ffmpeg mapping subtitles

[sambat]

I'm trying to convert x265 video to x264, copying the audio and the subtitles (vobsub).
The video is converted and the audio is copied ok, but the subs are missing.
I listed the results from ffprobe and the command line used for the conversion.


ffprobe:
Input #0, matroska,webm, from '1.mkv':
Metadata:
creation_time : 2022-05-12T17:49:26.000000Z
ENCODER : Lavf58.76.100
Duration: 00:44:48.30, start: 0.000000, bitrate: 1140 kb/s
Stream #0:0: Video: hevc (Main), yuv420p(tv, smpte170m/bt470bg/bt709), 720x406 [SAR 1:1 DAR 360:203], 25 fps, 25 tbr,
1k tbn (default)
Metadata:
DURATION : 00:44:48.301000000
Stream #0:1(eng): Audio: aac (LC), 48000 Hz, stereo, fltp (default)
Metadata:
title : Stereo
DURATION : 00:44:48.213000000
Stream #0:2(eng): Subtitle: dvd_subtitle, 720x576
Metadata:
DURATION : 00:43:11.405000000

ffmpeg -i 1.mkv -filter_complex "[0:v:0][0:s:0]overlay[v]" -map "[v]" -map 0:a:0 -acodec copy -c:v libx264 -crf 18 output.mkv

[

[jagabo]

I don't use vobsubs but I suspect they are being rendered below the bottom of the frame. Note the subs are 720x576 but the video is only 720x406. Try resizing the video to 1024x576 instead.

[Selur]

-scodec copy

should tell ffmpeg to also copy the subtitles,...

[jagabo]

I think you're right. I thought the ffprobe report was of the new file he created. But it's of his hevc source.

[sambat]

Thanks to both.

@jagabo, resizing didn't do it.
The subtitles being a larger resolution than the video, is that normal?

@Selur, changed the command and it worked (I had to add the extra map command before -scodec copy.
The logic of the map and overlay commands elude me.

ffmpeg -i 1.mkv -filter_complex "[0:v:0][0:s:0]overlay[v]" -map "[v]" -map 0:s:0 -scodec copy -map 0:a:0  -acodec copy -c:v libx264 -crf 18 output.mkv