ffmpeg: Combine/merge multiple mp4 videos not working, output only contains the first video

Question

Here is the command I am using to combine multiple videos:

ffmpeg -i 75_540_38HQ2.mp4 -i 76_70_20.mp4 -i 76_173_80.mp4 -i 81_186_35.mp4 -vcodec copy -acodec copy M         


        

Answer 1

You have to convert them into an MPEG format that can be easily concatenated. Below is a script I use and call "ffcat" for my GoPro videos. It essentially runs several "ffmpeg -i" commands which produce concatenate-able MPEG, which is piped to an ffmpeg command that then converts them to an H.264 mp4 file.

It also sizes the videos to 720p but you may not want that.

The "h264options" are flags I recently found on the internet at h264.code-shop.com

Hope this helps, Reid

---

cmd="( "

h264options="-vcodec libx264 -b 512k -flags +loop+mv4 -cmp 256 \
 -partitions +parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 \
 -me_method hex -subq 7 -trellis 1 -refs 5 -bf 3 \
 -flags2 +bpyramid+wpred+mixed_refs+dct8x8 -coder 1 -me_range 16 \
   -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -qmin 10\
 -qmax 51 -qdiff 4"

outfile="out-`date +%F-%H%M.%S`.mp4"

for i; do
    cmd="${cmd}ffmpeg -i $i -ab 256000 -vb 10000000 -mbd rd -trellis 2 -cmp 2 -subcmp 2 -g 100 -f mpeg -; "
done
cmd="${cmd} ) | ffmpeg -y -i - -threads 8 ${h264options} -vb 10000000 -acodec libfaac -ar 44100 -ab 128k -s 1280x720 ${outfile}"
echo "${cmd}"
eval ${cmd}