[FFmpeg-user] converting 1080p50 to PAL interlaced dv format

[Konrad Karl]

On Thu, Jan 26, 2012 at 11:54:00PM +0000, Carl Eugen Hoyos wrote:
> Konrad Karl <kk_konrad <at> gmx.at> writes:
> 
> > finally I managed to compile latest git ffmpeg and x264 on Fedora 16
> > which was a major pain because there are a lot of dependent
> > packages (e.g mplayer et al)
> 
> Note that ffmpeg can (and by default is) compiled as a static binary, so no
> dependencies should be hurt.

I just took the spec file from the rpmfusion ffmpeg package and had just 
to modify the spec file a little. 

during the ffmpeg configure process I was looking for a way to specify
an altenate location for x264 (libs,includes)

the only working solution I found was to add:

  --extra-ldflags="-L/usr/local/lib64" 
  --extra-cflags="-I/usr/local/include"

to the configure argument list and

export QA_RPATHS=$[0x0002]          -- suppress rpath checking
export LD_RUN_PATH=/usr/local/lib64 -- add RPATH

so you dont need to set LD_LIBRARY_PATH.
  
Is there a more fine-grained way to tell configure about locations of 
external libs + includes?

> (And if MPlayer really depends on FFmpeg - which I consider hard to believe -
> than your MPlayer installation is quite broken.)

ldd /usr/bin/mplayer|grep libav
        libavformat.so.53 => /usr/lib64/libavformat.so.53 (0x000000399da00000)
        libavcodec.so.53 => /usr/lib64/libavcodec.so.53 (0x000000399e600000)
        libavutil.so.51 => /usr/lib64/libavutil.so.51 (0x000000399de00000)

> This may seem different for x264, but if you compile a static x264 library (and
> do not install it), you can still build without any dependency troubles at all.

I will try the next time but I prefer to pollute my system as little as
possible and with rpm it it easy to get rid of installed packages and
it also warns about possible file conflicts.

> > Q1: how does the ffprobe and mplayer output tell me that it is
> > interlaced material?
> 
> The only way of knowing if material is interlaced or not is to visually inspect
> (DVB transmissions here are marked "interlaced" even if they are progressive and
> it is no problem to encode interlaced material with a "progressive-only" codec
> and then claim it is progressive). A filter could do the work, but I don't think
> it exists in FFmpeg / MPlayer.

the player has to know anyways and I am curious how it gets to
know.

Tried yesterday evening to compare an original DV file (inside an avi
container) and my dv-ized 1080p50 -  the results seem to look quite
similar in terms of perceived frame rate and interlace distortions.
(at a first glance the converted 1080p50 looks even better)

Thanks all for your suggestions,

Konrad