Bug Report Dazzle DVC 100 issues (Still under investigation)

I

iotku

New Member
Instead of spawning with a full set if resolution options and framerates my Dazzle DVC 100 only spawns with an incorrect resolution of 144x720 and no framerate options. Unsurprisingly nothing seems to display.

I've had it working with XawTV, VLC (with some visual corruption), and ffmpeg (which seems to now hang) somewhat
sporadically so I'm marking this as under investigation still.

One thing to note with VLC is that I set the resolution directly in it's "advanced options" (along with settings like ntsc etc), which seemed to work. One of my theories is that the device (or at least its driver) accept proper resolutions but may not provide them to applications.

For xawtv I changed the video standard to NTSC and input to s-video using its included v4lctl utility.

It's been a while since I've played with ffmpeg (used to have no problems), it's possible something broke in a newer version since I've used it last, not really sure. I'm not sure what ffmpeg is relevant to obs-studio, but I imagine if it's being used and doesn't work directly it wouldn't be working on obs-studio either.
EDIT: Seems to work fine now as of a recent kernel or ffmpeg - 08/04/2014

Even with the stuff I've gotten working it has been a bit quirky so I'm probably going to mess around with stuff the next few days to see if I can figure anything out.

Log (Don't see anything relevent but why not):
https://gist.github.com/anonymous/86ba7b8ca2875a1d203d

System Stuff
  • Distro: Arch Linux
  • OBS-Studio: 9cc1b43 (git)
  • FFmpeg: 2.2.4 (arch package)
  • x264: 1:142.20140311-4 (arch package)
I'm on mesa so a lot of things don't work atm, but that should be irrelevant to this. The DVC100 is a fairly popular capture device and does have a linux driver (em28xx btw) so it would be useful to have working. Saying of course it just isn't my system being a pain xD

Some perhaps useful output:
Code: 
$ v4l2-ctl --list-formats
ioctl: VIDIOC_ENUM_FMT
    Index       : 0
    Type        : Video Capture
    Pixel Format: 'YUYV'
    Name        : 16 bpp YUY2, 4:2:2, packed

    Index       : 1
    Type        : Video Capture
    Pixel Format: 'RGBP'
    Name        : 16 bpp RGB 565, LE

    Index       : 2
    Type        : Video Capture
    Pixel Format: 'BA81'
    Name        : 8 bpp Bayer BGBG..GRGR

    Index       : 3
    Type        : Video Capture
    Pixel Format: 'GRBG'
    Name        : 8 bpp Bayer GRGR..BGBG

    Index       : 4
    Type        : Video Capture
    Pixel Format: 'GBRG'
    Name        : 8 bpp Bayer GBGB..RGRG

    Index       : 5
    Type        : Video Capture
    Pixel Format: '411P'
    Name        : 12 bpp YUV411
 
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B

bazukas

Developer
Hello iotku. The problem is that your device uses stepwise framesize enumeration
and v4l2 plugin currently supports only discrete enumeration. Adding support
for stepwise enumeration is not a big problem, but I don't have a device to test with
so that can take a while. Maybe somebody else will be able to implement that in the
meantime.
 
I

iotku

New Member
Good to know, I'll be around most likely if someone needs me to test something whenever.

Nice to see how it's really starting to shape up.
 
L

leonhard

Developer
Hey, there were quite some changes merged to master. If you could test again and provide a new log file that would be highly appreciated.
 
L

leonhard

Developer
The log seems to indicate that the framerate is wrong, could you please check what framerates are supported ?
Code: 
v4l2-ctl --list-formats-ext
 
I

iotku

New Member
Code: 
$ v4l2-ctl --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
    Index       : 0
    Type        : Video Capture
    Pixel Format: 'YUYV'
    Name        : 16 bpp YUY2, 4:2:2, packed
        Size: Stepwise 144x115 - 720x576 with step 1/1

    Index       : 1
    Type        : Video Capture
    Pixel Format: 'RGBP'
    Name        : 16 bpp RGB 565, LE
        Size: Stepwise 144x115 - 720x576 with step 1/1

    Index       : 2
    Type        : Video Capture
    Pixel Format: 'BA81'
    Name        : 8 bpp Bayer BGBG..GRGR
        Size: Stepwise 144x115 - 720x576 with step 1/1

    Index       : 3
    Type        : Video Capture
    Pixel Format: 'GRBG'
    Name        : 8 bpp Bayer GRGR..BGBG
        Size: Stepwise 144x115 - 720x576 with step 1/1

    Index       : 4
    Type        : Video Capture
    Pixel Format: 'GBRG'
    Name        : 8 bpp Bayer GBGB..RGRG
        Size: Stepwise 144x115 - 720x576 with step 1/1

    Index       : 5
    Type        : Video Capture
    Pixel Format: '411P'
    Name        : 12 bpp YUV411
        Size: Stepwise 144x115 - 720x576 with step 1/1
 
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I

iotku

New Member
Code: 
$ v4l2-ctl --list-frameintervals=width=720,height=576,pixelformat=YUYV
ioctl: VIDIOC_ENUM_FRAMEINTERVALS

Doesn't look all too useful, generally (as it's a SD capture device) 29.97~ (NTSC) and whatever the PAL equivalent framerate is would be ideal
 
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