问题
I am trying to add text subtitles to an .mp4 container using ffmpeg:
ffmpeg -i input.mp4 -i input.srt -map 0.0 -map 0.1 -map 1.0 output.mp4
When I am trying to run this line, it gives me an error :
Nmber of stream maps must match number of output streams.
If I try to change the mp4 to mkv (although mp4 supports text subtitles), like this:
ffmpeg -i input.mp4 -i input.srt -map 0.0 -map 0.1 -map 1.0 output.mkv
It correctly maps the streams, but gives an error :
Encoder (codec id 94210) not found for output stream #0.2
When I launch
ffmpeg -codecs
I can see that srt codec is supported as decoder and encoder, however I am not sure what is used for mp4 and mkv subs encoding, and whether I need to switch it on or compile separately.
回答1:
ffmpeg -i infile.mp4 -i infile.srt -c copy -c:s mov_text outfile.mp4
-vf subtitles=infile.srt will not work with -c copy
The order of -c copy -c:s mov_text is important. You are telling FFmpeg:
- Video: copy, Audio: copy, Subtitle: copy
- Subtitle: mov_text
If you reverse them, you are telling FFmpeg:
- Subtitle: mov_text
- Video: copy, Audio: copy, Subtitle: copy
Alternatively you could just use -c:v copy -c:a copy -c:s mov_text in any
order.
回答2:
Use the libass library (make sure your ffmpeg install has the library in the configuration --enable-libass).
First convert the subtitles to .ass format:
ffmpeg -i subtitles.srt subtitles.ass
Then add them using a video filter:
ffmpeg -i mymovie.mp4 -vf ass=subtitles.ass mysubtitledmovie.mp4
回答3:
You are trying to mux subtitles as a subtitle stream. It is easy but different syntax is used for MP4 (or M4V) and MKV. In both cases you must specify video and audio codec, or just copy stream if you just want to add subtitle.
MP4:
ffmpeg -i input.mp4 -f srt -i input.srt \
-map 0:0 -map 0:1 -map 1:0 -c:v copy -c:a copy \
-c:s mov_text output.mp4
MKV:
ffmpeg -i input.mp4 -f srt -i input.srt \
-map 0:0 -map 0:1 -map 1:0 -c:v copy -c:a copy \
-c:s srt output.mkv
回答4:
MKV container supports video and audio codecs Virtually anything and also supports subtitles and DVD menus. So you can just copy codecs from input video to output video with MKV container with subtitles. First you should convert SRT to ASS subtitle format
ffmpeg -i input.srt input.ass
and embed ASS subtitles to video
ffmpeg -i input.mp4 -i input.ass -c:v copy -c:a copy -c:s copy -map 0:0 -map 0:1 -map 1:0 -y out.mkv
Also worked with VMW file.
ffmpeg -i input.wmv -i input.ass -c:v copy -c:a copy -c:s copy -map 0:0 -map 0:1 -map 1:0 -y out.mkv
see the wiki page Comparison of container formats
回答5:
ffmpeg supports the mov_text subtitle encoder which is about the only one supported in an MP4 container and playable by iTunes, Quicktime, iOS etc.
Your line would read:
ffmpeg -i input.mp4 -i input.srt -map 0:0 -map 0:1 -map 1:0 -c:s mov_text output.mp4
回答6:
I tried using MP4Box for this task, but it couldn't handle the M4V I was dealing with. I had success embedding the SRT as soft subtitles with ffmpeg with the following command line:
ffmpeg -i input.m4v -i input.srt -vcodec copy -acodec copy -scodec copy -map 0:0 -map 0:1 -map 1:0 -y output.mkv
Like you I had to use an MKV output file - I wasn't able to create an M4V file.
回答7:
I will provide a simple and general answer that works with any number of audios and srt subtitles and respects the metadata that may include the mkv container. So it will even add the images the matroska may include as attachments (though not another types AFAIK) and convert them to tracks; you will not be able to watch but they will be there (you can demux them). Ah, and if the mkv has chapters the mp4 too.
ffmpeg -i <mkv-input> -c copy -map 0 -c:s mov_text <mp4-output>
As you can see, it's all about the -map 0, that tells FFmpeg to add all the tracks, which includes metadata, chapters, attachments, etc. If there is an unrecognized "track" (mkv allows to attach any type of file), it will end with an error.
You can create a simple batch mkv2mp4.bat, if you usually do this, to create an mp4 with the same name as the mkv. It would be better with error control, a different output name, etc., but you get the point.
@ffmpeg -i %1 -c copy -map 0 -c:s mov_text "%~n1.mp4"
Now you can simply run
mkv2mp4 "Video with subtitles etc.mkv"
And it will create "Video with subtitles etc.mp4" with the maximum of information included.
回答8:
Simple Example:
videoSource=test.mp4
videoEncoded=test2.mp4
videoSubtitle=test.srt
videoFontSize=24
ffmpeg -i "$videoSource" -vf subtitles="$videoSubtitle":force_style='Fontsize="$videoFontSize"' "$videoEncoded"
Only replace the linux variables
回答9:
This is the reason why mkv is such a good container, especially now that it's mature:
mkvmerge -o output.mkv video.mp4 subtitle.srt
来源：https://stackoverflow.com/questions/8672809/use-ffmpeg-to-add-text-subtitles