1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328
|
/*
* Apple HTTP Live Streaming Protocol Handler
* Copyright (c) 2010 Martin Storsjo
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Apple HTTP Live Streaming Protocol Handler
* http://tools.ietf.org/html/draft-pantos-http-live-streaming
*/
#include "libavutil/avstring.h"
#include "libavutil/time.h"
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "url.h"
#include "version.h"
/*
* An apple http stream consists of a playlist with media segment files,
* played sequentially. There may be several playlists with the same
* video content, in different bandwidth variants, that are played in
* parallel (preferably only one bandwidth variant at a time). In this case,
* the user supplied the url to a main playlist that only lists the variant
* playlists.
*
* If the main playlist doesn't point at any variants, we still create
* one anonymous toplevel variant for this, to maintain the structure.
*/
struct segment {
int64_t duration;
char url[MAX_URL_SIZE];
};
struct variant {
int bandwidth;
char url[MAX_URL_SIZE];
};
typedef struct HLSContext {
char playlisturl[MAX_URL_SIZE];
int64_t target_duration;
int start_seq_no;
int finished;
int n_segments;
struct segment **segments;
int n_variants;
struct variant **variants;
int cur_seq_no;
URLContext *seg_hd;
int64_t last_load_time;
} HLSContext;
static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
{
int len = ff_get_line(s, buf, maxlen);
while (len > 0 && av_isspace(buf[len - 1]))
buf[--len] = '\0';
return len;
}
static void free_segment_list(HLSContext *s)
{
int i;
for (i = 0; i < s->n_segments; i++)
av_freep(&s->segments[i]);
av_freep(&s->segments);
s->n_segments = 0;
}
static void free_variant_list(HLSContext *s)
{
int i;
for (i = 0; i < s->n_variants; i++)
av_freep(&s->variants[i]);
av_freep(&s->variants);
s->n_variants = 0;
}
struct variant_info {
char bandwidth[20];
};
static void handle_variant_args(struct variant_info *info, const char *key,
int key_len, char **dest, int *dest_len)
{
if (!strncmp(key, "BANDWIDTH=", key_len)) {
*dest = info->bandwidth;
*dest_len = sizeof(info->bandwidth);
}
}
static int parse_playlist(URLContext *h, const char *url)
{
HLSContext *s = h->priv_data;
AVIOContext *in;
int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
int64_t duration = 0;
char line[1024];
const char *ptr;
if ((ret = ffio_open_whitelist(&in, url, AVIO_FLAG_READ,
&h->interrupt_callback, NULL,
h->protocol_whitelist, h->protocol_blacklist)) < 0)
return ret;
read_chomp_line(in, line, sizeof(line));
if (strcmp(line, "#EXTM3U")) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
free_segment_list(s);
s->finished = 0;
while (!avio_feof(in)) {
read_chomp_line(in, line, sizeof(line));
if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
struct variant_info info = {{0}};
is_variant = 1;
ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
&info);
bandwidth = atoi(info.bandwidth);
} else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
s->target_duration = atoi(ptr) * AV_TIME_BASE;
} else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
s->start_seq_no = atoi(ptr);
} else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
s->finished = 1;
} else if (av_strstart(line, "#EXTINF:", &ptr)) {
is_segment = 1;
duration = atof(ptr) * AV_TIME_BASE;
} else if (av_strstart(line, "#", NULL)) {
continue;
} else if (line[0]) {
if (is_segment) {
struct segment *seg = av_malloc(sizeof(struct segment));
if (!seg) {
ret = AVERROR(ENOMEM);
goto fail;
}
seg->duration = duration;
ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
dynarray_add(&s->segments, &s->n_segments, seg);
is_segment = 0;
} else if (is_variant) {
struct variant *var = av_malloc(sizeof(struct variant));
if (!var) {
ret = AVERROR(ENOMEM);
goto fail;
}
var->bandwidth = bandwidth;
ff_make_absolute_url(var->url, sizeof(var->url), url, line);
dynarray_add(&s->variants, &s->n_variants, var);
is_variant = 0;
}
}
}
s->last_load_time = av_gettime_relative();
fail:
avio_close(in);
return ret;
}
static int hls_close(URLContext *h)
{
HLSContext *s = h->priv_data;
free_segment_list(s);
free_variant_list(s);
ffurl_close(s->seg_hd);
return 0;
}
static int hls_open(URLContext *h, const char *uri, int flags)
{
HLSContext *s = h->priv_data;
int ret, i;
const char *nested_url;
if (flags & AVIO_FLAG_WRITE)
return AVERROR(ENOSYS);
h->is_streamed = 1;
if (av_strstart(uri, "hls+", &nested_url)) {
av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
} else if (av_strstart(uri, "hls://", &nested_url)) {
av_log(h, AV_LOG_ERROR,
"No nested protocol specified. Specify e.g. hls+http://%s\n",
nested_url);
ret = AVERROR(EINVAL);
goto fail;
} else {
av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
ret = AVERROR(EINVAL);
goto fail;
}
av_log(h, AV_LOG_WARNING,
"Using the hls protocol is discouraged, please try using the "
"hls demuxer instead. The hls demuxer should be more complete "
"and work as well as the protocol implementation. (If not, "
"please report it.) To use the demuxer, simply use %s as url.\n",
s->playlisturl);
if ((ret = parse_playlist(h, s->playlisturl)) < 0)
goto fail;
if (s->n_segments == 0 && s->n_variants > 0) {
int max_bandwidth = 0, maxvar = -1;
for (i = 0; i < s->n_variants; i++) {
if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
max_bandwidth = s->variants[i]->bandwidth;
maxvar = i;
}
}
av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
sizeof(s->playlisturl));
if ((ret = parse_playlist(h, s->playlisturl)) < 0)
goto fail;
}
if (s->n_segments == 0) {
av_log(h, AV_LOG_WARNING, "Empty playlist\n");
ret = AVERROR(EIO);
goto fail;
}
s->cur_seq_no = s->start_seq_no;
if (!s->finished && s->n_segments >= 3)
s->cur_seq_no = s->start_seq_no + s->n_segments - 3;
return 0;
fail:
hls_close(h);
return ret;
}
static int hls_read(URLContext *h, uint8_t *buf, int size)
{
HLSContext *s = h->priv_data;
const char *url;
int ret;
int64_t reload_interval;
start:
if (s->seg_hd) {
ret = ffurl_read(s->seg_hd, buf, size);
if (ret > 0)
return ret;
}
if (s->seg_hd) {
ffurl_close(s->seg_hd);
s->seg_hd = NULL;
s->cur_seq_no++;
}
reload_interval = s->n_segments > 0 ?
s->segments[s->n_segments - 1]->duration :
s->target_duration;
retry:
if (!s->finished) {
int64_t now = av_gettime_relative();
if (now - s->last_load_time >= reload_interval) {
if ((ret = parse_playlist(h, s->playlisturl)) < 0)
return ret;
/* If we need to reload the playlist again below (if
* there's still no more segments), switch to a reload
* interval of half the target duration. */
reload_interval = s->target_duration / 2;
}
}
if (s->cur_seq_no < s->start_seq_no) {
av_log(h, AV_LOG_WARNING,
"skipping %d segments ahead, expired from playlist\n",
s->start_seq_no - s->cur_seq_no);
s->cur_seq_no = s->start_seq_no;
}
if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
if (s->finished)
return AVERROR_EOF;
while (av_gettime_relative() - s->last_load_time < reload_interval) {
if (ff_check_interrupt(&h->interrupt_callback))
return AVERROR_EXIT;
av_usleep(100*1000);
}
goto retry;
}
url = s->segments[s->cur_seq_no - s->start_seq_no]->url,
av_log(h, AV_LOG_DEBUG, "opening %s\n", url);
ret = ffurl_open_whitelist(&s->seg_hd, url, AVIO_FLAG_READ,
&h->interrupt_callback, NULL,
h->protocol_whitelist, h->protocol_blacklist, h);
if (ret < 0) {
if (ff_check_interrupt(&h->interrupt_callback))
return AVERROR_EXIT;
av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url);
s->cur_seq_no++;
goto retry;
}
goto start;
}
const URLProtocol ff_hls_protocol = {
.name = "hls",
.url_open = hls_open,
.url_read = hls_read,
.url_close = hls_close,
.flags = URL_PROTOCOL_FLAG_NESTED_SCHEME,
.priv_data_size = sizeof(HLSContext),
};
|