[FFmpeg-user] Extract audio from video and use one frame as cover image

[Bernhard Döbler]

Hi,

I saw, today, FFMpeg, finally, allows for embedding a single image as 
cover image into an .M4A file using the "-disposition:v:1 attached_pic" 
argument as explained in an answer on StackOverflow: 
https://stackoverflow.com/a/61015965/577052

This works very well, when I convert a .FLAC file, that already has one 
single frame embedded as cover, to .M4A using a command line like
ffmpeg.exe -y -i "e:\01. Music.flac" -c:a aac -q:a 2 -c:v mjpeg -q:v 2 
-disposition:v:0 attached_pic -movflags +faststart "e:\01. Music.m4a"

I have video files. I want to extract the audio and use one single frame 
from the video track as cover image.
The command line looks like this
ffmpeg.exe -y -i "e:\01. Video.mp4" -filter:v 
"select=between(145\,prev_pts*TB\,pts*TB)" -frames:v 1 -c:a copy -c:v 
mjpeg -q:v 2 -disposition:v:0 attached_pic "e:\01. Audio.m4a"

This is supposed to embed a frame from around second 145 as cover image.
The issue is that the whole processing of the file stops after the 
single image was extracted and my resulting file has a length of 2:25 
minutes. I want the audio file to be as long as the video.

To overcome this, I provide the same video file twice as input and 
select the audio track of one file and the video track from the other 
using the map argument.
ffmpeg.exe -y -i "e:\01. Video.mp4" -i "e:\01. Video.mp4" -filter:v 
"select=between(145\,prev_pts*TB\,pts*TB)" -frames:v 1 -map 0:1 -map 1:0 
-c:a copy -c:v mjpeg -q:v 2 -disposition:v:0 attached_pic "e:\01. Audio.m4a"

This works!

I'm now wondering if there's a way to make this work providing the input 
file only once, selecting a single frame and the whole audio.

Is there a best practice to convert video files to audio files 
maintaining one single frame a cover image?


Best,
Bernhard