2 * Apple HTTP Live Streaming demuxer
3 * Copyright (c) 2010 Martin Storsjo
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * Apple HTTP Live Streaming demuxer
25 * http://tools.ietf.org/html/draft-pantos-http-live-streaming
28 #include "libavutil/avstring.h"
29 #include "libavutil/intreadwrite.h"
30 #include "libavutil/mathematics.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/dict.h"
33 #include "libavutil/time.h"
36 #include "avio_internal.h"
39 #define INITIAL_BUFFER_SIZE 32768
42 * An apple http stream consists of a playlist with media segment files,
43 * played sequentially. There may be several playlists with the same
44 * video content, in different bandwidth variants, that are played in
45 * parallel (preferably only one bandwidth variant at a time). In this case,
46 * the user supplied the url to a main playlist that only lists the variant
49 * If the main playlist doesn't point at any variants, we still create
50 * one anonymous toplevel variant for this, to maintain the structure.
60 char url[MAX_URL_SIZE];
61 char key[MAX_URL_SIZE];
62 enum KeyType key_type;
67 * Each variant has its own demuxer. If it currently is active,
68 * it has an open AVIOContext too, and potentially an AVPacket
69 * containing the next packet from this stream.
73 char url[MAX_URL_SIZE];
77 AVFormatContext *parent;
84 int64_t target_duration;
87 struct segment **segments;
88 int needed, cur_needed;
90 int64_t last_load_time;
92 char key_url[MAX_URL_SIZE];
96 typedef struct HLSContext {
98 struct variant **variants;
102 int64_t first_timestamp;
103 int64_t seek_timestamp;
105 AVIOInterruptCB *interrupt_callback;
106 char *user_agent; ///< holds HTTP user agent set as an AVOption to the HTTP protocol context
107 char *cookies; ///< holds HTTP cookie values set in either the initial response or as an AVOption to the HTTP protocol context
108 char *headers; ///< holds HTTP headers set as an AVOption to the HTTP protocol context
111 static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
113 int len = ff_get_line(s, buf, maxlen);
114 while (len > 0 && av_isspace(buf[len - 1]))
119 static void free_segment_list(struct variant *var)
122 for (i = 0; i < var->n_segments; i++)
123 av_free(var->segments[i]);
124 av_freep(&var->segments);
128 static void free_variant_list(HLSContext *c)
131 for (i = 0; i < c->n_variants; i++) {
132 struct variant *var = c->variants[i];
133 free_segment_list(var);
134 av_free_packet(&var->pkt);
135 av_free(var->pb.buffer);
137 ffurl_close(var->input);
140 avformat_close_input(&var->ctx);
144 av_freep(&c->variants);
145 av_freep(&c->cookies);
146 av_freep(&c->user_agent);
151 * Used to reset a statically allocated AVPacket to a clean slate,
152 * containing no data.
154 static void reset_packet(AVPacket *pkt)
160 static struct variant *new_variant(HLSContext *c, int bandwidth,
161 const char *url, const char *base)
163 struct variant *var = av_mallocz(sizeof(struct variant));
166 reset_packet(&var->pkt);
167 var->bandwidth = bandwidth;
168 ff_make_absolute_url(var->url, sizeof(var->url), base, url);
169 dynarray_add(&c->variants, &c->n_variants, var);
173 struct variant_info {
177 static void handle_variant_args(struct variant_info *info, const char *key,
178 int key_len, char **dest, int *dest_len)
180 if (!strncmp(key, "BANDWIDTH=", key_len)) {
181 *dest = info->bandwidth;
182 *dest_len = sizeof(info->bandwidth);
187 char uri[MAX_URL_SIZE];
192 static void handle_key_args(struct key_info *info, const char *key,
193 int key_len, char **dest, int *dest_len)
195 if (!strncmp(key, "METHOD=", key_len)) {
196 *dest = info->method;
197 *dest_len = sizeof(info->method);
198 } else if (!strncmp(key, "URI=", key_len)) {
200 *dest_len = sizeof(info->uri);
201 } else if (!strncmp(key, "IV=", key_len)) {
203 *dest_len = sizeof(info->iv);
207 static int parse_playlist(HLSContext *c, const char *url,
208 struct variant *var, AVIOContext *in)
210 int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
211 int64_t duration = 0;
212 enum KeyType key_type = KEY_NONE;
215 char key[MAX_URL_SIZE] = "";
216 char line[MAX_URL_SIZE];
221 AVDictionary *opts = NULL;
223 /* Some HLS servers don't like being sent the range header */
224 av_dict_set(&opts, "seekable", "0", 0);
226 // broker prior HTTP options that should be consistent across requests
227 av_dict_set(&opts, "user-agent", c->user_agent, 0);
228 av_dict_set(&opts, "cookies", c->cookies, 0);
229 av_dict_set(&opts, "headers", c->headers, 0);
231 ret = avio_open2(&in, url, AVIO_FLAG_READ,
232 c->interrupt_callback, &opts);
238 read_chomp_line(in, line, sizeof(line));
239 if (strcmp(line, "#EXTM3U")) {
240 ret = AVERROR_INVALIDDATA;
245 free_segment_list(var);
248 while (!url_feof(in)) {
249 read_chomp_line(in, line, sizeof(line));
250 if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
251 struct variant_info info = {{0}};
253 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
255 bandwidth = atoi(info.bandwidth);
256 } else if (av_strstart(line, "#EXT-X-KEY:", &ptr)) {
257 struct key_info info = {{0}};
258 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_key_args,
262 if (!strcmp(info.method, "AES-128"))
263 key_type = KEY_AES_128;
264 if (!strncmp(info.iv, "0x", 2) || !strncmp(info.iv, "0X", 2)) {
265 ff_hex_to_data(iv, info.iv + 2);
268 av_strlcpy(key, info.uri, sizeof(key));
269 } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
271 var = new_variant(c, 0, url, NULL);
273 ret = AVERROR(ENOMEM);
277 var->target_duration = atoi(ptr) * AV_TIME_BASE;
278 } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
280 var = new_variant(c, 0, url, NULL);
282 ret = AVERROR(ENOMEM);
286 var->start_seq_no = atoi(ptr);
287 } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
290 } else if (av_strstart(line, "#EXTINF:", &ptr)) {
292 duration = atof(ptr) * AV_TIME_BASE;
293 } else if (av_strstart(line, "#", NULL)) {
295 } else if (line[0]) {
297 if (!new_variant(c, bandwidth, line, url)) {
298 ret = AVERROR(ENOMEM);
307 var = new_variant(c, 0, url, NULL);
309 ret = AVERROR(ENOMEM);
313 seg = av_malloc(sizeof(struct segment));
315 ret = AVERROR(ENOMEM);
318 seg->duration = duration;
319 seg->key_type = key_type;
321 memcpy(seg->iv, iv, sizeof(iv));
323 int seq = var->start_seq_no + var->n_segments;
324 memset(seg->iv, 0, sizeof(seg->iv));
325 AV_WB32(seg->iv + 12, seq);
327 ff_make_absolute_url(seg->key, sizeof(seg->key), url, key);
328 ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
329 dynarray_add(&var->segments, &var->n_segments, seg);
335 var->last_load_time = av_gettime();
343 static int open_input(HLSContext *c, struct variant *var)
345 AVDictionary *opts = NULL;
347 struct segment *seg = var->segments[var->cur_seq_no - var->start_seq_no];
349 // broker prior HTTP options that should be consistent across requests
350 av_dict_set(&opts, "user-agent", c->user_agent, 0);
351 av_dict_set(&opts, "cookies", c->cookies, 0);
352 av_dict_set(&opts, "headers", c->headers, 0);
353 av_dict_set(&opts, "seekable", "0", 0);
355 if (seg->key_type == KEY_NONE) {
356 ret = ffurl_open(&var->input, seg->url, AVIO_FLAG_READ,
357 &var->parent->interrupt_callback, &opts);
359 } else if (seg->key_type == KEY_AES_128) {
360 char iv[33], key[33], url[MAX_URL_SIZE];
361 if (strcmp(seg->key, var->key_url)) {
363 if (ffurl_open(&uc, seg->key, AVIO_FLAG_READ,
364 &var->parent->interrupt_callback, &opts) == 0) {
365 if (ffurl_read_complete(uc, var->key, sizeof(var->key))
366 != sizeof(var->key)) {
367 av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",
372 av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",
375 av_strlcpy(var->key_url, seg->key, sizeof(var->key_url));
377 ff_data_to_hex(iv, seg->iv, sizeof(seg->iv), 0);
378 ff_data_to_hex(key, var->key, sizeof(var->key), 0);
379 iv[32] = key[32] = '\0';
380 if (strstr(seg->url, "://"))
381 snprintf(url, sizeof(url), "crypto+%s", seg->url);
383 snprintf(url, sizeof(url), "crypto:%s", seg->url);
384 if ((ret = ffurl_alloc(&var->input, url, AVIO_FLAG_READ,
385 &var->parent->interrupt_callback)) < 0)
387 av_opt_set(var->input->priv_data, "key", key, 0);
388 av_opt_set(var->input->priv_data, "iv", iv, 0);
389 /* Need to repopulate options */
391 av_dict_set(&opts, "seekable", "0", 0);
392 if ((ret = ffurl_connect(var->input, &opts)) < 0) {
393 ffurl_close(var->input);
400 ret = AVERROR(ENOSYS);
407 static int read_data(void *opaque, uint8_t *buf, int buf_size)
409 struct variant *v = opaque;
410 HLSContext *c = v->parent->priv_data;
415 /* If this is a live stream and the reload interval has elapsed since
416 * the last playlist reload, reload the variant playlists now. */
417 int64_t reload_interval = v->n_segments > 0 ?
418 v->segments[v->n_segments - 1]->duration :
423 av_gettime() - v->last_load_time >= reload_interval) {
424 if ((ret = parse_playlist(c, v->url, v, NULL)) < 0)
426 /* If we need to reload the playlist again below (if
427 * there's still no more segments), switch to a reload
428 * interval of half the target duration. */
429 reload_interval = v->target_duration / 2;
431 if (v->cur_seq_no < v->start_seq_no) {
432 av_log(NULL, AV_LOG_WARNING,
433 "skipping %d segments ahead, expired from playlists\n",
434 v->start_seq_no - v->cur_seq_no);
435 v->cur_seq_no = v->start_seq_no;
437 if (v->cur_seq_no >= v->start_seq_no + v->n_segments) {
440 while (av_gettime() - v->last_load_time < reload_interval) {
441 if (ff_check_interrupt(c->interrupt_callback))
445 /* Enough time has elapsed since the last reload */
449 ret = open_input(c, v);
453 ret = ffurl_read(v->input, buf, buf_size);
456 ffurl_close(v->input);
460 c->end_of_segment = 1;
461 c->cur_seq_no = v->cur_seq_no;
463 if (v->ctx && v->ctx->nb_streams &&
464 v->parent->nb_streams >= v->stream_offset + v->ctx->nb_streams) {
466 for (i = v->stream_offset; i < v->stream_offset + v->ctx->nb_streams;
468 if (v->parent->streams[i]->discard < AVDISCARD_ALL)
473 av_log(v->parent, AV_LOG_INFO, "No longer receiving variant %d\n",
480 static int hls_read_header(AVFormatContext *s)
482 URLContext *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb->opaque;
483 HLSContext *c = s->priv_data;
484 int ret = 0, i, j, stream_offset = 0;
486 c->interrupt_callback = &s->interrupt_callback;
488 // if the URL context is good, read important options we must broker later
489 if (u && u->prot->priv_data_class) {
490 // get the previous user agent & set back to null if string size is zero
491 av_freep(&c->user_agent);
492 av_opt_get(u->priv_data, "user-agent", 0, (uint8_t**)&(c->user_agent));
493 if (c->user_agent && !strlen(c->user_agent))
494 av_freep(&c->user_agent);
496 // get the previous cookies & set back to null if string size is zero
497 av_freep(&c->cookies);
498 av_opt_get(u->priv_data, "cookies", 0, (uint8_t**)&(c->cookies));
499 if (c->cookies && !strlen(c->cookies))
500 av_freep(&c->cookies);
502 // get the previous headers & set back to null if string size is zero
503 av_freep(&c->headers);
504 av_opt_get(u->priv_data, "headers", 0, (uint8_t**)&(c->headers));
505 if (c->headers && !strlen(c->headers))
506 av_freep(&c->headers);
509 if ((ret = parse_playlist(c, s->filename, NULL, s->pb)) < 0)
512 if (c->n_variants == 0) {
513 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
517 /* If the playlist only contained variants, parse each individual
518 * variant playlist. */
519 if (c->n_variants > 1 || c->variants[0]->n_segments == 0) {
520 for (i = 0; i < c->n_variants; i++) {
521 struct variant *v = c->variants[i];
522 if ((ret = parse_playlist(c, v->url, v, NULL)) < 0)
527 if (c->variants[0]->n_segments == 0) {
528 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
533 /* If this isn't a live stream, calculate the total duration of the
535 if (c->variants[0]->finished) {
536 int64_t duration = 0;
537 for (i = 0; i < c->variants[0]->n_segments; i++)
538 duration += c->variants[0]->segments[i]->duration;
539 s->duration = duration;
542 /* Open the demuxer for each variant */
543 for (i = 0; i < c->n_variants; i++) {
544 struct variant *v = c->variants[i];
545 AVInputFormat *in_fmt = NULL;
546 char bitrate_str[20];
549 if (v->n_segments == 0)
552 if (!(v->ctx = avformat_alloc_context())) {
553 ret = AVERROR(ENOMEM);
561 /* If this is a live stream with more than 3 segments, start at the
562 * third last segment. */
563 v->cur_seq_no = v->start_seq_no;
564 if (!v->finished && v->n_segments > 3)
565 v->cur_seq_no = v->start_seq_no + v->n_segments - 3;
567 v->read_buffer = av_malloc(INITIAL_BUFFER_SIZE);
568 ffio_init_context(&v->pb, v->read_buffer, INITIAL_BUFFER_SIZE, 0, v,
569 read_data, NULL, NULL);
571 ret = av_probe_input_buffer(&v->pb, &in_fmt, v->segments[0]->url,
574 /* Free the ctx - it isn't initialized properly at this point,
575 * so avformat_close_input shouldn't be called. If
576 * avformat_open_input fails below, it frees and zeros the
577 * context, so it doesn't need any special treatment like this. */
578 av_log(s, AV_LOG_ERROR, "Error when loading first segment '%s'\n", v->segments[0]->url);
579 avformat_free_context(v->ctx);
584 v->stream_offset = stream_offset;
585 ret = avformat_open_input(&v->ctx, v->segments[0]->url, in_fmt, NULL);
589 v->ctx->ctx_flags &= ~AVFMTCTX_NOHEADER;
590 ret = avformat_find_stream_info(v->ctx, NULL);
593 snprintf(bitrate_str, sizeof(bitrate_str), "%d", v->bandwidth);
595 program = av_new_program(s, i);
598 av_dict_set(&program->metadata, "variant_bitrate", bitrate_str, 0);
600 /* Create new AVStreams for each stream in this variant */
601 for (j = 0; j < v->ctx->nb_streams; j++) {
602 AVStream *st = avformat_new_stream(s, NULL);
603 AVStream *ist = v->ctx->streams[j];
605 ret = AVERROR(ENOMEM);
608 ff_program_add_stream_index(s, i, stream_offset + j);
610 avpriv_set_pts_info(st, ist->pts_wrap_bits, ist->time_base.num, ist->time_base.den);
611 avcodec_copy_context(st->codec, v->ctx->streams[j]->codec);
613 av_dict_set(&st->metadata, "variant_bitrate", bitrate_str,
616 stream_offset += v->ctx->nb_streams;
620 c->first_timestamp = AV_NOPTS_VALUE;
621 c->seek_timestamp = AV_NOPTS_VALUE;
625 free_variant_list(c);
629 static int recheck_discard_flags(AVFormatContext *s, int first)
631 HLSContext *c = s->priv_data;
634 /* Check if any new streams are needed */
635 for (i = 0; i < c->n_variants; i++)
636 c->variants[i]->cur_needed = 0;
638 for (i = 0; i < s->nb_streams; i++) {
639 AVStream *st = s->streams[i];
640 struct variant *var = c->variants[s->streams[i]->id];
641 if (st->discard < AVDISCARD_ALL)
644 for (i = 0; i < c->n_variants; i++) {
645 struct variant *v = c->variants[i];
646 if (v->cur_needed && !v->needed) {
649 v->cur_seq_no = c->cur_seq_no;
650 v->pb.eof_reached = 0;
651 av_log(s, AV_LOG_INFO, "Now receiving variant %d\n", i);
652 } else if (first && !v->cur_needed && v->needed) {
654 ffurl_close(v->input);
658 av_log(s, AV_LOG_INFO, "No longer receiving variant %d\n", i);
664 static int hls_read_packet(AVFormatContext *s, AVPacket *pkt)
666 HLSContext *c = s->priv_data;
667 int ret, i, minvariant = -1;
669 if (c->first_packet) {
670 recheck_discard_flags(s, 1);
675 c->end_of_segment = 0;
676 for (i = 0; i < c->n_variants; i++) {
677 struct variant *var = c->variants[i];
678 /* Make sure we've got one buffered packet from each open variant
680 if (var->needed && !var->pkt.data) {
684 ret = av_read_frame(var->ctx, &var->pkt);
686 if (!url_feof(&var->pb) && ret != AVERROR_EOF)
688 reset_packet(&var->pkt);
691 if (c->first_timestamp == AV_NOPTS_VALUE &&
692 var->pkt.dts != AV_NOPTS_VALUE)
693 c->first_timestamp = av_rescale_q(var->pkt.dts,
694 var->ctx->streams[var->pkt.stream_index]->time_base,
698 if (c->seek_timestamp == AV_NOPTS_VALUE)
701 if (var->pkt.dts == AV_NOPTS_VALUE) {
702 c->seek_timestamp = AV_NOPTS_VALUE;
706 st = var->ctx->streams[var->pkt.stream_index];
707 ts_diff = av_rescale_rnd(var->pkt.dts, AV_TIME_BASE,
708 st->time_base.den, AV_ROUND_DOWN) -
710 if (ts_diff >= 0 && (c->seek_flags & AVSEEK_FLAG_ANY ||
711 var->pkt.flags & AV_PKT_FLAG_KEY)) {
712 c->seek_timestamp = AV_NOPTS_VALUE;
715 av_free_packet(&var->pkt);
716 reset_packet(&var->pkt);
719 /* Check if this stream still is on an earlier segment number, or
720 * has the packet with the lowest dts */
722 struct variant *minvar = c->variants[minvariant];
723 if (minvariant < 0 || var->cur_seq_no < minvar->cur_seq_no) {
725 } else if (var->cur_seq_no == minvar->cur_seq_no) {
726 int64_t dts = var->pkt.dts;
727 int64_t mindts = minvar->pkt.dts;
728 AVStream *st = var->ctx->streams[var->pkt.stream_index];
729 AVStream *minst = minvar->ctx->streams[minvar->pkt.stream_index];
731 if (dts == AV_NOPTS_VALUE) {
733 } else if (mindts != AV_NOPTS_VALUE) {
734 if (st->start_time != AV_NOPTS_VALUE)
735 dts -= st->start_time;
736 if (minst->start_time != AV_NOPTS_VALUE)
737 mindts -= minst->start_time;
739 if (av_compare_ts(dts, st->time_base,
740 mindts, minst->time_base) < 0)
746 if (c->end_of_segment) {
747 if (recheck_discard_flags(s, 0))
750 /* If we got a packet, return it */
751 if (minvariant >= 0) {
752 *pkt = c->variants[minvariant]->pkt;
753 pkt->stream_index += c->variants[minvariant]->stream_offset;
754 reset_packet(&c->variants[minvariant]->pkt);
760 static int hls_close(AVFormatContext *s)
762 HLSContext *c = s->priv_data;
764 free_variant_list(c);
768 static int hls_read_seek(AVFormatContext *s, int stream_index,
769 int64_t timestamp, int flags)
771 HLSContext *c = s->priv_data;
774 if ((flags & AVSEEK_FLAG_BYTE) || !c->variants[0]->finished)
775 return AVERROR(ENOSYS);
777 c->seek_flags = flags;
778 c->seek_timestamp = stream_index < 0 ? timestamp :
779 av_rescale_rnd(timestamp, AV_TIME_BASE,
780 s->streams[stream_index]->time_base.den,
781 flags & AVSEEK_FLAG_BACKWARD ?
782 AV_ROUND_DOWN : AV_ROUND_UP);
783 timestamp = av_rescale_rnd(timestamp, AV_TIME_BASE, stream_index >= 0 ?
784 s->streams[stream_index]->time_base.den :
785 AV_TIME_BASE, flags & AVSEEK_FLAG_BACKWARD ?
786 AV_ROUND_DOWN : AV_ROUND_UP);
787 if (s->duration < c->seek_timestamp) {
788 c->seek_timestamp = AV_NOPTS_VALUE;
793 for (i = 0; i < c->n_variants; i++) {
795 struct variant *var = c->variants[i];
796 int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ?
797 0 : c->first_timestamp;
799 ffurl_close(var->input);
802 av_free_packet(&var->pkt);
803 reset_packet(&var->pkt);
804 var->pb.eof_reached = 0;
805 /* Clear any buffered data */
806 var->pb.buf_end = var->pb.buf_ptr = var->pb.buffer;
807 /* Reset the pos, to let the mpegts demuxer know we've seeked. */
810 /* Locate the segment that contains the target timestamp */
811 for (j = 0; j < var->n_segments; j++) {
812 if (timestamp >= pos &&
813 timestamp < pos + var->segments[j]->duration) {
814 var->cur_seq_no = var->start_seq_no + j;
818 pos += var->segments[j]->duration;
821 c->seek_timestamp = AV_NOPTS_VALUE;
826 static int hls_probe(AVProbeData *p)
828 /* Require #EXTM3U at the start, and either one of the ones below
829 * somewhere for a proper match. */
830 if (strncmp(p->buf, "#EXTM3U", 7))
832 if (strstr(p->buf, "#EXT-X-STREAM-INF:") ||
833 strstr(p->buf, "#EXT-X-TARGETDURATION:") ||
834 strstr(p->buf, "#EXT-X-MEDIA-SEQUENCE:"))
835 return AVPROBE_SCORE_MAX;
839 AVInputFormat ff_hls_demuxer = {
840 .name = "hls,applehttp",
841 .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
842 .priv_data_size = sizeof(HLSContext),
843 .read_probe = hls_probe,
844 .read_header = hls_read_header,
845 .read_packet = hls_read_packet,
846 .read_close = hls_close,
847 .read_seek = hls_read_seek,