Converting video formats and copying tags with ffmpeg

Question

I\'ve been trying to convert some videos I took on my camera to a compressed format in order to save some storage space. I figured out how to use ffmpeg to convert the video

Answer 1

Have a look at the documentation on dumping and loading metadata:

FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded INI-like text file and then load it back using the metadata muxer/demuxer.

The process might look something like this:

# First extract metadata
ffmpeg -i original.mov -f ffmetadata metadata.txt
# Next, transcode, including extracted metadata
ffmpeg -i original.mov -f ffmetadata -i metadata.txt compressed.mp4

I don't have a metadata-ful video to test with right now, but something like that should work.

Answer 2

Use "-map_metadata 0:g" to copy all global metadata.

0 means Input #0. g means global metadata.

Here's my ffprobe result. enjoy!

input.mp4

[FORMAT]
filename=input.mp4
nb_streams=2
nb_programs=0
format_name=mov,mp4,m4a,3gp,3g2,mj2
format_long_name=QuickTime / MOV
start_time=0.000000
duration=60.560500
size=190252680
bit_rate=25132246
probe_score=100
TAG:major_brand=mp42
TAG:minor_version=1
TAG:compatible_brands=mp42avc1
TAG:creation_time=2016-05-14 10:01:17
[/FORMAT]

output.mp4

[FORMAT]
filename=output.mp4
nb_streams=2
nb_programs=0
format_name=mov,mp4,m4a,3gp,3g2,mj2
format_long_name=QuickTime / MOV
start_time=0.000000
duration=60.632000
size=38636429
bit_rate=5097826
probe_score=100
TAG:major_brand=isom
TAG:minor_version=512
TAG:compatible_brands=isomiso2avc1mp41
TAG:creation_time=2016-05-14 01:01:17
TAG:encoder=Lavf57.36.100
[/FORMAT]

Answer 3

To write all metadata (global, video, audio) to a file use

ffmpeg -i in.mp4 -c copy -map_metadata 0 -map_metadata:s:v 0:s:v -map_metadata:s:a 0:s:a -f ffmetadata in.txt

To add all metadata from a file use

ffmpeg -i in.mp4 -f ffmetadata -i in.txt -c copy -map_metadata 1 out.mp4