Concat video files of different resolutions using FFmpeg

Question

I am using FFmpeg to concat videos in my android application.I have followed some of the steps to merge videos of different formats. For mp4 videos, i have to convert all input files to MPEG-2 TS files and then merge all the .ts files to get an output mp4 file.

• I have a problem in merging the videos if they are of different resolutions(say one is 640*480 and the other is 1280*720).The output video does not merge properly(sometimes it throws an error in Streams). Is there any way to handle this without losing the quality of videos?

• Lets say i am merging two videos one with audio and the other without audio.When i try to merge these two i am getting errors in Audio Streams.Is there any way to handle this also(videos should be merged with or without audio)?

I am facing problems in above two things and spent more time without success. Any idea is greatly appreciated.

Answer 1

For merging videos you need to work with the same resolution, you should scale the 640x480 video or compress the 1280x720, it is up to you. I would recommend you compress the bigger one it is faster.

Moreover, for merging videos you need a media file with audio and video part. You can create a silence audio with the same duration of your video and after you can add it to your video. Videos should be merged with audio.

ffmpeg -ar 48000 -t 60 -f s16le -acodec pcm_s16le -i /dev/zero -ab 128K -f mp2 -acodec mp2 -y silence.mp2

ffmpeg -i video_without_audio.mpg -i silence.mp2 video_to_merge.mpg