Bad HDTV performance despite hardware acceleration (1 Viewer)

[Spooky]

TV-Server Version: 1.0.0 RC1 (usually latest SVN)
MediaPortal Version: 1.0.0 RC1 (usually latest SVN)
MediaPortal Skin: BlueTwo wide
Windows Version: Win XP SP2
CPU Type: AMD A64 3200+
HDD: Seagate DB35 200GB
Memory: Kingston ValueRAM 2x512 MB
Motherboard: Shuttle FX83
Video Card: Radeon HD 2400 Pro AGP
Video Card Driver: Catalyst 8.4
Sound Card:
Sound Card AC3:
Sound Card Driver:
1. TV Card: digital everywhere FloppyDTV S2
1. TV Card Type: DVB-S2
1. TV Card Driver: 4.5.N
MPEG2 Video Codec: Cyberlink Video/SP Decoder (PDVD8)
MPEG2 Audio Codec: Cyberlink Audio Decoder (PDVD8)
h.264 Video Codec: Cyberlink H.264/AVC Decoder (PDVD8)
Satelite/CableTV Provider: Astra 19.2°E
HTPC Case: Shuttle SK83G
TV: Panasonic PT-AX100E, 1280x720
TV - HTPC Connection: VGA

Note: I use a server <-> client setup. The TV Server runs on a different machine.

After finally having the opportunity of viewing ORF 1 HD on our HTPC and after getting Hardware Acceleration to work flawlessly (or so I thought), I noticed that the performance when viewing HD channels isn't that good after all. At least not on ORF 1 HD.

Most of the time when viewing ORF 1 HD I get ~33 FPS (according to the Shift-1 overlay). When this is the case, everything seems rather 'jerky', not smooth at all, especially when there are fast or sudden movements involved. On Astra HD+ however, I get ~50 FPS most of the time and almost everything is fine there. Recently I noticed, that I can get 50 FPS on ORF 1 HD too, when I switch back and forth between channels or switch the TV on and off. So maybe there are some issues with the graph being build up.

I attached two logs. In the first one, I started with ORF 1 HD: 33 FPS, then switched to Astra HD+: 50 FPS, then switched back to ORF 1 HD: 50 FPS. Note: I used the PowerDVD 7.3 codec in this test, just to see if it makes any difference.. In the second test, I switched back and forth between ORF 1 HD and Astra HD+, always with 33 FPS on ORF 1 HD and 50 FPS on Astra HD+. However, when I turned the TV off and then on again, ORF 1 HD got 50 FPS... well at least the first 30 seconds or so. Then suddenly it dropped back to 33 FPS.


I experienced the same issue on my workstation (C2D E6600@3.2GHz, 2GB RAM, Radeon x1950 Pro, 1680x1050). When using the PowerDVD 8 codec with Hardware acceleration. I mostly got 33 FPS on ORF 1 HD and 50 FPS on Astra HD+. Interestingly, with the CoreAVC codec I always get 50 FPS on ORF 1 HD and 25 FPS on Astra HD+ (I guess the "worse" performance on Astra HD+ is due to it being 1080i, contrary to 720p on ORF 1 HD). However even with only 25 FPS on Astra HD+ (with CoreAVC), it never looks 'jerky' or anything, it's always smooth.


I know that getting smooth HDTV on a "computer" display (like our beamer) is somewhat troublesome, but there has to be some issue here somewhere (not necessarily in MediaPortal). It doesn't make much sense to me at least.


// I just found out that ORF 1 HD sends in 720p50, so no wonder it's not smooth with 33 FPS

 

[Spooky]

I did some further testing. I let the TV server make a recording of ORF 1 HD a few minutes. After that I played that recording via Media Portal and everything was fine. Video played smoothly at 50 FPS everytime I tried it (except a few seconds in the beginning). Playing the TS file via Media Player Classic (Home Cinema) through the same PowerDVD codec also works just fine.

I also tried letting the TV Server buffer the stream for a minute or so (by hitting pause) and then play it, but that didn't help, still only 33 FPS.

Initially I thought this might be a problem somewhere in the Codec -> VMR9 -> Driver -> Hardware pipeline, but maybe it's a problem in the Source Filter? Since the recording works fine, but direct viewing not. I also experienced a drop to back 33 FPS on ORF 1 HD on my own system (with CoreAVC, where it usually works with 50 FPS all the time) after pausing the stream.

 

[tourettes]

Initially I thought this might be a problem somewhere in the Codec -> VMR9 -> Driver -> Hardware pipeline, but maybe it's a problem in the Source Filter? Since the recording works fine, but direct viewing not. I also experienced a drop to back 33 FPS on ORF 1 HD on my own system (with CoreAVC, where it usually works with 50 FPS all the time) after pausing the stream.

Source filter (TsReader.ax in this case) doesnt see any difference between the live tv and recorded content that could affect the video decoding. I would suspect the video codec, it could have some issued detecting the deinterlace in the stream. Could you try some other codecs also?

 

[Spooky]

Source filter (TsReader.ax in this case) doesnt see any difference between the live tv and recorded content that could affect the video decoding. I would suspect the video codec, it could have some issued detecting the deinterlace in the stream. Could you try some other codecs also?

I suspected as much. But in both cases the video codec is the same and since there is no technical difference between the DVB source and the recorded source, why would the codec have troubles detecting the deinterlace in the stream when viewing the (permanently timeshifted) DVB source?

I can't try other codecs on the HTPC because I have to use hardware acceleration there. And as already mentioned I tried CoreAVC on my system, which works just fine (contrary to PowerDVD with HW accel, same issue as on the HTPC). 50 FPS every time... except the case where it dropped back to 33 FPS too after using pause, as mentioned in my post before.


// I just noticed, that on my system, the recording is also played only at 33 FPS with the PowerDVD codec. So it seems a bit random, that the recording is played at 50 FPS on the HTPC.

//² Gah, this is so random. Without changing anything, MP played the local file, the remote recorded file and the live tv with 50 FPS (with the PowerDVD codec) just now on my system (not on the HTPC). Then a few minutes later, everything played at 33 FPS again. Media Player Classic plays the files always at 50 FPS (through the PowerDVD codec).

 

[blackheart42]

Are you using AMD's processor driver to reduce power consumption and heat? Sometimes it doesn't play nice with multimedia apps.

Blackheart

 

[Spooky]

Are you using AMD's processor driver to reduce power consumption and heat? Sometimes it doesn't play nice with multimedia apps.

Blackheart

Well, the processor driver is installed, but I use RM clock to throttle down the CPU with the performance on demand profile. I already tried testing this at full throttle, but it didn't help.

 

[Spooky]

Hm, even on my system, with CoreAVC, I rarely get only 33 FPS on ORF 1 HD. Happened two times recently, always after a channel switch (switching back and forth again brought back 50 FPS again).

 

[Spooky]

Today I tried watching a football game on ORF 1 HD again on the HTPC and I made the following observations:

• If I go to Live-TV and activate it by selecting the video area and hitting Enter (rather than turning the TV on with the designated menu button) and then go into fullscreen when it runs, without activating any overlay windows from MP (e.g. the channel list/mini-epg), I get 50 FPS.
• Sometimes the video falls back to 33 FPS, then I have to deactivate the TV again and repeat the procedure above. Fortunately this happened only once before the game and one time in the pause and once after the game
• If I activate any overlay/context menu of MP (e.g. the channel list/mini-epg), it will immediately drop to 33 FPS and it won't recover by itself (I have to repeat the procedure again).

 

[jallahman]

The probable reason for this HD-bug is discussed here:

https://forum.team-mediaportal.com/watch-edit-videos-104/problem-hd-channels-live-recordings-41173/

Lets hope that the devs see it (and fixes it)

 

[Spooky]

The probable reason for this HD-bug is discussed here:

https://forum.team-mediaportal.com/watch-edit-videos-104/problem-hd-channels-live-recordings-41173/

Lets hope that the devs see it (and fixes it)

Unfortunately it isn't . I tried today's SVN version which includes this fix (TsReader now reads the video dimensions correctly), but it doesn't fix my problem. So it's still unclear where this weird behaviour comes from. Guess it's somewhere between Codec -> VMR9 -> Driver -> Hardware after all