ffmpeg concat video different resolutions

Concatenating Videos with Different Resolutions using FFmpeg

In today's world of on-demand video, it's becoming increasingly common for people to consume content across various devices and platforms. With the rise of streaming services, we often find ourselves wanting to watch our favorite videos at any time and from anywhere. However, some streaming services have restrictions in place that prevent us from downloading or saving their videos locally. This is where concatenating multiple video files into one using FFmpeg comes in handy.

FFmpeg is a powerful, open-source command-line tool that allows you to manipulate audio and video files with ease. One of its most useful features is the ability to concatenate multiple video files into a single file. However, when dealing with videos of different resolutions, things can get a bit tricky.

Recently, I encountered an issue where I was trying to create a single mp4 file by concatenating several smaller video files using FFmpeg. The process seemed straightforward enough, but I kept running into errors due to the varying resolutions and colorspaces of the input files.

The first error message I received indicated that the file was almost complete (99%) when it suddenly stopped processing. After some troubleshooting, I tried modifying the command by adjusting the -vf and -format options, but this didn't seem to make a difference.

Upon further investigation, I discovered that FFmpeg is quite particular about matching colorspace between input files. When it encounters a file with a different resolution or colorspace than the previous one, it will throw an error. This can be frustrating when you're trying to concatenate multiple files of varying resolutions into a single output file.

So, how do we overcome this issue? One solution is to use FFmpeg's scale filter to resize the input files to match a common resolution before concatenating them. Another approach is to convert all the input files to a common colorspace before concatenation.

To combine multiple files with different resolutions using FFmpeg, you can try the following command:

```

ffmpeg -f concat -i input.txt -c:v libx264 -crf 18 output.mp4

```

In this example, `input.txt` is a text file that contains the list of input files to be concatenated. Each line in the file should specify the input file followed by its start time and duration (e.g., `file 'in1.flv' -c:v 0 -t 00:00:10`).

If you encounter issues with colorspace mismatches, you can try adding the scale filter to your FFmpeg command:

```

ffmpeg -f concat -i input.txt -vf scale=w:h -c:v libx264 -crf 18 output.mp4

```

Replace `w` and `h` with the desired width and height for the scaled video.

In conclusion, concatenating multiple videos with different resolutions using FFmpeg can be a bit more challenging than expected. However, by understanding how to work around these issues and using the right tools and techniques, you can successfully merge your favorite videos into a single file that's ready to watch on any device.

Ffmpeg concat video different resolutions