init.mp4 contains first segment and first segment empty

[James009]

Hello when using the latest version (4.4) of ffmpeg on linux, I run into a strange issue when converting mp4 to hls with fmp4 segment.

the init.mp4 file doesn't not contain the headers info. but rather the first segment and the first segment empty.

How to reproduce:

% ffmpeg -i /test/video.mp4 -c copy -hls_time 10 -hls_playlist_type vod -hls_segment_type fmp4 -tune zerolatency -hl -hls_segment_type fmp4 -tune zerolatency -hls_fmp4_init_filename init.mp4 /test/org.m3u8

On version 4.3.1 and below this work as expected and doesn't seem to be an issuse.

but on 4.4 I is where I run it to this issue, build I tested that has this issue:
​https://pkgs.alpinelinux.org/package/edge/community/x86_64/ffmpeg
And
​https://hub.docker.com/r/jrottenberg/ffmpeg/ (jrottenberg/ffmpeg:4.4-alpine)

Thank you.