Adding a Subtitle(srt) to and MP4 Video File

[MHHMHH]

Hi,
I'd like to add an srt file to an mp4 video file, and would appreciate some help. I i the srt should set uponput the mp4 video and add an object (srt file) but once all is entered IU'm not sure of the next steps. It would seem that another video track should be set up but I can't see how to do it.

[ProWo]

You can use MkvToolnix to add the srt to your mp4 an remux to mkv.
If you want the mp4 container as output you could try my clever FFmpeg-GUI.

[MHHMHH]

Thanks for the reply. What you've suggested is what I normally do, but this is not making use of VSDC, which supposedly enables subtitle addition.

[MHHMHH]

Not sure if this works, but here is a very short mp4 and it's associated srt, for those who want to play with VSDC.


https://forum.videohelp.com/attachment.php?attachmentid=56869&stc=1&d=1611177688https://forum.videohelp.com/attachment.php?attachmentid=56870&stc=1&d=1611177688

[MHHMHH]

If you just click on the files above you can download them tomyour own PC, and then use them.

[jagabo]

but this is not making use of VSDC

How was anyone supposed to know you wanted to use VSDC? Maybe you should have mentioned that in the first post.

Here's an ffmpeg command line:

ffmpeg -i 1280.mp4 -i 1280.srt -c:v copy -c:a copy -c:s mov_text output.mp4

[MHHMHH]

Actually VSDC was mentioned in one of my replies, and along with its many video effects it would be nice to have it accept srt files as well. But you have a point: there are many ways to skin a cat!
So far mkvtoolnix is what I've been using to make soft-coded video.

[MHHMHH]

To Jagabo.
Could you use ffmpeg to make an mkv with softcoded subtitles (ass). and an mp4 or mkv as inputs? If so you'd be replicating MKVtools, so what's the point. Would it be quicker or what would be its advantage?

[butterw]

ffmpeg and mkvtoolnix having a large community user base would be an advantage.

[jagabo]

To Jagabo.
Could you use ffmpeg to make an mkv with softcoded subtitles (ass). and an mp4 or mkv as inputs?

MP4 doesn't support ass subs, they would have to be converted to Timed Text -- like in the example I already gave. To mux ass subs into MKV you can just remove the conversion to Timed Text and change the output format to mkv:

ffmpeg -i 1280.mp4 -i 1280.ass -c:v copy -c:a copy -c:s copy output.mkv

If so you'd be replicating MKVtools, so what's the point.

It's usually good to have options. MKVToolNix can't mux into MP4.

Would it be quicker or what would be its advantage?

I've never compared the speed. I doubt it would be much different.

[MHHMHH]

You are really a fountain of information!

You are right - MKVTools does not mux into mp4, but the workaround for this is Handbrake, which will mux into mp4, and will accept ass subtitles.
The other program, VSDC, has a lot of video editing tools making it a kind of video Photoshop, but it will not mux the input subtitles, and will not accept ass subs.

Luckily for us, the aphorism still holds true: There are many ways to skin a cat!

[jagabo]

You are right - MKVTools does not mux into mp4, but the workaround for this is Handbrake, which will mux into mp4, and will accept ass subtitles.

Handbrake will re-encode the video, lose quality, and take a long time.

[Selur]

as a side note: mp4box supports srt files for ages, so my guess would be that most mp4box guis should too,...

[MHHMHH]

I don't have ffmpeg on my PC; why don't you use it and upload muxed mkv and mp4 files, using the files I uploaded, so I can compare them with Handbrake. The video is tiny, so it shouldn't take much time.

I'd like to see the results. and maybe it's time for me to look at ffmpeg again. It has always scared me.

[jagabo]

Keep in mind that not all players will show embedded soft subs.

[MHHMHH]

https://files.videohelp.com/u/297490/1280.mp4

The above file is a muxed Handbrake file, For whatever reason Handbrake labelled it an m4v, but it wouldn't upload unless I changed its name to an mp4.
Maybe you can now compare these files for whatever differences exist.

[jagabo]

As expected, the Handbrake re-encoded video is lower quality. If it had been a 2 hour long movie it might have taken you an hour to reencode. Remuxing would only take a few minutes.

[MHHMHH]

I don't see any differences on my laptop or on my flat screen TV. It would be nice to know if you are using any criteria other than visual, and if so, what are they.

One other thing; there seem to be a number of ffmpeg front end (GUI) available. Do you have any preferences?

Thanks

[jagabo]

I compared them visually -- zooming in on still frames. Small low contrast detail is gone in the Hanbrake video. Edges of moving objects are rougher. Why waste time and reduce quality re-encoding the video when you can retain all the quality by simply muxing the subs? You can do the muxing with a batch file, even a whole folder full of files at once, reducing the effort to nearly nothing.

[MHHMHH]

OK, what about an ffmpeg gui?

[jagabo]

ProWo already suggested his ffmpeg GUI.

[MHHMHH]

Hello Again,

Perhaps you might make a few more comparisons. I used VSDC to convert the original mp4 to mkv and mkv with subtitles. If you will, could you compare these files with the ffmpegs you posted.
https://files.videohelp.com/u/297490/1280.mkv
https://files.videohelp.com/u/297490/1280_subs.mkv

Thanks

[ProWo]

You have lost quality unnecessarily and you have burned in the subtitles, which in most cases is undesirable and disturbs the picture quality.
For example, if you watch a movie with Ar 2.35:1 on the TV, there are black bars at the top and bottom.
The soft subtitles are displayed in this black area and do not interfere with the picture, unlike the burned-in subtitles.
If you use mkv as container, then you can set the soft subtitles as forced, i.e. on a pc they are displayed automatically by the player, with mp4 you can't set the forced flag (at least not with ffmpeg).
On TVs the forced flag is detected on some, not on others. Then you have to activate the subtitle in the TV player menu.
The soft subtitles are already included in jagabo's post #15. Download the two versions to a USB stick and watch them on your TV.
If it works, you can simply add the subtitles in the future without quality loss. This can be done g.e. with my clever FFmpeg GUI.

[jagabo]

Hello Again,

Perhaps you might make a few more comparisons. I used VSDC to convert the original mp4 to mkv and mkv with subtitles. If you will, could you compare these files with the ffmpegs you posted.
https://files.videohelp.com/u/297490/1280.mkv
https://files.videohelp.com/u/297490/1280_subs.mkv

Stop wasting your time re-encoding videos with hard subs. You only want to do that when you have a player that can't display soft subs.

[MHHMHH]

I only did it because VSDC won't do softcoded subs. Does the file without the subs show up as degraded?

[jagabo]

I only did it because VSDC won't do softcoded subs. Does the file without the subs show up as degraded?

Both of the files are degraded. By the reduced frame size and by the re-encoding. Quality is always lost when re-encoding with lossy codecs. That's why they're called "lossy" -- they discard some details to get more compression.