FFmpeg Conversion – How to Convert MKV to MP4 with Subtitles and Change DTS to AAC or AC3

audioconversionffmpegvideo

I have some MKV files that I would like to copy to my PS3, so I have to convert them.

Someone told me the easiest way without losing quality would be with ffmpeg.

However, I want them to have subtitles and when I use:

ffmpeg -i in.mkv -vcodec copy -acodec copy out.mp4

…they don't appear in my PS3.

Furthermore, some files have DTS audio – how can I convert them so I have audio in my PS3?

Is it possible to do everything with ffmpeg?

And one of my files, when I converted it, it ran too slowly in my PS3 as if it was in slow motion – Can I do anything to change that? Also, the subtitles are "inside" the MKV file. Do I need to do something different?

Best Answer

-acodec copy implies that you maintain the audio codec. Also, if your PS3 cannot keep up with the video codec, I would recommend converting everything.

The loss of quality in the conversion is usually negligible for video playback.

Try this:

ffmpeg -i in.mkv -c:v libx264 -c:a libvo_aacenc -b:v 35M -b:a 224k out.mp4

NOTE this values are quite high to start, so you could try lowering them if the file size is too much: 35M for 1080p, 15M for 720p, 5M for 480p

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FFmpeg – How to Convert MKV to Lossless MP4 for iOS on Windows

MP4 is indeed the best format for Apple devices and software. DTS is also indeed not supported, many MP4 video files contain two audio tracks, one DTS and one AAC.

There are multiple encoders available, all of them documented on the ffmpeg wiki. Which codec is available depends on how ffmpeg was compiled. libfdk_aac will give you the best results, but due to this codec being non-free it's not always available.

Things you can try (I put them in the order of my perceived quality, best first)

ffmpeg -i input.mkv -c:v copy -c:a libfdk_aac -b:a 128k output.mp4
ffmpeg -i input.mkv -strict experimental -c:v copy -c:a aac -b:a 192k output.mp4
ffmpeg -i input.mkv -c:v copy -c:a libfaac -b:a 192k output.mp4

If you want to retain the DTS track too, use the -map flag.

Not directly of use for OP, but the OS X program subler makes this process very easy.

EDIT: Comments tl;dr? OP solved problem with the following command

ffmpeg -i input.mkv -strict experimental -map 0:0 -map 0:1 -map 0:2 -map 0:3 -c:v copy -c:a aac -b:a 384 -c:s copy output.mp4

TIP: if -c:s copy for subtitles doesn't work, try -c:s mov_text.
Saved me on multiple occasions.

.MKV to .MP4 with 2 soundtrack (audio)

ffmpeg does not automatically map all tracks; default stream selection will only map one audio, one video, and one subtitle track to the output. If you want to map all streams, use -map 0. If you want to be able to select what to map, you'll have to parse the input file first (ffmpeg -i input.mkv) and use some scripting to construct the final conversion command. ffprobe can be helpful for that. See FFmpeg Wiki: FFprobe Tips for examples.

You can specify -c copy to stream copy all streams, no matter what type they are. You can also index video and audio streams separately, so your command can be shortened to:

ffmpeg -i input.mkv -c copy -map 0 output.mp4

Best Answer

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FFmpeg – How to Convert MKV to Lossless MP4 for iOS on Windows

.MKV to .MP4 with 2 soundtrack (audio)

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