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"
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
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.
49
char url[MAX_URL_SIZE];
54
char url[MAX_URL_SIZE];
57
typedef struct HLSContext {
58
char playlisturl[MAX_URL_SIZE];
59
int64_t target_duration;
63
struct segment **segments;
65
struct variant **variants;
68
int64_t last_load_time;
71
static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
73
int len = ff_get_line(s, buf, maxlen);
74
while (len > 0 && av_isspace(buf[len - 1]))
79
static void free_segment_list(HLSContext *s)
82
for (i = 0; i < s->n_segments; i++)
83
av_freep(&s->segments[i]);
84
av_freep(&s->segments);
88
static void free_variant_list(HLSContext *s)
91
for (i = 0; i < s->n_variants; i++)
92
av_freep(&s->variants[i]);
93
av_freep(&s->variants);
101
static void handle_variant_args(struct variant_info *info, const char *key,
102
int key_len, char **dest, int *dest_len)
104
if (!strncmp(key, "BANDWIDTH=", key_len)) {
105
*dest = info->bandwidth;
106
*dest_len = sizeof(info->bandwidth);
110
static int parse_playlist(URLContext *h, const char *url)
112
HLSContext *s = h->priv_data;
114
int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
115
int64_t duration = 0;
119
if ((ret = avio_open2(&in, url, AVIO_FLAG_READ,
120
&h->interrupt_callback, NULL)) < 0)
123
read_chomp_line(in, line, sizeof(line));
124
if (strcmp(line, "#EXTM3U")) {
125
ret = AVERROR_INVALIDDATA;
129
free_segment_list(s);
131
while (!avio_feof(in)) {
132
read_chomp_line(in, line, sizeof(line));
133
if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
134
struct variant_info info = {{0}};
136
ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
138
bandwidth = atoi(info.bandwidth);
139
} else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
140
s->target_duration = atoi(ptr) * AV_TIME_BASE;
141
} else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
142
s->start_seq_no = atoi(ptr);
143
} else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
145
} else if (av_strstart(line, "#EXTINF:", &ptr)) {
147
duration = atof(ptr) * AV_TIME_BASE;
148
} else if (av_strstart(line, "#", NULL)) {
150
} else if (line[0]) {
152
struct segment *seg = av_malloc(sizeof(struct segment));
154
ret = AVERROR(ENOMEM);
157
seg->duration = duration;
158
ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
159
dynarray_add(&s->segments, &s->n_segments, seg);
161
} else if (is_variant) {
162
struct variant *var = av_malloc(sizeof(struct variant));
164
ret = AVERROR(ENOMEM);
167
var->bandwidth = bandwidth;
168
ff_make_absolute_url(var->url, sizeof(var->url), url, line);
169
dynarray_add(&s->variants, &s->n_variants, var);
174
s->last_load_time = av_gettime_relative();
181
static int hls_close(URLContext *h)
183
HLSContext *s = h->priv_data;
185
free_segment_list(s);
186
free_variant_list(s);
187
ffurl_close(s->seg_hd);
191
static int hls_open(URLContext *h, const char *uri, int flags)
193
HLSContext *s = h->priv_data;
195
const char *nested_url;
197
if (flags & AVIO_FLAG_WRITE)
198
return AVERROR(ENOSYS);
202
if (av_strstart(uri, "hls+", &nested_url)) {
203
av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
204
} else if (av_strstart(uri, "hls://", &nested_url)) {
205
av_log(h, AV_LOG_ERROR,
206
"No nested protocol specified. Specify e.g. hls+http://%s\n",
208
ret = AVERROR(EINVAL);
211
av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
212
ret = AVERROR(EINVAL);
215
av_log(h, AV_LOG_WARNING,
216
"Using the hls protocol is discouraged, please try using the "
217
"hls demuxer instead. The hls demuxer should be more complete "
218
"and work as well as the protocol implementation. (If not, "
219
"please report it.) To use the demuxer, simply use %s as url.\n",
222
if ((ret = parse_playlist(h, s->playlisturl)) < 0)
225
if (s->n_segments == 0 && s->n_variants > 0) {
226
int max_bandwidth = 0, maxvar = -1;
227
for (i = 0; i < s->n_variants; i++) {
228
if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
229
max_bandwidth = s->variants[i]->bandwidth;
233
av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
234
sizeof(s->playlisturl));
235
if ((ret = parse_playlist(h, s->playlisturl)) < 0)
239
if (s->n_segments == 0) {
240
av_log(h, AV_LOG_WARNING, "Empty playlist\n");
244
s->cur_seq_no = s->start_seq_no;
245
if (!s->finished && s->n_segments >= 3)
246
s->cur_seq_no = s->start_seq_no + s->n_segments - 3;
255
static int hls_read(URLContext *h, uint8_t *buf, int size)
257
HLSContext *s = h->priv_data;
260
int64_t reload_interval;
264
ret = ffurl_read(s->seg_hd, buf, size);
269
ffurl_close(s->seg_hd);
273
reload_interval = s->n_segments > 0 ?
274
s->segments[s->n_segments - 1]->duration :
278
int64_t now = av_gettime_relative();
279
if (now - s->last_load_time >= reload_interval) {
280
if ((ret = parse_playlist(h, s->playlisturl)) < 0)
282
/* If we need to reload the playlist again below (if
283
* there's still no more segments), switch to a reload
284
* interval of half the target duration. */
285
reload_interval = s->target_duration / 2;
288
if (s->cur_seq_no < s->start_seq_no) {
289
av_log(h, AV_LOG_WARNING,
290
"skipping %d segments ahead, expired from playlist\n",
291
s->start_seq_no - s->cur_seq_no);
292
s->cur_seq_no = s->start_seq_no;
294
if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
297
while (av_gettime_relative() - s->last_load_time < reload_interval) {
298
if (ff_check_interrupt(&h->interrupt_callback))
304
url = s->segments[s->cur_seq_no - s->start_seq_no]->url,
305
av_log(h, AV_LOG_DEBUG, "opening %s\n", url);
306
ret = ffurl_open(&s->seg_hd, url, AVIO_FLAG_READ,
307
&h->interrupt_callback, NULL);
309
if (ff_check_interrupt(&h->interrupt_callback))
311
av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url);
318
URLProtocol ff_hls_protocol = {
320
.url_open = hls_open,
321
.url_read = hls_read,
322
.url_close = hls_close,
323
.flags = URL_PROTOCOL_FLAG_NESTED_SCHEME,
324
.priv_data_size = sizeof(HLSContext),