[Ffmpeg-devel] [ bug ] converting png to dv gives solid black

Måns Rullgård mru
Mon Mar 13 15:28:53 CET 2006

Erik Slagter said:
> On Mon, 2006-03-13 at 14:11 +0100, Michael Niedermayer wrote:
>> > I really hope this silly technical artifact dies very soon, as will NTSC
>> > (and PAL and SECAM).
>> iam surely in favor of having */1001 and interlacing killed but for
>> existing videos which have been sampled at */1001 interlaced theres
>> no choice, you cant losslessly convert them to progressive integer fps
> I'd suggest broadcasting everything in 30 fps and upsample the audio
> accordingly, just like movie -> B/G conversion. The difference is even
> less...

In fact, 3:2 telecined material would run at the correct rate rather than
slightly slow as is the case today.

> I am sure conventional analogue TV sets can display 30 fps
> equally well as 30000/1001 fps.

The reason for using 30000/1001 fps remains as long as NTSC TV sets are in use.
If 30 fps is used the chroma and audio subcarriers can beat at a multiple of
the horizontal scan frequency causing stationary dots in the picture.  If
the scan rate is lowered slightly these dots will move around and become less
visible.  Then again, maybe modern electronics have better separation of the
signals and would cope with 30 fps; I don't know.

M?ns Rullg?rd
mru at inprovide.com

More information about the ffmpeg-devel mailing list