Hauppauge HD-PVR

From MythTV Official Wiki
Revision as of 17:01, 4 October 2009 by Jhoyt (talk | contribs) (Steps to Add the HD-PVR as a Capture Device in MythTV)

Jump to: navigation, search
The Hauppauge HD-PVR Model 1212.

The Hauppauge HD-PVR is the first consumer-level analog HD capture device available. The HD-PVR is a USB device that captures the component video outputs and analog/optical audio outputs of any consumer device (including cable/satellite set-top-boxes, HD Disk Players, video game consoles, and various other home media devices). The HD-PVR is a highly anticipated capture device because it captures video via component output, permitting the user to capture High-Definition video from most sources and without concern for encryption. In other words, since component video is not and cannot be encrypted, previously un-capturable HD sources such as satellite and premium television will now be fully accessible in MythTV. Prior to this device, component capture devices were cost-prohibitive and were not directly supportable within Linux.

The HD PVR captures at resolutions from VGA/D1 (480i) up to 1080i, and encodes the component inputs in real time using the h.264/MPEG-4 video codec and the AAC audio codec. The streams are muxed into a slightly modified MPEG-2 Transport Stream container. Capture resolution is dependent on the source (ie 720p video with be captured as such, 1080i as 1080i, etc.) but the bitrate is user-selectable from 1 Megabit/second up to 13.5 Megabits/second. The h.264 video codec is, bit-for-bit, up to 40% more efficient than the MPEG-2 video codec commonly used in US HDTV broadcasts today. A 13.5 Mb/s h.264 stream is roughly equivalent to a full-channel-bitrate MPEG-2 recording at approximately 19 Mb/s.

The HD-PVR uses modern codecs capable of exceptional compression rates at excellent quality. The tradeoff is that decoding h.264 material is very processor-intensive. Systems which struggle or barely manage to play back US broadcast HD are likely to fail altogether when playing back recording from the HD-PVR. Hauppauge recommends a dual-core CPU as a minimum. A frequently cited minimum for medium-bitrate h.264 playback is a Core 2 Duo 1.8 Ghz processor. HD Playback Reports acts as a repository for processor requirements to play High Definition material. HD-PVR users are encouraged to contribute to the page to ascertain real-world playback requirements with MythTV.

In all HD-PVR firmwares later than 1.0.3.53, AC-3 muxing via S/PDIF is available, allowing one to mux the original 5.1 channel audio track into the captured stream. To enable this functionality, be sure to set the audio input to S/PDIF by editing the capture card definition in mythtv-setup and setting the preferred input device to S/PDIF.


Important.png Note: If you are running a firmware earlier than 1.5.6, you should update the firmware as soon as possible. Hauppauge has fixed a bug that can under certain conditions cause the HD-PVR to become inoperable.


Possible Countermeasures

Some UK television providers (notably Virgin and Freesat) have attempted to counter the HD-PVR and similar devices by selectively disabling the component outputs of their set-top-boxes. In the US, the Motion Picture Association of America has requested that the Federal Communications Commission allow providers to selectively disable the component outputs of their devices when showing recently released movies.

There is a new solution to this countermeasure. A company called HDFury makes HDCP-compliant HDMI converters. The HD-FURY2 converts HDMI input into sound and component outputs. It is available from http://www.curtpalme.com. The original HDFury converts HDMI to RGB. It is available from Monoprice or http://www.curtpalme.com. The RGB output of the HDFury can be converted to component with a second device called Box1020. A user with an HDMI-only device could use the following path to convert HDMI to component video:

HDMI Source -> HDMI to DVI cable -> HD Fury -> Box1020 -> Component Cable -> HD-PVR or using the HD Fury2 the chain could be shorted to HDMI Source -> HD Fury2 -> Component Cable -> HD-PVR

At the time of this writing, the original HDFury and Box1020 cost approximately $210 US. The HD Fury2 sells for $249 US, but it eliminates the need for the Box1020 and adds a host of picture quality and stability improvements. Some users will be put off by the high cost and circuitousness of the solution, but for an increasing number of MythTV users, it may be the only option.

Samples

To test if you machine is fast enough to play HD-PVR files short clips have been uploaded as torrents.

13.5Mbps/13.7MBPS Max (720p) http://www.mininova.org/get/1763048
10Mbps/10.2MBPS Max (720p) http://www.mininova.org/get/1762999
7Mbps/7.2MBPS Max (720p) http://www.mininova.org/get/1762988

HD-PVR Driver Compilation Howto

Note: As of Linux Kernel 2.6.30 the driver for the HD-PVR is now included by default. No compiling of the driver will be necessary assuming you have compiled the driver into the kernel.

The development branch of the HD-PVR Linux driver is available from the LinuxTV project.

Currently, firmware loading is unimplemented in the driver. As a result, if you have a "rev c1" unit you must install the HD-PVR at least once on a Windows machine to load the firmware into it. If you have a Revision 2 unit (including a sticker marked "rev c2" on the bottom of the unit) then it will come loaded with a firmware. Once you have done so, you will need a working build environment, Mercurial, and kernel headers installed on your system. In Debian and debian-based distros, the following command should install all necessary dependencies to build the driver.

sudo apt-get install build-essential mercurial linux-headers-`uname -r` 

MythDora 10.21 with kernel 2.6.27.9-159 includes drivers for the HD-PVR, no compilation is necessary.

In rpm based distros such as Mythdora, the following command should suffice assuming proper dev tools, kernel-headers and kernel-devel have already been installed.

sudo yum install mercurial

The HD-PVR driver is now included in v4l-dvb. You can check out the v4l-dvb repository with the following command:

hg clone http://linuxtv.org/hg/v4l-dvb

In best case scenarios, the following should be enough to compile and install the driver:

cd v4l-dvb
make
sudo make install 

If compilation and installation succeeded, it should be possible to load the HD-PVR driver with:

sudo modprobe hdpvr

If dmesg shows "wrong firmware version," and "device init failed," then you did not install the device in Windows first and the firmware has not been loaded. Install the HD-PVR on a windows machine, install the drivers, and after that the device should work fine in Linux.

In Ubuntu, the module may fail to load and refer you to the dmesg command. If this happens, reboot and see if the error resolves itself. It is also possible that Ubuntu is prioritizing another, older copy of the v4l-dvb modules above the one you just installed, and the hdpvr will fail because the two versions do not match. Try a command like:

locate cx88-dvb.ko |grep `uname -r`

This will search for the cx88-dvb kernel module, which is provided in the Hg tree you just built, and also in default Ubuntu installs. If you see more than one copy of this file, you may need to move the older versions out of the way. In at least one case, alternate versions of all the modules were located in "/opt/ltsp/amd64/lib/modules/kernel version number/ubuntu/". The symbol mismatch was solved by moving the "/opt/ltsp/amd64/lib/modules/kernel version number/ubuntu/media" directory into a backup directory in the user's home, then rebooting.

Testing the Driver

Once the module has loaded successfully, you can check dmesg for output and to determine which /dev/video node it has created. You can then test the device as with any hardware encoder:

cat /dev/video1 > test.ts

Press Ctrl-C to stop the capture, and play it back with any compatible media player (ie mplayer, xine, MythTV).

Bitrate and Picture Controls

The HD-PVR driver is compatible with the v4l2-ctl command line utility included in ivtv-tools. To see a list of adjustable controls, use the following command:

v4l2-ctl --device=/dev/video0 -l

Substitute the correct video# in the example above. The following controls are presently supported in the driver:

Control Name Values Default Description
brightness 0 to 255 134 Brightness picture control over recordings.
contrast 0 to 255 128 Contrast picture control over recordings.
saturation 0 to 255 128 Saturation picture control over recordings.
hue 0 to 255 128 Hue picture control over recordings.
sharpness 0 to 255 128 Sharpness picture control over recordings.
audio_encoding 3 to 4 3 Control for Audio Encoding. 3=AAC, 4=AC3.
video_encoding 2 2 Non-adjustable control for Video Encoding (H.264).
video_bitrate_mode 0 to 1 1 Control for VBR versus CBR. 0=VBR, 1=CBR.
video_bitrate 1000000 to 13500000 6500000 Bitrate control over recordings in bits, from 1 Mbit/s to 13.5 Mbit/s.
video_peak_bitrate 1100000 to 20200000 9000000 Peak bitrate control in bits, from 1.1 Mbit/s to 20.2 Mbit/s.

You can adjust any of these values with a command like:

v4l2-ctl --device=/dev/video0 --set-ctrl=controlname=value

Or, for example:

v4l2-ctl --device=/dev/video0 --set-ctrl=video_bitrate=13500000

This command will set the bitrate to the maximum of 13.5 Mbit/s for the HD-PVR at /dev/video0.

The audio_encoding selection only works for PCM input. If the HD-PVR is fed AC3, then AC3 will always be muxed into the H.264.

Miscellaneous Kernel Module Options

Several options exist that may be of assistance when troubleshooting or for certain use cases. If the audio output is too low, you can boost the audio signal by adding the following module option for the hdpvr module:

boost_audio=1

If you wish to see more verbose dmesg output, you can use the following module option:

hdpvr_debug=#

Where # = an integer between 1 and 7, increasing in level of verbosity.

video_nr=#

Sets the device node to /dev/video#

default_video_input=#

default video input: 0=Component, 1=S-Video, 2=Composite

default_audio_input=#

default audio input: 0=RCA back, 1=RCA front, 2=S/PDIF. For firmware 0xf, this must apparently be set to 2 to enable 5.1ch AC3 recording, otherwise it records stereo only.

Configuring the HD-PVR in MythTV

MythTV SVN Trunk now includes support for the HD-PVR. While it is still strongly recommended that the average user not switch to the Myth development branch, advanced users of Myth and Linux are invited to participate in development and bug squashing of the HD-PVR driver and its support in MythTV. With a few caveats, the HD-PVR can now be expected to work reliably for scheduled recordings.

Caveats

Once the tuner has been added as an encoder in MythTV, it is vital that the user not access the tuner in outside programs such as cat, VLC, and mplayer. This can lead to MythTV's connection with the driver becoming unstable, and subsequent recordings failing until the driver is reloaded and power is cycled on the HD-PVR.

The last sync with libavcodec did greatly improve stability when playing material from the HD-PVR. If you still get playback crashes, try compiling myth with --disable-ssse3.

For Motorola STBs, it is also important to set the "4:3 Override" option to Off or Stretch. For some Motorola STBs, both the aspect ratio settings and output resolution controls can be found by powering down the STB and then pressing the Menu button.

Myth can become non-responsive due to run-away "mythbackend --generate-preview" processes. If you check your mythbackend logs and see it being flooded with ac3 or faac errors, it is likely the "generate-preview" process doing it. A "pkill -f generate-preview" will return your myth system to a usable state. You may even want to add that pkill to a cronjob.

Updates

The HD-PVR previously had problems gracefully dealing with resolution changes but those issues have been fixed. You can now allow your receiver to float between 480i, 480p, 720p and 1080i without causing the HD-PVR or MythTV to hang.

Tracking Progress

The HD-PVR is completely usable when using Myth trunk, just make sure you are using the latest HD-PVR firmware.

As of changeset #19989, recordings are much more stable. LiveTV is now usable, however it can take awhile to change channels, and will still occasionally "bail out".

As of September 1, 2009 IR blasting and receiving is tentatively working. Jarod Wilson has created patches for the lirc and hdpvr drivers. He's in the process of having his patches approved and committed.


Two HD-PVR related patches are still pending review before being committed to trunk:

  • #6611 adds a "signal monitor" for the HD-PVR, which should improve LiveTV. The latest version of #6611 requires #6719 to be applied first.
  • #6602 resets the parsing on a buffer changed, which should improve LiveTV

While none of these patches are necessary to use the HD-PVR, they are all recommended. Please report if these patches either improve or cause problems with your installation.

Steps to Add the HD-PVR as a Capture Device in MythTV

  1. Compile the driver and test it for proper operation as described above.
  2. Run mythtv-setup, and enter option 2, Capture Cards.
  3. Add a new capture card. When prompted, select "H.264 Encoder Card (HD-PVR)" as the card type. Set the /dev/video node to the number of your HD-PVR. Finish adding the new capture card. You can also set the audio input on this screen.
  4. Enter option 3, "Video Sources." Set up a video source for your HD-PVR's tuner as described in User_Manual:Detailed_configuration_Backend.
  5. Enter option 4, "Input Connections." Connect the video source to the appropriate input on the HD-PVR. Important Note: You must set a channel change script for the HD-PVR to work properly. If you don't care about channel changes, you can set it to /bin/true, but there absolutely must be a channel change script defined. Important Note 2: You must leave Preset tuner to channel empty or LiveTV and channel changes will not work.


Assuming you followed the directions carefully, you should now be able to record with the HD-PVR. If you get "Select Timeout" errors, these can sometimes be overcome by stopping the backend, removing the hdpvr module, cycling the power on the HD-PVR, modprobing the hdpvr module, and restarting the backend.

You can set the bitrate for the HD-PVR by going into Recording Profiles, and editing the profiles associated with HD-PVR encoders. These recording profiles have bitrate settings for low (480i/p), medium (720p), and high (1080i) resolution material, allowing you to set appropriate bitrates based upon the resolution of the material. If the max bitrate is set lower than the average bitrate, the result is CBR (Constant Bit Rate) at the rate specified by the average slider. If you want VBR (Variable Bit Rate), set the max slider to maximum, and then use the average slider to achieve the desired bitrate.

If you have patched the driver or myth for any further functionality, or if you have a specific problem associated with the HD-PVR driver, you can join #hdpvr on Freenode. Under no circumstances will support in compiling mythtv be provided, nor will there be any walking through of the steps outlined above. If you are not comfortable with compilation, applying patches, or any other step of this process, just hang in there! Better, stable support is coming soon.

Please do not compile trunk simply to use the HD-PVR. The support load caused by everyday users who are not prepared to follow the dev and commit lists, and who ask the same questions that have been covered there, is *noticeably delaying* the stabilization of support and the subsequent release of .22. .22 will become stable in the very near future, and any backports (which break database upgrades) should be avoided at all costs. The HD-PVR will be in a stable version of myth soon, so please exercise patience.