H264. Pro Recorder - OUT OF SYNC!!!!

@Colin Barrett: Which specific version of Desktop Video are you using? I suppose that this can be origin of the problem. I use 10.4.1 and Recorder simply don't work.

I've rolled back to version 10.5.4 on three Mac workstations. The problem is that my main workstation had not long been upgraded to OSX El Capitan which itself was part of the problem, so I took the difficult decision to clean it down and install Yosemite instead. Desktop Video 10.5.4 has been running without a problem (8 hours a day, 5 days a week) since I did that.

Hi,

I am currently testing the h264.Pro Recorder and am getting an approx. 1-2 seconds delay at the end of a 1 1/2 hour capture session. The subject material is a PAL hi-8 tape.

I am using the latest and greatest Desktop Video /Media Express software (v. 10.8.4, Nov 2016) on a PC with an Intel Core I7 6700 quad core processor, 8 gigs of ram and a fast dedicated hard drive contained in an esata enclosure with a sustained writing speed of 80 Mbs or better.

I'm not sure this is true, but am thinking the out of sync condition may have to do with dropped frames, as the video seems to be "ahead" of the audio - is that a fair assumption?

Would a TBC help in terms of ensuring the original video duration is preserved by "filling in" dropped frames, and thus eliminate the audio sync issue? I am not too worried about the occasional video quality issue, but would consider spending the additional $3-400 on a TBC if it addresses the audio sync issue.

With a large amount of the footage I am dealing with, I would like to do a straight archive without having to put it through any post processing to fix the sync issue - I was hoping the h264 could help me in this regard - but maybe I'm wrong?

Any advice would be appreciated.

Thanks

Dennis

Hi Colin,

I just found this post of yours:

https://forum.blackmagicdesign.com/viewtopic.php?f=18&t=3928#p214466

- does the same conclusion apply to the h264 pro recorder, i.e. that a pro grade TBC would help address the audio sync issue? Also, you mention that you always delay the video to maintain sync (as the TBC processing presumably causes a delay). Would you be able to provide a little more detail on how that is achieved?

I am currently using a small pre-amp (Rolls Promatch) to tweak audio levels during capture..

Thanks

Dennis

- does the same conclusion apply to the h264 pro recorder, i.e. that a pro grade TBC would help address the audio sync issue? Also, you mention that you always delay the video to maintain sync (as the TBC processing presumably causes a delay). Would you be able to provide a little more detail on how that is achieved?

It's quite possible that passing the composite or component video signal through a TBC first will resolve the issue. However, I've been running a H264 Pro Recorder for about 3 years and even with lengthy captures (3 hours!) I don't encounter audio + video sync issues. I'm sure a broadcast-grade TBC helps.

The delay issue you refer to is caused by the fact that the TBC takes at least one frame to re-process and re-time sync pulses - it uses a buffer to do this - and if the audio isn't similarly delayed it will be a minimum of one frame ahead. In many, situations this won't be noticed, because lip sync is not really detectable to the untrained eye/ear until the delay hits 3 frames (although if you have a very tight shot of someone talking to camera you may notice it earlier). The way to overcome this is to use a video capture & processor that has the facility of delaying the audio. My Teranex 2D enables this via its audio setup menu where you can dial in the delay required, either in frames or milliseconds, etc.

Failing that, you'll need to acquire an audio delay unit which does the same job, which can then be run in parallel with the video TBC. Both the video and audio signals would then be fed to the H264 Pro Recorder which, hopefully, will perform its conversion with both inputs in sync with each other.

The way I do it is to feed the video TBC output to the Teranex along with the audio, which comes from a sound mixer, and get the Teranex to do the processing. I then take an SDI output from the Teranex and give this to the H264 Pro Recorder which completes the job.

Thanks Colin,

Based on your response, I did some more googling and stumbled upon this unit:

https://www.ensembledesigns.com/products/brighteye/be25#downloads

Since I don't have a whole lot of rack space and am not really looking to setup an extensive rig, this device may be a way to 1) perform some basic video corrections, 2) address the audio lag issues and 3) perhaps provide more control over the audio side of things.

I guess the best way to find out os to try it, but I was wondering if you had any thoughts on going this route?

Thanks again

Dennis

Dennis, I like the look of that unit! That could do the timebase correction of the video and audio inputs and then convert it to a single SDI output which can then be fed to the H.264 Pro Recorder. Of course, the main concern here is whether the timebase correction is sufficient for the unit to "ride out" the frame drops and big holes in incoming sync pulses without the H.264 Pro Recorder stopping capture.

I see it has a UK distributor who is based not far from me - I might try one of those units!

Thanks - I decided to try it out. They sell for +/- $1000 new on ebay, but I managed to pick one up used for about half that.

Perhaps because you always use a TBC and hence feed the signal in through the SDI side of the h264, you never ran into any audio sync issue. I tend to agree with one of your other posts which I think suggested that Blackmagic should be more upfront about the need to use a TBC in the first place (although they admittedly do mention "professional" quite a bit) - until I started looking into this, I had no idea what a TBC was - oh well it's all a learning experience.

Again, thanks for your patience with this newbie - for what its worth, Ill post results here.

Dennis

OK, so don't go out and drop any money on this as of yet. I received the unit this morning and am doing some testing, and have already run into a couple of issues:

1) the control software that goes with the device is only supported up to Windows XP per BrightEye support. I will try installing an XP VM to get that up and running.

2) When running the device in its "out of the box" config (since I dont yet have the above software running to change the config), the resulting video is unacceptable, e.g. although my source material is a decent hi8 PAL tape, the output has occasional jitter and horizontal lines, also the device sometimes simply stops and transmits a green screen, not sure why. Again, the source plays completely fine in those same locations.

The plan is to get the VM and software working and then exploring the configuration options to see if the video issues can be fixed - I will post results here as soon as I have them.

Thanks

Dennis

Here is an update on my odyssey to setup an analog to H.264 archiving rig without the need to post-process using software.

BrightEye 25
After spending an evening trying to figure out how to safely aquire an iso image of Windows XP, I threw in the towel. It can no longer be downloaded from MS, so the only remaining options are to download from less than reputable freeware sites - goodness knows what extra "goodies" they include in such an iso image! Anyways, thank goodness for 30 day return policies, the BrightEye is on its way back to its seller.

H.264 Pro
Just in case the audio lag issues were a device flaw, I also used the 30 day return policy to return the device and ordered a new one.

Next Steps
Hours of googling later, I found this "swiss army knife" of video conversion devices: "the Grass Valley / Canopus Video Conversion - ADVC3000", http://www.broadcastequipment.com/Canopus_ADVC_3000_p/can-advc3000.htm

According to the specs (and as can be seen from from the extensive number of connectivity options on the rear panel), it pretty much supports every type of video conversion under the sun, has audio embedding and some sort of frame correction capability called "Canopus PerfectSync technology" - not sure if this is similar to TBC, but if it works - it works.

Since I am not in a position to own dozens of video conversion and processing devices, it sounds like an appealing option as I also in addition to various analog formats have some DV to transfer and archive. I picked one up on e-bay for $825 - more than I would have liked although it used to retail for $3500, but the silver lining is: it comes with a 30 day return policy!

Stay tuned.

Dennis

Did you try and install the brighteye software on win7? It should probably work.


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Also the h264 that the pro recorder produces is not great quality. For archive purposes I would suggest capturing to prores or uncompressed via a decklink card. This will create *much* better files with preservation of the interlacing from your hi8 masters.

For DV then it's best to transfer via FireWire direct from the deck. This does a bit for bit transfer of the data from the tape. You can then recompress in software if you need a different viewing format.

If you are producing H264 for viewing then a software multipass encode using the X264 codec will produce files of far higher quality than any realtime hardware converter.

It seems like you are spending lots of money to make the ProRecorder work when it is really not a great quality solution (even if it was working to its full capability correctly)

I'd spend the extra on a decklink card and get your digitised files in the highest quality you can. Otherwise the whole expedition will be a waste of time.


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Hi Tom,

Thanks for your input. The idea with the H.264 was to have a method to perform "bulk archiving" of footage that simply needed to be preserved at a reasonable level of quality, but where the highest quality is not neccessarily required. The advantage with the H.264 is that it would not require any post-processing and therefore save a lot of time.

For the "higher priority" video which would need to be captured at a higher quality level and would be subject to post processing, it sounds like capturing via decklink would be a good idea. One thing I am not clear on is where the analog > digital conversion would take place in this case - would you think that the ADVC 3000 would work for this, or would you suggest a different approach?

Thanks in advance,

Dennis

Even for realtime capture you'll find a decklink and live h264 encoder (such as OBS) will produce better quality files. You should also get less audio drift as you are not depending on hardware which is widely considered broken.

Re A/D conversion you can use the ADVC3000 or the decklink itself. You might find the additional processing in the ADVC to be useful or you may find it reduces your final quality. You'd have to try it out. If you don't want to spend the extra for a decklink with analog connections then the ADVC will do all the A/D and audio embedding that you need. A decklink SDI recorder is all you need to go this route.


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Tom,

I forgot to address your comment re installing the BrightEye control software on Win 7. The answer is: yes I did test it on Win7. The software seemed to initially recognize the device and displayed a half dozen or so tabs in the leftmost panel with various options, however after a few minutes, the OS stopped recognizing the device and the tabs simply disappeared. That is when I decided to install it on an XP VM, but as mentioned this proved to be a time consuming process, if at all possible at this point in time given the availability of XP images etc.

Thanks again for your help.

Dennis

Also make sure you use the highest quality connections your deck has. Ideally component YUV. Then SVideo YC. Then Composite. This can make a surprisingly large difference to the final quality.


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Hi guys,

Thanks to Tom and Colin for all of your guidance and patience. I have now received the ADVC3000, the Decklink Mini Recorder and the new H264 Pro Recorder and am in the process of testing a variety of configurations using these devices.

Early findings: by inserting the ADVC3000 in the workflow, audio sync issues are resolved and the device introduces a long list of useful options to adjust video, convert unbalanced to balanced embedded audio as well as introduce a configurable audio delay. The device admittedly seems a bit "old school" with it's "green screen" and knobs and slight humming sound, but results are good and options are many - so far so good.

Quick question to Tom regarding the following config:

Hi8 PAL Deck -> (Svideo) -> ADVC3000 -> (SDI) -> Decklink Mini Recorder Card -> BM Express (AVI)

I assume this is what you mean by "uncompressed via a decklink card" ? If so, once I have captured the (massive) AVI files, what would be the preferred software/method to encode to H.264?

I found this online which seems to be a potential solution: http://www.h264encoder.com/.

Any other suggestions?

Thanks again

Dennis

Handbreak is a good gui based encoder which can use x264 codec to create very high quality h264 files.

You might also like to try direct capture to h264 with OBS.

https://handbrake.fr/
https://obsproject.com



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Thanks again. I tested handbrake and that seems pretty solid. Anyways, after a fair amount of testing, I see the options as:

1) Analog>(Svideo)>ADVC3000>(SDI)>h.264 Pro>(USB 2.00)>HDD/h.264
2) Analog>(Svideo)>ADVC3000>(SDI)>Decklink>BM Express>HDD/AVI>Handbrake>HDD/h.264
3) Analog>(Svideo)>ADVC3000>(SDI)>Decklink>OBS>HDD/h.264

Pros and cons:
1) Pros: Granular bitrate setting, final encoded files created during capture saving time and disk
Cons: Extra hardware, presumably lower quality output (to be verified)

2) Pros: Granular bitrate setting, presumably higher quality output (to be verified)
Cons: Requires huge disk to house transient AVI files, separate capture and encode takes longer

3) Pros: Final encoded files created during capture saving time and disk, better quality (TBV)
Cons: OBS does not have a granular bitrate setting

So with option 3, the closest OBS output settings I could use were:
a) "High Quality, Medium File Size"
b) "Indistinguishable Quality, Large File Size"

Option a) produced video files that had horizontal lines where the subject or camera moved whereas b) produced great quality files, but very large files.

Is there anyway to configure OBS output bitrate at a more granular level?

Thanks in advance,

Dennis

PS: Quality on all of the above options is "in the ballpark" but I have not yet gotten around viewing the output side by side to see the more subtle differences.

OBS should have lots more settings under advanced options...

OBS.png (131.34 KiB) Viewed 5640 times

Sorry I missed that - I figured it must exist somewhere.

I will run some more tests - thanks.

Dennis

One more quick question regarding OBS: when performing real-time capture, is there a way to get OBS to stop recording when the source video signal ends (but the tape keeps rolling with blue screen)? I couldn't seem to find anything in basic or advanced Output Mode.

The h.264 is somehow able to reliably sense this and shut down the BM Express capture which helps avoid further video editor processing for straight archiving situations.

Thanks again,

Dennis

I'm still running into this issue (100-300ms delays with the H.264 Pro Recorder and either MXPTiny or MediaExpress). Are there any workarounds or fixes available for this problem to prevent the audio delay and drift?

Unfortunately, BlackMagic say this is a legacy device which they don't test with current versions of Desktop Video Software. They say is should work but clearly there's a problem here and its been broken for a while. Oddly enough, support say one no has reported the audio latency issue even though there are multiple threads on these forums about audio sync issues.