[FFmpeg-user] converting 1080 to 720 mpeg2

[Andy Sheen]

Ian Evans wrote on Tue 28 Feb at 10:16 UK time
> On Tue, Feb 28, 2012 at 4:32 AM, Andy Sheen <sheen.andy at googlemail.com> wrote:
>> In which case try some of the tests suggested above (with my parameters
>> instead of Johns for the moment) but recode to mpeg2 not rawvideo. You
>> should be aiming for 720p 29.97 video encoded with the same encoder
>> before trying to remux the two together.
> 
> Andy,
> 
> Ok, not sure if I still have the command line wrong. Not sure if I
> incorporated your suggestions correctly. Tried this:
> 
> ffmpeg -vsync 2 -async 1 -i 1662_20120226204000.mpg -t 00:10:00.000 -f
> mpegts -vcodec mpeg2video -vf scale=1280:720 -an video-01.mpeg.ts
> 
> The resulting video was very blocky. Degraded quality from the original.

You'll need to give it a bitrate (-b 10000k might be a start - place it
after the -vcodec mpeg2video statement). Let's worry about getting the
two videos in the same format first before worrying about quality :)

I don't think you need the vsync or async parameters to start with.

Also, if you make the -vf statement: -vf 'yadif=0:-1,scale=1280:720'

you should get deinterlaced video at 29.97fps. You can also use yadif to
double the framerate up to 59.97 which is where you want it to be the
same as the 720p clip - I think that may be yadif=1,-1 - have a look at
the ffmpeg documentation on yadif.

Apologies, but I'm travelling in an hour or so, so may not be able to
help much beyond then for a few days :(

As I said, I think what you need to do is get both videos to the same
size, same frame rate and both deinterlaced before you can then tie them
together.