i have no idea where to ask for ffmpeg help :( guess I'll try here

I created a silent file with ffmpeg -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=44100 -t 7 silence.flac

then I tried to put it in between two files by making concat.txt

file 'a.flac'
file 'silence.flac'
file 'b.flac'

and doing ffmpeg -f concat -i input.txt output.flac

however ffmpeg doesn't like that and freaks out with a lot of blocksize 4608 > 4096 decode_frame() failed. it concatenates the two files but not my silence

how do I create a silent file with ffmpeg that has a normal blocksize/will work? (keep in mind that when I looked up 'flac blocksize' the only documentation I could find pointed directly to the ffmpeg source code and I'm not reading that lol)

@genevieve are you trying to do it without resampling / re-encoding ?

Honestly in my experience ffmpeg just does this sometimes. I use it quite a bit and I've never found any real solutions to these bugs / issues. I've had errors like this when concatting videos and also when trying to compress a single video.

I don't like it but the only solution I've found that works involves resampling. Sometimes if I convert the videos(s) or resample them, I can get it to work. If they are really high quality to start you might not notice the difference from it being re-encoded an extra time

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@genevieve sometimes I have to use a different program to resample / convert them 1stin order to make it work. For example I had this with a screen capture video on Mac osx. It was 300mb and I wanted to compress it properly using ffmpeg. But it would crash like this if I tried to convert it directly.

I tried to convert it using apples built in video program but it had a slider for the quality level and the lowest quality was way too high ( I don't think it was using variable bit-rate, so it was very bad at compressing screencasts). So it was like 70mb in the end.

After that I exported it at high quality via the built in video program, then tried to compress it properly from there with ffmpeg. It worked and I got it down to ~5mb before it started losing too much quality.

Might have been a bit better if it was only re encoded once but it worked out for what I wanted.

@genevieve maybe you could try generating the silence in a different way, like by recording silence and converting it to flac, or something. Or maybe if it was very quiet but not quite silent it might help

@genevieve I love ffmpeg but its so annoying to use sometimes 🫠

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