HVR-1800/1850 Analog support

After quite some time of talking about it, we finally got around to getting the analog support for the HVR-1850 submitted upstream. Support for all things analog is present and tested on all the various input types: the MPEG encoder, raw capture, analog audio. This patch series also includes a fix for a long-standing regression in the HVR-1800 as well.


Users are free to try it building from the above git tree, or they can wait a few days for it to be merged into the upstream linux-media tree.

The HVR-1850 is a really nice card (effectively the PCIe equivalent to the HVR-1600 that is already a popular choice with the MythTV crowd), and we will be happy to see the card fully supported in the mainline kernel.

Comments/feedback welcome!

5 thoughts on “HVR-1800/1850 Analog support

  1. I have been unable to get analog to work on my HVR-1800. I built linux-media about 2 weeks ago.

    dmesg shows the firmware is loaded and the mpeg encoder is at /dev/video3:
    [ 5.849706] cx23885 driver version 0.0.3 loaded
    [ 5.849787] cx23885 0000:02:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
    [ 5.849932] CORE cx23885[0]: subsystem: 0070:7809, board: Hauppauge WinTV-HVR1800 [card=2,autodetected]
    [ 6.239386] cx23885[0]: hauppauge eeprom: model=78631
    [ 6.289124] cx25840 8-0044: cx23887 A/V decoder found @ 0x88 (cx23885[0])
    [ 6.983004] cx25840 8-0044: loaded v4l-cx23885-avcore-01.fw firmware (16382 bytes)
    [ 9.670505] cx23885[0]: registered device video2 [v4l2]
    [ 9.670527] cx23885[0]: registered device vbi2
    [ 9.670749] cx23885[0]: registered ALSA audio device
    [ 10.605682] cx23885[0]: registered device video3 [mpeg]

    I then set the channel with ivtv-tune and used mplayer. This is what I get with cat /dev/video3: http://dl.dropbox.com/u/2429209/1800analog.mpg

    Am I doing something wrong?


  2. Just an update on my HVR-1800 analog support testing. Please note, I am primarily concerned with using my HVR-1800 with MythTv so please keep that in mind as you follow along.

    Earlier this week Devin and I discussed how in MythTv, the default image size setting of 480×480 (under recording profiles) triggers a driver bug that causes distorted colors. Changing the image size to 720×480 resolves this problem. This testing was done WITHOUT the January 2012 cx23885/cx25840 patches applied to the 3.2 and 3.3 kernels.

    I subsequently tested WITH the January 2012 cx23885/cx25840 patches applied to the 3.2 and 3.3 kernels and found several problems. First and foremost, one of the patches causes color distortion in ANY program that can only be reversed by reverting to an earlier version of the driver without the patches applied. Next, one of the patches prevents MythTv from accessing the mpeg device (/dev/video1 on my system) so live TV cannot be displayed at all. I am still working on determining exactly which patches trigger these two bugs.

    Lastly, the patch “[media] cx25840 / cx23885: Fixing audio/volume regression” causes NO AUDIO with the HVR-1800. With this patch REVERTED, the volume is so loud that the audio is actually clipping. I have been able to work around both issues by modifying the driver to force the volume register to a specific, fixed value. Interestingly, I found that increasing this value decreases the volume and vice versa. Since I control the volume of my system with my receiver, I am OK with having the volume level fixed. In order to have an adjustable volume level, someone would have to figure out the correct usable range for this value and modify the driver to reflect this.

    So in summary, with some modifications, the HVR-1800 can be used today with analog in MythTv. But If the latest patches are important for providing access to HVR-1800 features or performance improvements, we need to keep debugging these drivers.

    • tekdoc: Thanks for the feedback.

      Devin plans to look at my original patches. He picked up my HVR1850 sample hardware last week so, time permitting, we should get back to fixes in the near future.

      Stay tuned.

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