[FFmpeg-user] ntsc-dvd doesn't default to interlaced.
Carl Eugen Hoyos
cehoyos at ag.or.at
Fri Jul 26 10:51:18 CEST 2013
Andy Civil <andycivil <at> gmail.com> writes:
> Short description: I'm moaning that the default output
> for "ntsc-dvd" is progressive, even if I give it
> enough information to make it interlaced.
> c:\ffmpeg\bin\ffmpeg -i E:\temp\2013-06-07-hdp.mp4
> -target ntsc-dvd -acodec mp2 -ac 2 -b:a 128000
(Complete, uncut console output missing.)
Nothing about this command specifies that your input
is interlaced so why on earth should FFmpeg use
interlaced encoding (that of course hurts
Or in other words: You did not give enough information
to FFmpeg that you want interlaced content, so how
should it guess?
> I can see a day when interlacing is pointless,
> when all CRT displays are on the scrap
I use a CRT (all the time) and I certainly don't
want interlaced content.
> a video of 30fps interlaced (60 fields per second)
> does indeed look better than a straight 30p because
> there is more temporal information
I consider this "wrong" (please consider that an
If it is course perfectly fine that you disagree
but please don't claim that this is a universal
truth (especially since a large percentage of the
60p material that can be used as input to your
command line contains duplicated frames and
never had more temporal information).
> I found that I had to specifically add the flags
> -flags ildct+ilme to make it create a proper
> interlaced video.
As such this is simply not true.
The flags make the encoder use interlaced algorithms
which should only only be used on interlaced
material (and which of course should be used for
interlaced sources). In practice, it is often used
for progressive material (and interlaced pictures
were of course sometimes encoded without those flags).
Please note that FFmpeg supports producing
interlaced content with the appropriate filter.
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