[Cin] Images sequence

[Andrea paz]

This is the kind of error I get when rendering with image sequences:

FFStream::encode_frame: encode failed.
file: /home/paz/list/test%05d.png
  err: Resource temporarily unavailable
FFMPEG::mux_video  err: Operation not permitted
FFMPEG::open_decoder: some stream times estimated:
/home/paz/video_editing/free_video/vp9.webm
Render::render_single: Session finished.
** rendered 939 frames in 9.128 secs, 102.870 fps

(I remind you that the frames are correctly rendered, but in the TOC
there is no reference to these images)

If a solution is not found I propose to eliminate presets in CinGG and
manual; image sequences are probably not used much, but those who use
them are because they follow a very professional workflow, which also
involves exchanging with compositing and/or color correction programs,
and also switching from film to digital. So, in my opinion, it is
better to specify that CinGG does not support DPX than to displease
those possible users. I'm hoping for the work proposed by realvi, but
that concerns the internal engine and not ffmpeg:

https://www.cinelerra-gg.org/forum/everything-else/youtubes-video-edit-with-cingg/#post-2078