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-   -   seeking HD video/av capture device (https://www.linuxquestions.org/questions/linux-hardware-18/seeking-hd-video-av-capture-device-4175614936/)

tonj 10-03-2017 04:10 AM

seeking HD video/av capture device
 
I'm running fedora 20 and I need to get a vga/HD video capture device that will also capture audio. I'd appreciate feedback on any hardware that will do this in linux. I'd prefer a pci or pci-e card but will use a usb(2.0) device if there's anything out there. I've seen some startech.com pci cards but they're not supported in linux (as far as I know). I also need a low profile bracket card as space is limited. I could easily upgrade to fedora 26 if the hardware needs it. If anyone knows of a device that meets this requirement I'd be grateful.

tofino_surfer 10-04-2017 10:59 AM

Are you talking about analog standard definition (vga) and HD video and analog audio ? If so I have a Hauppauge HDPVR-1212 external USB 2.0 box that I use with my Raspberry Pi and my main Fedora/Centos PC. It works quite well. It has a hardware converter to convert analog signals to space efficient MPEG-4. The capture bit-rate is adjustable so you could capture standard definition as well as HD video. It is not made anymore but is available on eBay.

tonj 10-04-2017 11:23 AM

thanks for your feedback on this. The hauppauge looks good and I may go for one. I intend to capture and re-stream the av from such a device using ffmpeg command line. Do you know if this can be done with the hauppauge?

tofino_surfer 10-04-2017 01:23 PM

Quote:

I intend to capture and re-stream the av from such a device using ffmpeg command line. Do you know if this can be done with the hauppauge?
You can easily pipe the output of the HDPVR through ffmpeg or any other filter. The output stream out of the USB 2.0 connection is MPEG-4 but can easily be piped through any filter.

For recording with my Raspberry Pi I use the output of dd redirected to a file in a USB 2.0 HDD:

Code:

dd if=/dev/hdpvr conv=noerror ibs=1024 of=/media/pi/VANTEC/hdpvr-video/$1.mp4
In your case you could pipe it to ffmpeg:

Code:

dd if=/dev/hdpvr conv=noerror ibs=1024 | ffmpeg
I use a udev rule to get a fixed device node of /dev/hdpvr.

Code:

$ cat 80-hdpvr.rules
KERNEL=="video[0-9]*", SUBSYSTEM=="video4linux", SUBSYSTEMS=="usb", ATTR{name}=="Hauppauge HD PVR", ATTRS{idVendor}=="2040", ATTRS{idProduct}=="4901", SYMLINK+="hdpvr"


tonj 10-05-2017 04:35 AM

thanks for this further info. How does the 1212 actually show up in linux? does it appear as '/dev/videoX'? how does the audio show up? When you stated '/dev/hdpvr' was that just a generic example or the real thing?

tofino_surfer 10-05-2017 04:37 PM

Quote:

Thanks for this further info. How does the 1212 actually show up in linux? Does it appear as '/dev/videoX'?
Yes it appears as /dev/videoN where N = 0,1,2 ... In the udev rule this is visible as KERNEL=="video[0-9]*"
Basically the first time the driver is loaded it appears as /dev/video0. If the driver is reloaded without rebooting then the index advances to /dev/video1. The index advances each time the driver is reloaded without rebooting to /dev/video2, /dev/video3 ... As this changing link is troublesome I created a fixed udev link of /dev/hdpvr.

Quote:

When you stated '/dev/hdpvr' was that just a generic example or the real thing?
You need to read up on udev rules. You can create rules to create a named symlink for any piece of hardware you own. That way if the kernel device changes such as from /dev/video0 to /dev/video1 your link name will be constant. The rule you create uses hardware info such as ATTR{name}=="Hauppauge HD PVR", ATTRS{idProduct}=="4901" which identifies the hardware, a kernel device and subsystem KERNEL=="video[0-9]*", SUBSYSTEM=="video4linux" and allows you to create a fixed name for a symbolic link for this device SYMLINK+="hdpvr".

If you buy this device just use my rule and you will get a fixed /dev/hdpvr symlink.

Quote:

How does the audio show up?
The audio is digitized and becomes part of the MPEG-4 video stream that comes out of the USB port. You could probably filter the audio out with ffmpeg or some other filter.

The unit has settings for audio quality such as compressed or uncompressed .wav.

tonj 10-06-2017 03:55 AM

ok thanks very much tofino your feedback has been really informative.


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