Why does the HD-PVR use H.264 rather than MPEG-2

[Sam]

Originally Posted by dvd_maniac

What version do you use Sam?

I now use DVRMSToolbox 1.2.1.4 from Andy's website at http://babgvant.com/blogs/andyvt/arc...c-release.aspx or in the download pages here at http://forums.sagetv.com/forums/down...do=file&id=252

Come to think of it, I initially also had to install AVIVO, which is a free video converter by ATI available at their site: http://ati.amd.com/support/drivers/x...xavivo-xp.html

The installer checks if you have an ATI card (which I do), but according to Andy in a post on Aug 4 you can:

When you try to install it checks for the video card. After it fails (if you don't have an ATI card) drill into the folder that it extracted itself to and find the AVIVO.msi (C:\ATI\SUPPORT\8-1_xp_xcode_57717\AVIVO) and run that.

I don't know that the above path is always accurate, but just find the file and install it. In my case, I have an ATI card so it just installed by itself.

[dvd_maniac]

I have the same version. I installed the Avivo package and get the same error...
Oh well, no HD-PVR for me until I figure this out.

[nyle]

Originally Posted by wayner

What is the main reason that the HD-PVR encodes files to H.264 rather than MPEG-2? I can think of one advantage, smaller file size, but that is becoming less of an issue with the price of 1TB hard drives approaching $100. And there would be lots of advantages to using MPEG-2 - many of the problems relating to the HD-PVR seem to stem to using H.264, not the least of which is problems with codecs and the hardware requirements for decoding H.264. And using MPEG-2 would have been much more similar to other HD file types in Sage, such as OTA, QAM, firewire, etc.

Is there some other reason for using H.264 such as being easier to do hardware encoding that I am missing?

I guess we could all go back to RAW AVIs since the CPUs, GPUs and hard drives are all getting faster/bigger. However, from everything I've read MP4 offers not only smaller file size but actually slightly higher video quality even at lower bitrates than MP2. In the long run the gowing pains are worth the stransition.

I think a better question is - "Why haven't we had MP4 encoders sooner and why not from other vendors?" That way the cost would come down and Sage and codec companies would have more reason to concentrate on supporting MP4 versus MPEG2.

I'm just going to enjoy the ride. ;^)

[stanger89]

Originally Posted by nyle

I guess we could all go back to RAW AVIs since the CPUs, GPUs and hard drives are all getting faster/bigger.

Yeah, you could record about 2 hours of HD on a new 1.5TB seagate drive without compression.

[wayner]

Originally Posted by nyle

However, from everything I've read MP4 offers not only smaller file size but actually slightly higher video quality even at lower bitrates than MP2. In the long run the gowing pains are worth the stransition.

I think a better question is - "Why haven't we had MP4 encoders sooner and why not from other vendors?" That way the cost would come down and Sage and codec companies would have more reason to concentrate on supporting MP4 versus MPEG2.

Things should get better in the future but there are LOTS of issues right now. It seems like a large portion of the people using the HD-PVR have playback issues which result from needing a pretty fast PC to play H.264 files or other issues with the decoder. Sage also cannot play them natively, you have to addin a 3rd party (Arcsoft) encoder. You can't Placeshift these files, you can't easily edit them, you can't use the SageConverter to convert them to iPod, etc., etc.

I have changed the priorities of my tuners so that my OTA tuner is top priority. Therefore any HD on OTA will be saved in MPEG-2 rather than H.264 files. Sure the file is larger but there is so much more flexibility available to an MPEG-2 rather than an H.264 file.

[Taddeusz]

Originally Posted by wayner

Things should get better in the future but there are LOTS of issues right now. It seems like a large portion of the people using the HD-PVR have playback issues which result from needing a pretty fast PC to play H.264 files or other issues with the decoder. Sage also cannot play them natively, you have to addin a 3rd party (Arcsoft) encoder. You can't Placeshift these files, you can't easily edit them, you can't use the SageConverter to convert them to iPod, etc., etc.

I have changed the priorities of my tuners so that my OTA tuner is top priority. Therefore any HD on OTA will be saved in MPEG-2 rather than H.264 files. Sure the file is larger but there is so much more flexibility available to an MPEG-2 rather than an H.264 file.

But all your points are moot issues that will eventually be addressed. H.264 is still relatively new. MPEG2 was around a long time before proper editing tools were made available for it. In the beginning MPEG2 was not considered to be an editable format but that eventually changed as tools became available and better. I'm certain the same will happen with H.264. It's an ongoing process and it takes time for software to catch up with new technologies. It's not something that just happens overnight.

[wayner]

But that doesn't help me if I want to Placeshift a H.264 recording when I go to Asia next month! It might be years before an H.264 file offers the flexibility of where MPEG-2 is today. Maybe I will be indifferent between them in 2015 but I certainly am not today!

[Taddeusz]

Originally Posted by wayner

But that doesn't help me if I want to Placeshift a H.264 recording when I go to Asia next month! It might be years before an H.264 file offers the flexibility of where MPEG-2 is today. Maybe I will be indifferent between them in 2015 but I certainly am not today!

I doubt it will happen in a month but SageTV is waiting on a properly stable version of the transcoder that is compatible with HD-PVR recordings before they implement it. The current beta versions are compatible but are not yet quite completed.

Keep in mind that once SageTV does replace the transcoder you're going to need one heck of a CPU to do that in realtime. One of the major stumbling blocks for H.264 is that it requires quite a bit more processing power than MPEG-2.

[dvd_maniac]

But that doesn't help me if I want to Placeshift a H.264 recording when I go to Asia next month!

There are current workarounds to transcode the files to HD-MPEG2 files relatively quickly. This thread shows a few ways.

But all your points are moot issues that will eventually be addressed. H.264 is still relatively new. MPEG2 was around a long time before proper editing tools were made available for it. In the beginning MPEG2 was not considered to be an editable format but that eventually changed as tools became available and better. I'm certain the same will happen with H.264. It's an ongoing process and it takes time for software to catch up with new technologies. It's not something that just happens overnight.

The difference between H.264 and Mpeg-2 would be standards. I think that Mpeg-2 was a lot less complex and was more standardized and that is what will make it harder for H.264 tools to become more common place and stable.
So many different Audio & video codecs, containers, frame rates, etc... compared to Mpeg-2.

[wayner]

Originally Posted by dvd_maniac

There are current workarounds to transcode the files to HD-MPEG2 files relatively quickly. This thread shows a few ways.

I think you posted the wrong URL as this seems to be a circular link right back to this thread!

[dvd_maniac]

Hey Wayner,

That's what my wife calls a Brain Fart...I get these from time to time...

Thanx for pointing out what a idiot I can sometimes be.
But my point is that he can still go to Asia next month and Placeshift his recordings with relative ease.

[Djc208]

The hardware support is improving pretty drastically thanks to HD video. Essentially all the latest integrated graphics chipsets support full H.264 decode (some better than others). GPGPU processing could go a long way toward improving transcoding times and speed. Most of the portable MP3/Video players support certain versions of H.264 video as well.

The problem is the software side. Only a few expensive codecs support the native HD capabilities of the newer video cards/chipsets. ATI/nVidia have been very slow to release or support GPU transcoding (or many GPU related tasks) because of all the propriatary issues. Plus, while Vista is better about it, with all the different software and background tasks usually running on a PC a bottleneck in a certain location or bad coding in one program can cause issues for throughput sensitive tasks like video (I'm looking at you Adobe).

[nyle]

Originally Posted by wayner

Things should get better in the future but there are LOTS of issues right now. It seems like a large portion of the people using the HD-PVR have playback issues which result from needing a pretty fast PC to play H.264 files or other issues with the decoder. Sage also cannot play them natively, you have to add in a 3rd party (Arcsoft) encoder. You can't Placeshift these files, you can't easily edit them, you can't use the SageConverter to convert them to iPod, etc., etc.

I have changed the priorities of my tuners so that my OTA tuner is top priority. Therefore any HD on OTA will be saved in MPEG-2 rather than H.264 files. Sure the file is larger but there is so much more flexibility available to an MPEG-2 rather than an H.264 file.

So anyone try this new Shuttle? Is it fast enough for smooth capture and playback.
http://us.shuttle.com/barebone/Models/SN78SH7.html

Won't Nero Recode handle Mp4 -> Ipod. I know there are other programs that will handle MP4 to other formats.

I can understand those that want to Placeshift. I don't use it and I'm sure support will come over time. I mean the HD PVR just came out not long ago. The fact Sage supports it at all is really amazing.

It's all a matter of MP4 being new for this. The support will come.

[davephan]

Originally Posted by Sam

There are a few utilities out there which purport to do what you ask, such as TSCutter, but I have not had success with them and HD-PVR recordings. I am hoping VideoRedo gets H.264 support working, but I haven't heard a projected availability date. (It is what I use for mpeg-2 editing.)

In the meantime, what I'd suggest is getting DVRMSToolbox from babgvant.com -- he has worked out methods for transcoding the *.ts files to *.mpg in a very efficient manner. And it has an incredibly powerful file watcher and action editor.

Using it, you can have all your HD-PVR files transcoded to mpeg-2 concurrent with the recording. This gives the near equivalent to what you want; a HD-PVR with mpeg-2 output. It just requires some CPU on your server.

What I'd suggest is having the HD-PVR output at the max 13.5Mbps rate, so you have the highest quality input to the mpeg conversion, then output whatever mpeg rate you want for your archives.

What is the default recording rate for the HD-PVR, and how do I set it for the max 13.5Mbps rate?

I've been looking for a way to edit the TS files, but if transcoding TS to MPEG2 format works without video or audio quality loss, then I could edit the video files with VideoReDo.

Dave

[Taddeusz]

Originally Posted by davephan

I've been looking for a way to edit the TS files, but if transcoding TS to MPEG2 format works without video or audio quality loss, then I could edit the video files with VideoReDo.

Converting one lossy format to another will incure some quality loss. It is up to you to decide if that quality loss plus the time spent converting the video is worth it to you.

[HuMan321]

Originally Posted by Brent

I'm very happy with my HD-PVR now. I'm using it to record many shows in HD, watching sports live in HD and now have comskip working to detect the commercials. The device is definitely not perfect though as we can see by how many people have had trouble with it thus far.

Brent,
What setting if any did you change for ComSkip on your HDPVR files?