[FFmpeg-devel] [PATCH]lavf/mpegts: Do not print the character coding as part of service name

[Jan Ekström]

On Fri, Feb 8, 2019 at 12:26 AM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>
> 2019-02-07 23:17 GMT+01:00, Jan Ekström <jeebjp at gmail.com>:
> > On Thu, Feb 7, 2019 at 5:46 PM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
> >>
> >> 2019-02-07 16:34 GMT+01:00, Moritz Barsnick <barsnick at gmx.net>:
> >> > On Thu, Feb 07, 2019 at 14:40:40 +0100, Carl Eugen Hoyos wrote:
> >> >> +    if (p[0] < 0x20) {
> >> >> +        p++;
> >> >> +        if (--len < 0)
> >> >> +            return NULL;
> >> >> +    }
> >> >
> >> > If I understand section "A.2 Selection of character table" of ETSI EN
> >> > 300 468 correctly, you need to drop an additional byte if the first
> >> > byte (p[0]) is 0x1F, or an additional two bytes if the first one is
> >> > 0x10.
> >>
> >> New patch attached.
> >>
> >
> > This is weird.
> >
> > I applied this on top of my WIP ARIB branch
> > (https://github.com/jeeb/ffmpeg/commits/mpegts_arib_stuff) and now I
> > lost service name / provider altogether...
> > I mean, the stuff in the branch is "quick and dirty" at this point,
> > but it's still peculiar.
> >
> > This can be seen with both the PID switch sample I recently posted as
> > well as with the ARIB captions sample I posted in the libaribb24
> > wrapper thread.
>
> Reason is that instead of "(*p < 0x20)" it has to be "(len && *p < 0x20)".
>
> This is also the missing sample, I don't know if I'll succeed with the
> conversion.
>

It seems like the person who implemented the ARIB STD-B24 encoding and
got it merged to linuxtv also implemented ETSI EN 300 468?
https://git.linuxtv.org/v4l-utils.git/tree/contrib/gconv/en300-468-tab00.c

It is under LGPLv2.1+ so similarly usable. I did take a look at the
ARIB one yesterday and while it seems to base an awful lot on the
magic that comes from including iconv/{skeleton,loop}.c it doesn't
seem completely impenetrable...

Jan