[FFmpeg-user] image2 examples missing `-f image2`, can that be right?

[Gyan Doshi]

On 1/8/2018 12:31 AM, Moritz Barsnick wrote:

> I *believe* the detail that is missed in the documentation is that the
> use of a pattern "implies" the image2 demuxer (or muxer, if used as
> output). Apparently with such a high priority that I can't even open a
> single image named "%03d.jpg" without the image2 demuxer jumping in and
> trying to resolve that pattern. ;-)

Not exactly. FFmpeg iterates through all registered demuxers when 
probing. When it gets to image2, it first checks for an image codec, 
identified by the file extension. Then it checks if the filename can be 
parsed as a sequence. But if an image extension isn't found, that test 
doesn't happen. And string%d.ext is treated as a single input by 
whichever demuxer gets passed the input, so a%d.mp4 is opened as a 
single MP4.


Regards,
Gyan