2 * Apple HTTP Live Streaming Protocol Handler
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 Protocol Handler
25 * http://tools.ietf.org/html/draft-pantos-http-live-streaming
28 #include "libavutil/avstring.h"
29 #include "libavutil/time.h"
31 #include "avio_internal.h"
37 * An apple http stream consists of a playlist with media segment files,
38 * played sequentially. There may be several playlists with the same
39 * video content, in different bandwidth variants, that are played in
40 * parallel (preferably only one bandwidth variant at a time). In this case,
41 * the user supplied the url to a main playlist that only lists the variant
44 * If the main playlist doesn't point at any variants, we still create
45 * one anonymous toplevel variant for this, to maintain the structure.
50 char url[MAX_URL_SIZE];
55 char url[MAX_URL_SIZE];
58 typedef struct HLSContext {
59 char playlisturl[MAX_URL_SIZE];
60 int64_t target_duration;
64 struct segment **segments;
66 struct variant **variants;
69 int64_t last_load_time;
72 static void free_segment_list(HLSContext *s)
75 for (i = 0; i < s->n_segments; i++)
76 av_freep(&s->segments[i]);
77 av_freep(&s->segments);
81 static void free_variant_list(HLSContext *s)
84 for (i = 0; i < s->n_variants; i++)
85 av_freep(&s->variants[i]);
86 av_freep(&s->variants);
94 static void handle_variant_args(struct variant_info *info, const char *key,
95 int key_len, char **dest, int *dest_len)
97 if (!strncmp(key, "BANDWIDTH=", key_len)) {
98 *dest = info->bandwidth;
99 *dest_len = sizeof(info->bandwidth);
103 static int parse_playlist(URLContext *h, const char *url)
105 HLSContext *s = h->priv_data;
107 int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
108 int64_t duration = 0;
112 if ((ret = ffio_open_whitelist(&in, url, AVIO_FLAG_READ,
113 &h->interrupt_callback, NULL,
114 h->protocol_whitelist, h->protocol_blacklist)) < 0)
117 ff_get_chomp_line(in, line, sizeof(line));
118 if (strcmp(line, "#EXTM3U")) {
119 ret = AVERROR_INVALIDDATA;
123 free_segment_list(s);
125 while (!avio_feof(in)) {
126 ff_get_chomp_line(in, line, sizeof(line));
127 if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
128 struct variant_info info = {{0}};
130 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
132 bandwidth = atoi(info.bandwidth);
133 } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
134 s->target_duration = atoi(ptr) * AV_TIME_BASE;
135 } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
136 s->start_seq_no = atoi(ptr);
137 } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
139 } else if (av_strstart(line, "#EXTINF:", &ptr)) {
141 duration = atof(ptr) * AV_TIME_BASE;
142 } else if (av_strstart(line, "#", NULL)) {
144 } else if (line[0]) {
146 struct segment *seg = av_malloc(sizeof(struct segment));
148 ret = AVERROR(ENOMEM);
151 seg->duration = duration;
152 ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
153 dynarray_add(&s->segments, &s->n_segments, seg);
155 } else if (is_variant) {
156 struct variant *var = av_malloc(sizeof(struct variant));
158 ret = AVERROR(ENOMEM);
161 var->bandwidth = bandwidth;
162 ff_make_absolute_url(var->url, sizeof(var->url), url, line);
163 dynarray_add(&s->variants, &s->n_variants, var);
168 s->last_load_time = av_gettime_relative();
175 static int hls_close(URLContext *h)
177 HLSContext *s = h->priv_data;
179 free_segment_list(s);
180 free_variant_list(s);
181 ffurl_close(s->seg_hd);
185 static int hls_open(URLContext *h, const char *uri, int flags)
187 HLSContext *s = h->priv_data;
189 const char *nested_url;
191 if (flags & AVIO_FLAG_WRITE)
192 return AVERROR(ENOSYS);
196 if (av_strstart(uri, "hls+", &nested_url)) {
197 av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
198 } else if (av_strstart(uri, "hls://", &nested_url)) {
199 av_log(h, AV_LOG_ERROR,
200 "No nested protocol specified. Specify e.g. hls+http://%s\n",
202 ret = AVERROR(EINVAL);
205 av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
206 ret = AVERROR(EINVAL);
209 av_log(h, AV_LOG_WARNING,
210 "Using the hls protocol is discouraged, please try using the "
211 "hls demuxer instead. The hls demuxer should be more complete "
212 "and work as well as the protocol implementation. (If not, "
213 "please report it.) To use the demuxer, simply use %s as url.\n",
216 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
219 if (s->n_segments == 0 && s->n_variants > 0) {
220 int max_bandwidth = 0, maxvar = -1;
221 for (i = 0; i < s->n_variants; i++) {
222 if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
223 max_bandwidth = s->variants[i]->bandwidth;
227 av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
228 sizeof(s->playlisturl));
229 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
233 if (s->n_segments == 0) {
234 av_log(h, AV_LOG_WARNING, "Empty playlist\n");
238 s->cur_seq_no = s->start_seq_no;
239 if (!s->finished && s->n_segments >= 3)
240 s->cur_seq_no = s->start_seq_no + s->n_segments - 3;
249 static int hls_read(URLContext *h, uint8_t *buf, int size)
251 HLSContext *s = h->priv_data;
254 int64_t reload_interval;
258 ret = ffurl_read(s->seg_hd, buf, size);
263 ffurl_close(s->seg_hd);
267 reload_interval = s->n_segments > 0 ?
268 s->segments[s->n_segments - 1]->duration :
272 int64_t now = av_gettime_relative();
273 if (now - s->last_load_time >= reload_interval) {
274 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
276 /* If we need to reload the playlist again below (if
277 * there's still no more segments), switch to a reload
278 * interval of half the target duration. */
279 reload_interval = s->target_duration / 2;
282 if (s->cur_seq_no < s->start_seq_no) {
283 av_log(h, AV_LOG_WARNING,
284 "skipping %d segments ahead, expired from playlist\n",
285 s->start_seq_no - s->cur_seq_no);
286 s->cur_seq_no = s->start_seq_no;
288 if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
291 while (av_gettime_relative() - s->last_load_time < reload_interval) {
292 if (ff_check_interrupt(&h->interrupt_callback))
298 url = s->segments[s->cur_seq_no - s->start_seq_no]->url,
299 av_log(h, AV_LOG_DEBUG, "opening %s\n", url);
300 ret = ffurl_open_whitelist(&s->seg_hd, url, AVIO_FLAG_READ,
301 &h->interrupt_callback, NULL,
302 h->protocol_whitelist, h->protocol_blacklist, h);
304 if (ff_check_interrupt(&h->interrupt_callback))
306 av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url);
313 const URLProtocol ff_hls_protocol = {
315 .url_open = hls_open,
316 .url_read = hls_read,
317 .url_close = hls_close,
318 .flags = URL_PROTOCOL_FLAG_NESTED_SCHEME,
319 .priv_data_size = sizeof(HLSContext),