Can I use ffmpeg to output JPEGs to a memory strea

问题:

I have a C# app. I have 100 JPEGs (for an example).

I can easily encode this into a video file.

When it has finished encoding on the client app I FTP upload to my server.

It would be 'neater' if I could not write the video file to a disc but instead write it to a memory stream (or array of bytes) and upload via web service perhaps?

I have checked out the ffmpeg documentation but as a C# developer I do not find it natural to understand the C examples.

I guess my first question is it possible, and if so can anyone post an example code in C#? At the moment I am using the process class in C# to execute ffmpeg.

回答1:

Your process method is already good, just needs adjustments:

1. Set StartupInfo.RedirectStandardOutput = true and StartupInfo.UseShellExecute = false.
2. Instead of an output file name, call ffmpeg with pipe:, which will make it write to the standard output. Also, since the format cannot be determined from the file name anymore, make sure you use the -f <format> switch as well.
3. Start the process.
4. Read from Process.StandardOutput.BaseStream (.BaseStream, so the StreamReader that is .StandardOutput doesn't mess anything up) while the process is running into your memory stream.
5. Read anything still remaining buffered in Process.StandardOutput.BaseStream.
6. Profit.

I coded a thumbnailer a while back (BSD 2-clause), that has actual code that demonstrates this. Doesn't matter if it is an image or a video coming out of ffmpeg in the end.