add black bars to video without loss quality

1. Hello, I have problem, I have video 1920x800p, I need add black bars to add subtitles. video should be 1920x1080p. The problem is I tried with movavi and select same features from original video (used mediainfo) but video is very very worse than original. I heard about re-encoding programs loss quality and ffmpeg doesn't loss quality. Therefore I need to know how use ffmpeg to add black bars to my video.
however if you know other method to add black bars without loss quality I listen you
thanks
2. You can add subtitles (g.e. srt or ass) without reencoding, simply remuxing.
In this case the subtitles are shown in the lower black bar, added automatically by your player (or TV) with your 1920x800 video.
If you want hardcode the subs and add black bars then you have to reencode the video (with quality loss).
Both can be done with clever Ffmpeg-GUI.
3. Originally Posted by ProWo
You can add subtitles (g.e. srt or ass) without reencoding, simply remuxing.
In this case the subtitles are shown in the lower black bar, added automatically by your player (or TV) with your 1920x800 video.
If you want hardcode the subs and add black bars then you have to reencode the video (with quality loss).
Both can be done with clever Ffmpeg-GUI.
thanks for first solution
but If I heard ffmpeg not re-encoding after edition, but anywawy I don't know how use ffmpeg
by the way shutter encoer re-encoding videos?
4. It theoretically could be done with macroblock specific encoding where it leaves the original lines alone and only encodes the added lines (assuming they line up with whole macroblocks), but in reality if you make a visual change to the frame (and you are), you will ALWAYS have to re-encode, no matter which encoder you use. And if you are re-encoding using a lossy codec, there WILL be quality loss no matter what encoder you use. Amount of quality loss then is determined by bitrate and settings chosen.

You are not just "editing" here, so workarounds with gop-based smart rendering will not work on sections you make these frame changes to.

Scott
5. Originally Posted by glomizero
by the way shutter encoer re-encoding videos?
Shutter Encoder is built around ffmpeg. It's a well-designed front end with some added extras. It has a "Rewrap" function that does not reencode -- but that won't help you if you're adding black bars.
6. Originally Posted by smrpix
Originally Posted by glomizero
by the way shutter encoer re-encoding videos?
Shutter Encoder is built around ffmpeg. It's a well-designed front end with some added extras. It has a "Rewrap" function that does not reencode -- but that won't help you if you're adding black bars.
oh no I asked about shutter encoder because in other moment used shutter encoder to change audio of that video
7. The basic ffmpeg command to add borders and burn in subs is something like:

Code:
ffmpeg -y input.mp4 -vf pad=width=1920:height=1080:x=0:y=140,subtitles=input.srt output.mp4
y=140 creates equal black borders at the top and bottom, (1080-800)/2 = 140. You might want to create a larger border at the bottom than the top to make more room for subs at the bottom. For example y=100 will give you a 100 line border at the top and a 180 line border at the bottom.

Add whatever encoding parameters and audio handling you want.
8. Originally Posted by jagabo
The basic ffmpeg command to add borders and burn in subs is something like:

Code:
ffmpeg -y input.mp4 -vf pad=width=1920:height=1080:x=0:y=140,subtitles=input.srt output.mp4
y=140 creates equal black borders at the top and bottom, (1080-800)/2 = 140. You might want to create a larger border at the bottom than the top to make more room for subs at the bottom. For example y=100 will give you a 100 line border at the top and a 180 line border at the bottom.

Add whatever encoding parameters and audio handling you want.
ok (ffmpeg -y input.mp4 -vf pad=width=1920:height=1080=0:y=140,subtitles=input.srt output.mp4) should put movie in same folder as ffmpeg?
9. With that command line ffmpeg will need to be in your search path. output.mp4 will be created in the same folders as input.mp4, the current working directory. Use full path names if you want tp specify other locations.

Code:
"c:\path\to\ffmpeg.exe" -y "c:\my source videos\input.mp4" -vf pad=width=1920:height=1080:x=0:y=140,subtitles=input.srt "c:\ where you want your new video\output.mp4"

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