Goal:

The goal of this blog is to convert .webm files to .mp4 format with re-encoding using ffmpeg command

Input:

Sample webm video .

To check the video file properties like codec formats , bitrate , etc., please run the below command

ffprobe <file_location>

For example
ffprobe sample.webm

Process:

To converts webm to mp4 with re-encoding , run the below command

ffmpeg -y -i <input_webm_file_path> -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k <output_mp4_file_path>

-y : Overwrite output files without asking for confirmation.

-i <input_webm_file_path> : Specify the input file.

-c:v libx264 : Set the video codec to H.264 using the libx264 library. H.264 is a widely supported video codec.

-crf 23 : Set the constant rate factor (CRF) for the video. Lower values result in higher quality but larger file sizes, and higher values result in lower quality but smaller file sizes. The default value is 23. Adjust this value according to your desired trade-off between quality and file size.

-preset medium : Set the encoding preset for the video. The preset determines the trade-off between encoding speed and output file size. The available options are ultrafast, superfast, veryfast, faster, fast, medium (the one used in this example), slow, slower, veryslow, and placebo. Choose the preset that suits your requirements.

-c:a aac : Set the audio codec to AAC. AAC is a commonly used audio codec.

-b:a 128k : Set the audio bitrate to 128 kbps. Adjust this value if you want a different audio bitrate.

<output_mp4_file_path> : Specifies the output file path

For Example

ffmpeg -y -i sample.webm -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k output.mp4

Result:

After running the command, an mp4 converted output file will be generated.

To check the output file properties , run ffprobe <output_file> command

How to convert a video from webm format to mp4 format using FFmpeg.