I think FFmpeg cannot do this directly. In theory you can overlay the
subtitles with a video stream, then decimate, remove black frames and
use the image2 muxer with the PNG codec, but that's a very inefficient
approach. You will also lose the meta data, e.g. the bounding boxes,
unless you perfor
Thomas Ledoux (12024-07-21):
> I put the subtitle stream first so that the length of the "video" is driven
> by it, and I overlay a black transparent video. I end up having thousands
> of images (25 per second, of course) but they are all repetitions and only
> changing when the subtitle changes. S
> On 21 Jul 2024, at 23:59, Thomas Ledoux wrote:
>
> Hi Nicolas,
>
> Thanks a lot for the hint, that allows me to make great progress.
> Using an overlay I'm indeed able to extract the subtitles
> I use :
> ffmpeg -f dvdvideo -title 1 -i dvd.iso -copyts -f lavfi -i
> color=size=pal:rate=25:colo
Hi Nicolas,
Thanks a lot for the hint, that allows me to make great progress.
Using an overlay I'm indeed able to extract the subtitles
I use :
ffmpeg -f dvdvideo -title 1 -i dvd.iso -copyts -f lavfi -i
color=size=pal:rate=25:color=black@0.0,format=rgba -filter_complex
"[0:i:0x20][1:v]overlay[v]"
Thomas Ledoux (12024-07-21):
> Indeed, PNG is not supposed to be used for subtitles. But in this case,
> subtitles are images
>
> so they could be transform in PNG. Am I forgetting a filter to make it
> react as if it was a video ?
You need to overlay the subtitles on a dummy video.
Regards,
--
Hi all,
with the introduction of the new dvdvideo decoder, we are able to access
successfully any video and transcode it. Moreover, we can extract subtitles
in the native image-based subdvd format.
The command
ffmpeg -y -hide_banner -f dvdvideo -title 1 -i dvd.iso -vn -an -map
0:i:0x22 -c:s dvds
