[FFmpeg-user] Piping from FFmpeg to FFplay

[Michael Koch]

Am 13.11.2022 um 21:57 schrieb Reino Wijnsma:
> Hello Michael,
>
> On 2022-11-13T20:45:42+0100, Michael Koch <astroelectronic at t-online.de> wrote:
>> ffmpeg -f lavfi -i testsrc2 -f nut | ffplay -
>>
>> This command line works fine and I have used it many times.
> It shouldn't, because you forgot a "-" after "-f nut".

oops, sorry I forgot to type that "-" in the email. You are right that 
it doesn't work without it.


>
>> But I don't know what's the meaning of the - character after ffplay.
> Input or output. An url or a file-path. And in this case; stdout and stdin. FFmpeg's stdout is piped to FFplay's stdin.
> I'm surprised you didn't know.

Is the "-" at the end an (undocumented) option of FFplay, or is it a 
batch file operator?

Michael