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 #define _XOPEN_SOURCE 600
29 #include "libavutil/avstring.h"
35 * An apple http stream consists of a playlist with media segment files,
36 * played sequentially. There may be several playlists with the same
37 * video content, in different bandwidth variants, that are played in
38 * parallel (preferrably only one bandwidth variant at a time). In this case,
39 * the user supplied the url to a main playlist that only lists the variant
42 * If the main playlist doesn't point at any variants, we still create
43 * one anonymous toplevel variant for this, to maintain the structure.
48 char url[MAX_URL_SIZE];
53 char url[MAX_URL_SIZE];
56 typedef struct AppleHTTPContext {
57 char playlisturl[MAX_URL_SIZE];
62 struct segment **segments;
64 struct variant **variants;
67 int64_t last_load_time;
70 static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
72 int len = ff_get_line(s, buf, maxlen);
73 while (len > 0 && isspace(buf[len - 1]))
78 static void make_absolute_url(char *buf, int size, const char *base,
82 /* Absolute path, relative to the current server */
83 if (base && strstr(base, "://") && rel[0] == '/') {
85 av_strlcpy(buf, base, size);
86 sep = strstr(buf, "://");
89 sep = strchr(sep, '/');
93 av_strlcat(buf, rel, size);
96 /* If rel actually is an absolute url, just copy it */
97 if (!base || strstr(rel, "://") || rel[0] == '/') {
98 av_strlcpy(buf, rel, size);
102 av_strlcpy(buf, base, size);
103 /* Remove the file name from the base url */
104 sep = strrchr(buf, '/');
109 while (av_strstart(rel, "../", NULL) && sep) {
110 /* Remove the path delimiter at the end */
112 sep = strrchr(buf, '/');
113 /* If the next directory name to pop off is "..", break here */
114 if (!strcmp(sep ? &sep[1] : buf, "..")) {
115 /* Readd the slash we just removed */
116 av_strlcat(buf, "/", size);
119 /* Cut off the directory name */
126 av_strlcat(buf, rel, size);
129 static void free_segment_list(AppleHTTPContext *s)
132 for (i = 0; i < s->n_segments; i++)
133 av_free(s->segments[i]);
134 av_freep(&s->segments);
138 static void free_variant_list(AppleHTTPContext *s)
141 for (i = 0; i < s->n_variants; i++)
142 av_free(s->variants[i]);
143 av_freep(&s->variants);
147 struct variant_info {
151 static void handle_variant_args(struct variant_info *info, const char *key,
152 int key_len, char **dest, int *dest_len)
154 if (!strncmp(key, "BANDWIDTH=", key_len)) {
155 *dest = info->bandwidth;
156 *dest_len = sizeof(info->bandwidth);
160 static int parse_playlist(URLContext *h, const char *url)
162 AppleHTTPContext *s = h->priv_data;
164 int ret = 0, duration = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
168 if ((ret = avio_open(&in, url, URL_RDONLY)) < 0)
171 read_chomp_line(in, line, sizeof(line));
172 if (strcmp(line, "#EXTM3U"))
173 return AVERROR_INVALIDDATA;
175 free_segment_list(s);
177 while (!url_feof(in)) {
178 read_chomp_line(in, line, sizeof(line));
179 if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
180 struct variant_info info = {{0}};
182 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
184 bandwidth = atoi(info.bandwidth);
185 } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
186 s->target_duration = atoi(ptr);
187 } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
188 s->start_seq_no = atoi(ptr);
189 } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
191 } else if (av_strstart(line, "#EXTINF:", &ptr)) {
193 duration = atoi(ptr);
194 } else if (av_strstart(line, "#", NULL)) {
196 } else if (line[0]) {
198 struct segment *seg = av_malloc(sizeof(struct segment));
200 ret = AVERROR(ENOMEM);
203 seg->duration = duration;
204 make_absolute_url(seg->url, sizeof(seg->url), url, line);
205 dynarray_add(&s->segments, &s->n_segments, seg);
207 } else if (is_variant) {
208 struct variant *var = av_malloc(sizeof(struct variant));
210 ret = AVERROR(ENOMEM);
213 var->bandwidth = bandwidth;
214 make_absolute_url(var->url, sizeof(var->url), url, line);
215 dynarray_add(&s->variants, &s->n_variants, var);
220 s->last_load_time = av_gettime();
227 static int applehttp_open(URLContext *h, const char *uri, int flags)
231 const char *nested_url;
233 if (flags & (URL_WRONLY | URL_RDWR))
234 return AVERROR_NOTSUPP;
236 s = av_mallocz(sizeof(AppleHTTPContext));
238 return AVERROR(ENOMEM);
242 if (av_strstart(uri, "applehttp+", &nested_url)) {
243 av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
244 } else if (av_strstart(uri, "applehttp://", &nested_url)) {
245 av_strlcpy(s->playlisturl, "http://", sizeof(s->playlisturl));
246 av_strlcat(s->playlisturl, nested_url, sizeof(s->playlisturl));
248 av_log(NULL, AV_LOG_ERROR, "Unsupported url %s\n", uri);
249 ret = AVERROR(EINVAL);
253 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
256 if (s->n_segments == 0 && s->n_variants > 0) {
257 int max_bandwidth = 0, maxvar = -1;
258 for (i = 0; i < s->n_variants; i++) {
259 if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
260 max_bandwidth = s->variants[i]->bandwidth;
264 av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
265 sizeof(s->playlisturl));
266 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
270 if (s->n_segments == 0) {
271 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
275 s->cur_seq_no = s->start_seq_no;
276 if (!s->finished && s->n_segments >= 3)
277 s->cur_seq_no = s->start_seq_no + s->n_segments - 3;
286 static int applehttp_read(URLContext *h, uint8_t *buf, int size)
288 AppleHTTPContext *s = h->priv_data;
294 ret = url_read(s->seg_hd, buf, size);
299 url_close(s->seg_hd);
305 int64_t now = av_gettime();
306 if (now - s->last_load_time >= s->target_duration*1000000)
307 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
310 if (s->cur_seq_no < s->start_seq_no) {
311 av_log(NULL, AV_LOG_WARNING,
312 "skipping %d segments ahead, expired from playlist\n",
313 s->start_seq_no - s->cur_seq_no);
314 s->cur_seq_no = s->start_seq_no;
316 if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
319 while (av_gettime() - s->last_load_time < s->target_duration*1000000) {
320 if (url_interrupt_cb())
321 return AVERROR(EINTR);
326 url = s->segments[s->cur_seq_no - s->start_seq_no]->url,
327 av_log(NULL, AV_LOG_DEBUG, "opening %s\n", url);
328 ret = url_open(&s->seg_hd, url, URL_RDONLY);
330 if (url_interrupt_cb())
331 return AVERROR(EINTR);
332 av_log(NULL, AV_LOG_WARNING, "Unable to open %s\n", url);
339 static int applehttp_close(URLContext *h)
341 AppleHTTPContext *s = h->priv_data;
343 free_segment_list(s);
344 free_variant_list(s);
345 url_close(s->seg_hd);
350 URLProtocol ff_applehttp_protocol = {
357 .flags = URL_PROTOCOL_FLAG_NESTED_SCHEME,