[FFmpeg-user] SD Compress to h.265

[Ferdi Scholten]

On 13-06-2024 20:24, Richard Bartczak via ffmpeg-user wrote:
> Hello,
>
> SD e.g.:
>
>   Duration: 01:23:37.68, start: 90008.907967, bitrate: 4243 kb/s
>   Program 17501
>   Stream #0:0[0x21](deu): Subtitle: dvb_teletext ([6][0][0][0] /
> 0x0006), 492x250
>   Stream #0:1[0x1ff]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002),
> yuv420p(tv, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr,
> 90k tbn, 50 tbc
>     Side data:
>       cpb: bitrate max/min/avg: 15000000/0/0 buffer size: 1835008
> vbv_delay: N/A
>   Stream #0:2[0x200](deu): Audio: mp2 ([3][0][0][0] / 0x0003), 48000
> Hz, stereo, fltp, 192 kb/s (clean effects)
>   Stream #0:3[0x203](deu): Audio: ac3 ([129][0][0][0] / 0x0081), 48000
> Hz, 5.1(side), fltp, 384 kb/s (clean effects)
>
> It is very difficult to compress something like that.
>
> To compress it to half size, and a check with vivictpp give not
> acceptable results (the compression will be seen via vivictpp).
>
> Currently used :
>
> #SD rel. new Films,2 compression)
> #for f in *.ts; do ffmpeg -y -i "$f" -vcodec libx265 -crf 21 -preset
> slow -c:a copy "$(basename "$f" .ts).mkv";done
> #for f in *.ts; do ffmpeg -y -i "$f" -vcodec libx265 -crf 18 -preset
> slow -vf nlmeans="1.4:7:5:3:3" -c:a copy "$(basename "$f" .ts).mkv";done
>
> crf values only as example.
>
> Any ideas to improve ?
>
> Gloster
Use 2-pass VBR encoding to reach specific size with best quality.

Don't expect miracles!