Question 1

How to convert video to MP3 using FFmpex in Elixir?

Accepted Answer

Use the builder API to add an input file, specify audio stream options for MP3 codec, and set an output file with .mp3 extension. Refer to FFmpeg documentation for codec specifics and use FFmpex's stream specifiers for audio.

Question 2

FFmpex vs direct System.cmd for running FFmpeg in Elixir?

Accepted Answer

FFmpex offers a structured, type-safe API that reduces string manipulation errors and integrates better with Elixir patterns. Direct System.cmd is more flexible but requires manual command building and error handling, making FFmpex preferable for complex or repetitive tasks.

Question 3

Can FFmpex handle merging multiple video files?

Accepted Answer

Yes, by adding multiple input files and using FFmpeg's concat filter or demuxer options. Construct the command with appropriate file options and output specifications, but you need to understand FFmpeg's merging syntax as FFmpex doesn't abstract this.

Question 4

How to extract thumbnails from video with FFmpex?

Accepted Answer

Add input and output files, then use stream options with the -vf (video filter) for thumbnail extraction, such as setting frame rates or timestamps. Check FFmpex examples or FFmpeg docs for precise filter parameters.

Question 5

FFmpex configuration for custom FFmpeg path in Docker?

Accepted Answer

Set the ffmpeg_path in your application config (e.g., config/prod.exs) to point to the FFmpeg binary inside the Docker container. Ensure the path is accessible and the binary has execution permissions.

Question 6

FFmpex error handling and debugging examples?

Accepted Answer

The execute function returns {:ok, output} or {:error, reason}; pattern match on errors and log FFmpeg's stderr output. Use Elixir's built-in error handling, but note that FFmpex doesn't provide detailed error parsing beyond what FFmpeg outputs.

ffmpex

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