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00028 #include "libavutil/avstring.h"
00029 #include "libavutil/intreadwrite.h"
00030 #include "libavutil/mathematics.h"
00031 #include "libavutil/opt.h"
00032 #include "libavutil/dict.h"
00033 #include "avformat.h"
00034 #include "internal.h"
00035 #include <unistd.h>
00036 #include "avio_internal.h"
00037 #include "url.h"
00038
00039 #define INITIAL_BUFFER_SIZE 32768
00040
00041
00042
00043
00044
00045
00046
00047
00048
00049
00050
00051
00052
00053 enum KeyType {
00054 KEY_NONE,
00055 KEY_AES_128,
00056 };
00057
00058 struct segment {
00059 int duration;
00060 char url[MAX_URL_SIZE];
00061 char key[MAX_URL_SIZE];
00062 enum KeyType key_type;
00063 uint8_t iv[16];
00064 };
00065
00066
00067
00068
00069
00070
00071 struct variant {
00072 int bandwidth;
00073 char url[MAX_URL_SIZE];
00074 AVIOContext pb;
00075 uint8_t* read_buffer;
00076 URLContext *input;
00077 AVFormatContext *parent;
00078 int index;
00079 AVFormatContext *ctx;
00080 AVPacket pkt;
00081 int stream_offset;
00082
00083 int finished;
00084 int target_duration;
00085 int start_seq_no;
00086 int n_segments;
00087 struct segment **segments;
00088 int needed, cur_needed;
00089 int cur_seq_no;
00090 int64_t last_load_time;
00091
00092 char key_url[MAX_URL_SIZE];
00093 uint8_t key[16];
00094 };
00095
00096 typedef struct AppleHTTPContext {
00097 int n_variants;
00098 struct variant **variants;
00099 int cur_seq_no;
00100 int end_of_segment;
00101 int first_packet;
00102 int64_t first_timestamp;
00103 AVIOInterruptCB *interrupt_callback;
00104 } AppleHTTPContext;
00105
00106 static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
00107 {
00108 int len = ff_get_line(s, buf, maxlen);
00109 while (len > 0 && isspace(buf[len - 1]))
00110 buf[--len] = '\0';
00111 return len;
00112 }
00113
00114 static void free_segment_list(struct variant *var)
00115 {
00116 int i;
00117 for (i = 0; i < var->n_segments; i++)
00118 av_free(var->segments[i]);
00119 av_freep(&var->segments);
00120 var->n_segments = 0;
00121 }
00122
00123 static void free_variant_list(AppleHTTPContext *c)
00124 {
00125 int i;
00126 for (i = 0; i < c->n_variants; i++) {
00127 struct variant *var = c->variants[i];
00128 free_segment_list(var);
00129 av_free_packet(&var->pkt);
00130 av_free(var->pb.buffer);
00131 if (var->input)
00132 ffurl_close(var->input);
00133 if (var->ctx) {
00134 var->ctx->pb = NULL;
00135 av_close_input_file(var->ctx);
00136 }
00137 av_free(var);
00138 }
00139 av_freep(&c->variants);
00140 c->n_variants = 0;
00141 }
00142
00143
00144
00145
00146
00147 static void reset_packet(AVPacket *pkt)
00148 {
00149 av_init_packet(pkt);
00150 pkt->data = NULL;
00151 }
00152
00153 static struct variant *new_variant(AppleHTTPContext *c, int bandwidth,
00154 const char *url, const char *base)
00155 {
00156 struct variant *var = av_mallocz(sizeof(struct variant));
00157 if (!var)
00158 return NULL;
00159 reset_packet(&var->pkt);
00160 var->bandwidth = bandwidth;
00161 ff_make_absolute_url(var->url, sizeof(var->url), base, url);
00162 dynarray_add(&c->variants, &c->n_variants, var);
00163 return var;
00164 }
00165
00166 struct variant_info {
00167 char bandwidth[20];
00168 };
00169
00170 static void handle_variant_args(struct variant_info *info, const char *key,
00171 int key_len, char **dest, int *dest_len)
00172 {
00173 if (!strncmp(key, "BANDWIDTH=", key_len)) {
00174 *dest = info->bandwidth;
00175 *dest_len = sizeof(info->bandwidth);
00176 }
00177 }
00178
00179 struct key_info {
00180 char uri[MAX_URL_SIZE];
00181 char method[10];
00182 char iv[35];
00183 };
00184
00185 static void handle_key_args(struct key_info *info, const char *key,
00186 int key_len, char **dest, int *dest_len)
00187 {
00188 if (!strncmp(key, "METHOD=", key_len)) {
00189 *dest = info->method;
00190 *dest_len = sizeof(info->method);
00191 } else if (!strncmp(key, "URI=", key_len)) {
00192 *dest = info->uri;
00193 *dest_len = sizeof(info->uri);
00194 } else if (!strncmp(key, "IV=", key_len)) {
00195 *dest = info->iv;
00196 *dest_len = sizeof(info->iv);
00197 }
00198 }
00199
00200 static int parse_playlist(AppleHTTPContext *c, const char *url,
00201 struct variant *var, AVIOContext *in)
00202 {
00203 int ret = 0, duration = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
00204 enum KeyType key_type = KEY_NONE;
00205 uint8_t iv[16] = "";
00206 int has_iv = 0;
00207 char key[MAX_URL_SIZE] = "";
00208 char line[1024];
00209 const char *ptr;
00210 int close_in = 0;
00211
00212 if (!in) {
00213 close_in = 1;
00214 if ((ret = avio_open2(&in, url, AVIO_FLAG_READ,
00215 c->interrupt_callback, NULL)) < 0)
00216 return ret;
00217 }
00218
00219 read_chomp_line(in, line, sizeof(line));
00220 if (strcmp(line, "#EXTM3U")) {
00221 ret = AVERROR_INVALIDDATA;
00222 goto fail;
00223 }
00224
00225 if (var) {
00226 free_segment_list(var);
00227 var->finished = 0;
00228 }
00229 while (!url_feof(in)) {
00230 read_chomp_line(in, line, sizeof(line));
00231 if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
00232 struct variant_info info = {{0}};
00233 is_variant = 1;
00234 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
00235 &info);
00236 bandwidth = atoi(info.bandwidth);
00237 } else if (av_strstart(line, "#EXT-X-KEY:", &ptr)) {
00238 struct key_info info = {{0}};
00239 ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_key_args,
00240 &info);
00241 key_type = KEY_NONE;
00242 has_iv = 0;
00243 if (!strcmp(info.method, "AES-128"))
00244 key_type = KEY_AES_128;
00245 if (!strncmp(info.iv, "0x", 2) || !strncmp(info.iv, "0X", 2)) {
00246 ff_hex_to_data(iv, info.iv + 2);
00247 has_iv = 1;
00248 }
00249 av_strlcpy(key, info.uri, sizeof(key));
00250 } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
00251 if (!var) {
00252 var = new_variant(c, 0, url, NULL);
00253 if (!var) {
00254 ret = AVERROR(ENOMEM);
00255 goto fail;
00256 }
00257 }
00258 var->target_duration = atoi(ptr);
00259 } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
00260 if (!var) {
00261 var = new_variant(c, 0, url, NULL);
00262 if (!var) {
00263 ret = AVERROR(ENOMEM);
00264 goto fail;
00265 }
00266 }
00267 var->start_seq_no = atoi(ptr);
00268 } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
00269 if (var)
00270 var->finished = 1;
00271 } else if (av_strstart(line, "#EXTINF:", &ptr)) {
00272 is_segment = 1;
00273 duration = atoi(ptr);
00274 } else if (av_strstart(line, "#", NULL)) {
00275 continue;
00276 } else if (line[0]) {
00277 if (is_variant) {
00278 if (!new_variant(c, bandwidth, line, url)) {
00279 ret = AVERROR(ENOMEM);
00280 goto fail;
00281 }
00282 is_variant = 0;
00283 bandwidth = 0;
00284 }
00285 if (is_segment) {
00286 struct segment *seg;
00287 if (!var) {
00288 var = new_variant(c, 0, url, NULL);
00289 if (!var) {
00290 ret = AVERROR(ENOMEM);
00291 goto fail;
00292 }
00293 }
00294 seg = av_malloc(sizeof(struct segment));
00295 if (!seg) {
00296 ret = AVERROR(ENOMEM);
00297 goto fail;
00298 }
00299 seg->duration = duration;
00300 seg->key_type = key_type;
00301 if (has_iv) {
00302 memcpy(seg->iv, iv, sizeof(iv));
00303 } else {
00304 int seq = var->start_seq_no + var->n_segments;
00305 memset(seg->iv, 0, sizeof(seg->iv));
00306 AV_WB32(seg->iv + 12, seq);
00307 }
00308 ff_make_absolute_url(seg->key, sizeof(seg->key), url, key);
00309 ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
00310 dynarray_add(&var->segments, &var->n_segments, seg);
00311 is_segment = 0;
00312 }
00313 }
00314 }
00315 if (var)
00316 var->last_load_time = av_gettime();
00317
00318 fail:
00319 if (close_in)
00320 avio_close(in);
00321 return ret;
00322 }
00323
00324 static int open_input(struct variant *var)
00325 {
00326 struct segment *seg = var->segments[var->cur_seq_no - var->start_seq_no];
00327 if (seg->key_type == KEY_NONE) {
00328 return ffurl_open(&var->input, seg->url, AVIO_FLAG_READ,
00329 &var->parent->interrupt_callback, NULL);
00330 } else if (seg->key_type == KEY_AES_128) {
00331 char iv[33], key[33], url[MAX_URL_SIZE];
00332 int ret;
00333 if (strcmp(seg->key, var->key_url)) {
00334 URLContext *uc;
00335 if (ffurl_open(&uc, seg->key, AVIO_FLAG_READ,
00336 &var->parent->interrupt_callback, NULL) == 0) {
00337 if (ffurl_read_complete(uc, var->key, sizeof(var->key))
00338 != sizeof(var->key)) {
00339 av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",
00340 seg->key);
00341 }
00342 ffurl_close(uc);
00343 } else {
00344 av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",
00345 seg->key);
00346 }
00347 av_strlcpy(var->key_url, seg->key, sizeof(var->key_url));
00348 }
00349 ff_data_to_hex(iv, seg->iv, sizeof(seg->iv), 0);
00350 ff_data_to_hex(key, var->key, sizeof(var->key), 0);
00351 iv[32] = key[32] = '\0';
00352 if (strstr(seg->url, "://"))
00353 snprintf(url, sizeof(url), "crypto+%s", seg->url);
00354 else
00355 snprintf(url, sizeof(url), "crypto:%s", seg->url);
00356 if ((ret = ffurl_alloc(&var->input, url, AVIO_FLAG_READ,
00357 &var->parent->interrupt_callback)) < 0)
00358 return ret;
00359 av_opt_set(var->input->priv_data, "key", key, 0);
00360 av_opt_set(var->input->priv_data, "iv", iv, 0);
00361 if ((ret = ffurl_connect(var->input, NULL)) < 0) {
00362 ffurl_close(var->input);
00363 var->input = NULL;
00364 return ret;
00365 }
00366 return 0;
00367 }
00368 return AVERROR(ENOSYS);
00369 }
00370
00371 static int read_data(void *opaque, uint8_t *buf, int buf_size)
00372 {
00373 struct variant *v = opaque;
00374 AppleHTTPContext *c = v->parent->priv_data;
00375 int ret, i;
00376
00377 restart:
00378 if (!v->input) {
00379 reload:
00380
00381
00382 if (!v->finished &&
00383 av_gettime() - v->last_load_time >= v->target_duration*1000000 &&
00384 (ret = parse_playlist(c, v->url, v, NULL)) < 0)
00385 return ret;
00386 if (v->cur_seq_no < v->start_seq_no) {
00387 av_log(NULL, AV_LOG_WARNING,
00388 "skipping %d segments ahead, expired from playlists\n",
00389 v->start_seq_no - v->cur_seq_no);
00390 v->cur_seq_no = v->start_seq_no;
00391 }
00392 if (v->cur_seq_no >= v->start_seq_no + v->n_segments) {
00393 if (v->finished)
00394 return AVERROR_EOF;
00395 while (av_gettime() - v->last_load_time <
00396 v->target_duration*1000000) {
00397 if (ff_check_interrupt(c->interrupt_callback))
00398 return AVERROR_EXIT;
00399 usleep(100*1000);
00400 }
00401
00402 goto reload;
00403 }
00404
00405 ret = open_input(v);
00406 if (ret < 0)
00407 return ret;
00408 }
00409 ret = ffurl_read(v->input, buf, buf_size);
00410 if (ret > 0)
00411 return ret;
00412 if (ret < 0 && ret != AVERROR_EOF)
00413 return ret;
00414 ffurl_close(v->input);
00415 v->input = NULL;
00416 v->cur_seq_no++;
00417
00418 c->end_of_segment = 1;
00419 c->cur_seq_no = v->cur_seq_no;
00420
00421 if (v->ctx && v->ctx->nb_streams) {
00422 v->needed = 0;
00423 for (i = v->stream_offset; i < v->stream_offset + v->ctx->nb_streams;
00424 i++) {
00425 if (v->parent->streams[i]->discard < AVDISCARD_ALL)
00426 v->needed = 1;
00427 }
00428 }
00429 if (!v->needed) {
00430 av_log(v->parent, AV_LOG_INFO, "No longer receiving variant %d\n",
00431 v->index);
00432 return AVERROR_EOF;
00433 }
00434 goto restart;
00435 }
00436
00437 static int applehttp_read_header(AVFormatContext *s, AVFormatParameters *ap)
00438 {
00439 AppleHTTPContext *c = s->priv_data;
00440 int ret = 0, i, j, stream_offset = 0;
00441
00442 c->interrupt_callback = &s->interrupt_callback;
00443
00444 if ((ret = parse_playlist(c, s->filename, NULL, s->pb)) < 0)
00445 goto fail;
00446
00447 if (c->n_variants == 0) {
00448 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
00449 ret = AVERROR_EOF;
00450 goto fail;
00451 }
00452
00453
00454 if (c->n_variants > 1 || c->variants[0]->n_segments == 0) {
00455 for (i = 0; i < c->n_variants; i++) {
00456 struct variant *v = c->variants[i];
00457 if ((ret = parse_playlist(c, v->url, v, NULL)) < 0)
00458 goto fail;
00459 }
00460 }
00461
00462 if (c->variants[0]->n_segments == 0) {
00463 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
00464 ret = AVERROR_EOF;
00465 goto fail;
00466 }
00467
00468
00469
00470 if (c->variants[0]->finished) {
00471 int64_t duration = 0;
00472 for (i = 0; i < c->variants[0]->n_segments; i++)
00473 duration += c->variants[0]->segments[i]->duration;
00474 s->duration = duration * AV_TIME_BASE;
00475 }
00476
00477
00478 for (i = 0; i < c->n_variants; i++) {
00479 struct variant *v = c->variants[i];
00480 AVInputFormat *in_fmt = NULL;
00481 char bitrate_str[20];
00482 if (v->n_segments == 0)
00483 continue;
00484
00485 if (!(v->ctx = avformat_alloc_context())) {
00486 ret = AVERROR(ENOMEM);
00487 goto fail;
00488 }
00489
00490 v->index = i;
00491 v->needed = 1;
00492 v->parent = s;
00493
00494
00495
00496 v->cur_seq_no = v->start_seq_no;
00497 if (!v->finished && v->n_segments > 3)
00498 v->cur_seq_no = v->start_seq_no + v->n_segments - 3;
00499
00500 v->read_buffer = av_malloc(INITIAL_BUFFER_SIZE);
00501 ffio_init_context(&v->pb, v->read_buffer, INITIAL_BUFFER_SIZE, 0, v,
00502 read_data, NULL, NULL);
00503 v->pb.seekable = 0;
00504 ret = av_probe_input_buffer(&v->pb, &in_fmt, v->segments[0]->url,
00505 NULL, 0, 0);
00506 if (ret < 0) {
00507
00508
00509
00510
00511 avformat_free_context(v->ctx);
00512 v->ctx = NULL;
00513 goto fail;
00514 }
00515 v->ctx->pb = &v->pb;
00516 ret = avformat_open_input(&v->ctx, v->segments[0]->url, in_fmt, NULL);
00517 if (ret < 0)
00518 goto fail;
00519 v->stream_offset = stream_offset;
00520 snprintf(bitrate_str, sizeof(bitrate_str), "%d", v->bandwidth);
00521
00522 for (j = 0; j < v->ctx->nb_streams; j++) {
00523 AVStream *st = avformat_new_stream(s, NULL);
00524 if (!st) {
00525 ret = AVERROR(ENOMEM);
00526 goto fail;
00527 }
00528 st->id = i;
00529 avcodec_copy_context(st->codec, v->ctx->streams[j]->codec);
00530 if (v->bandwidth)
00531 av_dict_set(&st->metadata, "variant_bitrate", bitrate_str,
00532 0);
00533 }
00534 stream_offset += v->ctx->nb_streams;
00535 }
00536
00537 c->first_packet = 1;
00538 c->first_timestamp = AV_NOPTS_VALUE;
00539
00540 return 0;
00541 fail:
00542 free_variant_list(c);
00543 return ret;
00544 }
00545
00546 static int recheck_discard_flags(AVFormatContext *s, int first)
00547 {
00548 AppleHTTPContext *c = s->priv_data;
00549 int i, changed = 0;
00550
00551
00552 for (i = 0; i < c->n_variants; i++)
00553 c->variants[i]->cur_needed = 0;
00554
00555 for (i = 0; i < s->nb_streams; i++) {
00556 AVStream *st = s->streams[i];
00557 struct variant *var = c->variants[s->streams[i]->id];
00558 if (st->discard < AVDISCARD_ALL)
00559 var->cur_needed = 1;
00560 }
00561 for (i = 0; i < c->n_variants; i++) {
00562 struct variant *v = c->variants[i];
00563 if (v->cur_needed && !v->needed) {
00564 v->needed = 1;
00565 changed = 1;
00566 v->cur_seq_no = c->cur_seq_no;
00567 v->pb.eof_reached = 0;
00568 av_log(s, AV_LOG_INFO, "Now receiving variant %d\n", i);
00569 } else if (first && !v->cur_needed && v->needed) {
00570 if (v->input)
00571 ffurl_close(v->input);
00572 v->input = NULL;
00573 v->needed = 0;
00574 changed = 1;
00575 av_log(s, AV_LOG_INFO, "No longer receiving variant %d\n", i);
00576 }
00577 }
00578 return changed;
00579 }
00580
00581 static int applehttp_read_packet(AVFormatContext *s, AVPacket *pkt)
00582 {
00583 AppleHTTPContext *c = s->priv_data;
00584 int ret, i, minvariant = -1;
00585
00586 if (c->first_packet) {
00587 recheck_discard_flags(s, 1);
00588 c->first_packet = 0;
00589 }
00590
00591 start:
00592 c->end_of_segment = 0;
00593 for (i = 0; i < c->n_variants; i++) {
00594 struct variant *var = c->variants[i];
00595
00596
00597 if (var->needed && !var->pkt.data) {
00598 ret = av_read_frame(var->ctx, &var->pkt);
00599 if (ret < 0) {
00600 if (!url_feof(&var->pb))
00601 return ret;
00602 reset_packet(&var->pkt);
00603 } else {
00604 if (c->first_timestamp == AV_NOPTS_VALUE)
00605 c->first_timestamp = var->pkt.dts;
00606 }
00607 }
00608
00609 if (var->pkt.data) {
00610 if (minvariant < 0 ||
00611 var->pkt.dts < c->variants[minvariant]->pkt.dts)
00612 minvariant = i;
00613 }
00614 }
00615 if (c->end_of_segment) {
00616 if (recheck_discard_flags(s, 0))
00617 goto start;
00618 }
00619
00620 if (minvariant >= 0) {
00621 *pkt = c->variants[minvariant]->pkt;
00622 pkt->stream_index += c->variants[minvariant]->stream_offset;
00623 reset_packet(&c->variants[minvariant]->pkt);
00624 return 0;
00625 }
00626 return AVERROR_EOF;
00627 }
00628
00629 static int applehttp_close(AVFormatContext *s)
00630 {
00631 AppleHTTPContext *c = s->priv_data;
00632
00633 free_variant_list(c);
00634 return 0;
00635 }
00636
00637 static int applehttp_read_seek(AVFormatContext *s, int stream_index,
00638 int64_t timestamp, int flags)
00639 {
00640 AppleHTTPContext *c = s->priv_data;
00641 int i, j, ret;
00642
00643 if ((flags & AVSEEK_FLAG_BYTE) || !c->variants[0]->finished)
00644 return AVERROR(ENOSYS);
00645
00646 timestamp = av_rescale_rnd(timestamp, 1, stream_index >= 0 ?
00647 s->streams[stream_index]->time_base.den :
00648 AV_TIME_BASE, flags & AVSEEK_FLAG_BACKWARD ?
00649 AV_ROUND_DOWN : AV_ROUND_UP);
00650 ret = AVERROR(EIO);
00651 for (i = 0; i < c->n_variants; i++) {
00652
00653 struct variant *var = c->variants[i];
00654 int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ? 0 :
00655 av_rescale_rnd(c->first_timestamp, 1, stream_index >= 0 ?
00656 s->streams[stream_index]->time_base.den :
00657 AV_TIME_BASE, flags & AVSEEK_FLAG_BACKWARD ?
00658 AV_ROUND_DOWN : AV_ROUND_UP);
00659 if (var->input) {
00660 ffurl_close(var->input);
00661 var->input = NULL;
00662 }
00663 av_free_packet(&var->pkt);
00664 reset_packet(&var->pkt);
00665 var->pb.eof_reached = 0;
00666
00667
00668 for (j = 0; j < var->n_segments; j++) {
00669 if (timestamp >= pos &&
00670 timestamp < pos + var->segments[j]->duration) {
00671 var->cur_seq_no = var->start_seq_no + j;
00672 ret = 0;
00673 break;
00674 }
00675 pos += var->segments[j]->duration;
00676 }
00677 }
00678 return ret;
00679 }
00680
00681 static int applehttp_probe(AVProbeData *p)
00682 {
00683
00684
00685 if (strncmp(p->buf, "#EXTM3U", 7))
00686 return 0;
00687 if (strstr(p->buf, "#EXT-X-STREAM-INF:") ||
00688 strstr(p->buf, "#EXT-X-TARGETDURATION:") ||
00689 strstr(p->buf, "#EXT-X-MEDIA-SEQUENCE:"))
00690 return AVPROBE_SCORE_MAX;
00691 return 0;
00692 }
00693
00694 AVInputFormat ff_applehttp_demuxer = {
00695 .name = "applehttp",
00696 .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming format"),
00697 .priv_data_size = sizeof(AppleHTTPContext),
00698 .read_probe = applehttp_probe,
00699 .read_header = applehttp_read_header,
00700 .read_packet = applehttp_read_packet,
00701 .read_close = applehttp_close,
00702 .read_seek = applehttp_read_seek,
00703 };