Poor Analog Recording Quality in SageTV but not in WinTV (HVR-2250)

[rdellar17]

I'm trying to figure out why SageTV produces significantly lower quality analog recordings than WinTV when using the exact same recording settings.

Recording Source:

• Recording 4:3 Standard Definition Video over S-Video & Analog Audio
• I recorded the same ~5 min segment in both WinTV and SageTV

SageTV and WinTV Analog Recording setup:

• VBR / AvgBitRate: 4500000 / MaxBitRate: 5000000
• (Only a WinTV option: MinBitRate: 4000000)

SageTV ini Settings:

mmc/python2_encoding/Hi8CaptureForDVD=videobitrate\=4500000|width\=720|height\=480|audiobitrate\=384|vbr\=1|peakvideobitrate\=5000000|outputstreamtype\=10

WinTV Settings (From the registry entry for 'Good' quality):
AnalogBitrateAvg=4500000 / AnalogBitrateMax=5000000
/ AnalogBitrateMin=4000000 / AnalogBitrateMode=0

Output Information:

• Used GSpot to analyze the videos. See attachments.
• Bitrate of both videos were extremely similar. (~3.9Mbps)
• Noticed that SageTV recorded at 704x480 and WinTV recorded at 720x480 (the 704 just chops off some black pixels on either side.)
• Noticed that WinTV records in TS and converts to PS. SageTV writes a PS directly.
• Noticed that GSpot shows that the frame type and order are very different.

When comparing the videos there are significant 'blocking artifacts' in the SageTV recording that doesn't exist in the WinTV version. I used SMPlayer to compare a few sequences frame by frame with deinterlacing disabled. Every other frame or so the SageTV version would become blocky while the WinTV version stayed smooth.

I attached one frame of fast motion so you can see the difference between the SageTV and WinTV versions. (It is supposed to look jaggy and blurred since deinterlacing is off. The SageTV version has severe blocking artifacts almost every other frame, while the WinTV has very minimal to no blocking. Almost every frame with motion is like this...)

Since both applications are calling the same hardware encoder with the same options I don't see why there would be such a huge difference in quality. My only offhand guess is that since SageTV doesn't allow for a MinBitrate that it is getting set to some low default. (Is there is a way to override the minbitrate in SageTV? I didn't see it in the Recording Quality FAQ or HPQuality doc.)

I tested this out about 10 other different ways (CBR, various bitrates, flags, etc), but I didn't want to bore anyone with the details. In every case the SageTV videos were much more blocky.

Any ideas? I'm transferring lots of videos and the SageTV interface is much easier to use vs WinTV, but it isn't worth it at a great loss of quality.

SageTV (VBR 4.5) GSpot.JPG - Gspot analysis of SageTV recording
SageTV (VBR 4.5) screenshot.JPG - Note the many block artifacts
WinTV (VBR 4.5) GSpot.JPG - Gspot analysis of WinTV recording
WinTV (VBR 4.5) screenshot.JPG - Almost no blocks

[rdellar17]

Couple things I forgot to mention...

When viewing parts of video that are not in motion, the SageTV and WinTV videos look very similar. (When full scenes are in motion it is worst. But you will see severe blocking artifacts on any section of the video that is in motion like in the above examples.)

When I tried 6.0 Mbps CRB (SageTV Best) it still was very blocky, better looking than the SageTV 4.5 Mbps VBR, but worse looking than the WinTV 4.5 Mbps VBR. (The file size of the 6.0 Mbps CBR is about 25% larger also vs the 4.5 Mbps VBR.)

Below is a screen cap of the 6.0 Mbps CBR from SageTV
SageTV (CBR 6.0) screenshot.JPG

[SHS]

remove |outputstreamtype\=10 that only works with PVR model 150, 250, 350 and 500
The 2250 has diff a chipset so there for some thing may work better in WinTV then SageTV

[rdellar17]

Originally Posted by SHS

remove |outputstreamtype\=10 that only works with PVR model 150, 250, 350 and 500
The 2250 has diff a chipset so there for some thing may work better in WinTV then SageTV

Thanks for the idea. I tried it out and also tried a transport stream. But unfortunately it didn't make any difference. (i.e. It looked just the same as when I picked the DVD option. Note that I know it changed things though since I got a transport stream with one of the options.) Below are the details.

As a new test I watched 3 seconds of fast moving video frame by frame and I'd say 15-20% of the frames are clean in the SageTV capture. 100% were clean in the WinTV capture. (This kinda makes sense since MPEG2 files for DVD are required to have an I-frame every 18 or less frames. For that frame it should always look perfect.)

I still wonder if it isn't something to do with lots of B-Frames. (B-Frames make up about 60% of the SageTV encoding. In WinTV there are only I and P frames. More info HERE.)

I wonder if you can even pass an option to the encoder for that though. The Microsoft MPEG2 encoder let's you specify frame setup, but SageTV/WinTV are using the HVR-2250 hardware encoder.

Here are the new screen captures:
SageTV (VBR 4.5, Program Stream) screenshot.JPG - Went back a frame to get the blocky one
SageTV (VBR 4.5, Transport Stream) screenshot.JPG - Blocky Transport stream one. (same)
SageTV (VBR 4.5, Program Stream, random clean) screenshot.JPG - Random good frame. (Note that I had to go back one from this to get the blocky version above. The frame I captured here just happened to be a randomly clean one out of a list of blocky ones. Note that when it looks clean it looks exactly like the WinTV version.)

Details of the comparisons:

SageTV - VBR 4.5 Mbps remove outputstreamtype\=10 (0=program stream)

• mmc/python2_encoding/Hi8CaptureVBR4_5_noOST=videobitrate\=4500000|width\=720|height\=480|audiobitrate\=384|vbr\=1|peakvideobitrate\=5000000
• SageTV shows this as: MPEG2-PS @ 2.3 GB/hr

SageTV - VBR 4.5 Mbps change to outputstreamtype\=1 (1 = transport stream)

• mmc/python2_encoding/Hi8CaptureVBR4_5_OST1=videobitrate\=4500000|width\=720|height\=480|audiobitrate\=384|vbr\=1|peakvideobitrate\=5000000|outputstreamtype\=1
• SageTV shows this as: MPEG2-TS @ 2.3 GB/hr

So it isn't stream type...

[icon123]

Although my analog cable 2250 sage captures looks just like yours and I haven't did a comparison with wintv, but I can say that my cable directly hooked up to my tv looks soooo much better. Unfortunately, I just figured that was the way it is. It would be nice if you can figure something out though. Good luck.

[rdellar17]

Originally Posted by icon123

Although my analog cable 2250 sage captures looks just like yours and I haven't did a comparison with wintv, but I can say that my cable directly hooked up to my tv looks soooo much better. Unfortunately, I just figured that was the way it is. It would be nice if you can figure something out though. Good luck.

I opened an official support ticket. I'll update this thread with what I hear back.

My guess is that it is the Minimum Bitrate not being set or being set too low. (I set the min bitrate in a WinTV test to a low number (1Mbps) and it looks somewhat similar, but not exactly the same. In the WinTV test with the low bit rate it impacted more than just the frames in fast motion.) If SageTV had a minbitrate option then that might fix it assuming it is the underlying issue.

[SHS]

Give this driver a try http://www.shspvr.com/ftp/download/h...prerelease.zip

[rdellar17]

Originally Posted by SHS

Give this driver a try http://www.shspvr.com/ftp/download/h...prerelease.zip

Thanks for posting the link to the beta!

I did a quick check... I have 7.9.1.28162 which is the last non-beta released. I remember it was a pain to get that one working + setting up the new WinTV. (multiple reboots, hwclear, etc)

It doesn't look like a whole lot changed according to the release notes... So, I'll probably see what the SageTV folks say first before giving this a shot.

Thanks!

Version Check:
C:\WINDOWS\SYSTEM32\DRIVERS\hcw89.sys --> 7.9.1.28162

[rdellar17]

One more follow up. Basically working with SageTV support folks trying to figure out a solution...

In the mean time I tested out just using WinTV to do the recordings...

Unfortunately the mpeg2 files that WinTV creates are not DVD compliant. So to write these to a DVD I would have the reencode each video again.



The encoding for SageTV has frame types of IBBPBBPBBPBBP...
The encoding for WinTV has frame types of IPPPPPPPPPPPPPP...

After lots of hunting online I think WinTV is encoding frames in something called "low delay mode" See HERE and HERE According to the DVD spec low delay mode is not allowed for DVD mpeg2 video. Thus it has to be re encoded prior to burning. (The DVD authoring programs I've tried won't let me write those without reencoding either. They will let me write the SageTV mpeg files with no reencoding of the video.)

I did try reencoding the WinTV video to the DVD standard and the DVD authoring programs will process them without reencoding. And it looks pretty darn close to the original. (The WinTV video reencoded looks way better than the original SageTV encoding, so I know it's not the frame order that is impacting the quality.) Re-encoding just wastes a ton of time and I know the MPEG2 capture card can do it correctly in the first place.

So far WinTV and SageTV are the only two programs I've found that can work with the MPEG2 encoder in the HVR-2250 card. I would try another program, but I don't know of one.

So I'm stuck between bad looking video or having to re-encode everything before burning.

[SHS]

What DVD authoring programs are you using

[SHS]

The encoding for SageTV has frame types of IBBPBBPBBPBBP...
The encoding for WinTV has frame types of IPPPPPPPPPPPPPP...

This all about gop size
I is the primary
then P is based off I
then B is based off P
http://en.wikipedia.org/wiki/Video_c..._picture_types
or
http://en.wikipedia.org/wiki/Group_of_pictures
IPPP sufficient for little more accurate cutting and editing with some 3rdparty editor

[rdellar17]

Originally Posted by SHS

What DVD authoring programs are you using

Mainly was using Sony DVD Architect 4... I played with DVD Flick and it re-encoded everything also.


But I went back tonight and played with it some more and found an option I didn't notice before.

Project Settings -> Video -> Advanced -> Copy MPEG2 Streams

It gives a big warning about if you don't have a valid MPEG2 stream that it will fail to play, but I checked the box anyway.

To make a long story short, DVD Flick copied the Win TV MPEG2 to the DVD and the DVD seems to play just fine on my PS3 and PowerDVD app. (I could tell it wasn't re-encoded because it only took a few seconds to do the video step.)

I'm going to try the DVD out on 2-3 older players to make sure they don't have issues either. I think this is a good solution until Sage comes up with a workaround. (I still much prefer the Sage interface, but I can deal with Win TV for a while.)

Any other preferences for DVD Authoring programs? (DVD Flick seems to work good enough for me and the price is right. The simple DVD menus are fine also.)

Thanks SHS!!!

Edit: One funny thing... Just as a test I tried to write the SageTV video to DVD using DVD Flick, but it re-encoded it no matter what since it was 704x480... (So I guess if this is fixed in SageTV, I'll have to go back to DVD Arch. )

Edit2: I downloaded AVStoDVD. It seems more complex, but doesn't have any issues with 704x480 files. (It specifically lists on the GUI if it is going to reencode or copy the stream. It doesn't reencode any of the WinTV or SageTV mpeg2 files.) Other folks posted that the audio sync's better with DVDs authored from AVDtoDVD. Just tested it out and audio on AVStoDVD is WAY out of sync on both encoding types. (Tried MPEG 2 audio and existing AC3 Audio. All were out of sync on the final DVD even though they were ok in the original files. I went with all defaults, but there are tons of options to fix audio synching. So if I need to go the AVDtoDVD route I might do more research.)

[SHS]

The reason why they tell it not a valid MPEG2 stream that has to do with the audio being MPEG-1 Audio Layer 2 it has nothing to do with video it self.
Yes that why you need find a setting that some like Copy MPEG2 Streams or Do not convert compliant MPEG file.
The problem are DVD Authoring programs them self not allow MPEG-1 Audio Layer 2 even know it is valid for DVD compliant the problem was it was only under PAL only funny things is all Hardware/Software DVD Player support MPEG-1 Audio Layer 2.
So the Sony DVD Architect 4 maybe way out of date I think you need ver 4.5 or 5 in order get around that problem if I recall rigth.
The best one are DVD MovieFactory, Womble EasyDVD

[rdellar17]

Originally Posted by SHS

The reason why they tell it not a valid MPEG2 stream that has to do with the audio being MPEG-1 Audio Layer 2 it has nothing to do with video it self.
Yes that why you need find a setting that some like Copy MPEG2 Streams or Do not convert compliant MPEG file.
The problem are DVD Authoring programs them self not allow MPEG-1 Audio Layer 2 even know it is valid for DVD compliant the problem was it was only under PAL only funny things is all Hardware/Software DVD Player support MPEG-1 Audio Layer 2.
So the Sony DVD Architect 4 maybe way out of date I think you need ver 4.5 or 5 in order get around that problem if I recall rigth.
The best one are DVD MovieFactory, Womble EasyDVD

Thanks for the suggestions on the programs!

I don't think it is the "MPEG-1 Audio Layer 2" alone that is doing it on DVD Arch. The SageTV mpeg stream has "MPEG-1 Audio Layer 2" audio and DVD Arch reencodes the audio and not the video. (DVD Arch just extracts the video stream there. If you look at properties it will show you what it is going to re-encode. It just shows the audio as needed to be reencoded for the SageTV recordings. It shows everything as needing to be re-encoded for the WinTV recordings.)

DVD Flick and AVStoDVD just reencode the audio stream in all cases when the video is 720x480... (For the fun of it I reencoded the "MPEG-1 Audio Layer 2" stream in one of the mpeg2 to AC3 and then all programs will go with the Audio and Video streams with no re-encoding.

This has been a fun adventure. Thanks again! (I'll post back if I hear from the SageTV support folks again, it would still be nicer to use SageTV if possible to do this.)

[rdellar17]

Discussed the issue with SageTV support this week and last. They sent me test libraries to try, had lots of suggestions, tests, etc... But they weren't able to reproduce the issue I have. But I give them lots of credit for trying and spending time on trying to fix this.

In the end it looks like there isn't a way to fix this in SageTV... At least that anyone inside SageTV or outside SageTV has found.

I'll go with WinTV and just deal with the worse interface now that I found a program that will accept the mpeg2 files encoded by WinTV.

Thanks all who posted!