_close(v->input);
1093    v->input = NULL;
1094    v->cur_seq_no++;
1095
1096    c->cur_seq_no = v->cur_seq_no;
1097
1098    goto restart;
1099}
1100
1101static int playlist_in_multiple_variants(HLSContext *c, struct playlist *pls)
1102{
1103    int variant_count = 0;
1104    int i, j;
1105
1106    for (i = 0; i < c->n_variants && variant_count < 2; i++) {
1107        struct variant *v = c->variants[i];
1108
1109        for (j = 0; j < v->n_playlists; j++) {
1110            if (v->playlists[j] == pls) {
1111                variant_count++;
1112                break;
1113            }
1114        }
1115    }
1116
1117    return variant_count >= 2;
1118}
1119
1120static void add_renditions_to_variant(HLSContext *c, struct variant *var,
1121                                      enum AVMediaType type, const char *group_id)
1122{
1123    int i;
1124
1125    for (i = 0; i < c->n_renditions; i++) {
1126        struct rendition *rend = c->renditions[i];
1127
1128        if (rend->type == type && !strcmp(rend->group_id, group_id)) {
1129
1130            if (rend->playlist)
1131                /* rendition is an external playlist
1132                 * => add the playlist to the variant */
1133                dynarray_add(&var->playlists, &var->n_playlists, rend->playlist);
1134            else
1135                /* rendition is part of the variant main Media Playlist
1136                 * => add the rendition to the main Media Playlist */
1137                dynarray_add(&var->playlists[0]->renditions,
1138                             &var->playlists[0]->n_renditions,
1139                             rend);
1140        }
1141    }
1142}
1143
1144static void add_metadata_from_renditions(AVFormatContext *s, struct playlist *pls,
1145                                         enum AVMediaType type)
1146{
1147    int rend_idx = 0;
1148    int i;
1149
1150    for (i = 0; i < pls->ctx->nb_streams; i++) {
1151        AVStream *st = s->streams[pls->stream_offset + i];
1152
1153        if (st->codec->codec_type != type)
1154            continue;
1155
1156        for (; rend_idx < pls->n_renditions; rend_idx++) {
1157            struct rendition *rend = pls->renditions[rend_idx];
1158
1159            if (rend->type != type)
1160                continue;
1161
1162            if (rend->language[0])
1163                av_dict_set(&st->metadata, "language", rend->language, 0);
1164            if (rend->name[0])
1165                av_dict_set(&st->metadata, "comment", rend->name, 0);
1166
1167            st->disposition |= rend->disposition;
1168        }
1169        if (rend_idx >=pls->n_renditions)
1170            break;
1171    }
1172}
1173
1174/* if timestamp was in valid range: returns 1 and sets seq_no
1175 * if not: returns 0 and sets seq_no to closest segment */
1176static int find_timestamp_in_playlist(HLSContext *c, struct playlist *pls,
1177                                      int64_t timestamp, int *seq_no)
1178{
1179    int i;
1180    int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ?
1181                  0 : c->first_timestamp;
1182
1183    if (timestamp < pos) {
1184        *seq_no = pls->start_seq_no;
1185        return 0;
1186    }
1187
1188    for (i = 0; i < pls->n_segments; i++) {
1189        int64_t diff = pos + pls->segments[i]->duration - timestamp;
1190        if (diff > 0) {
1191            *seq_no = pls->start_seq_no + i;
1192            return 1;
1193        }
1194        pos += pls->segments[i]->duration;
1195    }
1196
1197    *seq_no = pls->start_seq_no + pls->n_segments - 1;
1198
1199    return 0;
1200}
1201
1202static int select_cur_seq_no(HLSContext *c, struct playlist *pls)
1203{
1204    int seq_no;
1205
1206    if (!pls->finished && !c->first_packet &&
1207        av_gettime() - pls->last_load_time >= default_reload_interval(pls))
1208        /* reload the playlist since it was suspended */
1209        parse_playlist(c, pls->url, pls, NULL);
1210
1211    /* If playback is already in progress (we are just selecting a new
1212     * playlist) and this is a complete file, find the matching segment
1213     * by counting durations. */
1214    if (pls->finished && c->cur_timestamp != AV_NOPTS_VALUE) {
1215        find_timestamp_in_playlist(c, pls, c->cur_timestamp, &seq_no);
1216        return seq_no;
1217    }
1218
1219    if (!pls->finished) {
1220        if (!c->first_packet && /* we are doing a segment selection during playback */
1221            c->cur_seq_no >= pls->start_seq_no &&
1222            c->cur_seq_no < pls->start_seq_no + pls->n_segments)
1223            /* While spec 3.4.3 says that we cannot assume anything about the
1224             * content at the same sequence number on different playlists,
1225             * in practice this seems to work and doing it otherwise would
1226             * require us to download a segment to inspect its timestamps. */
1227            return c->cur_seq_no;
1228
1229        /* If this is a live stream with more than 3 segments, start at the
1230         * third last segment. */
1231        if (pls->n_segments > 3)
1232            return pls->start_seq_no + pls->n_segments - 3;
1233    }
1234
1235    /* Otherwise just start on the first segment. */
1236    return pls->start_seq_no;
1237}
1238
1239static int hls_read_header(AVFormatContext *s)
1240{
1241    URLContext *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb->opaque;
1242    HLSContext *c = s->priv_data;
1243    int ret = 0, i, j, stream_offset = 0;
1244
1245    c->interrupt_callback = &s->interrupt_callback;
1246
1247    c->first_packet = 1;
1248    c->first_timestamp = AV_NOPTS_VALUE;
1249    c->cur_timestamp = AV_NOPTS_VALUE;
1250
1251    // if the URL context is good, read important options we must broker later
1252    if (u && u->prot->priv_data_class) {
1253        // get the previous user agent & set back to null if string size is zero
1254        av_freep(&c->user_agent);
1255        av_opt_get(u->priv_data, "user-agent", 0, (uint8_t**)&(c->user_agent));
1256        if (c->user_agent && !strlen(c->user_agent))
1257            av_freep(&c->user_agent);
1258
1259        // get the previous cookies & set back to null if string size is zero
1260        av_freep(&c->cookies);
1261        av_opt_get(u->priv_data, "cookies", 0, (uint8_t**)&(c->cookies));
1262        if (c->cookies && !strlen(c->cookies))
1263            av_freep(&c->cookies);
1264
1265        // get the previous headers & set back to null if string size is zero
1266        av_freep(&c->headers);
1267        av_opt_get(u->priv_data, "headers", 0, (uint8_t**)&(c->headers));
1268        if (c->headers && !strlen(c->headers))
1269            av_freep(&c->headers);
1270    }
1271
1272    if ((ret = parse_playlist(c, s->filename, NULL, s->pb)) < 0)
1273        goto fail;
1274
1275    if (c->n_variants == 0) {
1276        av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
1277        ret = AVERROR_EOF;
1278        goto fail;
1279    }
1280    /* If the playlist only contained playlists (Master Playlist),
1281     * parse each individual playlist. */
1282    if (c->n_playlists > 1 || c->playlists[0]->n_segments == 0) {
1283        for (i = 0; i < c->n_playlists; i++) {
1284            struct playlist *pls = c->playlists[i];
1285            if ((ret = parse_playlist(c, pls->url, pls, NULL)) < 0)
1286                goto fail;
1287        }
1288    }
1289
1290    if (c->variants[0]->playlists[0]->n_segments == 0) {
1291        av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
1292        ret = AVERROR_EOF;
1293        goto fail;
1294    }
1295
1296    /* If this isn't a live stream, calculate the total duration of the
1297     * stream. */
1298    if (c->variants[0]->playlists[0]->finished) {
1299        int64_t duration = 0;
1300        for (i = 0; i < c->variants[0]->playlists[0]->n_segments; i++)
1301            duration += c->variants[0]->playlists[0]->segments[i]->duration;
1302        s->duration = duration;
1303    }
1304
1305    /* Associate renditions with variants */
1306    for (i = 0; i < c->n_variants; i++) {
1307        struct variant *var = c->variants[i];
1308
1309        if (var->audio_group[0])
1310            add_renditions_to_variant(c, var, AVMEDIA_TYPE_AUDIO, var->audio_group);
1311        if (var->video_group[0])
1312            add_renditions_to_variant(c, var, AVMEDIA_TYPE_VIDEO, var->video_group);
1313        if (var->subtitles_group[0])
1314            add_renditions_to_variant(c, var, AVMEDIA_TYPE_SUBTITLE, var->subtitles_group);
1315    }
1316
1317    /* Open the demuxer for each playlist */
1318    for (i = 0; i < c->n_playlists; i++) {
1319        struct playlist *pls = c->playlists[i];
1320        AVInputFormat *in_fmt = NULL;
1321
1322        if (pls->n_segments == 0)
1323            continue;
1324
1325        if (!(pls->ctx = avformat_alloc_context())) {
1326            ret = AVERROR(ENOMEM);
1327            goto fail;
1328        }
1329
1330        pls->index  = i;
1331        pls->needed = 1;
1332        pls->parent = s;
1333        pls->cur_seq_no = select_cur_seq_no(c, pls);
1334
1335        pls->read_buffer = av_malloc(INITIAL_BUFFER_SIZE);
1336        ffio_init_context(&pls->pb, pls->read_buffer, INITIAL_BUFFER_SIZE, 0, pls,
1337                          read_data, NULL, NULL);
1338        pls->pb.seekable = 0;
1339        ret = av_probe_input_buffer(&pls->pb, &in_fmt, pls->segments[0]->url,
1340                                    NULL, 0, 0);
1341        if (ret < 0) {
1342            /* Free the ctx - it isn't initialized properly at this point,
1343             * so avformat_close_input shouldn't be called. If
1344             * avformat_open_input fails below, it frees and zeros the
1345             * context, so it doesn't need any special treatment like this. */
1346            av_log(s, AV_LOG_ERROR, "Error when loading first segment '%s'\n", pls->segments[0]->url);
1347            avformat_free_context(pls->ctx);
1348            pls->ctx = NULL;
1349            goto fail;
1350        }
1351        pls->ctx->pb       = &pls->pb;
1352        pls->stream_offset = stream_offset;
1353        ret = avformat_open_input(&pls->ctx, pls->segments[0]->url, in_fmt, NULL);
1354        if (ret < 0)
1355            goto fail;
1356
1357        if (pls->id3_deferred_extra && pls->ctx->nb_streams == 1) {
1358            ff_id3v2_parse_apic(pls->ctx, &pls->id3_deferred_extra);
1359            avformat_queue_attached_pictures(pls->ctx);
1360            ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);
1361            pls->id3_deferred_extra = NULL;
1362        }
1363
1364        pls->ctx->ctx_flags &= ~AVFMTCTX_NOHEADER;
1365        ret = avformat_find_stream_info(pls->ctx, NULL);
1366        if (ret < 0)
1367            goto fail;
1368
1369        if (pls->is_id3_timestamped == -1)
1370            av_log(s, AV_LOG_WARNING, "No expected HTTP requests have been made\n");
1371
1372        /* Create new AVStreams for each stream in this playlist */
1373        for (j = 0; j < pls->ctx->nb_streams; j++) {
1374            AVStream *st = avformat_new_stream(s, NULL);
1375            AVStream *ist = pls->ctx->streams[j];
1376            if (!st) {
1377                ret = AVERROR(ENOMEM);
1378                goto fail;
1379            }
1380            st->id = i;
1381
1382            avcodec_copy_context(st->codec, pls->ctx->streams[j]->codec);
1383
1384            if (pls->is_id3_timestamped) /* custom timestamps via id3 */
1385                avpriv_set_pts_info(st, 33, 1, MPEG_TIME_BASE);
1386            else
1387                avpriv_set_pts_info(st, ist->pts_wrap_bits, ist->time_base.num, ist->time_base.den);
1388        }
1389
1390        add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_AUDIO);
1391        add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_VIDEO);
1392        add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_SUBTITLE);
1393
1394        stream_offset += pls->ctx->nb_streams;
1395    }
1396
1397    /* Create a program for each variant */
1398    for (i = 0; i < c->n_variants; i++) {
1399        struct variant *v = c->variants[i];
1400        char bitrate_str[20];
1401        AVProgram *program;
1402
1403        snprintf(bitrate_str, sizeof(bitrate_str), "%d", v->bandwidth);
1404
1405        program = av_new_program(s, i);
1406        if (!program)
1407            goto fail;
1408        av_dict_set(&program->metadata, "variant_bitrate", bitrate_str, 0);
1409
1410        for (j = 0; j < v->n_playlists; j++) {
1411            struct playlist *pls = v->playlists[j];
1412            int is_shared = playlist_in_multiple_variants(c, pls);
1413            int k;
1414
1415            for (k = 0; k < pls->ctx->nb_streams; k++) {
1416                struct AVStream *st = s->streams[pls->stream_offset + k];
1417
1418                ff_program_add_stream_index(s, i, pls->stream_offset + k);
1419
1420                /* Set variant_bitrate for streams unique to this variant */
1421                if (!is_shared && v->bandwidth)
1422                    av_dict_set(&st->metadata, "variant_bitrate", bitrate_str, 0);
1423            }
1424        }
1425    }
1426
1427    return 0;
1428fail:
1429    free_playlist_list(c);
1430    free_variant_list(c);
1431    free_rendition_list(c);
1432    return ret;
1433}
1434
1435static int recheck_discard_flags(AVFormatContext *s, int first)
1436{
1437    HLSContext *c = s->priv_data;
1438    int i, changed = 0;
1439
1440    /* Check if any new streams are needed */
1441    for (i = 0; i < c->n_playlists; i++)
1442        c->playlists[i]->cur_needed = 0;
1443
1444    for (i = 0; i < s->nb_streams; i++) {
1445        AVStream *st = s->streams[i];
1446        struct playlist *pls = c->playlists[s->streams[i]->id];
1447        if (st->discard < AVDISCARD_ALL)
1448            pls->cur_needed = 1;
1449    }
1450    for (i = 0; i < c->n_playlists; i++) {
1451        struct playlist *pls = c->playlists[i];
1452        if (pls->cur_needed && !pls->needed) {
1453            pls->needed = 1;
1454            changed = 1;
1455            pls->cur_seq_no = select_cur_seq_no(c, pls);
1456            pls->pb.eof_reached = 0;
1457            if (c->cur_timestamp != AV_NOPTS_VALUE) {
1458                /* catch up */
1459                pls->seek_timestamp = c->cur_timestamp;
1460                pls->seek_flags = AVSEEK_FLAG_ANY;
1461                pls->seek_stream_index = -1;
1462            }
1463            av_log(s, AV_LOG_INFO, "Now receiving playlist %d, segment %d\n", i, pls->cur_seq_no);
1464        } else if (first && !pls->cur_needed && pls->needed) {
1465            if (pls->input)
1466                ffurl_close(pls->input);
1467            pls->input = NULL;
1468            pls->needed = 0;
1469            changed = 1;
1470            av_log(s, AV_LOG_INFO, "No longer receiving playlist %d\n", i);
1471        }
1472    }
1473    return changed;
1474}
1475
1476static void fill_timing_for_id3_timestamped_stream(struct playlist *pls)
1477{
1478    if (pls->id3_offset >= 0) {
1479        pls->pkt.dts = pls->id3_mpegts_timestamp +
1480                                 av_rescale_q(pls->id3_offset,
1481                                              pls->ctx->streams[pls->pkt.stream_index]->time_base,
1482                                              MPEG_TIME_BASE_Q);
1483        if (pls->pkt.duration)
1484            pls->id3_offset += pls->pkt.duration;
1485        else
1486            pls->id3_offset = -1;
1487    } else {
1488        /* there have been packets with unknown duration
1489         * since the last id3 tag, should not normally happen */
1490        pls->pkt.dts = AV_NOPTS_VALUE;
1491    }
1492
1493    if (pls->pkt.duration)
1494        pls->pkt.duration = av_rescale_q(pls->pkt.duration,
1495                                         pls->ctx->streams[pls->pkt.stream_index]->time_base,
1496                                         MPEG_TIME_BASE_Q);
1497
1498    pls->pkt.pts = AV_NOPTS_VALUE;
1499}
1500
1501static AVRational get_timebase(struct playlist *pls)
1502{
1503    if (pls->is_id3_timestamped)
1504        return MPEG_TIME_BASE_Q;
1505
1506    return pls->ctx->streams[pls->pkt.stream_index]->time_base;
1507}
1508
1509static int compare_ts_with_wrapdetect(int64_t ts_a, struct playlist *pls_a,
1510                                      int64_t ts_b, struct playlist *pls_b)
1511{
1512    int64_t scaled_ts_a = av_rescale_q(ts_a, get_timebase(pls_a), MPEG_TIME_BASE_Q);
1513    int64_t scaled_ts_b = av_rescale_q(ts_b, get_timebase(pls_b), MPEG_TIME_BASE_Q);
1514
1515    return av_compare_mod(scaled_ts_a, scaled_ts_b, 1LL << 33);
1516}
1517
1518static int hls_read_packet(AVFormatContext *s, AVPacket *pkt)
1519{
1520    HLSContext *c = s->priv_data;
1521    int ret, i, minplaylist = -1;
1522
1523    recheck_discard_flags(s, c->first_packet);
1524
1525    for (i = 0; i < c->n_playlists; i++) {
1526        struct playlist *pls = c->playlists[i];
1527        /* Make sure we've got one buffered packet from each open playlist
1528         * stream */
1529        if (pls->needed && !pls->pkt.data) {
1530            while (1) {
1531                int64_t ts_diff;
1532                AVRational tb;
1533                ret = av_read_frame(pls->ctx, &pls->pkt);
1534                if (ret < 0) {
1535                    if (!url_feof(&pls->pb) && ret != AVERROR_EOF)
1536                        return ret;
1537                    reset_packet(&pls->pkt);
1538                    break;
1539                } else {
1540                    /* stream_index check prevents matching picture attachments etc. */
1541                    if (pls->is_id3_timestamped && pls->pkt.stream_index == 0) {
1542                        /* audio elementary streams are id3 timestamped */
1543                        fill_timing_for_id3_timestamped_stream(pls);
1544                    }
1545
1546                    if (c->first_timestamp == AV_NOPTS_VALUE &&
1547                        pls->pkt.dts       != AV_NOPTS_VALUE)
1548                        c->first_timestamp = av_rescale_q(pls->pkt.dts,
1549                            get_timebase(pls), AV_TIME_BASE_Q);
1550                }
1551
1552                if (pls->seek_timestamp == AV_NOPTS_VALUE)
1553                    break;
1554
1555                if (pls->seek_stream_index < 0 ||
1556                    pls->seek_stream_index == pls->pkt.stream_index) {
1557
1558                    if (pls->pkt.dts == AV_NOPTS_VALUE) {
1559                        pls->seek_timestamp = AV_NOPTS_VALUE;
1560                        break;
1561                    }
1562
1563                    tb = get_timebase(pls);
1564                    ts_diff = av_rescale_rnd(pls->pkt.dts, AV_TIME_BASE,
1565                                            tb.den, AV_ROUND_DOWN) -
1566                            pls->seek_timestamp;
1567                    if (ts_diff >= 0 && (pls->seek_flags  & AVSEEK_FLAG_ANY ||
1568                                        pls->pkt.flags & AV_PKT_FLAG_KEY)) {
1569                        pls->seek_timestamp = AV_NOPTS_VALUE;
1570                        break;
1571                    }
1572                }
1573                av_free_packet(&pls->pkt);
1574                reset_packet(&pls->pkt);
1575            }
1576        }
1577        /* Check if this stream has the packet with the lowest dts */
1578        if (pls->pkt.data) {
1579            struct playlist *minpls = minplaylist < 0 ?
1580                                     NULL : c->playlists[minplaylist];
1581            if (minplaylist < 0) {
1582                minplaylist = i;
1583            } else {
1584                int64_t dts     =    pls->pkt.dts;
1585                int64_t mindts  = minpls->pkt.dts;
1586
1587                if (dts == AV_NOPTS_VALUE ||
1588                    (mindts != AV_NOPTS_VALUE && compare_ts_with_wrapdetect(dts, pls, mindts, minpls) < 0))
1589                    minplaylist = i;
1590            }
1591        }
1592    }
1593
1594    /* If we got a packet, return it */
1595    if (minplaylist >= 0) {
1596        struct playlist *pls = c->playlists[minplaylist];
1597        *pkt = pls->pkt;
1598        pkt->stream_index += pls->stream_offset;
1599        reset_packet(&c->playlists[minplaylist]->pkt);
1600
1601        if (pkt->dts != AV_NOPTS_VALUE)
1602            c->cur_timestamp = av_rescale_q(pkt->dts,
1603                                            pls->ctx->streams[pls->pkt.stream_index]->time_base,
1604                                            AV_TIME_BASE_Q);
1605
1606        return 0;
1607    }
1608    return AVERROR_EOF;
1609}
1610
1611static int hls_close(AVFormatContext *s)
1612{
1613    HLSContext *c = s->priv_data;
1614
1615    free_playlist_list(c);
1616    free_variant_list(c);
1617    free_rendition_list(c);
1618    return 0;
1619}
1620
1621static int hls_read_seek(AVFormatContext *s, int stream_index,
1622                               int64_t timestamp, int flags)
1623{
1624    HLSContext *c = s->priv_data;
1625    struct playlist *seek_pls = NULL;
1626    int i, seq_no;
1627    int64_t first_timestamp, seek_timestamp, duration;
1628
1629    if ((flags & AVSEEK_FLAG_BYTE) ||
1630        !(c->variants[0]->playlists[0]->finished || c->variants[0]->playlists[0]->type == PLS_TYPE_EVENT))
1631        return AVERROR(ENOSYS);
1632
1633    first_timestamp = c->first_timestamp == AV_NOPTS_VALUE ?
1634                      0 : c->first_timestamp;
1635
1636    seek_timestamp = av_rescale_rnd(timestamp, AV_TIME_BASE,
1637                                    s->streams[stream_index]->time_base.den,
1638                                    flags & AVSEEK_FLAG_BACKWARD ?
1639                                    AV_ROUND_DOWN : AV_ROUND_UP);
1640
1641    duration = s->duration == AV_NOPTS_VALUE ?
1642               0 : s->duration;
1643
1644    if (0 < duration && duration < seek_timestamp - first_timestamp)
1645        return AVERROR(EIO);
1646
1647    /* find the playlist with the specified stream */
1648    for (i = 0; i < c->n_playlists; i++) {
1649        struct playlist *pls = c->playlists[i];
1650        if (stream_index >= pls->stream_offset &&
1651            stream_index - pls->stream_offset < pls->ctx->nb_streams) {
1652            seek_pls = pls;
1653            break;
1654        }
1655    }
1656    /* check if the timestamp is valid for the playlist with the
1657     * specified stream index */
1658    if (!seek_pls || !find_timestamp_in_playlist(c, seek_pls, seek_timestamp, &seq_no))
1659        return AVERROR(EIO);
1660
1661    /* set segment now so we do not need to search again below */
1662    seek_pls->cur_seq_no = seq_no;
1663    seek_pls->seek_stream_index = stream_index - seek_pls->stream_offset;
1664
1665    for (i = 0; i < c->n_playlists; i++) {
1666        /* Reset reading */
1667        struct playlist *pls = c->playlists[i];
1668        if (pls->input) {
1669            ffurl_close(pls->input);
1670            pls->input = NULL;
1671        }
1672        av_free_packet(&pls->pkt);
1673        reset_packet(&pls->pkt);
1674        pls->pb.eof_reached = 0;
1675        /* Clear any buffered data */
1676        pls->pb.buf_end = pls->pb.buf_ptr = pls->pb.buffer;
1677        /* Reset the pos, to let the mpegts demuxer know we've seeked. */
1678        pls->pb.pos = 0;
1679        /* Flush the packet queue of the subdemuxer. */
1680        ff_read_frame_flush(pls->ctx);
1681
1682        pls->seek_timestamp = seek_timestamp;
1683        pls->seek_flags = flags;
1684
1685        if (pls != seek_pls) {
1686            /* set closest segment seq_no for playlists not handled above */
1687            find_timestamp_in_playlist(c, pls, seek_timestamp, &pls->cur_seq_no);
1688            /* seek the playlist to the given position without taking
1689             * keyframes into account since this playlist does not have the
1690             * specified stream where we should look for the keyframes */
1691            pls->seek_stream_index = -1;
1692            pls->seek_flags |= AVSEEK_FLAG_ANY;
1693        }
1694    }
1695
1696    c->cur_timestamp = seek_timestamp;
1697
1698    return 0;
1699}
1700
1701static int hls_probe(AVProbeData *p)
1702{
1703    /* Require #EXTM3U at the start, and either one of the ones below
1704     * somewhere for a proper match. */
1705    if (strncmp(p->buf, "#EXTM3U", 7))
1706        return 0;
1707    if (strstr(p->buf, "#EXT-X-STREAM-INF:")     ||
1708        strstr(p->buf, "#EXT-X-TARGETDURATION:") ||
1709        strstr(p->buf, "#EXT-X-MEDIA-SEQUENCE:"))
1710        return AVPROBE_SCORE_MAX;
1711    return 0;
1712}
1713
1714AVInputFormat ff_hls_demuxer = {
1715    .name           = "hls,applehttp",
1716    .long_name      = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
1717    .priv_data_size = sizeof(HLSContext),
1718    .read_probe     = hls_probe,
1719    .read_header    = hls_read_header,
1720    .read_packet    = hls_read_packet,
1721    .read_close     = hls_close,
1722    .read_seek      = hls_read_seek,
1723};
1724