I have been trying to modify the handler_name metadata field of an audio
stream in a video file within an mp4 container.
However, ffmpeg seems to be discarding the handler_name field and replacing
it with a generic "SoundHandler" value.
While the values in the input and output read-outs are correct, at the end
of the copy I see "[mp4 @ 0x558cdfba2000] Unknown hldr_type for text,
writing dummy values".
Here is the command I'm trying to use:
ffmpeg -i mystery_source.mp4 -map 0 -map_metadata 0 -c copy -metadata:s:a:0
I am trying to change these as I forgot to modify the name of the audio
stream when transcoding with HandBrake. I am trying to avoid re-encoding
the file just to rename the audio track (so it appears correctly in
programs such as VLC).
Thanks for any help.
On Wed, Jan 15, 2020 at 21:43:47 -0500, Andrew Brezovsky wrote:
> However, ffmpeg seems to be discarding the handler_name field and replacing
> it with a generic "SoundHandler" value.
I can't reproduce, at least not with my command line.
> Here is the command I'm trying to use:
> ffmpeg -i mystery_source.mp4 -map 0 -map_metadata 0 -c copy -metadata:s:a:0
> handler_name="Stereo" mystery.mp4
> Here is the output: https://pastebin.com/r8kgt7Ny
Please post that right to the list in future mails.
> ffmpeg version 3.4.6-0ubuntu0.18.04.1 Copyright (c) 2000-2019 the FFmpeg developers
This version is quite old, please try a newer one. You can grab a
static binary for your platform from
https://johnvansickle.com/ffmpeg/ (left column, "git master", please) and retry with that.
Here's my input, my conversion, and its output, just to show it
apparently works, changing stream 0:2's handler_name from "Surround
5.1" to "Stereo":