[gst-devel] videoscale fails with v4l2src

[Zheng, Huan]

When you implement ENUM_FRAMESIZES ioctl, take care of the resolution properly.

Best Regards, Zheng, Huan(ZBT)
OTC/SSD/SSG
Intel Asia-Pacific Research & Developement Ltd
Tel: 021-6116 6435
Inet: 8821 6435
Cub: 3W035
-----Original Message-----
From: Gabriel Johnson [mailto:johnsoga at gmail.com] 
Sent: Thursday, May 21, 2009 9:31 PM
To: Zheng, Huan
Cc: Discussion of the development of GStreamer
Subject: Re: [gst-devel] videoscale fails with v4l2src

Thanks for the reply Zheng,


> Your driver doesn't implement ENUM_FRAMESIZES ioctl, so V4l2Src uses
> v4l2_ioctl (fd, VIDIOC_TRY_FMT, &fmt);
> v4l2_ioctl (fd, VIDIOC_S_FMT, &fmt);
> to probe formats that maybe applied to driver. That may not be accurate if your driver's implementation is not complete or not good.
I was thinking that the v4l2 driver might still be missing something

> V4l2src works well on many other places, so I doubt it's your driver's issue. And perhaps related to your resolution.
>
> Perhaps you could try
> `gst-launch v4l2src ! video/x-raw-rgb,bpp=16,depth=16,width=640,height=480 ! ffmpegcolorspace ! videoscale ! fakesink`
This doesn't work either.

I don't under stand why if I skip using videoscale and
ffmpegcolorspace it works fine.  It appears that if I use any other
plugins between the source and sink it fails.  What could
ffmpegcolorspace or videoscale be requiring from the v4l2src that it
doesn't provide?

I am going to try and implement ENUM_FRAMESIZES ioctl and see if that helps.