/* * 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 "avformat.h" #include "internal.h" #include "url.h" #include <unistd.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 (preferrably 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 { int duration; char url[MAX_URL_SIZE]; }; struct variant { int bandwidth; char url[MAX_URL_SIZE]; }; typedef struct AppleHTTPContext { char playlisturl[MAX_URL_SIZE]; int 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; } AppleHTTPContext; static int read_chomp_line(AVIOContext *s, char *buf, int maxlen) { int len = ff_get_line(s, buf, maxlen); while (len > 0 && isspace(buf[len - 1])) buf[--len] = '\0'; return len; } static void free_segment_list(AppleHTTPContext *s) { int i; for (i = 0; i < s->n_segments; i++) av_free(s->segments[i]); av_freep(&s->segments); s->n_segments = 0; } static void free_variant_list(AppleHTTPContext *s) { int i; for (i = 0; i < s->n_variants; i++) av_free(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) { AppleHTTPContext *s = h->priv_data; AVIOContext *in; int ret = 0, duration = 0, is_segment = 0, is_variant = 0, bandwidth = 0; char line[1024]; const char *ptr; if ((ret = avio_open(&in, url, AVIO_FLAG_READ)) < 0) return ret; read_chomp_line(in, line, sizeof(line)); if (strcmp(line, "#EXTM3U")) return AVERROR_INVALIDDATA; free_segment_list(s); s->finished = 0; while (!url_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); } 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 = atoi(ptr); } 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(); fail: avio_close(in); return ret; } static int applehttp_open(URLContext *h, const char *uri, int flags) { AppleHTTPContext *s; int ret, i; const char *nested_url; if (flags & AVIO_FLAG_WRITE) return AVERROR(ENOSYS); s = av_mallocz(sizeof(AppleHTTPContext)); if (!s) return AVERROR(ENOMEM); h->priv_data = s; h->is_streamed = 1; if (av_strstart(uri, "applehttp+", &nested_url)) { av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl)); } else if (av_strstart(uri, "applehttp://", &nested_url)) { av_strlcpy(s->playlisturl, "http://", sizeof(s->playlisturl)); av_strlcat(s->playlisturl, nested_url, sizeof(s->playlisturl)); } else { av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri); ret = AVERROR(EINVAL); goto fail; } 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: av_free(s); return ret; } static int applehttp_read(URLContext *h, uint8_t *buf, int size) { AppleHTTPContext *s = h->priv_data; const char *url; int ret; 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++; } retry: if (!s->finished) { int64_t now = av_gettime(); if (now - s->last_load_time >= s->target_duration*1000000) if ((ret = parse_playlist(h, s->playlisturl)) < 0) return ret; } 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() - s->last_load_time < s->target_duration*1000000) { if (url_interrupt_cb()) return AVERROR_EXIT; 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(&s->seg_hd, url, AVIO_FLAG_READ); if (ret < 0) { if (url_interrupt_cb()) return AVERROR_EXIT; av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url); s->cur_seq_no++; goto retry; } goto start; } static int applehttp_close(URLContext *h) { AppleHTTPContext *s = h->priv_data; free_segment_list(s); free_variant_list(s); ffurl_close(s->seg_hd); av_free(s); return 0; } URLProtocol ff_applehttp_protocol = { .name = "applehttp", .url_open = applehttp_open, .url_read = applehttp_read, .url_close = applehttp_close, .flags = URL_PROTOCOL_FLAG_NESTED_SCHEME, };