avformat/hls: add http_persistent option

This teaches the HLS demuxer to use the HTTP protocols
multiple_requests=1 option, to take advantage of "Connection:
Keep-Alive" when downloading playlists and segments from the HLS server.

With the new option, you can avoid TCP connection and TLS negotiation
overhead, which is particularly beneficial when streaming via a
high-latency internet connection.

Similar to the http_persistent option recently implemented in hlsenc.c

Signed-off-by: Aman Gupta <aman@tmm1.net>
Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
This commit is contained in:
Aman Gupta 2017-10-04 14:52:52 -07:00
parent 9395e44b8d
commit b7d6c0cd48
2 changed files with 72 additions and 4 deletions

View File

@ -316,6 +316,10 @@ segment index to start live streams at (negative values are from the end).
@item max_reload
Maximum number of times a insufficient list is attempted to be reloaded.
Default value is 1000.
@item http_persistent
Use persistent HTTP connections. Applicable only for HTTP streams.
Enabled by default.
@end table
@section image2

View File

@ -26,6 +26,7 @@
* http://tools.ietf.org/html/draft-pantos-http-live-streaming
*/
#include "libavformat/http.h"
#include "libavutil/avstring.h"
#include "libavutil/avassert.h"
#include "libavutil/intreadwrite.h"
@ -94,6 +95,7 @@ struct playlist {
AVIOContext pb;
uint8_t* read_buffer;
AVIOContext *input;
int input_read_done;
AVFormatContext *parent;
int index;
AVFormatContext *ctx;
@ -206,6 +208,8 @@ typedef struct HLSContext {
int strict_std_compliance;
char *allowed_extensions;
int max_reload;
int http_persistent;
AVIOContext *playlist_pb;
} HLSContext;
static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
@ -256,6 +260,7 @@ static void free_playlist_list(HLSContext *c)
av_freep(&pls->pb.buffer);
if (pls->input)
ff_format_io_close(c->ctx, &pls->input);
pls->input_read_done = 0;
if (pls->ctx) {
pls->ctx->pb = NULL;
avformat_close_input(&pls->ctx);
@ -597,6 +602,20 @@ static void update_options(char **dest, const char *name, void *src)
av_freep(dest);
}
static int open_url_keepalive(AVFormatContext *s, AVIOContext **pb,
const char *url)
{
int ret;
URLContext *uc = ffio_geturlcontext(*pb);
av_assert0(uc);
(*pb)->eof_reached = 0;
ret = ff_http_do_new_request(uc, url);
if (ret < 0) {
ff_format_io_close(s, pb);
}
return ret;
}
static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
AVDictionary *opts, AVDictionary *opts2, int *is_http)
{
@ -640,7 +659,19 @@ static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
else if (strcmp(proto_name, "file") || !strncmp(url, "file,", 5))
return AVERROR_INVALIDDATA;
ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
if (c->http_persistent && *pb && av_strstart(proto_name, "http", NULL)) {
ret = open_url_keepalive(c->ctx, pb, url);
if (ret == AVERROR_EXIT) {
return ret;
} else if (ret < 0) {
av_log(s, AV_LOG_WARNING,
"keepalive request failed for '%s', retrying with new connection: %s\n",
url, av_err2str(ret));
ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
}
} else {
ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
}
if (ret >= 0) {
// update cookies on http response with setcookies.
char *new_cookies = NULL;
@ -683,10 +714,22 @@ static int parse_playlist(HLSContext *c, const char *url,
char tmp_str[MAX_URL_SIZE];
struct segment *cur_init_section = NULL;
if (!in && c->http_persistent && c->playlist_pb) {
in = c->playlist_pb;
ret = open_url_keepalive(c->ctx, &c->playlist_pb, url);
if (ret == AVERROR_EXIT) {
return ret;
} else if (ret < 0) {
av_log(c->ctx, AV_LOG_WARNING,
"keepalive request failed for '%s', retrying with new connection: %s\n",
url, av_err2str(ret));
in = NULL;
}
}
if (!in) {
#if 1
AVDictionary *opts = NULL;
close_in = 1;
/* Some HLS servers don't like being sent the range header */
av_dict_set(&opts, "seekable", "0", 0);
@ -696,10 +739,18 @@ static int parse_playlist(HLSContext *c, const char *url,
av_dict_set(&opts, "headers", c->headers, 0);
av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
if (c->http_persistent)
av_dict_set(&opts, "multiple_requests", "1", 0);
ret = c->ctx->io_open(c->ctx, &in, url, AVIO_FLAG_READ, &opts);
av_dict_free(&opts);
if (ret < 0)
return ret;
if (c->http_persistent)
c->playlist_pb = in;
else
close_in = 1;
#else
ret = open_in(c, &in, url);
if (ret < 0)
@ -1111,6 +1162,9 @@ static int open_input(HLSContext *c, struct playlist *pls, struct segment *seg)
av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
av_dict_set(&opts, "seekable", "0", 0);
if (c->http_persistent)
av_dict_set(&opts, "multiple_requests", "1", 0);
if (seg->size >= 0) {
/* try to restrict the HTTP request to the part we want
* (if this is in fact a HTTP request) */
@ -1316,7 +1370,7 @@ restart:
if (!v->needed)
return AVERROR_EOF;
if (!v->input) {
if (!v->input || (c->http_persistent && v->input_read_done)) {
int64_t reload_interval;
struct segment *seg;
@ -1368,6 +1422,7 @@ reload:
goto reload;
}
v->input_read_done = 0;
seg = current_segment(v);
/* load/update Media Initialization Section, if any */
@ -1405,7 +1460,11 @@ reload:
return ret;
}
ff_format_io_close(v->parent, &v->input);
if (c->http_persistent) {
v->input_read_done = 1;
} else {
ff_format_io_close(v->parent, &v->input);
}
v->cur_seq_no++;
c->cur_seq_no = v->cur_seq_no;
@ -1666,6 +1725,7 @@ static int hls_close(AVFormatContext *s)
free_rendition_list(c);
av_dict_free(&c->avio_opts);
ff_format_io_close(c->ctx, &c->playlist_pb);
return 0;
}
@ -1903,6 +1963,7 @@ static int recheck_discard_flags(AVFormatContext *s, int first)
} else if (first && !cur_needed && pls->needed) {
if (pls->input)
ff_format_io_close(pls->parent, &pls->input);
pls->input_read_done = 0;
pls->needed = 0;
changed = 1;
av_log(s, AV_LOG_INFO, "No longer receiving playlist %d\n", i);
@ -2137,6 +2198,7 @@ static int hls_read_seek(AVFormatContext *s, int stream_index,
struct playlist *pls = c->playlists[i];
if (pls->input)
ff_format_io_close(pls->parent, &pls->input);
pls->input_read_done = 0;
av_packet_unref(&pls->pkt);
reset_packet(&pls->pkt);
pls->pb.eof_reached = 0;
@ -2191,6 +2253,8 @@ static const AVOption hls_options[] = {
INT_MIN, INT_MAX, FLAGS},
{"max_reload", "Maximum number of times a insufficient list is attempted to be reloaded",
OFFSET(max_reload), AV_OPT_TYPE_INT, {.i64 = 1000}, 0, INT_MAX, FLAGS},
{"http_persistent", "Use persistent HTTP connections",
OFFSET(http_persistent), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, FLAGS },
{NULL}
};