diff mbox series

[FFmpeg-devel,2/2] Advertise current segment in streaming mode

Message ID 20210624125808.45663-2-kevin@aiera.com
State Withdrawn, archived
Headers show
Series [FFmpeg-devel,1/2] Fix double write of DASH manifest in streaming mode | expand

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Commit Message

Kevin LaFlamme June 24, 2021, 12:58 p.m. UTC 
In streaming mode when using a segment list, the current segment should
be listed so that clients can immediately request it even before
complete. Without this, even though the segment is being written in a
way that it can be requested while still writing, clients won't know
it's available.
---
 libavformat/dashenc.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Kevin LaFlamme July 14, 2021, 1:52 p.m. UTC | #1 
Any feedback on this?
On Jun 24, 2021, 8:58 AM -0400, Kevin LaFlamme <kevin@aiera.com>, wrote:
> In streaming mode when using a segment list, the current segment should
> be listed so that clients can immediately request it even before
> complete. Without this, even though the segment is being written in a
> way that it can be requested while still writing, clients won't know
> it's available.
> ---
> libavformat/dashenc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
> index 2b8fbcbe6e..901999324f 100644
> --- a/libavformat/dashenc.c
> +++ b/libavformat/dashenc.c
> @@ -706,6 +706,8 @@ static void output_segment_list(OutputStream *os, AVIOContext *out, AVFormatCont
> Segment *seg = os->segments[i];
> avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", seg->file);
> }
> + if (c->streaming)
> + avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", os->filename);
> avio_printf(out, "\t\t\t\t</SegmentList>\n");
> }
> if (!c->lhls || final) {
> --
> 2.31.1
>
Jeyapal, Karthick July 14, 2021, 2:45 p.m. UTC | #2 
On 6/24/21, 6:28 PM, "Kevin LaFlamme" <kevin@aiera.com> wrote:

>In streaming mode when using a segment list, the current segment should
>be listed so that clients can immediately request it even before
>complete. Without this, even though the segment is being written in a
>way that it can be requested while still writing, clients won't know
>it's available.
>---
> libavformat/dashenc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
>index 2b8fbcbe6e..901999324f 100644
>--- a/libavformat/dashenc.c
>+++ b/libavformat/dashenc.c
>@@ -706,6 +706,8 @@ static void output_segment_list(OutputStream *os, AVIOContext *out, >AVFormatCont
>             Segment *seg = os->segments[i];
>             avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", seg->file);
>         }
>+        if (c->streaming)
>+            avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", os->filename);
As far as I understand the streaming mode is better supported only with SegmentTemplate.
Adding the yet-to-be-completed segment in the SegmentList might break some backward compatibility with clients that doesn't support low latency streaming.
After we added streaming support in ffmpeg, DASH-IF came up with a spec for low latency streaming.
https://dashif.org/docs/CR-Low-Latency-Live-r8.pdf. This spec also specifies that SegmentTemplate is mandatory for low latency streaming.
>         avio_printf(out, "\t\t\t\t</SegmentList>\n");
>     }
>     if (!c->lhls || final) {
>-- 
>2.31.1
>
Kevin LaFlamme July 14, 2021, 2:48 p.m. UTC | #3 
Ah I didn’t realize the SegmentTemplate was actually required in the spec for streaming mode. This should be closed then, thanks.
On Jul 14, 2021, 10:45 AM -0400, Jeyapal, Karthick <kjeyapal@akamai.com>, wrote:
>
>
> On 6/24/21, 6:28 PM, "Kevin LaFlamme" <kevin@aiera.com> wrote:
>
> > In streaming mode when using a segment list, the current segment should
> > be listed so that clients can immediately request it even before
> > complete. Without this, even though the segment is being written in a
> > way that it can be requested while still writing, clients won't know
> > it's available.
> > ---
> > libavformat/dashenc.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
> > index 2b8fbcbe6e..901999324f 100644
> > --- a/libavformat/dashenc.c
> > +++ b/libavformat/dashenc.c
> > @@ -706,6 +706,8 @@ static void output_segment_list(OutputStream *os, AVIOContext *out, >AVFormatCont
> > Segment *seg = os->segments[i];
> > avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", seg->file);
> > }
> > + if (c->streaming)
> > + avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", os->filename);
> As far as I understand the streaming mode is better supported only with SegmentTemplate.
> Adding the yet-to-be-completed segment in the SegmentList might break some backward compatibility with clients that doesn't support low latency streaming.
> After we added streaming support in ffmpeg, DASH-IF came up with a spec for low latency streaming.
> https://dashif.org/docs/CR-Low-Latency-Live-r8.pdf. This spec also specifies that SegmentTemplate is mandatory for low latency streaming.
> > avio_printf(out, "\t\t\t\t</SegmentList>\n");
> > }
> > if (!c->lhls || final) {
> > --
> > 2.31.1
> >
>
diff mbox series

Patch

diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 2b8fbcbe6e..901999324f 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -706,6 +706,8 @@  static void output_segment_list(OutputStream *os, AVIOContext *out, AVFormatCont
             Segment *seg = os->segments[i];
             avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", seg->file);
         }
+        if (c->streaming)
+            avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", os->filename);
         avio_printf(out, "\t\t\t\t</SegmentList>\n");
     }
     if (!c->lhls || final) {