[FFmpeg-devel] [PATCH] avformat/hlsenc: Use HLS version 2 if rounded durations are enabled

[Steven Liu]

<lucy at absolucy.moe> 于2022年6月27日周一 10:28写道：
>
> Yes. Version 3 is just Version 2 with floating point durations.
LGTM
>
> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Steven Liu
> Sent: Sunday, June 26, 2022 10:17 PM
> To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH] avformat/hlsenc: Use HLS version 2 if rounded durations are enabled
>
> Lucy <lucy at absolucy.moe> 于2022年6月27日周一 09:12写道：
> >
> > This allows for wider compatibility with older devices, such as those
> > running iOS 3. The only difference between HLS version 2 and version 3
> > is that version 3 supports non-integer EXTINF values, and as such, we
> > can default to version 2 if we're using whole-integer EXTINFs anyways,
> > when `-hls_flags round_durations` is set.
> >
> > As this code seems to otherwise consistently use the lowest compatible
> > version, this seems to fit in properly with existing behavior.
> >
> > Testing confirms with that this patch, HLS output can work all the way
> > back to iOS 3.
> >
> > This is my first contribution to ffmpeg, so please tell me if I did
> > anything wrong, and I'll try my best to fix it.
> >
> > Signed-off-by: Lucy <lucy at absolucy.moe>
> > ---
> >  doc/muxers.texi      | 2 ++
> >  libavformat/hlsenc.c | 6 +++++-
> >  2 files changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/doc/muxers.texi b/doc/muxers.texi index
> > b6cafaa5fd..b2f4326aae 100644
> > --- a/doc/muxers.texi
> > +++ b/doc/muxers.texi
> > @@ -1060,6 +1060,8 @@ and remove the @code{#EXT-X-ENDLIST} from the
> > old segment list.
> >  @item round_durations
> >  Round the duration info in the playlist file segment info to integer
> > values, instead of using floating point.
> > +If there are no other features requiring higher HLS versions be used,
> > +then this will allow ffmpeg to output a HLS version 2 m3u8.
> >
> >  @item discont_start
> >  Add the @code{#EXT-X-DISCONTINUITY} tag to the playlist, before the
> > diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c index
> > 3bafddfa61..7c097b4bf2 100644
> > --- a/libavformat/hlsenc.c
> > +++ b/libavformat/hlsenc.c
> > @@ -1550,7 +1550,11 @@ static int hls_window(AVFormatContext *s, int
> > last, VariantStream *vs)
> >      double *prog_date_time_p = (hls->flags & HLS_PROGRAM_DATE_TIME) ?
> > &prog_date_time : NULL;
> >      int byterange_mode = (hls->flags & HLS_SINGLE_FILE) ||
> > (hls->max_seg_size > 0);
> >
> > -    hls->version = 3;
> > +    hls->version = 2;
> Do you mean the functions which support from version 3 but not use HLS_ROUND_DURATIONS should use version 2?
> > +    if (!(hls->flags & HLS_ROUND_DURATIONS)) {
> > +        hls->version = 3;
> > +    }
> > +
> >      if (byterange_mode) {
> >          hls->version = 4;
> >          sequence = 0;
> > --
> > 2.36.1
> >
> >
> > _______________________________________________
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> >
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>
> Thanks
> Steven
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Thanks
Steven