It is always a pleasure to deal with a company and a technology that is operating system agnostic. The level of support they provide both the Mac and Linux communities is excellent.

If you want to catch up on the previous instalments the links are below.

• Part 1 – HDHomeRun under OS-X
• Part 2 – HDHomeRun on Linux with VLC
• Part 3 – HDHomeRun on Linux with MythTV

A big thank you to Blair from Digital Pride for the extended loan the review unit. Also for all readers of this site they have provided a special discount code. Simply visit the order page at

If you enter the coupon code mythtv.co.nz you will save $30 off the normal $349 price tag, and get free delivery.

• Part 1 – HDHomeRun under OS-X
• Part 2 – HDHomeRun on Linux with VLC

Here in part 3 we are trying to get the device to work with a recent build of MythTV. As Ubuntu 9.04 (Jaunty) has recently been released we are going to use the Mythbuntu 9.04 build as our base.

Sadly the DVB-T HDHomeRun doesn’t work with the build of MythTV shipped with Mythbunto 9.04, so we are using a modified build produced by Jean-Yves Avenard. Jean-Yves produces regular updates to his builds, and I’m running

I’m starting with a clean environment so we need to add a new capture device. As I only have a single device on my network I can use the generic device ID.

I start mythtv-setup and choose the first option to setup a Capture Card.

Next we need to define a new video source

Now attach the video source to the capture card

Then we can run the channel scan. Note that we have to select Finland for the country as selecting New Zealand always fails to perform a channel scan.

The scan appears to work and we have full set of NZ DVB-T channels.

Sadly I now run into a number of issues that I have been unable to resolve.

From the MythTV Frontend I select LiveTV to check that channel tuning is working. This returns immediately with no video playback.

A look into the mythtv backend logs shows the following messages

2009-05-20 21:04:02.234 adding: mythtv as a client (events: 0)

2009-05-20 21:04:02.241 TVRec(4): Changing from None to WatchingLiveTV

2009-05-20 21:04:02.252 TVRec(4): HW Tuner: 4->4

2009-05-20 21:04:02.264 HDHRChan(ffffffff/0): device found at address 192.168.0.147

2009-05-20 21:04:02.279 HDHRChan(ffffffff/0), Error: dtv_multiplex data is required for tuning

2009-05-20 21:04:02.286 TVRec(4) Error: Failed to set channel to 4. Reverting to kState_None

2009-05-20 21:04:02.296 TVRec(4): Changing from WatchingLiveTV to None

It looks like we don’t have valid entries in the dtv_multiplex table which maps channels onto the DVB multiplexes. A check of the mysql database shows the following for the channel C4.

mysqldump --skip-opt -u $DBUserName -p$DBPassword
-h $DBHostName $DBName -t --compact  channel --where 'name="C4"'

INSERT INTO `channel` VALUES (3004,'4',NULL,3,'C4','C4','',NULL,'','',0,
32768,32768,32768,32768,'Default',0,1,'',1,39,1301,NULL,0,0,0,'0000-00-00 00:00:00','crid://c4tv.co.nz',-1);

mysqldump --skip-opt -u $DBUserName -p$DBPassword
-h $DBHostName $DBName -t --compact  dtv_multiplex --where 'mplexid="39"'

INSERT INTO `dtv_multiplex` VALUES (39,3,29,8746,0,'a',NULL,NULL,
NULL,NULL,'8','3/4','8','1/16',0,'qam_64','n','3/4','dvb',13,'2009-05-20 08:47:24');

It looks like the frequency and modulation entries aren’t set correctly. I fixed these up by manually updating entries in the database.

mysqldump --skip-opt -u $DBUserName -p$DBPassword
-h $DBHostName $DBName -t --compact  dtv_multiplex --where 'mplexid="39"'

INSERT INTO `dtv_multiplex` VALUES (39,3,29,8746,570000000,'a',NULL,NULL,
NULL,'auto','8','3/4','8','1/16',0,'qam_64','n','3/4','dvb',13,'2009-05-20 09:05:55');

Then I tried LiveTV again which produced better output in the mythtv backend logs, but sadly still fails to produce a TV picture, although it does report on signal strength.

2009-05-20 21:39:14.403 TVRec(4): Changing from None to WatchingLiveTV

2009-05-20 21:39:14.408 TVRec(4): HW Tuner: 4->4

2009-05-20 21:39:15.461 AutoExpire: CalcParams(): Max required Free Space: 3.0 GB w/freq: 15 min

2009-05-20 21:39:16.647 Finished recording Unknown: channel 3004

2009-05-20 21:39:17.779 Finished recording Unknown: channel 3004

2009-05-20 21:39:17.825 AutoExpire: CalcParams(): Max required Free Space: 3.0 GB w/freq: 15 min

2009-05-20 21:39:17.940 Using runtime prefix = /usr

2009-05-20 21:39:17.948 Empty LocalHostName.

2009-05-20 21:39:17.950 Using localhost value of mythtv

2009-05-20 21:39:17.961 New DB connection, total: 1

2009-05-20 21:39:17.970 Connected to database 'mythconverg' at host: localhost

2009-05-20 21:39:17.973 Closing DB connection named 'DBManager0'

2009-05-20 21:39:17.975 Connected to database 'mythconverg' at host: localhost

2009-05-20 21:39:17.977 New DB connection, total: 2

2009-05-20 21:39:17.989 Connected to database 'mythconverg' at host: localhost

2009-05-20 21:39:18.000 Current Schema Version: 1214

2009-05-20 21:39:18.033 Preview Error: Previewer file '/var/lib/mythtv/recordings/3004_20090520213914.mpg' is not valid.

2009-05-20 21:39:18.046 Preview Error: Run() file not local: '/var/lib/mythtv/recordings/3004_20090520213914.mpg'

2009-05-20 21:39:18.065 Preview Error: Preview process not ok.

            fileinfo(/var/lib/mythtv/recordings/3004_20090520213914.mpg.png) exists: 0 readable: 0 size: 0

2009-05-20 21:39:24.333 TVRec(4): Changing from WatchingLiveTV to None

2009-05-20 21:39:25.346 Finished recording Unknown: channel 3004

At this point I tried upgrading to a slightly more recent build from Jean-Yves (0.21.0+fixes-20573-openglvdpau-0ubuntu0), but had the same LiveTV issues.

By using tcpdump to monitor the network traffic, I managed to confirm that the HDHomeRun is being set to the correct channel, and a valid DVB stream is being sent to the MythTV box over the network.

I tested my Mythbuntu install with a USB DVB-T tuner with no issues, and also dumped a transport stream from the HDHomeRun using the command line tools that the MythTV frontend could playback.

I’ve opened a ticket in the MythTV trac environment #6527 to keep an eye on the issue. If this gets resolved before I need to return the review unit I’ll post an update here, and I’m very interested in hearing from anyone who has a combination similar to NZ working. I’ve seen reports of it working with MPEG-2 based streams in Australia, but I haven’t seen any get it working with the H.264 + HE-AACv2 combination we have here in NZ.

The changes from the original test setup are as follows

•  Nvidia 185.19 Video driver
• mythtv 1:0.21.0+fixes-20453-openglvdpau-0ubuntu2

Jean-Yves has applied a number of fixed to his MythTV builds that have resolved many of the playback issues. A number of buffer sizes had to be increased to deal with the delay between the audio and video streams on freeview|HD. Playback on TV3 is now near perfect and there are considerably less issues when changing channels on Live TV.

The NVidia driver update has also dramatically reduced the amount of video tearing so most of the channels now look a lot better.

Outstanding Issues

Sadly there are a couple of outstanding issues that need resolving before I’d consider the MythTV 0.21 builds to be fully freview|HD ready

• I’m still seeing some frontend segfaults when changing channels
• Large playback delay when selecting an audio only radio station
• Starting the MHEG-5 support causes the GUI to exit.

The MHEG-5 problem has been around since freeview introduced their PVR ready MHEG-5 update and just needs a bit of time to investigate further.

Overall a great improvement and beginning to feel we are almost there now.

HDHomeRun and Ubuntu 8.10

The Ubuntu Linux distribution has excellent documentation on getting the US ATSC version of HDHomeRun working, most of which applies with the DVB-T version. If you are running Ubuntu Intrepid (8.10) or Ubuntu Gutsy (8.04) you can install a command line tool direct from the Ubuntu package archive

sudo apt-get install hdhomerun-config

Now lets try and find the HDHomeRun on our network via the discovery command

hdhomerun_config discover

hdhomerun device 121052A4 found at 192.168.0.147

Nice and easy, and we can now start talking to the device. Let’s try a channel scan

hdhomerun_config 121052A4 scan 0

SCANNING: 474000000 (uk-bcast:21)

LOCK: none (ss=51 snq=0 seq=0)

SCANNING: 482000000 (uk-bcast:22)

LOCK: none (ss=37 snq=0 seq=0)

SCANNING: 490000000 (uk-bcast:23)

LOCK: none (ss=46 snq=0 seq=0)

SCANNING: 498000000 (uk-bcast:24)

LOCK: none (ss=45 snq=0 seq=0)

SCANNING: 506000000 (uk-bcast:25, nz-bcast:25)

LOCK: none (ss=23 snq=0 seq=0)

SCANNING: 514000000 (uk-bcast:26, nz-bcast:26)

LOCK: none (ss=44 snq=0 seq=0)

SCANNING: 522000000 (uk-bcast:27, nz-bcast:27)

LOCK: none (ss=72 snq=0 seq=0)

SCANNING: 530000000 (uk-bcast:28, nz-bcast:28)

LOCK: none (ss=45 snq=0 seq=0)

SCANNING: 538000000 (uk-bcast:29, nz-bcast:29)

LOCK: t8qam64 (ss=59 snq=58 seq=100)

PROGRAM: 1200: 0.0 TV ONE

PROGRAM: 1201: 0.0 TV2

PROGRAM: 1202: 0.0 TVNZ 6

PROGRAM: 1203: 0.0 TVNZ 7

PROGRAM: 1204: 0.0 TVNZ SPORT EXTR

SCANNING: 546000000 (uk-bcast:30, nz-bcast:30)

LOCK: none (ss=49 snq=0 seq=0)

SCANNING: 554000000 (uk-bcast:31, nz-bcast:31)

LOCK: none (ss=73 snq=0 seq=0)

SCANNING: 562000000 (uk-bcast:32, nz-bcast:32)

LOCK: none (ss=45 snq=0 seq=0)

SCANNING: 570000000 (uk-bcast:33, nz-bcast:33)

LOCK: t8qam64 (ss=81 snq=62 seq=100)

PROGRAM: 1300: 0.0 TV3

PROGRAM: 1301: 0.0 C4

PROGRAM: 11302: 0.0 TV3 PLUS1

SCANNING: 578000000 (uk-bcast:34, nz-bcast:34)

LOCK: none (ss=46 snq=0 seq=0)

SCANNING: 586000000 (uk-bcast:35, nz-bcast:35)

LOCK: none (ss=32 snq=0 seq=0)

SCANNING: 594000000 (uk-bcast:36, nz-bcast:36)

LOCK: none (ss=41 snq=0 seq=0)

SCANNING: 602000000 (uk-bcast:37, nz-bcast:37)

LOCK: none (ss=42 snq=0 seq=0)

SCANNING: 610000000 (uk-bcast:38, nz-bcast:38)

LOCK: none (ss=42 snq=0 seq=0)

SCANNING: 618000000 (uk-bcast:39, nz-bcast:39)

LOCK: none (ss=51 snq=0 seq=0)

SCANNING: 626000000 (uk-bcast:40, nz-bcast:40)

LOCK: none (ss=40 snq=0 seq=0)

SCANNING: 634000000 (uk-bcast:41, nz-bcast:41)

LOCK: none (ss=0 snq=0 seq=0)

SCANNING: 642000000 (uk-bcast:42, nz-bcast:42)

LOCK: none (ss=34 snq=0 seq=0)

SCANNING: 650000000 (uk-bcast:43, nz-bcast:43)

LOCK: none (ss=59 snq=0 seq=0)

SCANNING: 658000000 (uk-bcast:44, nz-bcast:44)

LOCK: none (ss=43 snq=0 seq=0)

SCANNING: 666000000 (uk-bcast:45, nz-bcast:45)

LOCK: t8qam64 (ss=83 snq=56 seq=100)

PROGRAM: 1400: 0.0 Maori Televisio

PROGRAM: 1401: 0.0 Parliament TV

PROGRAM: 1402: 0.0 Test Channel

PROGRAM: 1403: 0.0 ChineseTV

PROGRAM: 1404: 0.0 Reserved 5KSD

PROGRAM: 1405: 0.0 Reserved 6KSD

PROGRAM: 1406: 0.0 Freeview | HD

PROGRAM: 1408: 0.0 tvCentral

PROGRAM: 2000: 0.0 Radio NZ Nation

PROGRAM: 2001: 0.0 Radio NZ Concer

PROGRAM: 2002: 0.0 BaseFM

SCANNING: 674000000 (uk-bcast:46, nz-bcast:46)

LOCK: none (ss=23 snq=0 seq=0)

SCANNING: 682000000 (uk-bcast:47, nz-bcast:47)

LOCK: none (ss=17 snq=0 seq=0)

SCANNING: 690000000 (uk-bcast:48, nz-bcast:48)

LOCK: none (ss=44 snq=0 seq=0)

SCANNING: 698000000 (uk-bcast:49, nz-bcast:49)

LOCK: none (ss=23 snq=0 seq=0)

SCANNING: 706000000 (uk-bcast:50, nz-bcast:50)

LOCK: none (ss=35 snq=0 seq=0)

SCANNING: 714000000 (uk-bcast:51, nz-bcast:51)

Like under OS-X all 3 DVB-T multiplexes have been found.

Installing the Linux GUI

Silicon Dust have now released a beta gui for Linux with equivalent features to the OS-X GUI. At present you need to pull down the source and compile it yourself.

I download the libhdhomerun and hdhomerun_config_gui sources from

• http://www.silicondust.com/forum/viewtopic.php?t=2484

First compile libhdhomerun as we need the shared library for the gui

tar -zxf libhdhomerun_20090305a.tgz

cd libhdhomerun

make

Now unpack and compile the GUI application

cd ..

tar -zxf hdhomerun_config_gui_20090305a.tgz

cd hdhomerun_config_gui

./configure

make

Now at this stage I haven’t performed a “make install” as I want to try out the gui.

cd src/

./hdhomerun_config_gui

./hdhomerun_config_gui: error while loading shared libraries: libhdhomerun.so:

cannot open shared object file: No such file or directory

Opps. I need the shared library.

cp ../../libhdhomerun/libhdhomerun.so .

export LD_LIBRARY_PATH=.

./hdhomerun_config_gui

We now have the same features as the OS-X gui. Any HDHomeRun devices on your network are automatically discoverd.

VLC Support

Once you have selected a channel clicking on “View” will open VLC to talk to the UDP stream. Sadly the current Ubuntu 8.10 release of VLC is 0.9.4 which has limited support for the interlaced H.264 variant used on some of New Zealand’s freeview channels. The main visible issues were artifacts with the 576i interlaced channels like TVNZ6/7 and C4.

The 720p HD channels played perfectly, although with a high CPU load as my VLC install did not suport hardware acceleration.

TV One 720p


TVNZ 7 576i

Freeview|HD Demo Channel 720p

Overall the device worked well with VLC and I do need to try a more recent build. Similar to under OS-X you don’t get any EPG information over the UDP stream which is a shame.

What about MythTV?

In part3 I’ll take a look at how well the unit works with MythTV 0.21 under Ubuntu.

This review is likely to comprise several parts as I’ll be using it with a Mac under OSX as well as using VLC and MythTV under Linux. If you’d like an overview of the US version, Engadget did a review a couple of years ago.

What’s in the box?

When the unit first arrived I was very impressed with the overall package. Unlike most other TV tuners this device does not connect directly to your PC via USB or PCI/PCIe, and instead can stream to multiple computers over your network.

The HDHomeRun unit is a very tidy little box. At the rear you have two aerial connections, an ethernet port and a power connector. In the box you get two aerial fly-leads, a network patch cable, software CD and a nice compact wall wart.

At the time of this write up the NZ retail price is $349 direct from DigitalPRIDE, which compares well with the UK and AU pricing.

To initially get the unit up and running I simply plugged a UHF aerial connection, power and connect to my home LAN.

Mac OS-X Support

My laptop these days is a 2.4 GHz 3rd Generation Santa Rosa Macbook which dual boots OS-X and Ubuntu 8.10. I thought it would be interesting to see how well it integrated with the Mac first.

Now in theory with the following software it should “just work” -

1. Download the beta OS X configuration tool from
   http://www.silicondust.com/forum/viewtopic.php?t=2484
2. Get the latest version of VLC from
   http://www.videolan.org/vlc/download-macosx.html

This is where I hit my first issue. The OS-X tools also require GTK to be installed for the GUI. This part of the installer failed and the hdhomerun_config_gui application failed to run. I managed to resolve this by removing the installed application and forcing GTK to re-install from the HDHomeRun installer.

Once over this hurdle things worked well. The installer automatically upgraded the firmware of my unit to the latest release. I then told the hdhomerun_config_gui to perform a channel scan and it picked up all three DVB-T multiplexes. I could then select a channel and press view to watch it.

This is where I hit my second issue. I’d moved my install of VLC from the OS-X applications folder to a subfolder. This meant that the gui failed to locate it and display the video. There are two solutions to this -

1. Move VLC back to the applications directory, or
2. Start VLC and specify the network stream manually
   UDP/RDP – host 127.0.0.1, port 5000

I was using a wired ethernet connection on the Macbook and the video quality with VLC 0.9.8 was excellent on the 720p and 576i channels. I had some issues trying to watch TV3, which transmits in 1080i, as sadly my Macbook isn’t fast enough to display the video with the current builds of VLC. The freeview|HD service here in New Zealand uses H.264 as the video codec, and requires much higher CPU resources than MPEG-2 which is currently using in Australia and the US.

I then tried the same playback over an 802.11g wireless connection. For the most part the 576i channels worked with little or no issues, but I’d have occasional break up on the 720p channels, especially if someone else was making heavy use of the wireless network.

The popular OS-X application EyeTV also has support for HDHomeRun, but I was unable to test this as my trial licence has now expired.

Mac OS-X Conclusion

The HDHomeRun works incredibly well but there are a couple of niggles.

1. The gui installer should deal with failures in required components. It took me quite a while to troubleshoot the failed install.
2. Gui should allow for saving of channels. At the moment you can only view the channels on the currently tuned multiplex.
3. Improve VLC integration. It would be great if VLC could natively support the HDHomeRun and change channels directly
4. No EPG information is provided over the UDP stream. Whilst freeview|HD only provides limited now/next information over DVB EIT, it would be great if VLC could display the name of the current show.
5. Twin aerial connections means you need to use an external splitter on your TV aerial.
6. No bundled OS-X software. It would be great if they could include a “lite” version of EyeTV.

In Part 2 I’ll start looking at support under Linux.

Test Setup

Rather than using a laptop I moved onto one of the myPVR test environments, with the addition of a VDPAU capable PCIe card.

• Asus M2NPV-VM Motherboard
• AMD Athlon X2 6000+
• 2GB Ram
• Asus 8400 GS PCIe card with 512MB Ram
• Ubuntu 8.10
• Nvidia 180.37 Video driver
• Hauppage HVR 900 digital tuner
• freeview|HD terrestrial signal

MythTV Install

Before I could use Jean’s Ubuntu packages I needed to

• upgrade the myPVR test environment from Ubuntu 8.04 to 8.10.
• remove Ubuntu supplied NVidia drivers.
• Install NVidia 180.37 binary driver
• Add Jean-Yves’s Ubuntu repository.

I created a file /etc/apt/sources.list.d/jean.list

deb http://www.avenard.org/files/ubuntu-repos release/

and then upgraded mythtv, mythtv-backend, mythtv-frontend.

Configuring MythTV

Before using VDPAU under MythTV we need to defined a display profile for TV that specifies VDPAU for both. The MythTV Wiki has a reference on configuring VDPAU

• http://www.mythtv.org/wiki/VDPAU

I didn’t need to re-scan for any channels as they were already loaded from previous testing of ffmpeg’s software based decoder.

Playback testing

Here in New Zealand our freeview|HD service currently broadcasts in three different resolutions

• 576i H.264 video with HE-AAC Audio
• 720p H.264 video with HE-AAC Audio
• 1080i H.264 video with HE-AAC and AC3 Audio.

With all of the formats there was minimal CPU utilisation, but quite a high degree of video tearing on the HD Channels. First i disabled the Composite extension by adding the following to my /etc/init.d/xorg.conf

Section "Extensions"

      Option  "Composite"     "Disable"

EndSection

Then I tried various de-interlacers. I found good performance with Temporal 2x good, but Advanced 2x caused the playback of 1080i video to get very jerky.

Issues

There is still a little bit of tearing from time to time with H.264 playback when compared with the older MPEG2 based freeview service.

There are some stability issues, especially with LiveTV. The frontend will either exit from TV playback with an error, or crash.

Quite often I can have the front end produce a series of audio sync errors and the playback becomes very erratic. Usually the frontend will report

NVP: Video is 3.12705 frames behind audio (too slow), dropping frame to catch up.

Our other audio related errors like this

2009-03-11 21:51:57.506 Video sync method can't support double framerate (refresh rate too low for bob deint)

2009-03-11 21:51:57.507 Video timing method: USleep with busy wait

2009-03-11 21:51:57.890 Audio -83 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:57.910 Audio -63 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:57.933 Audio -43 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:57.985 Audio -99 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:57.995 Audio -86 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.015 Audio -66 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.026 Audio -46 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.223 NVP: prebuffering pause

GetBootInfo ResidentProgram is not implemented

2009-03-11 21:51:58.251 Audio -87 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.267 Audio -67 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.289 Audio -55 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.299 Audio -35 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.315 Audio -15 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.326 Audio 5 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.354 NVP: prebuffering pause

2009-03-11 21:51:58.520 Audio -98 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.550 Audio -78 ms behind video but already 75 video frames queued. AV-Sync might be broken.

2009-03-11 21:51:58.571 Audio -58 ms behind video but already 75 video frames queued. AV-Sync might be broken.

or this

2009-03-11 21:56:37.977 NVP: prebuffering pause

2009-03-11 21:56:38.047 WriteAudio: buffer underrun

2009-03-11 21:56:38.590 NVP: prebuffering pause

2009-03-11 21:56:38.885 NVP: prebuffering pause

2009-03-11 21:56:39.557 NVP: prebuffering pause

GetBootInfo ResidentProgram is not implemented

2009-03-11 21:56:40.467 NVP: prebuffering pause

2009-03-11 21:56:40.769 NVP: prebuffering pause

2009-03-11 21:56:42.067 NVP: prebuffering pause

2009-03-11 21:56:42.953 NVP: prebuffering pause

2009-03-11 21:56:43.102 NVP: prebuffering pause

2009-03-11 21:56:43.851 NVP: prebuffering pause

2009-03-11 21:56:44.511 NVP: prebuffering pause

2009-03-11 21:56:44.594 NVP: prebuffering pause

2009-03-11 21:56:45.030 NVP: prebuffering pause

2009-03-11 21:56:45.924 NVP: prebuffering pause

2009-03-11 21:56:46.443 WriteAudio: buffer underrun

2009-03-11 21:56:46.807 NVP: prebuffering pause

2009-03-11 21:56:47.837 NVP: prebuffering pause

2009-03-11 21:56:49.232 NVP: prebuffering pause

2009-03-11 21:56:49.234 WriteAudio: buffer underrun

2009-03-11 21:56:49.438 NVP: Prebuffer wait timed out 10 times.

2009-03-11 21:56:50.069 NVP: prebuffering pause

I’ve managed to produce these errors with both 720p and 1080i content, and now have some samples on disk for further testing.

Conclusion

Sadly the same as my initial VDPA testing report, great steps forward but not WAF proof yet if you want HD playback. In the space of a couple of hours testing I managed to crash the front end over a dozen times. Ok most of these were during LiveTV channel changing, but some were down to fast forwarding material. Less issues with the 576i content compared with the 1080i content, but still far from stable.

Next up is the fact that the video tearing is too much, especially on a large screen. I’d rather have the slightly lower quality MPEG2 based freeview service than suffer the video tearing.

Here is hoping that future updates from NVidia remove some of these issues, while the numerous testers of VDPAU + MythTV here in NZ and elsewhere in the world can resolve any other problems.

Test Setup

• Dell Inspiron 1420 Laptop
  • NVidia GeForce 8400M GS 128MB Video
  • Intel Core 2 Duo T7500  @ 2.20GHz
  • 3GB Ram
• Ubuntu 8.10
• Nvidia 180.25 Video driver
• Compiz disabled
• CPU locked in performance mode of 2.2 GHz
• mplayer-vdpau-3402051
• Hauppage HVR 900 digital tuner
• freeview|HD terrestrial signal

Channel Playback Comparison

Stats were collected via vmstat and the following commands were used to initiate DVB tuning and plaback

mplayer -vc ffh264 -vo xv -mc 2 dvb://CHANNEL

mplayer -vc ffh264vdpau -mc 2 dvb://CHANNEL

We specify -mc 2 so that interlaced video has a chance to synchronise correctly.

The percentages above are based off a dual core CPU. When decoding in software ffmpeg only uses a single core so we are actually doing over 100% of a CPU

Outstanding Issues

My attempts to play TV3 with VDPAU resulting in the following error message

VO: [vdpau] 1920x1080 => 1920x1080 H.264 HIGH VDPAU acceleration
[ASPECT] Warning: No suitable new res found!
[ASPECT] Warning: No suitable new res found!
[ASPECT] Warning: No suitable new res found!
Error 23 at libvo/vo_vdpau.c:736

There is a good chance this is because the laptop only has 128MB of video ram and NVidia recomment 512MB for 1080 HD sized frames.

The higher software CPU load on C4 compared with other 576i channels is likely due to the much higher bitrate on C4.

Stability wise most of the crashes were because of the HE-AAC/FAAD audio support in MPlayer, although there were some video related crashes. Typically if I changed channel sometimes it would crash when it tried to lock onto the new audio or video stream.

Mostly the video quality with VDPAU was good, but there was some obvious video tearing on playback that I didn’t see with the ffmpeg decoder.

Conclusion

Great strides forward but sadly not ready for primetime. The WAF around my own myPVR would drop dramatically if I switched to freeview|HD and VDPAU due to the stability and video tearing issues.

Still well worth keeping my eye on future releases, and nice to have a laptop that can play most of freeview|HD without stressing the CPU.

First of all I’m using a vanilla HVR 900, watch out for those pesky HVR-900H versions that are knocking around. There is some work underway to get the newest versions of the Em2880 driver merged into the mainline kernel, but it appears that the em28xx.ko module that ships with Intrepid works with my tuner with no patching required. Your own mileage might vary.

There is one gotcha, Ubuntu doesn’t ship with the required firmware. This is relatively simple to acquire, and should be installed prior to plugging in your tuner.

It is worth checking the md5sum on the firmware file

Then plugin in your tuner and you should see the driver and firmware load

I haven’t tried stress testing this driver for an extended period, but I can tune to both analogue and DVB-T as shown in my previous HVR 900 articles.

Linux and Unix news site Phoronix was amongst the first to break the announcement, and has already benchmarked the new api showing some quite startling results when compared with existing software based decoders.

The current API documentation is here:

ftp://download.nvidia.com/XFree86/vdpau/doxygen/html/index.html

Some highlights of VDPAU:

• Defines an API for GPU-accelerated decode of MPEG-1, MPEG-2, H.264, and VC-1 bitstreams.
• Defines an API for post-processing of decoded video, including temporal and spatial deinterlacing, inverse telecine, and noise reduction.
• Defines an API for timestamp-based presentation of final video frames.
• Defines an API for compositing sub-picture, on-screen display, and other UI elements.

Sadly this new API doesn’t support some of the older 6xxx and 7xxx series graphics cards, and VC1 support will require a 9xxx or newer card. The code is still relatively new so don’t expect it to be part of your favourite distribution for a while.

This announcement now means that all of the three major graphics chipset companies, Intel, AMD and NVidia, have all announced methods to hardware accelerate complex video codecs like H.264. We can only hope that freedesktop.org manages to come up with unified API, such as VAAPI, that works across all chipsets.

First a word of warning. There appears to be a new model of the HVR-900 labeled the HVR-900H. This is a new hardware revision and uses a totally different chipset, and as such won’t work with the Em2880 drivers. Work is believed to be underway on a driver, but it would be worth checking the linux-dvb mailinglist.

Updated useful reference docs for the empia driver can now be found here -

• Installation Guide
• Using Guide
• Bug #204578 in Ubuntu – 2.6.24.12 won’t boot with em28xx device

Whilst my previous posts have focused on building from source, Markus has now released a kernel package for Ubuntu Hardy kernel version 2.6.24-16, which can be made to work on later kernels providing you remove any conflicting kernel modules.

These tips should work for all supported em28xx based cards under Ubuntu Hardy and Mythbuntu 8.04.

1. Install appropriate firmware for your device.
2. Download and install the pre-built driver package.
3. Copy the modules to your current kernel and clean up any conflicting modules by running the following script as root -

   # First backup the existing kernel modules
   
   cd /lib/modules
   
   tar -zcf `uname -r`.orig.modules.tgz `uname -r`# Then copy over the empia driver from 2.6.24-16-generic
   
   cp -a /lib/modules/2.6.24-16-generic/empia `uname -r`
   
   # Then delete any conflicting packages
   
   cd `uname -r`/kernel
   
   ls ../empia/ | while read i; do find . -name $i -exec rm -f {} \; ; done
   
   # Them make sure our modules will load correctly
   
   depmod -a

   On the recently released 2.6.24-18 kernel the script will remove the following conflicting packages from the Ubuntu kernel install.

   ./drivers/media/video/em28xx/em28xx.ko
   
   ./drivers/media/dvb/frontends/qt1010.ko
   
   ./drivers/media/video/tvp5150.ko
   
   ./drivers/media/dvb/frontends/zl10353.ko

4. Plug in your device and check the kernel messages are similar to the following

   [ 330.299346] Linux video capture interface: v2.00
   
   [ 330.304618] em28xx v4l2 driver version 0.0.1 loaded
   
   [ 330.304829] em28xx new video device (2040:6500): interface 0, class 255
   
   [ 330.304833] em28xx: device is attached to a USB 2.0 bus
   
   [ 330.305238] em28xx #0: Alternate settings: 8
   
   [ 330.305240] em28xx #0: Alternate setting 0, max size= 0
   
   [ 330.305242] em28xx #0: Alternate setting 1, max size= 0
   
   [ 330.305244] em28xx #0: Alternate setting 2, max size= 1448
   
   [ 330.305246] em28xx #0: Alternate setting 3, max size= 2048
   
   [ 330.305248] em28xx #0: Alternate setting 4, max size= 2304
   
   [ 330.305250] em28xx #0: Alternate setting 5, max size= 2580
   
   [ 330.305251] em28xx #0: Alternate setting 6, max size= 2892
   
   [ 330.305253] em28xx #0: Alternate setting 7, max size= 3072
   
   [ 330.348854] i2c-adapter i2c-2: SMBus Quick command not supported, can't probe for chips
   
   [ 330.537728] trying to set disabled gpio? (00)
   
   [ 330.539442] tuner 6-0061: chip found @ 0xc2 (em28xx #0)
   
   [ 330.539645] attach inform (default): detected I2C address c2
   
   [ 330.542825] attach_inform: tvp5150 detected.
   
   [ 330.543509] attach_inform: eeprom detected.
   
   [ 330.558049] em28xx #0: i2c eeprom 00: 1a eb 67 95 40 20 00 65 50 12 5c 03 82 1e 6a 18
   
   [ 330.558056] em28xx #0: i2c eeprom 10: 00 00 24 57 66 07 00 00 60 00 00 00 02 00 00 00
   
   [ 330.558062] em28xx #0: i2c eeprom 20: 46 00 01 00 f0 10 02 00 b8 00 00 00 5b 00 00 00
   
   [ 330.558068] em28xx #0: i2c eeprom 30: 00 00 20 40 20 6e 02 20 10 01 01 01 00 00 00 00
   
   [ 330.558074] em28xx #0: i2c eeprom 40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   
   [ 330.558080] em28xx #0: i2c eeprom 50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   
   [ 330.558085] em28xx #0: i2c eeprom 60: 00 00 00 00 00 00 00 00 00 00 18 03 34 00 30 00
   
   [ 330.558091] em28xx #0: i2c eeprom 70: 32 00 36 00 39 00 30 00 39 00 39 00 39 00 30 00
   
   [ 330.558097] em28xx #0: i2c eeprom 80: 00 00 1e 03 57 00 69 00 6e 00 54 00 56 00 20 00
   
   [ 330.558103] em28xx #0: i2c eeprom 90: 48 00 56 00 52 00 2d 00 39 00 30 00 30 00 00 00
   
   [ 330.558108] em28xx #0: i2c eeprom a0: 84 12 00 00 05 50 1a 7f d4 78 23 f0 fd d0 18 85
   
   [ 330.558114] em28xx #0: i2c eeprom b0: ff 00 00 00 04 84 0a 00 01 01 20 77 00 40 26 c5
   
   [ 330.558120] em28xx #0: i2c eeprom c0: 05 f0 74 02 01 00 01 79 78 00 00 00 00 00 00 00
   
   [ 330.558126] em28xx #0: i2c eeprom d0: 84 12 00 00 05 50 1a 7f d4 78 23 f0 fd d0 18 85
   
   [ 330.558132] em28xx #0: i2c eeprom e0: ff 00 00 00 04 84 0a 00 01 01 20 77 00 40 26 c5
   
   [ 330.558138] em28xx #0: i2c eeprom f0: 05 f0 74 02 01 00 01 79 78 00 00 00 00 00 00 00
   
   [ 330.558144] EEPROM ID= 0x9567eb1a
   
   [ 330.558145] Vendor/Product ID= 2040:6500
   
   [ 330.558147] AC97 audio (5 sample rates)
   
   [ 330.558148] 500mA max power
   
   [ 330.558149] Table at 0x24, strings=0x1e82, 0x186a, 0x0000
   
   [ 330.590328] tvp5150 6-005c: tvp5150am1 detected.
   
   [ 331.369015] successfully attached tuner
   
   [ 331.371002] em28xx #0: V4L2 VBI device registered as /dev/vbi0
   
   [ 331.380375] em28xx #0: V4L2 device registered as /dev/video0
   
   [ 331.380568] em28xx #0: Found Hauppauge WinTV HVR 900
   
   [ 331.386799] analog tv open()
   
   [ 331.386804] modelock active!
   
   [ 331.386800] usbcore: registered new interface driver em28xx
   
   [ 331.388502] em2880-dvb.c: DVB Init
   
   [ 331.415417] vbi open()
   
   [ 331.415423] modelock active!
   
   [ 331.555256] DVB: registering new adapter (em2880 DVB-T)
   
   [ 331.555263] DVB: registering frontend 1 (Zarlink ZL10353 DVB-T)...
   
   [ 331.555449] Em28xx: Initialized (Em2880 DVB Extension) extension

5. Now try the digital tuner using scan or w_scan.
6. Check analogue tuning, for example using tvtime. In order to get working audio with tvtime you will currently need to install the project’s patched version.

Analogue Samples

These were taken from NZ analogue channels TV2 and Maori TV. As you can see the analogue reception in my office is less than perfect. The linked images are the original unmodified PNG screen captures.

TV2 – 576i SD

Maori TV – 576i SD

Digital Samples

Here is a mix of samples pulled from New Zealand’s freeview|HD service. The images below have been re-scaled, but you can click through to the PNGs from the original screen captures. All of the freeview|HD broadcasts are in H.264.

Sadly none of the broadcasters were showing native HD content whilst I was performing these tests so any HD video was upscaled prior to broadcast.

TVNZ 7 – 576i SD

TV One – 720p HD

TV 2 – 720p HD

TV 3 – 1080i HD

The picture issues shown in the TV 3 1080i sample are due to missing support for PAFF interlaced spatial direct video in FFMPEG’s H.264 decoder.

Using HVR 900 with MythTV

Recent builds of MythTV will detect both the analogue and digital tuners of the HVR 900. The device can only operate a single tuner at a time, and MythTV already has the required patches to understand this.

When setting up the V4L based analogue tuner you need to make sure you select the correct audio device as the driver exposes its own DSP interface.

At the moment the support for New Zealand’s H.264 terrestrial service freeview|HD is rather limited, but you can scan for the 3 active multiplexes. For other countries you might have more luck.