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ffmpeg/libavformat/hls.c
Anssi Hannula 9371d70bad avformat/hls: decouple playlists from variants 
Not all "sub-playlists" are variant playlists (containing the same
content with a different bitrate, etc) in the current version of the HLS
specification. They can now also be alternative renditions, containing
e.g. alternative audio tracks etc.

Decouple playlists from variants to prepare for handling the new
features.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
2014-01-03 15:05:48 +02:00

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/*
* Apple HTTP Live Streaming demuxer
* 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 demuxer
* http://tools.ietf.org/html/draft-pantos-http-live-streaming
*/
#include "libavutil/avstring.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"
#define INITIAL_BUFFER_SIZE 32768
/*
* 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;
char url[MAX_URL_SIZE];
char key[MAX_URL_SIZE];
enum KeyType key_type;
uint8_t iv[16];
};
/*
* 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;
int64_t target_duration;
int start_seq_no;
int n_segments;
struct segment **segments;
int needed, cur_needed;
int cur_seq_no;
int64_t last_load_time;
char key_url[MAX_URL_SIZE];
uint8_t key[16];
};
struct variant {
int bandwidth;
int n_playlists;
struct playlist **playlists;
};
typedef struct HLSContext {
int n_variants;
struct variant **variants;
int n_playlists;
struct playlist **playlists;
int cur_seq_no;
int end_of_segment;
int first_packet;
int64_t first_timestamp;
int64_t seek_timestamp;
int seek_flags;
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]);
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_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;
}
/*
* 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);
dynarray_add(&c->playlists, &c->n_playlists, pls);
return pls;
}
static struct variant *new_variant(HLSContext *c, int bandwidth,
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;
var->bandwidth = bandwidth;
dynarray_add(&c->variants, &c->n_variants, var);
dynarray_add(&var->playlists, &var->n_playlists, pls);
return var;
}
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);
}
}
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);
}
}
static int parse_playlist(HLSContext *c, const char *url,
struct playlist *pls, AVIOContext *in)
{
int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 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;
uint8_t *new_url = NULL;
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;
}
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-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-TARGETDURATION:", &ptr)) {
if (!pls) {
if (!new_variant(c, 0, url, NULL)) {
ret = AVERROR(ENOMEM);
goto fail;
}
pls = c->playlists[c->n_playlists - 1];
}
pls->target_duration = atoi(ptr) * AV_TIME_BASE;
} else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
if (!pls) {
if (!new_variant(c, 0, url, NULL)) {
ret = AVERROR(ENOMEM);
goto fail;
}
pls = c->playlists[c->n_playlists - 1];
}
pls->start_seq_no = atoi(ptr);
} 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, "#", NULL)) {
continue;
} else if (line[0]) {
if (is_variant) {
if (!new_variant(c, bandwidth, line, url)) {
ret = AVERROR(ENOMEM);
goto fail;
}
is_variant = 0;
bandwidth = 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);
}
ff_make_absolute_url(seg->key, sizeof(seg->key), url, key);
ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
dynarray_add(&pls->segments, &pls->n_segments, seg);
is_segment = 0;
}
}
}
if (pls)
pls->last_load_time = av_gettime();
fail:
av_free(new_url);
if (close_in)
avio_close(in);
return ret;
}
static int open_input(HLSContext *c, struct playlist *pls)
{
AVDictionary *opts = 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);
if (seg->key_type == KEY_NONE) {
ret = ffurl_open(&pls->input, seg->url, AVIO_FLAG_READ,
&pls->parent->interrupt_callback, &opts);
goto cleanup;
} 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, &opts) == 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);
/* Need to repopulate options */
av_dict_free(&opts);
av_dict_set(&opts, "seekable", "0", 0);
if ((ret = ffurl_connect(pls->input, &opts)) < 0) {
ffurl_close(pls->input);
pls->input = NULL;
goto cleanup;
}
ret = 0;
}
else
ret = AVERROR(ENOSYS);
cleanup:
av_dict_free(&opts);
return ret;
}
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;
restart:
if (!v->input) {
/* If this is a live stream and the reload interval has elapsed since
* the last playlist reload, reload the playlists now. */
int64_t reload_interval = v->n_segments > 0 ?
v->segments[v->n_segments - 1]->duration :
v->target_duration;
reload:
if (!v->finished &&
av_gettime() - v->last_load_time >= reload_interval) {
if ((ret = parse_playlist(c, v->url, v, NULL)) < 0)
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)
return ret;
}
ret = ffurl_read(v->input, buf, buf_size);
if (ret > 0)
return ret;
ffurl_close(v->input);
v->input = NULL;
v->cur_seq_no++;
c->end_of_segment = 1;
c->cur_seq_no = v->cur_seq_no;
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;
}
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 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;
// 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;
}
/* 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;
/* If this is a live stream with more than 3 segments, start at the
* third last segment. */
pls->cur_seq_no = pls->start_seq_no;
if (!pls->finished && pls->n_segments > 3)
pls->cur_seq_no = pls->start_seq_no + pls->n_segments - 3;
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;
pls->ctx->ctx_flags &= ~AVFMTCTX_NOHEADER;
ret = avformat_find_stream_info(pls->ctx, NULL);
if (ret < 0)
goto fail;
/* 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;
avpriv_set_pts_info(st, ist->pts_wrap_bits, ist->time_base.num, ist->time_base.den);
avcodec_copy_context(st->codec, pls->ctx->streams[j]->codec);
}
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);
}
}
}
c->first_packet = 1;
c->first_timestamp = AV_NOPTS_VALUE;
c->seek_timestamp = AV_NOPTS_VALUE;
return 0;
fail:
free_playlist_list(c);
free_variant_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 = c->cur_seq_no;
pls->pb.eof_reached = 0;
av_log(s, AV_LOG_INFO, "Now receiving playlist %d\n", i);
} 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 int hls_read_packet(AVFormatContext *s, AVPacket *pkt)
{
HLSContext *c = s->priv_data;
int ret, i, minplaylist = -1;
if (c->first_packet) {
recheck_discard_flags(s, 1);
c->first_packet = 0;
}
start:
c->end_of_segment = 0;
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;
AVStream *st;
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 {
if (c->first_timestamp == AV_NOPTS_VALUE &&
pls->pkt.dts != AV_NOPTS_VALUE)
c->first_timestamp = av_rescale_q(pls->pkt.dts,
pls->ctx->streams[pls->pkt.stream_index]->time_base,
AV_TIME_BASE_Q);
}
if (c->seek_timestamp == AV_NOPTS_VALUE)
break;
if (pls->pkt.dts == AV_NOPTS_VALUE) {
c->seek_timestamp = AV_NOPTS_VALUE;
break;
}
st = pls->ctx->streams[pls->pkt.stream_index];
ts_diff = av_rescale_rnd(pls->pkt.dts, AV_TIME_BASE,
st->time_base.den, AV_ROUND_DOWN) -
c->seek_timestamp;
if (ts_diff >= 0 && (c->seek_flags & AVSEEK_FLAG_ANY ||
pls->pkt.flags & AV_PKT_FLAG_KEY)) {
c->seek_timestamp = AV_NOPTS_VALUE;
break;
}
av_free_packet(&pls->pkt);
reset_packet(&pls->pkt);
}
}
/* Check if this stream still is on an earlier segment number, or
* has the packet with the lowest dts */
if (pls->pkt.data) {
struct playlist *minpls = minplaylist < 0 ?
NULL : c->playlists[minplaylist];
if (minplaylist < 0 || pls->cur_seq_no < minpls->cur_seq_no) {
minplaylist = i;
} else if (pls->cur_seq_no == minpls->cur_seq_no) {
int64_t dts = pls->pkt.dts;
int64_t mindts = minpls->pkt.dts;
AVStream *st = pls->ctx->streams[pls->pkt.stream_index];
AVStream *minst = minpls->ctx->streams[minpls->pkt.stream_index];
if (dts == AV_NOPTS_VALUE) {
minplaylist = i;
} else if (mindts != AV_NOPTS_VALUE) {
if (st->start_time != AV_NOPTS_VALUE)
dts -= st->start_time;
if (minst->start_time != AV_NOPTS_VALUE)
mindts -= minst->start_time;
if (av_compare_ts(dts, st->time_base,
mindts, minst->time_base) < 0)
minplaylist = i;
}
}
}
}
if (c->end_of_segment) {
if (recheck_discard_flags(s, 0))
goto start;
}
/* If we got a packet, return it */
if (minplaylist >= 0) {
*pkt = c->playlists[minplaylist]->pkt;
pkt->stream_index += c->playlists[minplaylist]->stream_offset;
reset_packet(&c->playlists[minplaylist]->pkt);
return 0;
}
return AVERROR_EOF;
}
static int hls_close(AVFormatContext *s)
{
HLSContext *c = s->priv_data;
free_playlist_list(c);
free_variant_list(c);
return 0;
}
static int hls_read_seek(AVFormatContext *s, int stream_index,
int64_t timestamp, int flags)
{
HLSContext *c = s->priv_data;
int i, j, ret;
if ((flags & AVSEEK_FLAG_BYTE) || !c->variants[0]->playlists[0]->finished)
return AVERROR(ENOSYS);
c->seek_flags = flags;
c->seek_timestamp = stream_index < 0 ? 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);
timestamp = av_rescale_rnd(timestamp, AV_TIME_BASE, stream_index >= 0 ?
s->streams[stream_index]->time_base.den :
AV_TIME_BASE, flags & AVSEEK_FLAG_BACKWARD ?
AV_ROUND_DOWN : AV_ROUND_UP);
if (s->duration < c->seek_timestamp) {
c->seek_timestamp = AV_NOPTS_VALUE;
return AVERROR(EIO);
}
ret = AVERROR(EIO);
for (i = 0; i < c->n_playlists; i++) {
/* Reset reading */
struct playlist *pls = c->playlists[i];
int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ?
0 : c->first_timestamp;
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;
/* Locate the segment that contains the target timestamp */
for (j = 0; j < pls->n_segments; j++) {
if (timestamp >= pos &&
timestamp < pos + pls->segments[j]->duration) {
pls->cur_seq_no = pls->start_seq_no + j;
ret = 0;
break;
}
pos += pls->segments[j]->duration;
}
if (ret)
c->seek_timestamp = AV_NOPTS_VALUE;
}
return ret;
}
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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