On Wed, 13 Jan 2016, Michael Niedermayer wrote:
On Wed, Jan 13, 2016 at 05:01:01AM +0300, Andrey Turkin wrote:
Why not use libzvbi's slicer? It should be pretty robust with
less-than-ideal signal.
Regarding your code - is there a need to calculate a frequency? I did
something similar a while back with VBI from TV signal and in my experience:
a) this kind of frequency/phase estimation doesn't work that well on a
noisy signal.
b) there's really no need to estimate frequency - it's a known constant
(well it depends on a standard but in each standard it is a constant) and
generators usually don't deviate from it; you just need to get a good phase
estimation based on, say, local maxima/minima of run-in bits.
to calculate the phase
[...]
Thank you all for the comments and suggestions, I have learned a lot from
it. The reason why I did not use libzvbi was not licensing, I simply
wasn't sure at first that this can be done conveniently with it, and
instead of checking the docs, writing it from scratch was more fun.
Anyway, now I know that I can almost seamlessly replace the
teletext_qunatizer stuff with libzvbi's vbi_bit_slicer, so I will rework
the patch series to use that. The higher level interface of libzvbi -
vbi_raw_decoder seems too high level (bloated) for my use case.
As for the licensing, I believe now that libzvbi is LGPL because it
references the GNU Library General Public License wich is the predecessor
of the LGPL, so I will submit a patch to remove the GPL depdendency from
libzvbi as well.
Regards,
Marton
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
