[FFmpeg-user] converting 1080 to 720 mpeg2

[Andy Sheen]

On 29 February 2012 16:09, Ian Evans <dheianevans at gmail.com> wrote:

> On Wed, Feb 29, 2012 at 3:46 AM, Andy Sheen <sheen.andy at googlemail.com>
> wrote:
> > What does ffprobe (or similar) say the  file formats are now. I think
> > specifying the yadif=1 will give 1 frame for every field which would give
> > you 59.99 fps, but you've probably overriden that with the -r line.
> >
> > Basically, you need to get the two files with exactly the same size, same
> > rate (which will be ~60fps), same interlacing (i.e. none as the 720 is
> > progressive)
>
>
> Okay here's ffprobe on the 720 file:
> Duration: 00:17:40.20, start: 0.338367, bitrate: 11065 kb/s
> Stream #0.0[0x1e0]: Video: mpeg2video (Main), yuv420p, 1280x720 [PAR
> 1:1 DAR 16:9], 65000 kb/s, 59.96 fps, 59.96 tbr, 90k tbn, 119.88 tbc
> Stream #0.1[0x80]: Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s
>
> and on the 1080 test file after using this command line:
>  sudo ffmpeg -i 1662_20120226204000.mpg -t 00:5:00.000 -f mpegts
> -vcodec mpeg2video -qscale 2  -vf 'yadif=1,scale=1280:720'
> video-01.mpeg.ts
>
> Stream #0.0[0x100]: Video: mpeg2video (Main), yuv420p, 1280x720 [PAR
> 1:1 DAR 16:9], 104857 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
> Stream #0.1[0x101]: Audio: mp2, 48000 Hz, stereo, s16, 64 kb/s
>
> So it looks like my command line didn't get the frame rate doubled on
> the test file. Also it seems to have chosen the second of the two
> available audio tracks, which were:
>
>
As Carl suggests, full uncut output would be useful. Also, I think you need
to use -r 60000/1001 as you were forcing the rate to 29.97 fps, whereas the
720p is 59.96. The yadif=1 should double the framerate, but you're just
forcing it back to 29.97.