How to Fix: Why do I get "Option 'all' not found" error for adelay filter when trying to create a mosaic video?

                The primary reason for this error is that the adelay filter requires a specific option called 'all' to be set to true in order to work correctly. This option allows the filter to delay all audio streams simultaneously.An alternative reason could be that there might be a typo or incorrect formatting in the command line, preventing FFmpeg from recognizing the adelay filter properly.

            ✅ Best Solutions to Fix It

                Enabling the 'all' Option for adelay Filter

                    Step 1: To enable the 'all' option for the adelay filter, modify the command line to include '-af all=true'. This will ensure that FFmpeg recognizes the 'all' option and applies it correctly.Step 2: Open the command prompt or PowerShell in Windows Terminal and update the original command with the new -af argument. The corrected command should look like this: `ffmpeg -i 1.mp4 -i 2.mp4 -i 3.mp4 -i 4.mp4 -filter_complex "[1]tpad=start_mode=clone:start_duration=15[tr];[2]tpad=start_mode=clone:start_duration=30[bl];[3]tpad=start_mode=clone:start_duration=45[br];[0][tr][bl][br]xstack=inputs=4:layout=0_0|w0_0|0_h0|w0_h0[v];[1:a]adelay=15s:all=true[a1];[2:a]adelay=30s:all=true[a2];[3:a]adelay=45s:all=true[a3];[0:a][a1][a2][a3]amix=inputs=4[a]" -map "[v]" -map "[a]" output.mp4 -af all=trueStep 3: Save the changes and re-run the command. This should resolve the 'Option 'all' not found' error and allow you to create your mosaic video successfully.



                Alternative Fix (Using Separate Audio Filters)

                    Step 1: As an alternative, you can also use separate audio filters for each input video. This approach requires more complex command lines but can be effective in resolving the 'Option 'all' not found' error.Step 2: To implement this method, create a new command line with separate audio filters for each input video. For example: `ffmpeg -i 1.mp4 -i 2.mp4 -i 3.mp4 -i 4.mp4 -filter_complex "[1]tpad=start_mode=clone:start_duration=15[tr];[2]tpad=start_mode=clone:start_duration=30[bl];[3]tpad=start_mode=clone:start_duration=45[br];[0][tr][bl][br]xstack=inputs=4:layout=0_0|w0_0|0_h0|w0_h0[v];[1:a]adelay=15s[a1];[2:a]adelay=30s[a2];[3:a]adelay=45s[a3];[0:a][a1][a2][a3]amix=inputs=4[a]" -map "[v]" -map "[a]" output.mp4


            💡 Conclusion
            By following these steps, users should be able to resolve the 'Option 'all' not found' error and successfully create their mosaic videos. Remember to enable the 'all' option for the adelay filter or use separate audio filters if necessary.