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ffmpeg/libavformat/hls.c
Michael Schenk 513a431e07 avformat/hls: reduce memory usage by using dynamically allocated url/key 
Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
2014-04-12 03:14:52 +03:00

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/*
* Apple HTTP Live Streaming demuxer
* Copyright (c) 2010 Martin Storsjo
* Copyright (c) 2013 Anssi Hannula
*
* 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 demuxer
* http://tools.ietf.org/html/draft-pantos-http-live-streaming
*/
#include "libavutil/avstring.h"
#include "libavutil/avassert.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavutil/dict.h"
#include "libavutil/time.h"
#include "avformat.h"
#include "internal.h"
#include "avio_internal.h"
#include "url.h"
#include "id3v2.h"
#define INITIAL_BUFFER_SIZE 32768
#define MAX_FIELD_LEN 64
#define MAX_CHARACTERISTICS_LEN 512
#define MPEG_TIME_BASE 90000
#define MPEG_TIME_BASE_Q (AVRational){1, MPEG_TIME_BASE}
/*
* 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 (preferably 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.
*/
enum KeyType {
KEY_NONE,
KEY_AES_128,
};
struct segment {
int64_t duration;
int64_t url_offset;
int64_t size;
char *url;
char *key;
enum KeyType key_type;
uint8_t iv[16];
};
struct rendition;
enum PlaylistType {
PLS_TYPE_UNSPECIFIED,
PLS_TYPE_EVENT,
PLS_TYPE_VOD
};
/*
* Each playlist has its own demuxer. If it currently is active,
* it has an open AVIOContext too, and potentially an AVPacket
* containing the next packet from this stream.
*/
struct playlist {
char url[MAX_URL_SIZE];
AVIOContext pb;
uint8_t* read_buffer;
URLContext *input;
AVFormatContext *parent;
int index;
AVFormatContext *ctx;
AVPacket pkt;
int stream_offset;
int finished;
enum PlaylistType type;
int64_t target_duration;
int start_seq_no;
int n_segments;
struct segment **segments;
int needed, cur_needed;
int cur_seq_no;
int64_t cur_seg_offset;
int64_t last_load_time;
char key_url[MAX_URL_SIZE];
uint8_t key[16];
/* ID3 timestamp handling (elementary audio streams have ID3 timestamps
* (and possibly other ID3 tags) in the beginning of each segment) */
int is_id3_timestamped; /* -1: not yet known */
int64_t id3_mpegts_timestamp; /* in mpegts tb */
int64_t id3_offset; /* in stream original tb */
uint8_t* id3_buf; /* temp buffer for id3 parsing */
unsigned int id3_buf_size;
AVDictionary *id3_initial; /* data from first id3 tag */
int id3_found; /* ID3 tag found at some point */
int id3_changed; /* ID3 tag data has changed at some point */
ID3v2ExtraMeta *id3_deferred_extra; /* stored here until subdemuxer is opened */
int64_t seek_timestamp;
int seek_flags;
int seek_stream_index; /* into subdemuxer stream array */
/* Renditions associated with this playlist, if any.
* Alternative rendition playlists have a single rendition associated
* with them, and variant main Media Playlists may have
* multiple (playlist-less) renditions associated with them. */
int n_renditions;
struct rendition **renditions;
};
/*
* Renditions are e.g. alternative subtitle or audio streams.
* The rendition may either be an external playlist or it may be
* contained in the main Media Playlist of the variant (in which case
* playlist is NULL).
*/
struct rendition {
enum AVMediaType type;
struct playlist *playlist;
char group_id[MAX_FIELD_LEN];
char language[MAX_FIELD_LEN];
char name[MAX_FIELD_LEN];
int disposition;
};
struct variant {
int bandwidth;
/* every variant contains at least the main Media Playlist in index 0 */
int n_playlists;
struct playlist **playlists;
char audio_group[MAX_FIELD_LEN];
char video_group[MAX_FIELD_LEN];
char subtitles_group[MAX_FIELD_LEN];
};
typedef struct HLSContext {
int n_variants;
struct variant **variants;
int n_playlists;
struct playlist **playlists;
int n_renditions;
struct rendition **renditions;
int cur_seq_no;
int first_packet;
int64_t first_timestamp;
int64_t cur_timestamp;
AVIOInterruptCB *interrupt_callback;
char *user_agent; ///< holds HTTP user agent set as an AVOption to the HTTP protocol context
char *cookies; ///< holds HTTP cookie values set in either the initial response or as an AVOption to the HTTP protocol context
char *headers; ///< holds HTTP headers set as an AVOption to the HTTP protocol context
} HLSContext;
static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
{
int len = ff_get_line(s, buf, maxlen);
while (len > 0 && av_isspace(buf[len - 1]))
buf[--len] = '\0';
return len;
}
static void free_segment_list(struct playlist *pls)
{
int i;
for (i = 0; i < pls->n_segments; i++) {
av_free(pls->segments[i]->key);
av_free(pls->segments[i]->url);
av_free(pls->segments[i]);
}
av_freep(&pls->segments);
pls->n_segments = 0;
}
static void free_playlist_list(HLSContext *c)
{
int i;
for (i = 0; i < c->n_playlists; i++) {
struct playlist *pls = c->playlists[i];
free_segment_list(pls);
av_freep(&pls->renditions);
av_freep(&pls->id3_buf);
av_dict_free(&pls->id3_initial);
ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);
av_free_packet(&pls->pkt);
av_free(pls->pb.buffer);
if (pls->input)
ffurl_close(pls->input);
if (pls->ctx) {
pls->ctx->pb = NULL;
avformat_close_input(&pls->ctx);
}
av_free(pls);
}
av_freep(&c->playlists);
av_freep(&c->cookies);
av_freep(&c->user_agent);
c->n_playlists = 0;
}
static void free_variant_list(HLSContext *c)
{
int i;
for (i = 0; i < c->n_variants; i++) {
struct variant *var = c->variants[i];
av_freep(&var->playlists);
av_free(var);
}
av_freep(&c->variants);
c->n_variants = 0;
}
static void free_rendition_list(HLSContext *c)
{
int i;
for (i = 0; i < c->n_renditions; i++)
av_free(c->renditions[i]);
av_freep(&c->renditions);
c->n_renditions = 0;
}
/*
* Used to reset a statically allocated AVPacket to a clean slate,
* containing no data.
*/
static void reset_packet(AVPacket *pkt)
{
av_init_packet(pkt);
pkt->data = NULL;
}
static struct playlist *new_playlist(HLSContext *c, const char *url,
const char *base)
{
struct playlist *pls = av_mallocz(sizeof(struct playlist));
if (!pls)
return NULL;
reset_packet(&pls->pkt);
ff_make_absolute_url(pls->url, sizeof(pls->url), base, url);
pls->seek_timestamp = AV_NOPTS_VALUE;
pls->is_id3_timestamped = -1;
pls->id3_mpegts_timestamp = AV_NOPTS_VALUE;
dynarray_add(&c->playlists, &c->n_playlists, pls);
return pls;
}
struct variant_info {
char bandwidth[20];
/* variant group ids: */
char audio[MAX_FIELD_LEN];
char video[MAX_FIELD_LEN];
char subtitles[MAX_FIELD_LEN];
};
static struct variant *new_variant(HLSContext *c, struct variant_info *info,
const char *url, const char *base)
{
struct variant *var;
struct playlist *pls;
pls = new_playlist(c, url, base);
if (!pls)
return NULL;
var = av_mallocz(sizeof(struct variant));
if (!var)
return NULL;
if (info) {
var->bandwidth = atoi(info->bandwidth);
strcpy(var->audio_group, info->audio);
strcpy(var->video_group, info->video);
strcpy(var->subtitles_group, info->subtitles);
}
dynarray_add(&c->variants, &c->n_variants, var);
dynarray_add(&var->playlists, &var->n_playlists, pls);
return var;
}
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);
} else if (!strncmp(key, "AUDIO=", key_len)) {
*dest = info->audio;
*dest_len = sizeof(info->audio);
} else if (!strncmp(key, "VIDEO=", key_len)) {
*dest = info->video;
*dest_len = sizeof(info->video);
} else if (!strncmp(key, "SUBTITLES=", key_len)) {
*dest = info->subtitles;
*dest_len = sizeof(info->subtitles);
}
}
struct key_info {
char uri[MAX_URL_SIZE];
char method[10];
char iv[35];
};
static void handle_key_args(struct key_info *info, const char *key,
int key_len, char **dest, int *dest_len)
{
if (!strncmp(key, "METHOD=", key_len)) {
*dest = info->method;
*dest_len = sizeof(info->method);
} else if (!strncmp(key, "URI=", key_len)) {
*dest = info->uri;
*dest_len = sizeof(info->uri);
} else if (!strncmp(key, "IV=", key_len)) {
*dest = info->iv;
*dest_len = sizeof(info->iv);
}
}
struct rendition_info {
char type[16];
char uri[MAX_URL_SIZE];
char group_id[MAX_FIELD_LEN];
char language[MAX_FIELD_LEN];
char assoc_language[MAX_FIELD_LEN];
char name[MAX_FIELD_LEN];
char defaultr[4];
char forced[4];
char characteristics[MAX_CHARACTERISTICS_LEN];
};
static struct rendition *new_rendition(HLSContext *c, struct rendition_info *info,
const char *url_base)
{
struct rendition *rend;
enum AVMediaType type = AVMEDIA_TYPE_UNKNOWN;
char *characteristic;
char *chr_ptr;
char *saveptr;
if (!strcmp(info->type, "AUDIO"))
type = AVMEDIA_TYPE_AUDIO;
else if (!strcmp(info->type, "VIDEO"))
type = AVMEDIA_TYPE_VIDEO;
else if (!strcmp(info->type, "SUBTITLES"))
type = AVMEDIA_TYPE_SUBTITLE;
else if (!strcmp(info->type, "CLOSED-CAPTIONS"))
/* CLOSED-CAPTIONS is ignored since we do not support CEA-608 CC in
* AVC SEI RBSP anyway */
return NULL;
if (type == AVMEDIA_TYPE_UNKNOWN)
return NULL;
/* URI is mandatory for subtitles as per spec */
if (type == AVMEDIA_TYPE_SUBTITLE && !info->uri[0])
return NULL;
/* TODO: handle subtitles (each segment has to parsed separately) */
if (type == AVMEDIA_TYPE_SUBTITLE)
return NULL;
rend = av_mallocz(sizeof(struct rendition));
if (!rend)
return NULL;
dynarray_add(&c->renditions, &c->n_renditions, rend);
rend->type = type;
strcpy(rend->group_id, info->group_id);
strcpy(rend->language, info->language);
strcpy(rend->name, info->name);
/* add the playlist if this is an external rendition */
if (info->uri[0]) {
rend->playlist = new_playlist(c, info->uri, url_base);
if (rend->playlist)
dynarray_add(&rend->playlist->renditions,
&rend->playlist->n_renditions, rend);
}
if (info->assoc_language[0]) {
int langlen = strlen(rend->language);
if (langlen < sizeof(rend->language) - 3) {
rend->language[langlen] = ',';
strncpy(rend->language + langlen + 1, info->assoc_language,
sizeof(rend->language) - langlen - 2);
}
}
if (!strcmp(info->defaultr, "YES"))
rend->disposition |= AV_DISPOSITION_DEFAULT;
if (!strcmp(info->forced, "YES"))
rend->disposition |= AV_DISPOSITION_FORCED;
chr_ptr = info->characteristics;
while ((characteristic = av_strtok(chr_ptr, ",", &saveptr))) {
if (!strcmp(characteristic, "public.accessibility.describes-music-and-sound"))
rend->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
else if (!strcmp(characteristic, "public.accessibility.describes-video"))
rend->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
chr_ptr = NULL;
}
return rend;
}
static void handle_rendition_args(struct rendition_info *info, const char *key,
int key_len, char **dest, int *dest_len)
{
if (!strncmp(key, "TYPE=", key_len)) {
*dest = info->type;
*dest_len = sizeof(info->type);
} else if (!strncmp(key, "URI=", key_len)) {
*dest = info->uri;
*dest_len = sizeof(info->uri);
} else if (!strncmp(key, "GROUP-ID=", key_len)) {
*dest = info->group_id;
*dest_len = sizeof(info->group_id);
} else if (!strncmp(key, "LANGUAGE=", key_len)) {
*dest = info->language;
*dest_len = sizeof(info->language);
} else if (!strncmp(key, "ASSOC-LANGUAGE=", key_len)) {
*dest = info->assoc_language;
*dest_len = sizeof(info->assoc_language);
} else if (!strncmp(key, "NAME=", key_len)) {
*dest = info->name;
*dest_len = sizeof(info->name);
} else if (!strncmp(key, "DEFAULT=", key_len)) {
*dest = info->defaultr;
*dest_len = sizeof(info->defaultr);
} else if (!strncmp(key, "FORCED=", key_len)) {
*dest = info->forced;
*dest_len = sizeof(info->forced);
} else if (!strncmp(key, "CHARACTERISTICS=", key_len)) {
*dest = info->characteristics;
*dest_len = sizeof(info->characteristics);
}
/*
* ignored:
* - AUTOSELECT: client may autoselect based on e.g. system language
* - INSTREAM-ID: EIA-608 closed caption number ("CC1".."CC4")
*/
}
/* used by parse_playlist to allocate a new variant+playlist when the
* playlist is detected to be a Media Playlist (not Master Playlist)
* and we have no parent Master Playlist (parsing of which would have
* allocated the variant and playlist already) */
static int ensure_playlist(HLSContext *c, struct playlist **pls, const char *url)
{
if (*pls)
return 0;
if (!new_variant(c, NULL, url, NULL))
return AVERROR(ENOMEM);
*pls = c->playlists[c->n_playlists - 1];
return 0;
}
/* pls = NULL => Master Playlist or parentless Media Playlist
* pls = !NULL => parented Media Playlist, playlist+variant allocated */
static int parse_playlist(HLSContext *c, const char *url,
struct playlist *pls, AVIOContext *in)
{
int ret = 0, is_segment = 0, is_variant = 0;
int64_t duration = 0;
enum KeyType key_type = KEY_NONE;
uint8_t iv[16] = "";
int has_iv = 0;
char key[MAX_URL_SIZE] = "";
char line[MAX_URL_SIZE];
const char *ptr;
int close_in = 0;
int64_t seg_offset = 0;
int64_t seg_size = -1;
uint8_t *new_url = NULL;
struct variant_info variant_info;
char tmp_str[MAX_URL_SIZE];
if (!in) {
AVDictionary *opts = NULL;
close_in = 1;
/* Some HLS servers don't like being sent the range header */
av_dict_set(&opts, "seekable", "0", 0);
// broker prior HTTP options that should be consistent across requests
av_dict_set(&opts, "user-agent", c->user_agent, 0);
av_dict_set(&opts, "cookies", c->cookies, 0);
av_dict_set(&opts, "headers", c->headers, 0);
ret = avio_open2(&in, url, AVIO_FLAG_READ,
c->interrupt_callback, &opts);
av_dict_free(&opts);
if (ret < 0)
return ret;
}
if (av_opt_get(in, "location", AV_OPT_SEARCH_CHILDREN, &new_url) >= 0)
url = new_url;
read_chomp_line(in, line, sizeof(line));
if (strcmp(line, "#EXTM3U")) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
if (pls) {
free_segment_list(pls);
pls->finished = 0;
pls->type = PLS_TYPE_UNSPECIFIED;
}
while (!url_feof(in)) {
read_chomp_line(in, line, sizeof(line));
if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
is_variant = 1;
memset(&variant_info, 0, sizeof(variant_info));
ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
&variant_info);
} else if (av_strstart(line, "#EXT-X-KEY:", &ptr)) {
struct key_info info = {{0}};
ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_key_args,
&info);
key_type = KEY_NONE;
has_iv = 0;
if (!strcmp(info.method, "AES-128"))
key_type = KEY_AES_128;
if (!strncmp(info.iv, "0x", 2) || !strncmp(info.iv, "0X", 2)) {
ff_hex_to_data(iv, info.iv + 2);
has_iv = 1;
}
av_strlcpy(key, info.uri, sizeof(key));
} else if (av_strstart(line, "#EXT-X-MEDIA:", &ptr)) {
struct rendition_info info = {{0}};
ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_rendition_args,
&info);
new_rendition(c, &info, url);
} else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
ret = ensure_playlist(c, &pls, url);
if (ret < 0)
goto fail;
pls->target_duration = atoi(ptr) * AV_TIME_BASE;
} else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
ret = ensure_playlist(c, &pls, url);
if (ret < 0)
goto fail;
pls->start_seq_no = atoi(ptr);
} else if (av_strstart(line, "#EXT-X-PLAYLIST-TYPE:", &ptr)) {
ret = ensure_playlist(c, &pls, url);
if (ret < 0)
goto fail;
if (!strcmp(ptr, "EVENT"))
pls->type = PLS_TYPE_EVENT;
else if (!strcmp(ptr, "VOD"))
pls->type = PLS_TYPE_VOD;
} else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
if (pls)
pls->finished = 1;
} else if (av_strstart(line, "#EXTINF:", &ptr)) {
is_segment = 1;
duration = atof(ptr) * AV_TIME_BASE;
} else if (av_strstart(line, "#EXT-X-BYTERANGE:", &ptr)) {
seg_size = atoi(ptr);
ptr = strchr(ptr, '@');
if (ptr)
seg_offset = atoi(ptr+1);
} else if (av_strstart(line, "#", NULL)) {
continue;
} else if (line[0]) {
if (is_variant) {
if (!new_variant(c, &variant_info, line, url)) {
ret = AVERROR(ENOMEM);
goto fail;
}
is_variant = 0;
}
if (is_segment) {
struct segment *seg;
if (!pls) {
if (!new_variant(c, 0, url, NULL)) {
ret = AVERROR(ENOMEM);
goto fail;
}
pls = c->playlists[c->n_playlists - 1];
}
seg = av_malloc(sizeof(struct segment));
if (!seg) {
ret = AVERROR(ENOMEM);
goto fail;
}
seg->duration = duration;
seg->key_type = key_type;
if (has_iv) {
memcpy(seg->iv, iv, sizeof(iv));
} else {
int seq = pls->start_seq_no + pls->n_segments;
memset(seg->iv, 0, sizeof(seg->iv));
AV_WB32(seg->iv + 12, seq);
}
if (key_type != KEY_NONE) {
ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, key);
seg->key = av_strdup(tmp_str);
if (!seg->key) {
av_free(seg);
ret = AVERROR(ENOMEM);
goto fail;
}
} else {
seg->key = NULL;
}
ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, line);
seg->url = av_strdup(tmp_str);
if (!seg->url) {
av_free(seg->key);
av_free(seg);
ret = AVERROR(ENOMEM);
goto fail;
}
dynarray_add(&pls->segments, &pls->n_segments, seg);
is_segment = 0;
seg->size = seg_size;
if (seg_size >= 0) {
seg->url_offset = seg_offset;
seg_offset += seg_size;
seg_size = -1;
} else {
seg->url_offset = 0;
seg_offset = 0;
}
}
}
}
if (pls)
pls->last_load_time = av_gettime();
fail:
av_free(new_url);
if (close_in)
avio_close(in);
return ret;
}
enum ReadFromURLMode {
READ_NORMAL,
READ_COMPLETE,
};
/* read from URLContext, limiting read to current segment */
static int read_from_url(struct playlist *pls, uint8_t *buf, int buf_size,
enum ReadFromURLMode mode)
{
int ret;
struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
/* limit read if the segment was only a part of a file */
if (seg->size >= 0)
buf_size = FFMIN(buf_size, seg->size - pls->cur_seg_offset);
if (mode == READ_COMPLETE)
ret = ffurl_read_complete(pls->input, buf, buf_size);
else
ret = ffurl_read(pls->input, buf, buf_size);
if (ret > 0)
pls->cur_seg_offset += ret;
return ret;
}
/* Parse the raw ID3 data and pass contents to caller */
static void parse_id3(AVFormatContext *s, AVIOContext *pb,
AVDictionary **metadata, int64_t *dts,
ID3v2ExtraMetaAPIC **apic, ID3v2ExtraMeta **extra_meta)
{
static const char id3_priv_owner_ts[] = "com.apple.streaming.transportStreamTimestamp";
ID3v2ExtraMeta *meta;
ff_id3v2_read_dict(pb, metadata, ID3v2_DEFAULT_MAGIC, extra_meta);
for (meta = *extra_meta; meta; meta = meta->next) {
if (!strcmp(meta->tag, "PRIV")) {
ID3v2ExtraMetaPRIV *priv = meta->data;
if (priv->datasize == 8 && !strcmp(priv->owner, id3_priv_owner_ts)) {
/* 33-bit MPEG timestamp */
int64_t ts = AV_RB64(priv->data);
av_log(s, AV_LOG_DEBUG, "HLS ID3 audio timestamp %"PRId64"\n", ts);
if ((ts & ~((1ULL << 33) - 1)) == 0)
*dts = ts;
else
av_log(s, AV_LOG_ERROR, "Invalid HLS ID3 audio timestamp %"PRId64"\n", ts);
}
} else if (!strcmp(meta->tag, "APIC") && apic)
*apic = meta->data;
}
}
/* Check if the ID3 metadata contents have changed */
static int id3_has_changed_values(struct playlist *pls, AVDictionary *metadata,
ID3v2ExtraMetaAPIC *apic)
{
AVDictionaryEntry *entry = NULL;
AVDictionaryEntry *oldentry;
/* check that no keys have changed values */
while ((entry = av_dict_get(metadata, "", entry, AV_DICT_IGNORE_SUFFIX))) {
oldentry = av_dict_get(pls->id3_initial, entry->key, NULL, AV_DICT_MATCH_CASE);
if (!oldentry || strcmp(oldentry->value, entry->value) != 0)
return 1;
}
/* check if apic appeared */
if (apic && (pls->ctx->nb_streams != 2 || !pls->ctx->streams[1]->attached_pic.data))
return 1;
if (apic) {
int size = pls->ctx->streams[1]->attached_pic.size;
if (size != apic->buf->size - FF_INPUT_BUFFER_PADDING_SIZE)
return 1;
if (memcmp(apic->buf->data, pls->ctx->streams[1]->attached_pic.data, size) != 0)
return 1;
}
return 0;
}
/* Parse ID3 data and handle the found data */
static void handle_id3(AVIOContext *pb, struct playlist *pls)
{
AVDictionary *metadata = NULL;
ID3v2ExtraMetaAPIC *apic = NULL;
ID3v2ExtraMeta *extra_meta = NULL;
int64_t timestamp = AV_NOPTS_VALUE;
parse_id3(pls->ctx, pb, &metadata, &timestamp, &apic, &extra_meta);
if (timestamp != AV_NOPTS_VALUE) {
pls->id3_mpegts_timestamp = timestamp;
pls->id3_offset = 0;
}
if (!pls->id3_found) {
/* initial ID3 tags */
av_assert0(!pls->id3_deferred_extra);
pls->id3_found = 1;
/* get picture attachment and set text metadata */
if (pls->ctx->nb_streams)
ff_id3v2_parse_apic(pls->ctx, &extra_meta);
else
/* demuxer not yet opened, defer picture attachment */
pls->id3_deferred_extra = extra_meta;
av_dict_copy(&pls->ctx->metadata, metadata, 0);
pls->id3_initial = metadata;
} else {
if (!pls->id3_changed && id3_has_changed_values(pls, metadata, apic)) {
avpriv_report_missing_feature(pls->ctx, "Changing ID3 metadata in HLS audio elementary stream");
pls->id3_changed = 1;
}
av_dict_free(&metadata);
}
if (!pls->id3_deferred_extra)
ff_id3v2_free_extra_meta(&extra_meta);
}
/* Intercept and handle ID3 tags between URLContext and AVIOContext */
static void intercept_id3(struct playlist *pls, uint8_t *buf,
int buf_size, int *len)
{
/* intercept id3 tags, we do not want to pass them to the raw
* demuxer on all segment switches */
int bytes;
int id3_buf_pos = 0;
int fill_buf = 0;
/* gather all the id3 tags */
while (1) {
/* see if we can retrieve enough data for ID3 header */
if (*len < ID3v2_HEADER_SIZE && buf_size >= ID3v2_HEADER_SIZE) {
bytes = read_from_url(pls, buf + *len, ID3v2_HEADER_SIZE - *len, READ_COMPLETE);
if (bytes > 0) {
if (bytes == ID3v2_HEADER_SIZE - *len)
/* no EOF yet, so fill the caller buffer again after
* we have stripped the ID3 tags */
fill_buf = 1;
*len += bytes;
} else if (*len <= 0) {
/* error/EOF */
*len = bytes;
fill_buf = 0;
}
}
if (*len < ID3v2_HEADER_SIZE)
break;
if (ff_id3v2_match(buf, ID3v2_DEFAULT_MAGIC)) {
struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
int64_t maxsize = seg->size >= 0 ? seg->size : 1024*1024;
int taglen = ff_id3v2_tag_len(buf);
int tag_got_bytes = FFMIN(taglen, *len);
int remaining = taglen - tag_got_bytes;
if (taglen > maxsize) {
av_log(pls->ctx, AV_LOG_ERROR, "Too large HLS ID3 tag (%d > %"PRId64" bytes)\n",
taglen, maxsize);
break;
}
/*
* Copy the id3 tag to our temporary id3 buffer.
* We could read a small id3 tag directly without memcpy, but
* we would still need to copy the large tags, and handling
* both of those cases together with the possibility for multiple
* tags would make the handling a bit complex.
*/
pls->id3_buf = av_fast_realloc(pls->id3_buf, &pls->id3_buf_size, id3_buf_pos + taglen);
if (!pls->id3_buf)
break;
memcpy(pls->id3_buf + id3_buf_pos, buf, tag_got_bytes);
id3_buf_pos += tag_got_bytes;
/* strip the intercepted bytes */
*len -= tag_got_bytes;
memmove(buf, buf + tag_got_bytes, *len);
av_log(pls->ctx, AV_LOG_DEBUG, "Stripped %d HLS ID3 bytes\n", tag_got_bytes);
if (remaining > 0) {
/* read the rest of the tag in */
if (read_from_url(pls, pls->id3_buf + id3_buf_pos, remaining, READ_COMPLETE) != remaining)
break;
id3_buf_pos += remaining;
av_log(pls->ctx, AV_LOG_DEBUG, "Stripped additional %d HLS ID3 bytes\n", remaining);
}
} else {
/* no more ID3 tags */
break;
}
}
/* re-fill buffer for the caller unless EOF */
if (*len >= 0 && (fill_buf || *len == 0)) {
bytes = read_from_url(pls, buf + *len, buf_size - *len, READ_NORMAL);
/* ignore error if we already had some data */
if (bytes >= 0)
*len += bytes;
else if (*len == 0)
*len = bytes;
}
if (pls->id3_buf) {
/* Now parse all the ID3 tags */
AVIOContext id3ioctx;
ffio_init_context(&id3ioctx, pls->id3_buf, id3_buf_pos, 0, NULL, NULL, NULL, NULL);
handle_id3(&id3ioctx, pls);
}
if (pls->is_id3_timestamped == -1)
pls->is_id3_timestamped = (pls->id3_mpegts_timestamp != AV_NOPTS_VALUE);
}
static int open_input(HLSContext *c, struct playlist *pls)
{
AVDictionary *opts = NULL;
AVDictionary *opts2 = NULL;
int ret;
struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
// broker prior HTTP options that should be consistent across requests
av_dict_set(&opts, "user-agent", c->user_agent, 0);
av_dict_set(&opts, "cookies", c->cookies, 0);
av_dict_set(&opts, "headers", c->headers, 0);
av_dict_set(&opts, "seekable", "0", 0);
// Same opts for key request (ffurl_open mutilates the opts so it cannot be used twice)
av_dict_copy(&opts2, opts, 0);
if (seg->size >= 0) {
/* try to restrict the HTTP request to the part we want
* (if this is in fact a HTTP request) */
char offset[24] = { 0 };
char end_offset[24] = { 0 };
snprintf(offset, sizeof(offset) - 1, "%"PRId64,
seg->url_offset);
snprintf(end_offset, sizeof(end_offset) - 1, "%"PRId64,
seg->url_offset + seg->size);
av_dict_set(&opts, "offset", offset, 0);
av_dict_set(&opts, "end_offset", end_offset, 0);
}
av_log(pls->parent, AV_LOG_VERBOSE, "HLS request for url '%s', offset %"PRId64", playlist %d\n",
seg->url, seg->url_offset, pls->index);
if (seg->key_type == KEY_NONE) {
ret = ffurl_open(&pls->input, seg->url, AVIO_FLAG_READ,
&pls->parent->interrupt_callback, &opts);
} else if (seg->key_type == KEY_AES_128) {
char iv[33], key[33], url[MAX_URL_SIZE];
if (strcmp(seg->key, pls->key_url)) {
URLContext *uc;
if (ffurl_open(&uc, seg->key, AVIO_FLAG_READ,
&pls->parent->interrupt_callback, &opts2) == 0) {
if (ffurl_read_complete(uc, pls->key, sizeof(pls->key))
!= sizeof(pls->key)) {
av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",
seg->key);
}
ffurl_close(uc);
} else {
av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",
seg->key);
}
av_strlcpy(pls->key_url, seg->key, sizeof(pls->key_url));
}
ff_data_to_hex(iv, seg->iv, sizeof(seg->iv), 0);
ff_data_to_hex(key, pls->key, sizeof(pls->key), 0);
iv[32] = key[32] = '\0';
if (strstr(seg->url, "://"))
snprintf(url, sizeof(url), "crypto+%s", seg->url);
else
snprintf(url, sizeof(url), "crypto:%s", seg->url);
if ((ret = ffurl_alloc(&pls->input, url, AVIO_FLAG_READ,
&pls->parent->interrupt_callback)) < 0)
goto cleanup;
av_opt_set(pls->input->priv_data, "key", key, 0);
av_opt_set(pls->input->priv_data, "iv", iv, 0);
if ((ret = ffurl_connect(pls->input, &opts)) < 0) {
ffurl_close(pls->input);
pls->input = NULL;
goto cleanup;
}
ret = 0;
}
else
ret = AVERROR(ENOSYS);
/* Seek to the requested position. If this was a HTTP request, the offset
* should already be where want it to, but this allows e.g. local testing
* without a HTTP server. */
if (ret == 0 && seg->key_type == KEY_NONE) {
int seekret = ffurl_seek(pls->input, seg->url_offset, SEEK_SET);
if (seekret < 0) {
av_log(pls->parent, AV_LOG_ERROR, "Unable to seek to offset %"PRId64" of HLS segment '%s'\n", seg->url_offset, seg->url);
ret = seekret;
ffurl_close(pls->input);
pls->input = NULL;
}
}
cleanup:
av_dict_free(&opts);
av_dict_free(&opts2);
pls->cur_seg_offset = 0;
return ret;
}
static int64_t default_reload_interval(struct playlist *pls)
{
return pls->n_segments > 0 ?
pls->segments[pls->n_segments - 1]->duration :
pls->target_duration;
}
static int read_data(void *opaque, uint8_t *buf, int buf_size)
{
struct playlist *v = opaque;
HLSContext *c = v->parent->priv_data;
int ret, i;
int just_opened = 0;
restart:
if (!v->needed)
return AVERROR_EOF;
if (!v->input) {
int64_t reload_interval;
/* Check that the playlist is still needed before opening a new
* segment. */
if (v->ctx && v->ctx->nb_streams &&
v->parent->nb_streams >= v->stream_offset + v->ctx->nb_streams) {
v->needed = 0;
for (i = v->stream_offset; i < v->stream_offset + v->ctx->nb_streams;
i++) {
if (v->parent->streams[i]->discard < AVDISCARD_ALL)
v->needed = 1;
}
}
if (!v->needed) {
av_log(v->parent, AV_LOG_INFO, "No longer receiving playlist %d\n",
v->index);
return AVERROR_EOF;
}
/* If this is a live stream and the reload interval has elapsed since
* the last playlist reload, reload the playlists now. */
reload_interval = default_reload_interval(v);
reload:
if (!v->finished &&
av_gettime() - v->last_load_time >= reload_interval) {
if ((ret = parse_playlist(c, v->url, v, NULL)) < 0) {
av_log(v->parent, AV_LOG_WARNING, "Failed to reload playlist %d\n",
v->index);
return ret;
}
/* If we need to reload the playlist again below (if
* there's still no more segments), switch to a reload
* interval of half the target duration. */
reload_interval = v->target_duration / 2;
}
if (v->cur_seq_no < v->start_seq_no) {
av_log(NULL, AV_LOG_WARNING,
"skipping %d segments ahead, expired from playlists\n",
v->start_seq_no - v->cur_seq_no);
v->cur_seq_no = v->start_seq_no;
}
if (v->cur_seq_no >= v->start_seq_no + v->n_segments) {
if (v->finished)
return AVERROR_EOF;
while (av_gettime() - v->last_load_time < reload_interval) {
if (ff_check_interrupt(c->interrupt_callback))
return AVERROR_EXIT;
av_usleep(100*1000);
}
/* Enough time has elapsed since the last reload */
goto reload;
}
ret = open_input(c, v);
if (ret < 0) {
av_log(v->parent, AV_LOG_WARNING, "Failed to open segment of playlist %d\n",
v->index);
return ret;
}
just_opened = 1;
}
ret = read_from_url(v, buf, buf_size, READ_NORMAL);
if (ret > 0) {
if (just_opened && v->is_id3_timestamped != 0) {
/* Intercept ID3 tags here, elementary audio streams are required
* to convey timestamps using them in the beginning of each segment. */
intercept_id3(v, buf, buf_size, &ret);
}
return ret;
}
ffurl_close(v->input);
v->input = NULL;
v->cur_seq_no++;
c->cur_seq_no = v->cur_seq_no;
goto restart;
}
static int playlist_in_multiple_variants(HLSContext *c, struct playlist *pls)
{
int variant_count = 0;
int i, j;
for (i = 0; i < c->n_variants && variant_count < 2; i++) {
struct variant *v = c->variants[i];
for (j = 0; j < v->n_playlists; j++) {
if (v->playlists[j] == pls) {
variant_count++;
break;
}
}
}
return variant_count >= 2;
}
static void add_renditions_to_variant(HLSContext *c, struct variant *var,
enum AVMediaType type, const char *group_id)
{
int i;
for (i = 0; i < c->n_renditions; i++) {
struct rendition *rend = c->renditions[i];
if (rend->type == type && !strcmp(rend->group_id, group_id)) {
if (rend->playlist)
/* rendition is an external playlist
* => add the playlist to the variant */
dynarray_add(&var->playlists, &var->n_playlists, rend->playlist);
else
/* rendition is part of the variant main Media Playlist
* => add the rendition to the main Media Playlist */
dynarray_add(&var->playlists[0]->renditions,
&var->playlists[0]->n_renditions,
rend);
}
}
}
static void add_metadata_from_renditions(AVFormatContext *s, struct playlist *pls,
enum AVMediaType type)
{
int rend_idx = 0;
int i;
for (i = 0; i < pls->ctx->nb_streams; i++) {
AVStream *st = s->streams[pls->stream_offset + i];
if (st->codec->codec_type != type)
continue;
for (; rend_idx < pls->n_renditions; rend_idx++) {
struct rendition *rend = pls->renditions[rend_idx];
if (rend->type != type)
continue;
if (rend->language[0])
av_dict_set(&st->metadata, "language", rend->language, 0);
if (rend->name[0])
av_dict_set(&st->metadata, "comment", rend->name, 0);
st->disposition |= rend->disposition;
}
if (rend_idx >=pls->n_renditions)
break;
}
}
/* if timestamp was in valid range: returns 1 and sets seq_no
* if not: returns 0 and sets seq_no to closest segment */
static int find_timestamp_in_playlist(HLSContext *c, struct playlist *pls,
int64_t timestamp, int *seq_no)
{
int i;
int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ?
0 : c->first_timestamp;
if (timestamp < pos) {
*seq_no = pls->start_seq_no;
return 0;
}
for (i = 0; i < pls->n_segments; i++) {
int64_t diff = pos + pls->segments[i]->duration - timestamp;
if (diff > 0) {
*seq_no = pls->start_seq_no + i;
return 1;
}
pos += pls->segments[i]->duration;
}
*seq_no = pls->start_seq_no + pls->n_segments - 1;
return 0;
}
static int select_cur_seq_no(HLSContext *c, struct playlist *pls)
{
int seq_no;
if (!pls->finished && !c->first_packet &&
av_gettime() - pls->last_load_time >= default_reload_interval(pls))
/* reload the playlist since it was suspended */
parse_playlist(c, pls->url, pls, NULL);
/* If playback is already in progress (we are just selecting a new
* playlist) and this is a complete file, find the matching segment
* by counting durations. */
if (pls->finished && c->cur_timestamp != AV_NOPTS_VALUE) {
find_timestamp_in_playlist(c, pls, c->cur_timestamp, &seq_no);
return seq_no;
}
if (!pls->finished) {
if (!c->first_packet && /* we are doing a segment selection during playback */
c->cur_seq_no >= pls->start_seq_no &&
c->cur_seq_no < pls->start_seq_no + pls->n_segments)
/* While spec 3.4.3 says that we cannot assume anything about the
* content at the same sequence number on different playlists,
* in practice this seems to work and doing it otherwise would
* require us to download a segment to inspect its timestamps. */
return c->cur_seq_no;
/* If this is a live stream with more than 3 segments, start at the
* third last segment. */
if (pls->n_segments > 3)
return pls->start_seq_no + pls->n_segments - 3;
}
/* Otherwise just start on the first segment. */
return pls->start_seq_no;
}
static int hls_read_header(AVFormatContext *s)
{
URLContext *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb->opaque;
HLSContext *c = s->priv_data;
int ret = 0, i, j, stream_offset = 0;
c->interrupt_callback = &s->interrupt_callback;
c->first_packet = 1;
c->first_timestamp = AV_NOPTS_VALUE;
c->cur_timestamp = AV_NOPTS_VALUE;
// if the URL context is good, read important options we must broker later
if (u && u->prot->priv_data_class) {
// get the previous user agent & set back to null if string size is zero
av_freep(&c->user_agent);
av_opt_get(u->priv_data, "user-agent", 0, (uint8_t**)&(c->user_agent));
if (c->user_agent && !strlen(c->user_agent))
av_freep(&c->user_agent);
// get the previous cookies & set back to null if string size is zero
av_freep(&c->cookies);
av_opt_get(u->priv_data, "cookies", 0, (uint8_t**)&(c->cookies));
if (c->cookies && !strlen(c->cookies))
av_freep(&c->cookies);
// get the previous headers & set back to null if string size is zero
av_freep(&c->headers);
av_opt_get(u->priv_data, "headers", 0, (uint8_t**)&(c->headers));
if (c->headers && !strlen(c->headers))
av_freep(&c->headers);
}
if ((ret = parse_playlist(c, s->filename, NULL, s->pb)) < 0)
goto fail;
if (c->n_variants == 0) {
av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
ret = AVERROR_EOF;
goto fail;
}
/* If the playlist only contained playlists (Master Playlist),
* parse each individual playlist. */
if (c->n_playlists > 1 || c->playlists[0]->n_segments == 0) {
for (i = 0; i < c->n_playlists; i++) {
struct playlist *pls = c->playlists[i];
if ((ret = parse_playlist(c, pls->url, pls, NULL)) < 0)
goto fail;
}
}
if (c->variants[0]->playlists[0]->n_segments == 0) {
av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
ret = AVERROR_EOF;
goto fail;
}
/* If this isn't a live stream, calculate the total duration of the
* stream. */
if (c->variants[0]->playlists[0]->finished) {
int64_t duration = 0;
for (i = 0; i < c->variants[0]->playlists[0]->n_segments; i++)
duration += c->variants[0]->playlists[0]->segments[i]->duration;
s->duration = duration;
}
/* Associate renditions with variants */
for (i = 0; i < c->n_variants; i++) {
struct variant *var = c->variants[i];
if (var->audio_group[0])
add_renditions_to_variant(c, var, AVMEDIA_TYPE_AUDIO, var->audio_group);
if (var->video_group[0])
add_renditions_to_variant(c, var, AVMEDIA_TYPE_VIDEO, var->video_group);
if (var->subtitles_group[0])
add_renditions_to_variant(c, var, AVMEDIA_TYPE_SUBTITLE, var->subtitles_group);
}
/* Open the demuxer for each playlist */
for (i = 0; i < c->n_playlists; i++) {
struct playlist *pls = c->playlists[i];
AVInputFormat *in_fmt = NULL;
if (pls->n_segments == 0)
continue;
if (!(pls->ctx = avformat_alloc_context())) {
ret = AVERROR(ENOMEM);
goto fail;
}
pls->index = i;
pls->needed = 1;
pls->parent = s;
pls->cur_seq_no = select_cur_seq_no(c, pls);
pls->read_buffer = av_malloc(INITIAL_BUFFER_SIZE);
ffio_init_context(&pls->pb, pls->read_buffer, INITIAL_BUFFER_SIZE, 0, pls,
read_data, NULL, NULL);
pls->pb.seekable = 0;
ret = av_probe_input_buffer(&pls->pb, &in_fmt, pls->segments[0]->url,
NULL, 0, 0);
if (ret < 0) {
/* Free the ctx - it isn't initialized properly at this point,
* so avformat_close_input shouldn't be called. If
* avformat_open_input fails below, it frees and zeros the
* context, so it doesn't need any special treatment like this. */
av_log(s, AV_LOG_ERROR, "Error when loading first segment '%s'\n", pls->segments[0]->url);
avformat_free_context(pls->ctx);
pls->ctx = NULL;
goto fail;
}
pls->ctx->pb = &pls->pb;
pls->stream_offset = stream_offset;
ret = avformat_open_input(&pls->ctx, pls->segments[0]->url, in_fmt, NULL);
if (ret < 0)
goto fail;
if (pls->id3_deferred_extra && pls->ctx->nb_streams == 1) {
ff_id3v2_parse_apic(pls->ctx, &pls->id3_deferred_extra);
avformat_queue_attached_pictures(pls->ctx);
ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);
pls->id3_deferred_extra = NULL;
}
pls->ctx->ctx_flags &= ~AVFMTCTX_NOHEADER;
ret = avformat_find_stream_info(pls->ctx, NULL);
if (ret < 0)
goto fail;
if (pls->is_id3_timestamped == -1)
av_log(s, AV_LOG_WARNING, "No expected HTTP requests have been made\n");
/* Create new AVStreams for each stream in this playlist */
for (j = 0; j < pls->ctx->nb_streams; j++) {
AVStream *st = avformat_new_stream(s, NULL);
AVStream *ist = pls->ctx->streams[j];
if (!st) {
ret = AVERROR(ENOMEM);
goto fail;
}
st->id = i;
avcodec_copy_context(st->codec, pls->ctx->streams[j]->codec);
if (pls->is_id3_timestamped) /* custom timestamps via id3 */
avpriv_set_pts_info(st, 33, 1, MPEG_TIME_BASE);
else
avpriv_set_pts_info(st, ist->pts_wrap_bits, ist->time_base.num, ist->time_base.den);
}
add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_AUDIO);
add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_VIDEO);
add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_SUBTITLE);
stream_offset += pls->ctx->nb_streams;
}
/* Create a program for each variant */
for (i = 0; i < c->n_variants; i++) {
struct variant *v = c->variants[i];
char bitrate_str[20];
AVProgram *program;
snprintf(bitrate_str, sizeof(bitrate_str), "%d", v->bandwidth);
program = av_new_program(s, i);
if (!program)
goto fail;
av_dict_set(&program->metadata, "variant_bitrate", bitrate_str, 0);
for (j = 0; j < v->n_playlists; j++) {
struct playlist *pls = v->playlists[j];
int is_shared = playlist_in_multiple_variants(c, pls);
int k;
for (k = 0; k < pls->ctx->nb_streams; k++) {
struct AVStream *st = s->streams[pls->stream_offset + k];
ff_program_add_stream_index(s, i, pls->stream_offset + k);
/* Set variant_bitrate for streams unique to this variant */
if (!is_shared && v->bandwidth)
av_dict_set(&st->metadata, "variant_bitrate", bitrate_str, 0);
}
}
}
return 0;
fail:
free_playlist_list(c);
free_variant_list(c);
free_rendition_list(c);
return ret;
}
static int recheck_discard_flags(AVFormatContext *s, int first)
{
HLSContext *c = s->priv_data;
int i, changed = 0;
/* Check if any new streams are needed */
for (i = 0; i < c->n_playlists; i++)
c->playlists[i]->cur_needed = 0;
for (i = 0; i < s->nb_streams; i++) {
AVStream *st = s->streams[i];
struct playlist *pls = c->playlists[s->streams[i]->id];
if (st->discard < AVDISCARD_ALL)
pls->cur_needed = 1;
}
for (i = 0; i < c->n_playlists; i++) {
struct playlist *pls = c->playlists[i];
if (pls->cur_needed && !pls->needed) {
pls->needed = 1;
changed = 1;
pls->cur_seq_no = select_cur_seq_no(c, pls);
pls->pb.eof_reached = 0;
if (c->cur_timestamp != AV_NOPTS_VALUE) {
/* catch up */
pls->seek_timestamp = c->cur_timestamp;
pls->seek_flags = AVSEEK_FLAG_ANY;
pls->seek_stream_index = -1;
}
av_log(s, AV_LOG_INFO, "Now receiving playlist %d, segment %d\n", i, pls->cur_seq_no);
} else if (first && !pls->cur_needed && pls->needed) {
if (pls->input)
ffurl_close(pls->input);
pls->input = NULL;
pls->needed = 0;
changed = 1;
av_log(s, AV_LOG_INFO, "No longer receiving playlist %d\n", i);
}
}
return changed;
}
static void fill_timing_for_id3_timestamped_stream(struct playlist *pls)
{
if (pls->id3_offset >= 0) {
pls->pkt.dts = pls->id3_mpegts_timestamp +
av_rescale_q(pls->id3_offset,
pls->ctx->streams[pls->pkt.stream_index]->time_base,
MPEG_TIME_BASE_Q);
if (pls->pkt.duration)
pls->id3_offset += pls->pkt.duration;
else
pls->id3_offset = -1;
} else {
/* there have been packets with unknown duration
* since the last id3 tag, should not normally happen */
pls->pkt.dts = AV_NOPTS_VALUE;
}
if (pls->pkt.duration)
pls->pkt.duration = av_rescale_q(pls->pkt.duration,
pls->ctx->streams[pls->pkt.stream_index]->time_base,
MPEG_TIME_BASE_Q);
pls->pkt.pts = AV_NOPTS_VALUE;
}
static AVRational get_timebase(struct playlist *pls)
{
if (pls->is_id3_timestamped)
return MPEG_TIME_BASE_Q;
return pls->ctx->streams[pls->pkt.stream_index]->time_base;
}
static int compare_ts_with_wrapdetect(int64_t ts_a, struct playlist *pls_a,
int64_t ts_b, struct playlist *pls_b)
{
int64_t scaled_ts_a = av_rescale_q(ts_a, get_timebase(pls_a), MPEG_TIME_BASE_Q);
int64_t scaled_ts_b = av_rescale_q(ts_b, get_timebase(pls_b), MPEG_TIME_BASE_Q);
return av_compare_mod(scaled_ts_a, scaled_ts_b, 1LL << 33);
}
static int hls_read_packet(AVFormatContext *s, AVPacket *pkt)
{
HLSContext *c = s->priv_data;
int ret, i, minplaylist = -1;
recheck_discard_flags(s, c->first_packet);
for (i = 0; i < c->n_playlists; i++) {
struct playlist *pls = c->playlists[i];
/* Make sure we've got one buffered packet from each open playlist
* stream */
if (pls->needed && !pls->pkt.data) {
while (1) {
int64_t ts_diff;
AVRational tb;
ret = av_read_frame(pls->ctx, &pls->pkt);
if (ret < 0) {
if (!url_feof(&pls->pb) && ret != AVERROR_EOF)
return ret;
reset_packet(&pls->pkt);
break;
} else {
/* stream_index check prevents matching picture attachments etc. */
if (pls->is_id3_timestamped && pls->pkt.stream_index == 0) {
/* audio elementary streams are id3 timestamped */
fill_timing_for_id3_timestamped_stream(pls);
}
if (c->first_timestamp == AV_NOPTS_VALUE &&
pls->pkt.dts != AV_NOPTS_VALUE)
c->first_timestamp = av_rescale_q(pls->pkt.dts,
get_timebase(pls), AV_TIME_BASE_Q);
}
if (pls->seek_timestamp == AV_NOPTS_VALUE)
break;
if (pls->seek_stream_index < 0 ||
pls->seek_stream_index == pls->pkt.stream_index) {
if (pls->pkt.dts == AV_NOPTS_VALUE) {
pls->seek_timestamp = AV_NOPTS_VALUE;
break;
}
tb = get_timebase(pls);
ts_diff = av_rescale_rnd(pls->pkt.dts, AV_TIME_BASE,
tb.den, AV_ROUND_DOWN) -
pls->seek_timestamp;
if (ts_diff >= 0 && (pls->seek_flags & AVSEEK_FLAG_ANY ||
pls->pkt.flags & AV_PKT_FLAG_KEY)) {
pls->seek_timestamp = AV_NOPTS_VALUE;
break;
}
}
av_free_packet(&pls->pkt);
reset_packet(&pls->pkt);
}
}
/* Check if this stream has the packet with the lowest dts */
if (pls->pkt.data) {
struct playlist *minpls = minplaylist < 0 ?
NULL : c->playlists[minplaylist];
if (minplaylist < 0) {
minplaylist = i;
} else {
int64_t dts = pls->pkt.dts;
int64_t mindts = minpls->pkt.dts;
if (dts == AV_NOPTS_VALUE ||
(mindts != AV_NOPTS_VALUE && compare_ts_with_wrapdetect(dts, pls, mindts, minpls) < 0))
minplaylist = i;
}
}
}
/* If we got a packet, return it */
if (minplaylist >= 0) {
struct playlist *pls = c->playlists[minplaylist];
*pkt = pls->pkt;
pkt->stream_index += pls->stream_offset;
reset_packet(&c->playlists[minplaylist]->pkt);
if (pkt->dts != AV_NOPTS_VALUE)
c->cur_timestamp = av_rescale_q(pkt->dts,
pls->ctx->streams[pls->pkt.stream_index]->time_base,
AV_TIME_BASE_Q);
return 0;
}
return AVERROR_EOF;
}
static int hls_close(AVFormatContext *s)
{
HLSContext *c = s->priv_data;
free_playlist_list(c);
free_variant_list(c);
free_rendition_list(c);
return 0;
}
static int hls_read_seek(AVFormatContext *s, int stream_index,
int64_t timestamp, int flags)
{
HLSContext *c = s->priv_data;
struct playlist *seek_pls = NULL;
int i, seq_no;
int64_t first_timestamp, seek_timestamp, duration;
if ((flags & AVSEEK_FLAG_BYTE) ||
!(c->variants[0]->playlists[0]->finished || c->variants[0]->playlists[0]->type == PLS_TYPE_EVENT))
return AVERROR(ENOSYS);
first_timestamp = c->first_timestamp == AV_NOPTS_VALUE ?
0 : c->first_timestamp;
seek_timestamp = av_rescale_rnd(timestamp, AV_TIME_BASE,
s->streams[stream_index]->time_base.den,
flags & AVSEEK_FLAG_BACKWARD ?
AV_ROUND_DOWN : AV_ROUND_UP);
duration = s->duration == AV_NOPTS_VALUE ?
0 : s->duration;
if (0 < duration && duration < seek_timestamp - first_timestamp)
return AVERROR(EIO);
/* find the playlist with the specified stream */
for (i = 0; i < c->n_playlists; i++) {
struct playlist *pls = c->playlists[i];
if (stream_index >= pls->stream_offset &&
stream_index - pls->stream_offset < pls->ctx->nb_streams) {
seek_pls = pls;
break;
}
}
/* check if the timestamp is valid for the playlist with the
* specified stream index */
if (!seek_pls || !find_timestamp_in_playlist(c, seek_pls, seek_timestamp, &seq_no))
return AVERROR(EIO);
/* set segment now so we do not need to search again below */
seek_pls->cur_seq_no = seq_no;
seek_pls->seek_stream_index = stream_index - seek_pls->stream_offset;
for (i = 0; i < c->n_playlists; i++) {
/* Reset reading */
struct playlist *pls = c->playlists[i];
if (pls->input) {
ffurl_close(pls->input);
pls->input = NULL;
}
av_free_packet(&pls->pkt);
reset_packet(&pls->pkt);
pls->pb.eof_reached = 0;
/* Clear any buffered data */
pls->pb.buf_end = pls->pb.buf_ptr = pls->pb.buffer;
/* Reset the pos, to let the mpegts demuxer know we've seeked. */
pls->pb.pos = 0;
/* Flush the packet queue of the subdemuxer. */
ff_read_frame_flush(pls->ctx);
pls->seek_timestamp = seek_timestamp;
pls->seek_flags = flags;
if (pls != seek_pls) {
/* set closest segment seq_no for playlists not handled above */
find_timestamp_in_playlist(c, pls, seek_timestamp, &pls->cur_seq_no);
/* seek the playlist to the given position without taking
* keyframes into account since this playlist does not have the
* specified stream where we should look for the keyframes */
pls->seek_stream_index = -1;
pls->seek_flags |= AVSEEK_FLAG_ANY;
}
}
c->cur_timestamp = seek_timestamp;
return 0;
}
static int hls_probe(AVProbeData *p)
{
/* Require #EXTM3U at the start, and either one of the ones below
* somewhere for a proper match. */
if (strncmp(p->buf, "#EXTM3U", 7))
return 0;
if (strstr(p->buf, "#EXT-X-STREAM-INF:") ||
strstr(p->buf, "#EXT-X-TARGETDURATION:") ||
strstr(p->buf, "#EXT-X-MEDIA-SEQUENCE:"))
return AVPROBE_SCORE_MAX;
return 0;
}
AVInputFormat ff_hls_demuxer = {
.name = "hls,applehttp",
.long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
.priv_data_size = sizeof(HLSContext),
.read_probe = hls_probe,
.read_header = hls_read_header,
.read_packet = hls_read_packet,
.read_close = hls_close,
.read_seek = hls_read_seek,
};
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