[FFmpeg-devel] [PATCH v2 3/5] avformat/hls: add http_persistent option

Aman Gupta ffmpeg at tmm1.net
Wed Dec 20 21:36:57 EET 2017


On Sun, Dec 17, 2017 at 1:13 PM, Anssi Hannula <anssi.hannula at iki.fi> wrote:

> Aman Gupta kirjoitti 2017-12-17 22:41:
>
>> On Sun, Dec 17, 2017 at 12:34 PM Anssi Hannula <anssi.hannula at iki.fi>
>> wrote:
>>
>> Hi!
>>>
>>> Aman Gupta kirjoitti 2017-12-13 02:35:
>>> > From: Aman Gupta <aman at tmm1.net>
>>> >
>>> > 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
>>>
>>> Why is this implemented as an option instead of simply being always used
>>> by the demuxer?
>>>
>>
>>
>> I have no strong feeling on this either way. I've tested the new option
>> against a few different HLS servers and would be comfortable enabling it
>> by
>> default. I do think it's worth keeping as an option in case someone wants
>> to turn it off for whatever reason.
>>
>
> OK. The only other demuxer that reuses HTTP connections seems to be
> rtmphttp, and it does not have an option.
> I think I'd prefer no option here as well unless a use case is known, but
> I'm not too strongly against it so I guess it could stay (but default to
> true).
>
> Does anyone else have any thoughts?
>

If no one objects, I will push this patchset with the requested changed in
a few days.

Aman


>
>
> Also, what happens if the hostname in the URI varies, does it properly
> open a new connection then?
>
>
>>
>>> > ---
>>> >  doc/demuxers.texi |  3 +++
>>> >  libavformat/hls.c | 68
>>> > +++++++++++++++++++++++++++++++++++++++++++++++++++----
>>> >  2 files changed, 67 insertions(+), 4 deletions(-)
>>> >
>>> > diff --git a/doc/demuxers.texi b/doc/demuxers.texi
>>> > index 73dc0feec1..18ff7101ac 100644
>>> > --- a/doc/demuxers.texi
>>> > +++ b/doc/demuxers.texi
>>> > @@ -316,6 +316,9 @@ 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.
>>> > +
>>> > + at item http_persistent
>>> > +Use persistent HTTP connections. Applicable only for HTTP streams.
>>> >  @end table
>>> >
>>> >  @section image2
>>> > diff --git a/libavformat/hls.c b/libavformat/hls.c
>>> > index ab6ff187a6..5c1895c180 100644
>>> > --- a/libavformat/hls.c
>>> > +++ b/libavformat/hls.c
>>> > @@ -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);
>>> > @@ -640,7 +645,24 @@ 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)) {
>>> > +        URLContext *uc = ffio_geturlcontext(*pb);
>>> > +        av_assert0(uc);
>>> > +        (*pb)->eof_reached = 0;
>>> > +        ret = ff_http_do_new_request(uc, url);
>>> > +        if (ret == AVERROR_EXIT) {
>>> > +            ff_format_io_close(c->ctx, &c->playlist_pb);
>>> > +            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));
>>> > +            ff_format_io_close(c->ctx, pb);
>>> > +            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 +705,27 @@ 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;
>>> > +        URLContext *uc = ffio_geturlcontext(in);
>>> > +        av_assert0(uc);
>>> > +        in->eof_reached = 0;
>>> > +        ret = ff_http_do_new_request(uc, url);
>>> > +        if (ret == AVERROR_EXIT) {
>>> > +            ff_format_io_close(c->ctx, &c->playlist_pb);
>>> > +            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));
>>> > +            ff_format_io_close(c->ctx, &c->playlist_pb);
>>> > +            in = NULL;
>>> > +        }
>>> > +    }
>>> > +
>>>
>>> The above code seems duplicated, please put it in a common function.
>>>
>>
>>
>> Sure, will do.
>>
>> Thanks for reviewing!
>>
>>
>>
>>>
>>> [..]
>>> --
>>> Anssi Hannula
>>>
>>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>
> --
> Anssi Hannula
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>


More information about the ffmpeg-devel mailing list