[FFmpeg-devel] [PATCH] hlsenc: added floating point time support.

Michael Niedermayer michaelni at gmx.at
Thu Apr 3 12:28:49 CEST 2014


On Thu, Apr 03, 2014 at 08:20:56AM +0200, Reimar Döffinger wrote:
> 
> 
> On 03.04.2014, at 00:39, Michael Niedermayer <michaelni at gmx.at> wrote:
> 
> > On Thu, Apr 03, 2014 at 12:57:44AM +0530, Senthil wrote:
> >> On Wed, Apr 2, 2014 at 10:56 AM, Reimar Döffinger
> >> <Reimar.Doeffinger at gmx.de>wrote:
> >> 
> >>> On 02.04.2014, at 05:29, Senthil <senthil.codr at gmail.com> wrote:
> >>>> Necessary for HLS version 3 and above.  Fixes ticket #3505.
> >>> 
> >> Either way, both float itself and %f have very limited precision.
> >>> I'd suggest going with double and explicitly specifying a higher precision
> >>> in the format string.
> >>> Possibly even going with %e if the spec allows for it and there are no
> >>> compatibility issues.
> >>> 
> >> Here is the relevant portion in the spec:
> >> http://tools.ietf.org/html/draft-pantos-http-live-streaming-12#section-3.3.2
> >> 
> >> Though it does not mention about double precision, I have produced a double
> >> version of the patch below.
> >> 
> >> Necessary for HLS version 3 and above.  Fixes ticket #3505.
> >> 
> >> Signed-off-by: Senthilnathan M <senthil.codr at gmail.com>
> > 
> > applied
> 
> Sorry, but I disagree.
> The specification says _should_ use float, so it is absolutely _not_ in any way necessary for HLS3.
> At the same time it is _not_ allowed for HLS2, so unless I missed a check this breaks anything that only supports HLS2.
> Lastly, the latest change did nothing to address the very limited precision of the %f format specifier (even though it might not be that relevant).
> Lastly, the ticket does not even mention what the point/advantage of sub-second precision would be.
> In summary: It looks to me like the patch break things without actually fixing anything at all.

our hls code unconditionally adds "#EXT-X-VERSION:3" thus these files
are not version 2 compatible and i would expect version 2 players
to not even try to play them but i might be wrong or miss something


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

If a bugfix only changes things apparently unrelated to the bug with no
further explanation, that is a good sign that the bugfix is wrong.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20140403/a753d6db/attachment.asc>


More information about the ffmpeg-devel mailing list