[FFmpeg-user] Best way for converting HD 1080i to DVCPRO25 DV?

[Andy Furniss]

Iban Garcia wrote:
> Hi,
>
> I go on with searching the best way to convert HD-1080i content to SD-576i
> content, with losing the minimun detail... :-O
>
> Well... I have making some new tests... but when transcoding from HD 1080i
> to SD-PAL the video loses a lot of detail (i.e., 720x576i video is a little
> bit blurred)
>
> I have tested with this option UNSHARP filter in order to get a SHARPer SD
> content: $comando="ffmpeg -y -threads 8 -i ".$input_file.".mxf -pix_fmt
> yuv411p -aspect 16:9 -vf
> \"scale=720:576:interl=1,fieldorder=bff,unsharp=7:7:2.5\" -vcodec dvvideo
> -map 0:v -map 0:a:2 -ac 2 ".$output_file.".dv";
>
> But there is a problem... unsharp filter is acting with frames and not with
> fields. So, the video after filtering gets a wrong output: blinking.
>
> Is there any way to use "sharp filter" with fields and not with frames?
>
> Many Thanks in advance!!

I'm still not sure that sharpening is a good idea on interlaced, but 
it's not my video and I suppose it's more likely not to be played on a 
"real" interlaced display than in the past.

Prompted by this thread I had a look at what the BBC scale was like by 
recording HD and SD channels showing F1 at the same time.

TBH their SD looked quite soft and I could get something sharper looking 
at the same bitrate just using lanczos.

For some strange reason my version also deinterlaced better than theirs 
  - I maybe lucked into that one. Sometime I am going to repeat and see.