This project exists to work with the FFMpegCore .NET library for analyzing and transcoding audio files. The nested C# projects test use cases for passing data into and getting data out of the FFMpegCore, and are described individually below.
cd App1
dotnet run -in ../sample_data/test.wav -- expect: 2643
dotnet run -in ../sample_data/test.mp3 -- expect: 2690
cd App2
dotnet run -in ../sample_data/test.wav -out ../generated_data/test-wav.webm
dotnet run -in ../sample_data/test.mp3 -out ../generated_data/test-mp3.webm
dotnet run -in ../sample_data/B01___01_Matthew_____ENGCAVN2DA.mp3 -out ../generated_data/MATT1.webm
Expected size: 452,473 bytes
Expected duration: 195000 ms
This is a stripped down version of App1 for testing FFProbe with a MemoryStream. The input file's data is put into a stream prior to being sent through the FFMpegCore library.
Unfortunately this does not seem to work as we want it to due to the encoding used: https://trac.ffmpeg.org/wiki/FFprobeTips#Streamduration
cd App3
dotnet run -in ../sample_data/test.mp3
This is basically App2 and App3 combined. Many lines are commented, showing testing of options to tweak results. Duration is grabbed from the stderr output that is generated during transcoding operation.
cd App4
dotnet run -in ../sample_data/test.mp3 -out ../generated_data/test-mp3.webm
This builds on App4 and adds additional piped input for appending audio streams.
cd App5
dotnet run -in ../generated_data/test-wav.webm -in ../generated_data/test-mp3.webm -out ../generated_data/test-concat.webm
- FFProbe may not be able to determine the duration of certain audio formats. (See link below for more details). Due to the duration being output by FFmpeg, we were able to use the information from there during processing of audio.
- When processing streams, the
-f webmparameter may be necessary to force the audio format. Without this, you may encounter errors notifying you of a broken pipe. - If you find that no data is being output, it may be that the position of your input stream(s) need to be reset prior to processing.
- FFmpeg places information on
stderr. When using FFMpegCore, theNotifyOnErrorfunction can be used to parse this information. The callback you provide is called for each line sent to stderr.