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How can I remove all metadata from all formats via FFmpeg?

I can just set special metadata for each format per man ffmpeg. Any option or method to clear all metadata and strip media from all metadata available on ffmpeg?

   -metadata key=value
       Set a metadata key/value pair.

       For example, for setting the title in the output file:

               ffmpeg -i in.avi -metadata title="my title" out.flv
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2 Answers 2

Slightly modifying the command line by @izx, I got this:

ffmpeg -i in.mov -map_metadata -1 -c:v copy -c:a copy out.mov

The result is (again, checked with exiftool), a metadata record reduced from 81 to 52 lines. Note that you can't simply remove all metadata, some things will stay. However, I didn't get the creation date to change, which is strange because it seemed to work in the Ubuntu version.

I posted on the FFmpeg mailing list, asking whether there were any updates or comments on that. Let's see what they have to say.

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In mov or mp4 files, creation date is an integer field in the movie header and track headers (expressed as seconds since 1904). Although you could set it to 0 or some other fixed value, there is no way to remove it and still have a valid mov or mp4 file. –  mark4o Dec 18 '12 at 7:34
    
I know I couldn't remove it entirely, but changing wasn't possible for some reason. –  slhck Dec 18 '12 at 7:39
    
Using the current ffmpeg, the creation time can be changed with -metadata creation_time=2012-12-17T21:30:00 (UTC). –  mark4o Dec 18 '12 at 7:46
    
How can i modify this to remove the title too? Currently it sets the title to something automatically generated. I want to see the full filename as title in the end. –  Rookie Jun 15 at 11:26
    
@Rookie Then you need to set -metadata title="Some Value". Or, for a file, something like this for an MP4 file: ffmpeg -i "$file" -map_metadata -1 -c copy -metadata title="$file" "${file%%*.mp4}-new.mp4 –  slhck Jun 15 at 13:25

NOTE: I have since gotten an up-to-date ffmpeg (not the outdated version of avconv in the Ubuntu repositories), and now shlck's -map_metadata -1 works perfectly. If you can, use that solution instead (less typing). I'm leaving this here for anyone using an outdated version.


The easiest way to do this is to set -map_metadata to use one of the input streams, rather than using global metadata. 99% of the time this should work. NOTE: I'm using avconv, because that's in the Ubuntu 12.04 repositories; this will probably be drop-in compatible with ffmpeg, since their syntax always is in my experience.

avconv -i input.mp4 -map 0 -map_metadata 0:s:0 -c copy output.mp4

This will take the metadata from the first data stream (normally the video stream) and use that to replace the global metadata of the container file. This works because most of the time, the data streams have no meaningful metadata written to them; however, sometimes they do, and you want to completely get rid of that metadata. Unfortunately, the only way I can think of to do this used a pipe and two avconv processes.

avconv -i input.mp4 -f wav - | avconv -i - -i input.mp4 -map 1 -map_metadata 0 -c copy output.mp4

This takes advantage of the fact that WAV files can't contain metadata (since the format was created before metadata tags existed).

Both of these methods blanked all metadata on a file I just tested them on - all that exiftool reported on was the codec information, and avprobe reported no metadata to me. Using a pipe for this is pretty ugly, and the first method will work in 99% of cases, so that should be preferred.

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