[FFmpeg-user] R: R: Cannot generate a UDP stream of JPEG frames because there's no way to specify JPEG output if the output is not a file?

[Marcello Antonucci]

>> Afaict (and I may of course be wrong), mjpeg is a sequence of jpeg
images.

Almost; to convert From MJPEG to JPEG you have to strip off the AVI header
(that each MJPEG frame has), and then you have to add another header with
specific JPEG information. This is documented in ffmpeg user guide, if you
search for "mjpeg2jpeg". Due to this, however, the conversion from MJPEG to
JPEG is very fast and uses very little CPU.
The bottom line is that I really need to stream in JPEG format, but I am
unable to tell ffmpeg to do so because it seems able to extract the image2
specific format (JPEG, PNG, or what else) only from the extension of the
output file, which in my case is absent.
Can anybody confirm this, i.e., is there a way to specify WHICH image2
format is wanted, when the only wanted output is not a file but just a UDP
stream?