[FFmpeg-user] help to use -atag

[Stefano Sabatini]

On date Thursday 2011-03-17 20:01:42 -0300, rramos at unl.edu.ar encoded:
> Hello
> I need to tag to mp3 for separate MP3 audiobooks into chapters for
> blind people.
> I used the option -atag to try to create a tag called Chapter 1
> as follows:
> 
> ffmpeg -i audio.mp3 -atag chapter1 audio.mp3
> 
> The resulting ouput was av_internal_write_frame(): Error while opening file
> 
> And try:
> 
> ffmpeg -i clasicos.mp3 -ss 00:00:00 -atag c/tag clasicos.mp3
> ffmpeg -i clasicos.mp3 -ss 00:00:00 -atag fource/chap clasicos.mp3
> 
> But the resulting output file was the same, has no tag.
> 
> How to use the -atag to generate multiple tag in the audio?
> Is it possible to insert tags to an audio and followed with any MP3
> player, and someone can jump from chapter to chapter?

You're looking for the -metadata title='...' option, e.g. -metadata
title="Chapter 1". 

-atag is used for a completely different usage (force the audio FourCC
of the output file, which you shouldn't do if you don't know what it
means).
-- 
ffmpeg-user random tip #3
Some few multimedia formats (mpeg-1, mpeg-2:PS, DV) support physical merge 
consistency, which means you can merge two files with cat. E.g.:
cat input1.mpeg input2.mpeg > output.mpeg
See: http://www.ffmpeg.org/faq.html#SEC25