Conversion of webm to mp4 with streams

[cakong10]

Is it possible to convert a webm input stream to mp4 output stream? I tried to do so in my code but always get a pipe is broken error.

Also, is it possible to use the FFMpegCore DLL by itself, or do I always need to have the .exe file in my repository as well?

[tiesont]

For your second question, FFMpegCore is managed code, ffmpeg is not. FFMpegCore is more or less Pinvokeing the exe on your behalf. So, yes, you need a compiled executable.

For your first question, WebM is a container format, which may or may not already contain an H.264 file of some sort. You can convert it (almost anything you can do with ffmpeg can be done in FFMpegCore, with enough patience). Here's a Q&A from Stack Overflow that gives some examples: https://stackoverflow.com/questions/18123376/webm-to-mp4-conversion-using-ffmpeg

[rosenbjerg]

No what you are attempting is not possible. mp4 requires a seekable stream, which means that you cannot output to a stream but only to a file.
And as @tiesont mentioned, this is just a library that wraps ffmpeg, so the actual ffmpeg/ffprobe binaries are required.