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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 avformat_close_input(&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 (!in->eof_reached) {
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
00380
00381 int64_t reload_interval = v->n_segments > 0 ?
00382 v->segments[v->n_segments - 1]->duration :
00383 v->target_duration;
00384 reload_interval *= 1000000;
00385
00386 reload:
00387 if (!v->finished &&
00388 av_gettime() - v->last_load_time >= reload_interval) {
00389 if ((ret = parse_playlist(c, v->url, v, NULL)) < 0)
00390 return ret;
00391
00392
00393
00394 reload_interval = v->target_duration * 500000;
00395 }
00396 if (v->cur_seq_no < v->start_seq_no) {
00397 av_log(NULL, AV_LOG_WARNING,
00398 "skipping %d segments ahead, expired from playlists\n",
00399 v->start_seq_no - v->cur_seq_no);
00400 v->cur_seq_no = v->start_seq_no;
00401 }
00402 if (v->cur_seq_no >= v->start_seq_no + v->n_segments) {
00403 if (v->finished)
00404 return AVERROR_EOF;
00405 while (av_gettime() - v->last_load_time < reload_interval) {
00406 if (ff_check_interrupt(c->interrupt_callback))
00407 return AVERROR_EXIT;
00408 usleep(100*1000);
00409 }
00410
00411 goto reload;
00412 }
00413
00414 ret = open_input(v);
00415 if (ret < 0)
00416 return ret;
00417 }
00418 ret = ffurl_read(v->input, buf, buf_size);
00419 if (ret > 0)
00420 return ret;
00421 if (ret < 0 && ret != AVERROR_EOF)
00422 return ret;
00423 ffurl_close(v->input);
00424 v->input = NULL;
00425 v->cur_seq_no++;
00426
00427 c->end_of_segment = 1;
00428 c->cur_seq_no = v->cur_seq_no;
00429
00430 if (v->ctx && v->ctx->nb_streams) {
00431 v->needed = 0;
00432 for (i = v->stream_offset; i < v->stream_offset + v->ctx->nb_streams;
00433 i++) {
00434 if (v->parent->streams[i]->discard < AVDISCARD_ALL)
00435 v->needed = 1;
00436 }
00437 }
00438 if (!v->needed) {
00439 av_log(v->parent, AV_LOG_INFO, "No longer receiving variant %d\n",
00440 v->index);
00441 return AVERROR_EOF;
00442 }
00443 goto restart;
00444 }
00445
00446 static int applehttp_read_header(AVFormatContext *s, AVFormatParameters *ap)
00447 {
00448 AppleHTTPContext *c = s->priv_data;
00449 int ret = 0, i, j, stream_offset = 0;
00450
00451 c->interrupt_callback = &s->interrupt_callback;
00452
00453 if ((ret = parse_playlist(c, s->filename, NULL, s->pb)) < 0)
00454 goto fail;
00455
00456 if (c->n_variants == 0) {
00457 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
00458 ret = AVERROR_EOF;
00459 goto fail;
00460 }
00461
00462
00463 if (c->n_variants > 1 || c->variants[0]->n_segments == 0) {
00464 for (i = 0; i < c->n_variants; i++) {
00465 struct variant *v = c->variants[i];
00466 if ((ret = parse_playlist(c, v->url, v, NULL)) < 0)
00467 goto fail;
00468 }
00469 }
00470
00471 if (c->variants[0]->n_segments == 0) {
00472 av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
00473 ret = AVERROR_EOF;
00474 goto fail;
00475 }
00476
00477
00478
00479 if (c->variants[0]->finished) {
00480 int64_t duration = 0;
00481 for (i = 0; i < c->variants[0]->n_segments; i++)
00482 duration += c->variants[0]->segments[i]->duration;
00483 s->duration = duration * AV_TIME_BASE;
00484 }
00485
00486
00487 for (i = 0; i < c->n_variants; i++) {
00488 struct variant *v = c->variants[i];
00489 AVInputFormat *in_fmt = NULL;
00490 char bitrate_str[20];
00491 if (v->n_segments == 0)
00492 continue;
00493
00494 if (!(v->ctx = avformat_alloc_context())) {
00495 ret = AVERROR(ENOMEM);
00496 goto fail;
00497 }
00498
00499 v->index = i;
00500 v->needed = 1;
00501 v->parent = s;
00502
00503
00504
00505 v->cur_seq_no = v->start_seq_no;
00506 if (!v->finished && v->n_segments > 3)
00507 v->cur_seq_no = v->start_seq_no + v->n_segments - 3;
00508
00509 v->read_buffer = av_malloc(INITIAL_BUFFER_SIZE);
00510 ffio_init_context(&v->pb, v->read_buffer, INITIAL_BUFFER_SIZE, 0, v,
00511 read_data, NULL, NULL);
00512 v->pb.seekable = 0;
00513 ret = av_probe_input_buffer(&v->pb, &in_fmt, v->segments[0]->url,
00514 NULL, 0, 0);
00515 if (ret < 0) {
00516
00517
00518
00519
00520 avformat_free_context(v->ctx);
00521 v->ctx = NULL;
00522 goto fail;
00523 }
00524 v->ctx->pb = &v->pb;
00525 ret = avformat_open_input(&v->ctx, v->segments[0]->url, in_fmt, NULL);
00526 if (ret < 0)
00527 goto fail;
00528 v->stream_offset = stream_offset;
00529 snprintf(bitrate_str, sizeof(bitrate_str), "%d", v->bandwidth);
00530
00531 for (j = 0; j < v->ctx->nb_streams; j++) {
00532 AVStream *st = avformat_new_stream(s, NULL);
00533 if (!st) {
00534 ret = AVERROR(ENOMEM);
00535 goto fail;
00536 }
00537 st->id = i;
00538 avcodec_copy_context(st->codec, v->ctx->streams[j]->codec);
00539 if (v->bandwidth)
00540 av_dict_set(&st->metadata, "variant_bitrate", bitrate_str,
00541 0);
00542 }
00543 stream_offset += v->ctx->nb_streams;
00544 }
00545
00546 c->first_packet = 1;
00547 c->first_timestamp = AV_NOPTS_VALUE;
00548
00549 return 0;
00550 fail:
00551 free_variant_list(c);
00552 return ret;
00553 }
00554
00555 static int recheck_discard_flags(AVFormatContext *s, int first)
00556 {
00557 AppleHTTPContext *c = s->priv_data;
00558 int i, changed = 0;
00559
00560
00561 for (i = 0; i < c->n_variants; i++)
00562 c->variants[i]->cur_needed = 0;;
00563
00564 for (i = 0; i < s->nb_streams; i++) {
00565 AVStream *st = s->streams[i];
00566 struct variant *var = c->variants[s->streams[i]->id];
00567 if (st->discard < AVDISCARD_ALL)
00568 var->cur_needed = 1;
00569 }
00570 for (i = 0; i < c->n_variants; i++) {
00571 struct variant *v = c->variants[i];
00572 if (v->cur_needed && !v->needed) {
00573 v->needed = 1;
00574 changed = 1;
00575 v->cur_seq_no = c->cur_seq_no;
00576 v->pb.eof_reached = 0;
00577 av_log(s, AV_LOG_INFO, "Now receiving variant %d\n", i);
00578 } else if (first && !v->cur_needed && v->needed) {
00579 if (v->input)
00580 ffurl_close(v->input);
00581 v->input = NULL;
00582 v->needed = 0;
00583 changed = 1;
00584 av_log(s, AV_LOG_INFO, "No longer receiving variant %d\n", i);
00585 }
00586 }
00587 return changed;
00588 }
00589
00590 static int applehttp_read_packet(AVFormatContext *s, AVPacket *pkt)
00591 {
00592 AppleHTTPContext *c = s->priv_data;
00593 int ret, i, minvariant = -1;
00594
00595 if (c->first_packet) {
00596 recheck_discard_flags(s, 1);
00597 c->first_packet = 0;
00598 }
00599
00600 start:
00601 c->end_of_segment = 0;
00602 for (i = 0; i < c->n_variants; i++) {
00603 struct variant *var = c->variants[i];
00604
00605
00606 if (var->needed && !var->pkt.data) {
00607 ret = av_read_frame(var->ctx, &var->pkt);
00608 if (ret < 0) {
00609 if (!var->pb.eof_reached)
00610 return ret;
00611 reset_packet(&var->pkt);
00612 } else {
00613 if (c->first_timestamp == AV_NOPTS_VALUE)
00614 c->first_timestamp = var->pkt.dts;
00615 }
00616 }
00617
00618 if (var->pkt.data) {
00619 if (minvariant < 0 ||
00620 var->pkt.dts < c->variants[minvariant]->pkt.dts)
00621 minvariant = i;
00622 }
00623 }
00624 if (c->end_of_segment) {
00625 if (recheck_discard_flags(s, 0))
00626 goto start;
00627 }
00628
00629 if (minvariant >= 0) {
00630 *pkt = c->variants[minvariant]->pkt;
00631 pkt->stream_index += c->variants[minvariant]->stream_offset;
00632 reset_packet(&c->variants[minvariant]->pkt);
00633 return 0;
00634 }
00635 return AVERROR_EOF;
00636 }
00637
00638 static int applehttp_close(AVFormatContext *s)
00639 {
00640 AppleHTTPContext *c = s->priv_data;
00641
00642 free_variant_list(c);
00643 return 0;
00644 }
00645
00646 static int applehttp_read_seek(AVFormatContext *s, int stream_index,
00647 int64_t timestamp, int flags)
00648 {
00649 AppleHTTPContext *c = s->priv_data;
00650 int i, j, ret;
00651
00652 if ((flags & AVSEEK_FLAG_BYTE) || !c->variants[0]->finished)
00653 return AVERROR(ENOSYS);
00654
00655 timestamp = av_rescale_rnd(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 ret = AVERROR(EIO);
00660 for (i = 0; i < c->n_variants; i++) {
00661
00662 struct variant *var = c->variants[i];
00663 int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ? 0 :
00664 av_rescale_rnd(c->first_timestamp, 1,
00665 stream_index >= 0 ? s->streams[stream_index]->time_base.den : AV_TIME_BASE,
00666 flags & AVSEEK_FLAG_BACKWARD ? AV_ROUND_DOWN : AV_ROUND_UP);
00667 if (var->input) {
00668 ffurl_close(var->input);
00669 var->input = NULL;
00670 }
00671 av_free_packet(&var->pkt);
00672 reset_packet(&var->pkt);
00673 var->pb.eof_reached = 0;
00674
00675
00676 for (j = 0; j < var->n_segments; j++) {
00677 if (timestamp >= pos &&
00678 timestamp < pos + var->segments[j]->duration) {
00679 var->cur_seq_no = var->start_seq_no + j;
00680 ret = 0;
00681 break;
00682 }
00683 pos += var->segments[j]->duration;
00684 }
00685 }
00686 return ret;
00687 }
00688
00689 static int applehttp_probe(AVProbeData *p)
00690 {
00691
00692
00693 if (strncmp(p->buf, "#EXTM3U", 7))
00694 return 0;
00695 if (strstr(p->buf, "#EXT-X-STREAM-INF:") ||
00696 strstr(p->buf, "#EXT-X-TARGETDURATION:") ||
00697 strstr(p->buf, "#EXT-X-MEDIA-SEQUENCE:"))
00698 return AVPROBE_SCORE_MAX;
00699 return 0;
00700 }
00701
00702 AVInputFormat ff_applehttp_demuxer = {
00703 .name = "applehttp",
00704 .long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming format"),
00705 .priv_data_size = sizeof(AppleHTTPContext),
00706 .read_probe = applehttp_probe,
00707 .read_header = applehttp_read_header,
00708 .read_packet = applehttp_read_packet,
00709 .read_close = applehttp_close,
00710 .read_seek = applehttp_read_seek,
00711 };