[FFmpeg-user] question about joining multiple video files

[Alex Yelluas]

Hello fellow ffmpeg users,

I've been trying to figure out how to join multiple files, and finally
found a solution that works, but it's not very clear to me.

Basically the idea is to convert orignal files into mpegts like this:

ffmpeg -i sample_fxp_17kbps_sample_1.mp4 -f mpegts -vcodec copy -acodec
copy -vbsf h264_mp4toannexb sample_fxp_17kbps_sample_1.ts
ffmpeg -i sample_fxp_17kbps_sample_2.mp4 -f mpegts -vcodec copy -acodec
copy -vbsf h264_mp4toannexb sample_fxp_17kbps_sample_2.ts

and then join them like this:

ffmpeg -isync -i
"concat:sample_fxp_17kbps_sample_1.ts|sample_fxp_17kbps_sample_2.ts"
-vcodec copy -acodec copy merged.mp4

Why do i need to create the mpegts files?

What specifically does mpegts provide that makes this possible?

Why doesn't it work directly work from mp4? (i tried and it didn't work,
files don't get concatenated, only the 1st file is present in the
merged.mp4)

Thank you,

Alex