[FFmpeg-user] How to append silence to AAC without reencoding

[Costin Chirvasuta]

Hello,

Is it possible to add silence to an AAC file without reencoding?

I'm trying to concatenate AAC files with the same encoding (but from
different encoders) and it works fine for AAC-LC but HE-AACv1 and
HE-AACv2 have frames with the SBR extension and these frames depend on
previous frames. I want to get a silence frame with SBR settings that
match a certain AAC encoded file so I can add it between concatenated
files. This works well right now if I search the file I want to add
for frames with low volume and an SBR header (frames that have
bs_header_flag set) and add it in between. If I don't add this frame
the first few frames from the second file aren't properly decoded and
I get "Expected to read %d SBR bytes actually read %d" errors.

Thanks.