FFMPEG Merge mp4 to mp4 batch

Question

Hi sorry if this has already been asked but ive got intro.mp4 and over 1000 mp4 in another folder what i need is intro.mp4 to be added to every mp4 in folder im using ubuntu whats the best way to do this.

all the mp4 have the same encoding

ffmpeg -i intro.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate1.ts
ffmpeg -i 1.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate2.ts
ffmpeg -i "concat:intermediate1.ts|intermediate2.ts" -c copy output.mp4

this command words for one at a time this my attempt at batch but the var doesnt work

for f in *.mp4; do ffmpeg -i "$f" -c copy -bsf:v h264_mp4toannexb -f mpegts "$f.ts"; done

this code works fine

 for i in *.mp4;  
do
test="concat:intro.mp4.ts|"${i%.*}".mp4.ts";
ffmpeg -i  "$test" -c copy anime2/"${i%.mp4}.mp4"; done

Got it working with these 2 commands did the whole batch in one script

 for f in *.mp4; do ffmpeg -i "$f" -c copy -bsf:v h264_mp4toannexb -f mpegts "$f.ts"; done


     for i in *.mp4;  
    do
    test="concat:intro.mp4.ts|"${i%.*}".mp4.ts";
    ffmpeg -i  "$test" -c copy anime2/"${i%.mp4}.mp4"; done

thank you

Answer 1

The parameters must match so first you must conform the intro to match the other videos (or vice versa).

Use ffprobe to view differences:

ffprove -loglevel error -show_streams intro.mp4
ffprove -loglevel error -show_streams 1.mp4

Re-encode intro.mp4 to match 1.mp4:

ffmpeg -i intro.mp4 -filter_complex "[0:v]fps=500/21,scale=848:480:force_original_aspect_ratio=increase,crop=848:480,setsar=171/170[v]" -map "[v]" -map 0:a -c:v libx264 -profile:v main -c:a aac -ar 44100 intro_b.mp4

Now use the concat demuxer. Make a text file listing inputs to be concatenated:

file 'intro_b.mp4'
file '1.mp4'

Then concatenate:

ffmpeg -f concat -i input.txt -c copy output.mp4