Imported Debian version 2.5.2~trusty
[deb_ffmpeg.git] / ffmpeg / libavformat / hlsproto.c
... / ...
CommitLineData
1/*
2 * Apple HTTP Live Streaming Protocol Handler
3 * Copyright (c) 2010 Martin Storsjo
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22/**
23 * @file
24 * Apple HTTP Live Streaming Protocol Handler
25 * http://tools.ietf.org/html/draft-pantos-http-live-streaming
26 */
27
28#include "libavutil/avstring.h"
29#include "libavutil/time.h"
30#include "avformat.h"
31#include "internal.h"
32#include "url.h"
33#include "version.h"
34
35/*
36 * An apple http stream consists of a playlist with media segment files,
37 * played sequentially. There may be several playlists with the same
38 * video content, in different bandwidth variants, that are played in
39 * parallel (preferably only one bandwidth variant at a time). In this case,
40 * the user supplied the url to a main playlist that only lists the variant
41 * playlists.
42 *
43 * If the main playlist doesn't point at any variants, we still create
44 * one anonymous toplevel variant for this, to maintain the structure.
45 */
46
47struct segment {
48 int64_t duration;
49 char url[MAX_URL_SIZE];
50};
51
52struct variant {
53 int bandwidth;
54 char url[MAX_URL_SIZE];
55};
56
57typedef struct HLSContext {
58 char playlisturl[MAX_URL_SIZE];
59 int64_t target_duration;
60 int start_seq_no;
61 int finished;
62 int n_segments;
63 struct segment **segments;
64 int n_variants;
65 struct variant **variants;
66 int cur_seq_no;
67 URLContext *seg_hd;
68 int64_t last_load_time;
69} HLSContext;
70
71static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
72{
73 int len = ff_get_line(s, buf, maxlen);
74 while (len > 0 && av_isspace(buf[len - 1]))
75 buf[--len] = '\0';
76 return len;
77}
78
79static void free_segment_list(HLSContext *s)
80{
81 int i;
82 for (i = 0; i < s->n_segments; i++)
83 av_free(s->segments[i]);
84 av_freep(&s->segments);
85 s->n_segments = 0;
86}
87
88static void free_variant_list(HLSContext *s)
89{
90 int i;
91 for (i = 0; i < s->n_variants; i++)
92 av_free(s->variants[i]);
93 av_freep(&s->variants);
94 s->n_variants = 0;
95}
96
97struct variant_info {
98 char bandwidth[20];
99};
100
101static void handle_variant_args(struct variant_info *info, const char *key,
102 int key_len, char **dest, int *dest_len)
103{
104 if (!strncmp(key, "BANDWIDTH=", key_len)) {
105 *dest = info->bandwidth;
106 *dest_len = sizeof(info->bandwidth);
107 }
108}
109
110static int parse_playlist(URLContext *h, const char *url)
111{
112 HLSContext *s = h->priv_data;
113 AVIOContext *in;
114 int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
115 int64_t duration = 0;
116 char line[1024];
117 const char *ptr;
118
119 if ((ret = avio_open2(&in, url, AVIO_FLAG_READ,
120 &h->interrupt_callback, NULL)) < 0)
121 return ret;
122
123 read_chomp_line(in, line, sizeof(line));
124 if (strcmp(line, "#EXTM3U"))
125 return AVERROR_INVALIDDATA;
126
127 free_segment_list(s);
128 s->finished = 0;
129 while (!avio_feof(in)) {
130 read_chomp_line(in, line, sizeof(line));
131 if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
132 struct variant_info info = {{0}};
133 is_variant = 1;
134 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
135 &info);
136 bandwidth = atoi(info.bandwidth);
137 } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
138 s->target_duration = atoi(ptr) * AV_TIME_BASE;
139 } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
140 s->start_seq_no = atoi(ptr);
141 } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
142 s->finished = 1;
143 } else if (av_strstart(line, "#EXTINF:", &ptr)) {
144 is_segment = 1;
145 duration = atof(ptr) * AV_TIME_BASE;
146 } else if (av_strstart(line, "#", NULL)) {
147 continue;
148 } else if (line[0]) {
149 if (is_segment) {
150 struct segment *seg = av_malloc(sizeof(struct segment));
151 if (!seg) {
152 ret = AVERROR(ENOMEM);
153 goto fail;
154 }
155 seg->duration = duration;
156 ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
157 dynarray_add(&s->segments, &s->n_segments, seg);
158 is_segment = 0;
159 } else if (is_variant) {
160 struct variant *var = av_malloc(sizeof(struct variant));
161 if (!var) {
162 ret = AVERROR(ENOMEM);
163 goto fail;
164 }
165 var->bandwidth = bandwidth;
166 ff_make_absolute_url(var->url, sizeof(var->url), url, line);
167 dynarray_add(&s->variants, &s->n_variants, var);
168 is_variant = 0;
169 }
170 }
171 }
172 s->last_load_time = av_gettime_relative();
173
174fail:
175 avio_close(in);
176 return ret;
177}
178
179static int hls_close(URLContext *h)
180{
181 HLSContext *s = h->priv_data;
182
183 free_segment_list(s);
184 free_variant_list(s);
185 ffurl_close(s->seg_hd);
186 return 0;
187}
188
189static int hls_open(URLContext *h, const char *uri, int flags)
190{
191 HLSContext *s = h->priv_data;
192 int ret, i;
193 const char *nested_url;
194
195 if (flags & AVIO_FLAG_WRITE)
196 return AVERROR(ENOSYS);
197
198 h->is_streamed = 1;
199
200 if (av_strstart(uri, "hls+", &nested_url)) {
201 av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
202 } else if (av_strstart(uri, "hls://", &nested_url)) {
203 av_log(h, AV_LOG_ERROR,
204 "No nested protocol specified. Specify e.g. hls+http://%s\n",
205 nested_url);
206 ret = AVERROR(EINVAL);
207 goto fail;
208 } else {
209 av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
210 ret = AVERROR(EINVAL);
211 goto fail;
212 }
213 av_log(h, AV_LOG_WARNING,
214 "Using the hls protocol is discouraged, please try using the "
215 "hls demuxer instead. The hls demuxer should be more complete "
216 "and work as well as the protocol implementation. (If not, "
217 "please report it.) To use the demuxer, simply use %s as url.\n",
218 s->playlisturl);
219
220 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
221 goto fail;
222
223 if (s->n_segments == 0 && s->n_variants > 0) {
224 int max_bandwidth = 0, maxvar = -1;
225 for (i = 0; i < s->n_variants; i++) {
226 if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
227 max_bandwidth = s->variants[i]->bandwidth;
228 maxvar = i;
229 }
230 }
231 av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
232 sizeof(s->playlisturl));
233 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
234 goto fail;
235 }
236
237 if (s->n_segments == 0) {
238 av_log(h, AV_LOG_WARNING, "Empty playlist\n");
239 ret = AVERROR(EIO);
240 goto fail;
241 }
242 s->cur_seq_no = s->start_seq_no;
243 if (!s->finished && s->n_segments >= 3)
244 s->cur_seq_no = s->start_seq_no + s->n_segments - 3;
245
246 return 0;
247
248fail:
249 hls_close(h);
250 return ret;
251}
252
253static int hls_read(URLContext *h, uint8_t *buf, int size)
254{
255 HLSContext *s = h->priv_data;
256 const char *url;
257 int ret;
258 int64_t reload_interval;
259
260start:
261 if (s->seg_hd) {
262 ret = ffurl_read(s->seg_hd, buf, size);
263 if (ret > 0)
264 return ret;
265 }
266 if (s->seg_hd) {
267 ffurl_close(s->seg_hd);
268 s->seg_hd = NULL;
269 s->cur_seq_no++;
270 }
271 reload_interval = s->n_segments > 0 ?
272 s->segments[s->n_segments - 1]->duration :
273 s->target_duration;
274retry:
275 if (!s->finished) {
276 int64_t now = av_gettime_relative();
277 if (now - s->last_load_time >= reload_interval) {
278 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
279 return ret;
280 /* If we need to reload the playlist again below (if
281 * there's still no more segments), switch to a reload
282 * interval of half the target duration. */
283 reload_interval = s->target_duration / 2;
284 }
285 }
286 if (s->cur_seq_no < s->start_seq_no) {
287 av_log(h, AV_LOG_WARNING,
288 "skipping %d segments ahead, expired from playlist\n",
289 s->start_seq_no - s->cur_seq_no);
290 s->cur_seq_no = s->start_seq_no;
291 }
292 if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
293 if (s->finished)
294 return AVERROR_EOF;
295 while (av_gettime_relative() - s->last_load_time < reload_interval) {
296 if (ff_check_interrupt(&h->interrupt_callback))
297 return AVERROR_EXIT;
298 av_usleep(100*1000);
299 }
300 goto retry;
301 }
302 url = s->segments[s->cur_seq_no - s->start_seq_no]->url,
303 av_log(h, AV_LOG_DEBUG, "opening %s\n", url);
304 ret = ffurl_open(&s->seg_hd, url, AVIO_FLAG_READ,
305 &h->interrupt_callback, NULL);
306 if (ret < 0) {
307 if (ff_check_interrupt(&h->interrupt_callback))
308 return AVERROR_EXIT;
309 av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url);
310 s->cur_seq_no++;
311 goto retry;
312 }
313 goto start;
314}
315
316URLProtocol ff_hls_protocol = {
317 .name = "hls",
318 .url_open = hls_open,
319 .url_read = hls_read,
320 .url_close = hls_close,
321 .flags = URL_PROTOCOL_FLAG_NESTED_SCHEME,
322 .priv_data_size = sizeof(HLSContext),
323};