[FFmpeg-devel] [PATCH]lavf/subviewerdec: Support higher sub-second precision

[Michael Niedermayer]

On Thu, Mar 19, 2020 at 10:18:33PM +0100, Carl Eugen Hoyos wrote:
> Am Do., 19. März 2020 um 19:32 Uhr schrieb Michael Niedermayer
> <michael at niedermayer.cc>:
> >
> > On Wed, Mar 18, 2020 at 02:16:30AM +0100, Carl Eugen Hoyos wrote:
> > > Hi!
> > >
> > > Attached patch fixes ticket #8575 for me, Google describes such files.
> > >
> > > Please comment, Carl Eugen
> >
> > >  subviewerdec.c |   10 +++++++---
> > >  1 file changed, 7 insertions(+), 3 deletions(-)
> > > 1a6133ed3dbb66945d6bf16e212c0e77e3fd0579  0001-lavf-subviewerdec-Support-higher-sub-second-precisio.patch
> > > From 39d0748782bb3e37fb2f92c679ffa58b239374c7 Mon Sep 17 00:00:00 2001
> > > From: Carl Eugen Hoyos <ceffmpeg at gmail.com>
> > > Date: Wed, 18 Mar 2020 02:11:33 +0100
> > > Subject: [PATCH] lavf/subviewerdec: Support higher sub-second precision.
> > >
> > > Fixes ticket #8575.
> > > ---
> > >  libavformat/subviewerdec.c | 10 +++++++---
> > >  1 file changed, 7 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/libavformat/subviewerdec.c b/libavformat/subviewerdec.c
> > > index 06b827b70f..ed48b3388d 100644
> > > --- a/libavformat/subviewerdec.c
> > > +++ b/libavformat/subviewerdec.c
> > > @@ -56,11 +56,15 @@ static int read_ts(const char *s, int64_t *start, int *duration)
> > >      int64_t end;
> > >      int hh1, mm1, ss1, ms1;
> > >      int hh2, mm2, ss2, ms2;
> > > +    int multiplier = 1;
> > >
> > > +    if (sscanf(s, "%u:%u:%u.%2u,%u:%u:%u.%2u",
> > > +               &hh1, &mm1, &ss1, &ms1, &hh2, &mm2, &ss2, &ms2) == 8)
> > > +        multiplier = 10;
> > >      if (sscanf(s, "%u:%u:%u.%u,%u:%u:%u.%u",
> > >                 &hh1, &mm1, &ss1, &ms1, &hh2, &mm2, &ss2, &ms2) == 8) {
> >
> > which lengths can the ms1 / ms2 part have ?
> > do all of the following work ?
> > x.1
> > x.19
> > x.199
> > x.1999
> >
> > or are some of these guranteed not to occur ?
> 
> I have no idea but my suspicion is that whoever created the files
> in question misunderstood the original format.

then i would suggest that the code either supports all variants of this
or checks if the input is one of the supported ones.
basically checking how long the ms1/ms2 fields are IIUC

thx

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Any man who breaks a law that conscience tells him is unjust and willingly 
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very highest respect for law. - Martin Luther King Jr
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