FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
hlsproto.c
Go to the documentation of this file.
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 "avio_internal.h"
32 #include "internal.h"
33 #include "url.h"
34 #include "version.h"
35 
36 /*
37  * An apple http stream consists of a playlist with media segment files,
38  * played sequentially. There may be several playlists with the same
39  * video content, in different bandwidth variants, that are played in
40  * parallel (preferably only one bandwidth variant at a time). In this case,
41  * the user supplied the url to a main playlist that only lists the variant
42  * playlists.
43  *
44  * If the main playlist doesn't point at any variants, we still create
45  * one anonymous toplevel variant for this, to maintain the structure.
46  */
47 
48 struct segment {
49  int64_t duration;
51 };
52 
53 struct variant {
54  int bandwidth;
56 };
57 
58 typedef struct HLSContext {
60  int64_t target_duration;
62  int finished;
64  struct segment **segments;
65  int n_variants;
66  struct variant **variants;
67  int cur_seq_no;
69  int64_t last_load_time;
70 } HLSContext;
71 
73 {
74  int i;
75  for (i = 0; i < s->n_segments; i++)
76  av_freep(&s->segments[i]);
77  av_freep(&s->segments);
78  s->n_segments = 0;
79 }
80 
82 {
83  int i;
84  for (i = 0; i < s->n_variants; i++)
85  av_freep(&s->variants[i]);
86  av_freep(&s->variants);
87  s->n_variants = 0;
88 }
89 
90 struct variant_info {
91  char bandwidth[20];
92 };
93 
94 static void handle_variant_args(struct variant_info *info, const char *key,
95  int key_len, char **dest, int *dest_len)
96 {
97  if (!strncmp(key, "BANDWIDTH=", key_len)) {
98  *dest = info->bandwidth;
99  *dest_len = sizeof(info->bandwidth);
100  }
101 }
102 
103 static int parse_playlist(URLContext *h, const char *url)
104 {
105  HLSContext *s = h->priv_data;
106  AVIOContext *in;
107  int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
108  int64_t duration = 0;
109  char line[1024];
110  const char *ptr;
111 
112  if ((ret = ffio_open_whitelist(&in, url, AVIO_FLAG_READ,
115  return ret;
116 
117  ff_get_chomp_line(in, line, sizeof(line));
118  if (strcmp(line, "#EXTM3U")) {
119  ret = AVERROR_INVALIDDATA;
120  goto fail;
121  }
122 
124  s->finished = 0;
125  while (!avio_feof(in)) {
126  ff_get_chomp_line(in, line, sizeof(line));
127  if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
128  struct variant_info info = {{0}};
129  is_variant = 1;
131  &info);
132  bandwidth = atoi(info.bandwidth);
133  } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
134  s->target_duration = atoi(ptr) * AV_TIME_BASE;
135  } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
136  s->start_seq_no = atoi(ptr);
137  } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
138  s->finished = 1;
139  } else if (av_strstart(line, "#EXTINF:", &ptr)) {
140  is_segment = 1;
141  duration = atof(ptr) * AV_TIME_BASE;
142  } else if (av_strstart(line, "#", NULL)) {
143  continue;
144  } else if (line[0]) {
145  if (is_segment) {
146  struct segment *seg = av_malloc(sizeof(struct segment));
147  if (!seg) {
148  ret = AVERROR(ENOMEM);
149  goto fail;
150  }
151  seg->duration = duration;
152  ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
153  dynarray_add(&s->segments, &s->n_segments, seg);
154  is_segment = 0;
155  } else if (is_variant) {
156  struct variant *var = av_malloc(sizeof(struct variant));
157  if (!var) {
158  ret = AVERROR(ENOMEM);
159  goto fail;
160  }
161  var->bandwidth = bandwidth;
162  ff_make_absolute_url(var->url, sizeof(var->url), url, line);
163  dynarray_add(&s->variants, &s->n_variants, var);
164  is_variant = 0;
165  }
166  }
167  }
169 
170 fail:
171  avio_close(in);
172  return ret;
173 }
174 
175 static int hls_close(URLContext *h)
176 {
177  HLSContext *s = h->priv_data;
178 
181  ffurl_close(s->seg_hd);
182  return 0;
183 }
184 
185 static int hls_open(URLContext *h, const char *uri, int flags)
186 {
187  HLSContext *s = h->priv_data;
188  int ret, i;
189  const char *nested_url;
190 
191  if (flags & AVIO_FLAG_WRITE)
192  return AVERROR(ENOSYS);
193 
194  h->is_streamed = 1;
195 
196  if (av_strstart(uri, "hls+", &nested_url)) {
197  av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
198  } else if (av_strstart(uri, "hls://", &nested_url)) {
199  av_log(h, AV_LOG_ERROR,
200  "No nested protocol specified. Specify e.g. hls+http://%s\n",
201  nested_url);
202  ret = AVERROR(EINVAL);
203  goto fail;
204  } else {
205  av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
206  ret = AVERROR(EINVAL);
207  goto fail;
208  }
210  "Using the hls protocol is discouraged, please try using the "
211  "hls demuxer instead. The hls demuxer should be more complete "
212  "and work as well as the protocol implementation. (If not, "
213  "please report it.) To use the demuxer, simply use %s as url.\n",
214  s->playlisturl);
215 
216  if ((ret = parse_playlist(h, s->playlisturl)) < 0)
217  goto fail;
218 
219  if (s->n_segments == 0 && s->n_variants > 0) {
220  int max_bandwidth = 0, maxvar = -1;
221  for (i = 0; i < s->n_variants; i++) {
222  if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
223  max_bandwidth = s->variants[i]->bandwidth;
224  maxvar = i;
225  }
226  }
227  av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
228  sizeof(s->playlisturl));
229  if ((ret = parse_playlist(h, s->playlisturl)) < 0)
230  goto fail;
231  }
232 
233  if (s->n_segments == 0) {
234  av_log(h, AV_LOG_WARNING, "Empty playlist\n");
235  ret = AVERROR(EIO);
236  goto fail;
237  }
238  s->cur_seq_no = s->start_seq_no;
239  if (!s->finished && s->n_segments >= 3)
240  s->cur_seq_no = s->start_seq_no + s->n_segments - 3;
241 
242  return 0;
243 
244 fail:
245  hls_close(h);
246  return ret;
247 }
248 
249 static int hls_read(URLContext *h, uint8_t *buf, int size)
250 {
251  HLSContext *s = h->priv_data;
252  const char *url;
253  int ret;
254  int64_t reload_interval;
255 
256 start:
257  if (s->seg_hd) {
258  ret = ffurl_read(s->seg_hd, buf, size);
259  if (ret > 0)
260  return ret;
261  }
262  if (s->seg_hd) {
263  ffurl_close(s->seg_hd);
264  s->seg_hd = NULL;
265  s->cur_seq_no++;
266  }
267  reload_interval = s->n_segments > 0 ?
268  s->segments[s->n_segments - 1]->duration :
269  s->target_duration;
270 retry:
271  if (!s->finished) {
272  int64_t now = av_gettime_relative();
273  if (now - s->last_load_time >= reload_interval) {
274  if ((ret = parse_playlist(h, s->playlisturl)) < 0)
275  return ret;
276  /* If we need to reload the playlist again below (if
277  * there's still no more segments), switch to a reload
278  * interval of half the target duration. */
279  reload_interval = s->target_duration / 2;
280  }
281  }
282  if (s->cur_seq_no < s->start_seq_no) {
284  "skipping %d segments ahead, expired from playlist\n",
285  s->start_seq_no - s->cur_seq_no);
286  s->cur_seq_no = s->start_seq_no;
287  }
288  if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
289  if (s->finished)
290  return AVERROR_EOF;
291  while (av_gettime_relative() - s->last_load_time < reload_interval) {
293  return AVERROR_EXIT;
294  av_usleep(100*1000);
295  }
296  goto retry;
297  }
298  url = s->segments[s->cur_seq_no - s->start_seq_no]->url,
299  av_log(h, AV_LOG_DEBUG, "opening %s\n", url);
303  if (ret < 0) {
305  return AVERROR_EXIT;
306  av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url);
307  s->cur_seq_no++;
308  goto retry;
309  }
310  goto start;
311 }
312 
314  .name = "hls",
315  .url_open = hls_open,
316  .url_read = hls_read,
317  .url_close = hls_close,
319  .priv_data_size = sizeof(HLSContext),
320 };
#define NULL
Definition: coverity.c:32
void ff_make_absolute_url(char *buf, int size, const char *base, const char *rel)
Convert a relative url into an absolute url, given a base url.
Definition: url.c:80
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int bandwidth
Definition: hls.c:178
int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options, const char *whitelist, const char *blacklist, URLContext *parent)
Create an URLContext for accessing to the resource indicated by url, and open it. ...
Definition: avio.c:307
void(* ff_parse_key_val_cb)(void *context, const char *key, int key_len, char **dest, int *dest_len)
Callback function type for ff_parse_key_value.
Definition: internal.h:350
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
int is_streamed
true if streamed (no seek possible), default = false
Definition: url.h:45
AVIOInterruptCB interrupt_callback
Definition: url.h:47
#define AVIO_FLAG_READ
read-only
Definition: avio.h:654
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:655
const char * key
int av_usleep(unsigned usec)
Sleep for a period of time.
Definition: time.c:84
char * url
Definition: hls.c:72
#define MAX_URL_SIZE
Definition: internal.h:30
uint8_t
int n_variants
Definition: hls.c:192
#define av_malloc(s)
int64_t duration
Definition: movenc.c:63
#define AVERROR_EOF
End of file.
Definition: error.h:55
ptrdiff_t size
Definition: opengl_enc.c:101
static void free_variant_list(HLSContext *s)
Definition: hlsproto.c:81
#define flags(name, subs,...)
Definition: cbs_h2645.c:263
char playlisturl[MAX_URL_SIZE]
Definition: hlsproto.c:59
#define av_log(a,...)
struct variant ** variants
Definition: hls.c:193
int n_segments
Definition: hlsproto.c:63
URLContext * seg_hd
Definition: hlsproto.c:68
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
char bandwidth[20]
Definition: hls.c:322
const char * protocol_whitelist
Definition: url.h:49
#define AVERROR(e)
Definition: error.h:43
int avio_close(AVIOContext *s)
Close the resource accessed by the AVIOContext s and free it.
Definition: aviobuf.c:1190
static int parse_playlist(URLContext *h, const char *url)
Definition: hlsproto.c:103
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
#define URL_PROTOCOL_FLAG_NESTED_SCHEME
Definition: url.h:33
Definition: graph2dot.c:48
size_t av_strlcpy(char *dst, const char *src, size_t size)
Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.
Definition: avstring.c:83
#define fail()
Definition: checkasm.h:117
Definition: hls.c:68
#define dynarray_add(tab, nb_ptr, elem)
Definition: internal.h:198
static void handle_variant_args(struct variant_info *info, const char *key, int key_len, char **dest, int *dest_len)
Definition: hlsproto.c:94
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:254
static int hls_read(URLContext *h, uint8_t *buf, int size)
Definition: hlsproto.c:249
#define s(width, name)
Definition: cbs_vp9.c:257
Libavformat version macros.
#define AVERROR_EXIT
Immediate exit was requested; the called function should not be restarted.
Definition: error.h:56
const char * protocol_blacklist
Definition: url.h:50
int ff_check_interrupt(AVIOInterruptCB *cb)
Check if the user has requested to interrupt a blocking function associated with cb.
Definition: avio.c:664
char url[MAX_URL_SIZE]
Definition: hlsproto.c:55
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(constint16_t *) pi >>8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(constint32_t *) pi >>24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(constfloat *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(constfloat *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(constfloat *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(constdouble *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(constdouble *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(constdouble *) pi *(1U<< 31))))#defineSET_CONV_FUNC_GROUP(ofmt, ifmt) staticvoidset_generic_function(AudioConvert *ac){}voidff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enumAVSampleFormatout_fmt, enumAVSampleFormatin_fmt, intchannels, intsample_rate, intapply_map){AudioConvert *ac;intin_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) returnNULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt)>2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);returnNULL;}returnac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}elseif(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;elseac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);returnac;}intff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){intuse_generic=1;intlen=in->nb_samples;intp;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%dsamples-audio_convert:%sto%s(dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));returnff_convert_dither(ac-> in
void * buf
Definition: avisynth_c.h:690
Definition: url.h:38
void * priv_data
Definition: url.h:41
int64_t last_load_time
Definition: hlsproto.c:69
int ffio_open_whitelist(AVIOContext **s, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options, const char *whitelist, const char *blacklist)
Definition: aviobuf.c:1159
const char * name
Definition: url.h:55
int64_t av_gettime_relative(void)
Get the current time in microseconds since some unspecified starting point.
Definition: time.c:56
int ffurl_close(URLContext *h)
Definition: avio.c:467
void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf, void *context)
Parse a string with comma-separated key=value pairs.
Definition: utils.c:4857
int start_seq_no
Definition: hlsproto.c:61
int64_t target_duration
Definition: hlsproto.c:60
int av_strstart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str.
Definition: avstring.c:34
Main libavformat public API header.
struct segment ** segments
Definition: hlsproto.c:64
int cur_seq_no
Definition: hls.c:199
static void free_segment_list(HLSContext *s)
Definition: hlsproto.c:72
static int hls_open(URLContext *h, const char *uri, int flags)
Definition: hlsproto.c:185
const URLProtocol ff_hls_protocol
Definition: hlsproto.c:313
static int hls_close(URLContext *h)
Definition: hlsproto.c:175
Definition: hls.c:177
#define av_freep(p)
void INT64 start
Definition: avisynth_c.h:690
unbuffered private I/O API
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:358
int finished
Definition: hlsproto.c:62
int64_t duration
Definition: hls.c:69
int ff_get_chomp_line(AVIOContext *s, char *buf, int maxlen)
Same as ff_get_line but strip the white-space characters in the text tail.
Definition: aviobuf.c:826
int ffurl_read(URLContext *h, unsigned char *buf, int size)
Read up to size bytes from the resource accessed by h, and store the read bytes in buf...
Definition: avio.c:407