FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/hlsproto.c
Date: 2022-12-05 03:11:11
Exec Total Coverage
Lines: 0 154 0.0%
Functions: 0 7 0.0%
Branches: 0 88 0.0%

Line Branch Exec Source
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 * https://www.rfc-editor.org/rfc/rfc8216.txt
26 */
27
28 #include "libavutil/avstring.h"
29 #include "libavutil/time.h"
30 #include "avformat.h"
31 #include "avio_internal.h"
32 #include "internal.h"
33 #include "url.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
47 struct segment {
48 int64_t duration;
49 char url[MAX_URL_SIZE];
50 };
51
52 struct variant {
53 int bandwidth;
54 char url[MAX_URL_SIZE];
55 };
56
57 typedef 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
71 static void free_segment_list(HLSContext *s)
72 {
73 int i;
74 for (i = 0; i < s->n_segments; i++)
75 av_freep(&s->segments[i]);
76 av_freep(&s->segments);
77 s->n_segments = 0;
78 }
79
80 static void free_variant_list(HLSContext *s)
81 {
82 int i;
83 for (i = 0; i < s->n_variants; i++)
84 av_freep(&s->variants[i]);
85 av_freep(&s->variants);
86 s->n_variants = 0;
87 }
88
89 struct variant_info {
90 char bandwidth[20];
91 };
92
93 static void handle_variant_args(struct variant_info *info, const char *key,
94 int key_len, char **dest, int *dest_len)
95 {
96 if (!strncmp(key, "BANDWIDTH=", key_len)) {
97 *dest = info->bandwidth;
98 *dest_len = sizeof(info->bandwidth);
99 }
100 }
101
102 static int parse_playlist(URLContext *h, const char *url)
103 {
104 HLSContext *s = h->priv_data;
105 AVIOContext *in;
106 int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
107 int64_t duration = 0;
108 char line[1024];
109 const char *ptr;
110
111 if ((ret = ffio_open_whitelist(&in, url, AVIO_FLAG_READ,
112 &h->interrupt_callback, NULL,
113 h->protocol_whitelist, h->protocol_blacklist)) < 0)
114 return ret;
115
116 ff_get_chomp_line(in, line, sizeof(line));
117 if (strcmp(line, "#EXTM3U")) {
118 ret = AVERROR_INVALIDDATA;
119 goto fail;
120 }
121
122 free_segment_list(s);
123 s->finished = 0;
124 while (!avio_feof(in)) {
125 ff_get_chomp_line(in, line, sizeof(line));
126 if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
127 struct variant_info info = {{0}};
128 is_variant = 1;
129 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
130 &info);
131 bandwidth = atoi(info.bandwidth);
132 } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
133 s->target_duration = atoi(ptr) * AV_TIME_BASE;
134 } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
135 s->start_seq_no = atoi(ptr);
136 } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
137 s->finished = 1;
138 } else if (av_strstart(line, "#EXTINF:", &ptr)) {
139 is_segment = 1;
140 duration = atof(ptr) * AV_TIME_BASE;
141 } else if (av_strstart(line, "#", NULL)) {
142 continue;
143 } else if (line[0]) {
144 if (is_segment) {
145 struct segment *seg = av_malloc(sizeof(struct segment));
146 if (!seg) {
147 ret = AVERROR(ENOMEM);
148 goto fail;
149 }
150 seg->duration = duration;
151 ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
152 dynarray_add(&s->segments, &s->n_segments, seg);
153 is_segment = 0;
154 } else if (is_variant) {
155 struct variant *var = av_malloc(sizeof(struct variant));
156 if (!var) {
157 ret = AVERROR(ENOMEM);
158 goto fail;
159 }
160 var->bandwidth = bandwidth;
161 ff_make_absolute_url(var->url, sizeof(var->url), url, line);
162 dynarray_add(&s->variants, &s->n_variants, var);
163 is_variant = 0;
164 }
165 }
166 }
167 s->last_load_time = av_gettime_relative();
168
169 fail:
170 avio_close(in);
171 return ret;
172 }
173
174 static int hls_close(URLContext *h)
175 {
176 HLSContext *s = h->priv_data;
177
178 free_segment_list(s);
179 free_variant_list(s);
180 ffurl_closep(&s->seg_hd);
181 return 0;
182 }
183
184 static int hls_open(URLContext *h, const char *uri, int flags)
185 {
186 HLSContext *s = h->priv_data;
187 int ret, i;
188 const char *nested_url;
189
190 if (flags & AVIO_FLAG_WRITE)
191 return AVERROR(ENOSYS);
192
193 h->is_streamed = 1;
194
195 if (av_strstart(uri, "hls+", &nested_url)) {
196 av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
197 } else if (av_strstart(uri, "hls://", &nested_url)) {
198 av_log(h, AV_LOG_ERROR,
199 "No nested protocol specified. Specify e.g. hls+http://%s\n",
200 nested_url);
201 ret = AVERROR(EINVAL);
202 goto fail;
203 } else {
204 av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
205 ret = AVERROR(EINVAL);
206 goto fail;
207 }
208 av_log(h, AV_LOG_WARNING,
209 "Using the hls protocol is discouraged, please try using the "
210 "hls demuxer instead. The hls demuxer should be more complete "
211 "and work as well as the protocol implementation. (If not, "
212 "please report it.) To use the demuxer, simply use %s as url.\n",
213 s->playlisturl);
214
215 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
216 goto fail;
217
218 if (s->n_segments == 0 && s->n_variants > 0) {
219 int max_bandwidth = 0, maxvar = -1;
220 for (i = 0; i < s->n_variants; i++) {
221 if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
222 max_bandwidth = s->variants[i]->bandwidth;
223 maxvar = i;
224 }
225 }
226 av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
227 sizeof(s->playlisturl));
228 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
229 goto fail;
230 }
231
232 if (s->n_segments == 0) {
233 av_log(h, AV_LOG_WARNING, "Empty playlist\n");
234 ret = AVERROR(EIO);
235 goto fail;
236 }
237 s->cur_seq_no = s->start_seq_no;
238 if (!s->finished && s->n_segments >= 3)
239 s->cur_seq_no = s->start_seq_no + s->n_segments - 3;
240
241 return 0;
242
243 fail:
244 hls_close(h);
245 return ret;
246 }
247
248 static int hls_read(URLContext *h, uint8_t *buf, int size)
249 {
250 HLSContext *s = h->priv_data;
251 const char *url;
252 int ret;
253 int64_t reload_interval;
254
255 start:
256 if (s->seg_hd) {
257 ret = ffurl_read(s->seg_hd, buf, size);
258 if (ret > 0)
259 return ret;
260 }
261 if (s->seg_hd) {
262 ffurl_closep(&s->seg_hd);
263 s->cur_seq_no++;
264 }
265 reload_interval = s->n_segments > 0 ?
266 s->segments[s->n_segments - 1]->duration :
267 s->target_duration;
268 retry:
269 if (!s->finished) {
270 int64_t now = av_gettime_relative();
271 if (now - s->last_load_time >= reload_interval) {
272 if ((ret = parse_playlist(h, s->playlisturl)) < 0)
273 return ret;
274 /* If we need to reload the playlist again below (if
275 * there's still no more segments), switch to a reload
276 * interval of half the target duration. */
277 reload_interval = s->target_duration / 2;
278 }
279 }
280 if (s->cur_seq_no < s->start_seq_no) {
281 av_log(h, AV_LOG_WARNING,
282 "skipping %d segments ahead, expired from playlist\n",
283 s->start_seq_no - s->cur_seq_no);
284 s->cur_seq_no = s->start_seq_no;
285 }
286 if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
287 if (s->finished)
288 return AVERROR_EOF;
289 while (av_gettime_relative() - s->last_load_time < reload_interval) {
290 if (ff_check_interrupt(&h->interrupt_callback))
291 return AVERROR_EXIT;
292 av_usleep(100*1000);
293 }
294 goto retry;
295 }
296 url = s->segments[s->cur_seq_no - s->start_seq_no]->url;
297 av_log(h, AV_LOG_DEBUG, "opening %s\n", url);
298 ret = ffurl_open_whitelist(&s->seg_hd, url, AVIO_FLAG_READ,
299 &h->interrupt_callback, NULL,
300 h->protocol_whitelist, h->protocol_blacklist, h);
301 if (ret < 0) {
302 if (ff_check_interrupt(&h->interrupt_callback))
303 return AVERROR_EXIT;
304 av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url);
305 s->cur_seq_no++;
306 goto retry;
307 }
308 goto start;
309 }
310
311 const URLProtocol ff_hls_protocol = {
312 .name = "hls",
313 .url_open = hls_open,
314 .url_read = hls_read,
315 .url_close = hls_close,
316 .flags = URL_PROTOCOL_FLAG_NESTED_SCHEME,
317 .priv_data_size = sizeof(HLSContext),
318 };
319