How to make ATSC streams compatible w/o recomp?

Sebaz wrote on 7/1/2008, 8:27 PM

I have ATSC Mpeg 2 1080i streams transferred from my cable DVR (SA8300HD). I edit them with VideoRedo and save the result to separate A/V streams. I've took some of these to a friend's studio that has Scenarist HDMV and he was able to make BD 4.7 with them without recompressing or doing anything extra. They play just fine in my Sony BDP-S300.

But so far, everything I've tried in DVDA 5 has less than perfect results. For ATSC streams, whether I render to separate streams, render to TS, render to MPG, or use the original stream without going through VideoRedo, DVDA5 reads it differently but it never gives me what I want, which is the original stream without any recompression. In some cases it will accept the video stream, but then it produces a disc that plays the audio fine but the video at like 1 frame per second. For most streams, it simply says that it needs to recompress.

Then I tried some small AVC files from my Canon HF100 camcorder. Luckily the video doesn't need to be recompressed, and it plays fine on my BD player, but DVDA 5 wants to recompress the audio, even though it's 256 kbps AC3 stereo, the same setting the project has. The crappy software that comes with the Canon, Pixela ImageMixer, produces an AVCHD DVD without ever recompressing the audio or video.

It seems to me that DVDA 5 needs more work, because as it is, it's too picky. Probably it would behave better with files rendered from Vegas, but that's my point, I don't want to recompress the already compressed to death ATSC streams, because of image quality, and because of the time and extra expense in electricity from the computer working at full power for extended periods of time.

Now, has anybody been playing with ATSC streams, and if so, did anybody find the way to make them compatible without recompression?

Comments

alk3997 wrote on 7/2/2008, 6:47 AM

OK, I thought I was the only one the 1 frame / second problem...

After splitting the audio and video into separate elementary stream files, DVD-A 5.0 no longer tries to recompress my .ts files. However, the result is a Blu-Ray disc (luckily an RE) that plays video at 1fps but plays audio at the normal speed. A very interesting (but unusable) result.

I'm going to double-check that I really did produce elementary streams and the proper format. However, right now DVD-A 5.0 still seems like it needs a lot of extra care that other software does not to produce a BD disc without recompression.

I'm trying different programs to produce the elementary streams and so far, no luck. The .ts files I've tried so far are 12 mbps, 15 mbps and 32 mbps video. I'm almost thinking this has something to do with DVD-A (prior to 5.0) using program streams and now with BR having to handle transport streams (of course with an elementary stream it shouldn't matter).
Andy

Sebaz wrote on 7/2/2008, 7:10 AM

Actually, even when you separate streams, DVDA 5 will recompress or not depending on what network you got the content from. I tried a small segment of "Chuck" from NBC, and it didn't recompress, but it gave me the 1 fps glitch. However, a small segment from MHD wanted to recompress, and I think also one from CBS. So it's like a lottery. My main problem is that is Scenarist HDMV takes these forward with no problem, I don't see why DVDA 5 can't take them.

alk3997 wrote on 7/2/2008, 9:36 AM

I'm wondering if the 1 fps glitch isn't because VideoDoDo is making a non-compliant video elementary stream. I'm trying to find another piece of software that I trust which will strip out each stream individually.

So far the programs I've tried produce streams that DVD-A 5.0 wants to reencode with the exception of the VideoDoDo output, which produces the glitch.

I'm about to put DVD-A on the backburner and go back to the software that I had been using (successfully) while waiting for DVD-A 5.0. That would be disappointing.

TheHappyFriar wrote on 7/2/2008, 10:03 AM

I had issues like this with mpeg back before I started using DVDA. What I did to find the issue was take a video file that worked perfectly (in my case, an mpeg) & figure out ALL it's settings: res, audio, video size, etc. & then tried to duplicate that. Took some figuring out but I did figure it out. I know it doesn't help here but I don't have a BD player, or burner so I can't help on the technical side. If I did I'd make some discs just to impress people. :D

MPM wrote on 7/2/2008, 2:43 PM

"What I did to find the issue was take a video file that worked perfectly (in my case, an mpeg) & figure out ALL it's settings: res, audio, video size, etc. & then tried to duplicate that."

'Bout all you can do, plus maybe hit up the forums where folks have been playing with HD &/or BD for a while and see if they've got templates you can dissect.

DVB streams, whether HD or SD, are still capped streams - not necessarily discreet files with the expected structures. There is no std for a DVR to record to its hdd - in fact, accessing the stored files is becoming a rarity. There are different h264 encoders (AVC - AVCHD), & their output isn't universally compatible. AC3, especially recorded, can have padding to keep sync, that you won't see encoding wav files. The way a file is muxed can have an effect, as can the file extension.

That goes for all software - not just DVDA5, which is unfortunately too new to have much of this stuff nailed down by users yet. ProjectX is still a good tool for playing with mpg2, and can change a whole lot of variables in the file without re-encoding, but there's a bunch you can try like Restream. For AC3 there are also a few apps that can repair it, re-write it, & methods using them to strip out padding, all without re-encoding. AVC is still a royal pita, but there are a couple of tools I think that *might* alter the files enough re-writing them that they *might* work.

alk3997 wrote on 7/2/2008, 7:51 PM

Well, I tried a different application for creating the elementary streams. DVD-A 5.0, of course, wanted to recompress the video.

From what I've been able to tell so far is the only video it didn't want to recompress actually should have been recompressed. On the other hand, the video files that DVD-A believes needed recompression seemed compliant on other programs.

Looks like if I use Vegas and render with MainConcept MPEG2 encoder, the new DVD-A 5.0 will be great for creating the Blu-Ray disc. However, if I am using MPEG2 from some other source then I really want to look elsewhere for BDMV disc creation.

Maybe DVD-A 5.1 will be better...

TheHappyFriar wrote on 7/3/2008, 5:50 AM

be sure to check out DVR sites. many people have figured out how to get files from DVR's to DVD/BD/HD already & they may have the answer for you. Here's one I used when I had my own HTPC/DVR: [url=http://www.byopvr.com/].

MPM wrote on 7/6/2008, 4:48 PM

If it helps, just posted in a new thread how I believe the audio problem is the AC3 being Intel Endian rather than Motorola. That doesn't help a whole lot at the moment unless you know of a way to convert them without re-encoding - it can also help if you have a choice of how you render your AC3 (Motorola or Intel).

For the video that doesn't work (1 fps etc), where DVDA5 finds it Blu Ray compatible, could you please check the video stream in the prepared disc or iso? If the size of the m2ts file looks about right, tsMuxeR (videohelp.com) will extract the video file for you... I've found at least one case where DVDA5 only includes part of the video on the timeline. The resultant, broken file can play back pretty much as you've described - i.e. 1 fps.

Don't know more than that yet, but, it would at least verify something about the problem, & hopefully prompt a quicker cure from SCS.

Thanks