# Test Report: Long Delay in Audio Return after FF/RW/PAUSE/etc.



## TigerDriver (Jul 27, 2007)

*HR-20: Long Delay in Audio Return after FF/RW/PAUSE/SLIP/etc.*

I set out to test why my HR20-100 introduces a long (5-10 seconds) delay after any program disruption, such as FF, RW, 30-sec slip, etc. This occurs only when using Dolby Digital audio, either via a HDMI or optical connection.

[Author's note: since writing this test report, I've obtained an HR21-700. It behaves as the HR20-100 I used for this article.]

[Author's note 4/19/08: This problem was fixed on my HR21-700 with CE software 0x0202 and on the HR20-100 with CE software 0x021C. It remains fixed on both machines in CE releases 0x022B.]

As my HR10-250 does not exhibit this problem, I used it as a reference to ascertain how the Dolby Digital audio data stream ought to behave under the same test conditions.

The test setup included a borrowed Dolby DM100 Bitstream Analyzer (hereafter referred to as the DBSA), which is installed in the digital audio line as a pass-through device. It not only enables the operator to look at the incoming Dolby Digital stream, but also (if desired) to change various parameters in the data stream on-the-fly and pass the changes to downstream devices (TV, AVR, etc.).

The test setup connected the component video output from the DVR to the A/V receiver via RCA cables. The Dolby Digital signal was connected to the DBSA via Toslink cable. The digital audio output from the DBSA was connected to my Onkyo 705 A/V receiver via a Toslink cable.
*

DOLBY DIGITAL BASICS*
The Dolby Digital Bitstream is a synchronous packet protocol, with redundant error checking via 16-bit CRC. Each packet contains bits to describe the type of data being transported. These are displayed on the DBSA:


Dolby Digital
PCM 
Data Type X: digital stream not recognized.
NULL data: no audio stream present
Pause data: This is merely a valid Dolby packet without audio content. I didn't want to pay a fortune for the from IEC 61937 standards document referred to in the DBSA manual, so I used the translation from the parallel EBU (European Broadcast Union) document: "The receiver shall send pause data-bursts to the home audio equipment in cases where there is no audio data available due to transmission interruptions. _This maintains synchronization of the decoder in the home audio equipment and allows quick reacquisition of the audio signal._"

Note: the term _synchronization _as used here refers only to the synchronization between the DVR and the A/VR at the packet level. It has nothing do with the loss of synchronization between the audio and video streams (i.e., 'lip sync').

The DBSA's front panel also has an LED error-indicator. This indicator latches; that is, when an error occurs, the LED turns on and remains on until reset. The cause of errors can be retrieved using the DBSA's Error Stats feature.

*TEST METHODOLOGY*
For the sake of simplicity, I'll refer to DVR normal audio as "standard play mode," and "audio-interruption mode" is when the DVR is in pause, rewind, fast-forward, jump/slip, or backward/forward.

*HR10*
When the HR10 enters standard play mode, the DBSA's status display identifies the stream "Dolby Digital." When the HR10 is put in any audio interruption mode the DBSA's display switches to "PAUSE data." The LED error indicator on the DBSA does not illuminate. Upon resuming standard play mode, the DBSA's display returns to "Dolby Digital." This behavior is reflected in the A/V receiver's behavior: during audio interruption (Pause data), the Dolby Digital indicator is steadily illuminated and audio returns immediately upon resumption of standard play mode.

*HR20*
Like the HR10, when the HR20 enters audio-interruption mode, "Pause Data," appears on the DBSA's display. After resuming standard play mode, the DBSA's oscillates very rapidly between "Pause Data" and "Data Type X," and the LED error-indicator illuminates. After 3-10 seconds the DBSA's display returns to a constant display of "Dolby Digital." This behavior is reflected in the A/V receiver's behavior: during audio interruption, the "Dolby Digital" indicator remains illuminated. However, upon reactivating standard play mode, the "Dolby Digital" indicator flickers more-or-less in concert with the DBSA's status display for 3-10 seconds. When the DBSA's display returns to "Dolby Digital," the A/V receiver's Dolby Digital indicator steadily illuminates and audio returns shortly thereafter.

After running through the normal-play-to-interruption cycle just described, the cause for the error-indicator's illumination is gleaned by examining the DBSA's Error Stats Menu (page 47). The HR20 consistently identified the error as "Invalid Format."

*CONCLUSIONS*
Some have placed the blame for this problem on the Dolby Digital decoders in AV receivers. My tests clearly show, however, that the output from the HR20 becomes and remains defective for 3-10 seconds after return to standard play mode. Therefore, those with receivers that are slow to synchronize with a Dolby Digital signal will find that receiver delays and those of the HR20 are additive, causing delays greater than the 3-10 seconds I experience.

It's impossible to infer the underlying pathology associated with this bug. The best (but least likely) case is that the problem is caused by application software--and therefore can be corrected in an ordinary software upgrade. From my experience, however, such problems are more likely caused by DSPs whose firmware has not been thoroughly vetted. I don't know enough about the hardware architecture of the HR20 to say whether the DSP code resides in fixed ROM or some sort of EPROM.

If the code is in ROM, the only fix is to replace the DSP itself, which means replacing the entire HR20 with a unit with updated firmware. Getting you a known-good unit requires that DirecTV be able to distinguish a "fixed" unit from a defective one merely by knowing its serial number. Given DirecTV's penchant for focusing on quantity control instead of quality control, this is probably too much to hope for; it requires Engineering to maintain a pristine documentation trail that is sustained through Production, Distribution, and RMA.

If the code is in EPROM, we have to hope that the boot loader that performs software upgrades knows how to flash the offending DSP.

Thanks for reading. 
Comments/rants/insults welcome.


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## breevesdc (Aug 14, 2007)

Joe,

Thanks for this detailed explanation of the problem. I have been having this problem ever since I switched to using an HDMI connection to my TV (through my Onkyo TX-SR705 receiver) about 1 month ago. I don't recall having this issue when I was using my old receiver with a component video and optical audio connection.

I'm not doubting your findings at all. I'm just curious to understand why I would not have been having this problem on my old receiver (Onkyo TX-NR901) using the same HR20 with component/optical connections. It's possible that I wasn't using dolby digital (on the HR20) when I had it connected to my old receiver. If so, it was inadvertant on my part.

Assuming that I was using dolby digital on my old setup, then the only two differences are a new receiver and using HDMI when I was using component/optical before.

Any thoughts on this? Thanks.

Brian

PS- I was hoping that this was a firmware issue which is why I was glad to see your post. But when I saw that you were also using the TX-SR705, it piqued my curiousity.


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## TigerDriver (Jul 27, 2007)

breevesdc said:


> Joe,
> 
> Thanks for this detailed explanation of the problem. I have been having this problem ever since I switched to using an HDMI connection to my TV (through my Onkyo TX-SR705 receiver) about 1 month ago. I don't recall having this issue when I was using my old receiver with a component video and optical audio connection.
> 
> ...


Thanks.

Since software is a sub-category of Black Magic, another data point is always useful. If you have an unused input, can you try switching your HR20 from HDMI to component/optical?

I'd guess that this problem is probably fairly far down on D* bug-fix list. As annoying as it is, I think there are more important bugs to fix; for example, late-starting recording. I'd also rate some of the proposed improvements to the interface as higher priority than this problem.


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## breevesdc (Aug 14, 2007)

TigerDriver said:


> Thanks.
> 
> Since software is a sub-category of Black Magic, another data point is always useful. If you have an unused input, can you try switching your HR20 from HDMI to component/optical?
> 
> I'd guess that this problem is probably fairly far down on D* bug-fix list. As annoying as it is, I think there are more important bugs to fix; for example, late-starting recording. I'd also rate some of the proposed improvements to the interface as higher priority than this problem.


I finally got around to doing this componet cable test. I turned off the HDMI audio option and turned on the Optical option for the input I have assigned to my HR20 on my Onkyo receiver. Same problem. I got the audio delay just like I was getting with HDMI.

At this point, the only other factor that has changed is the receiver I am using. However, I agree with you that I don't think the receiver is the problem. I did some tests using the skip forward/skip back and FF/RW functions on my DVD player and I never got any kind of audio delays on resume.

I just decided to turn off the Dolby Digital function on the HR20. It has just got beyond annoying waiting for the audio to come back when skipping from play to play during NFL games. It's kind of a bummer to have such a high tech peice of equipment with so many bugs. I hope that D* can work out the issues with this box over the next few months instead of continually adding more functionality. How about fixing the bugs and getting a stable application before adding more bells and whistles?

Thanks again for your very thorough testing and explanation of the problem.

Brian


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## TigerDriver (Jul 27, 2007)

breevesdc said:


> It's kind of a bummer to have such a high tech peice of equipment with so many bugs. I hope that D* can work out the issues with this box over the next few months instead of continually adding more functionality. How about fixing the bugs and getting a stable application before adding more b ells and whistles?
> Brian


Bummer, indeed. And the bugs are big, right-up-front hairy ones like this one. Of course, not everyone has them, or the have them and don't know that they're bugs, or have them and don't care.

I pay D* more each month than the mortgage payment on my first house (granted, that was back in-the-day), and I won't brook second-rate service or equipment. My plan is to get a second HR20, keep getting replacements for it until it works as its supposed to. Then I'm going to do the same with my existing HR20.

Nothing hurts the bottom line like RMAs.


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## cartrivision (Jul 25, 2007)

Now, good luck getting DirecTV to fix this bug instead of just telling their customers to "fix" it themselves by using some combination of the trick play buttons.


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## TigerDriver (Jul 27, 2007)

cartrivision said:


> Now, good luck getting DirecTV to fix this bug instead of just telling their customers to "fix" it themselves by using some combination of the trick play buttons.


I have a Harmony 880 remote control that makes it easy to write macros, and I can find no combination of trickplay buttons that affect this problem. If anybody knows a trickplay combo that works, I'd love to hear it.

I have no doubt the bug will get fixed sooner or later--but not by D*. Upon reflection, I feel that it's unlikely that the fault lies in D*'s application code, which has very little to do with this kind of thing. It's far more likely that DSP code--either external or internal--is at fault; if internal, it will get fixed on the next die production; if external it will be fixed in the next rev of the DSP firmware. For all I know, that's already happened...maybe I've got old DSP parts in my HR20.


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## cartrivision (Jul 25, 2007)

TigerDriver said:


> I have a Harmony 880 remote control that makes it easy to write macros, and I can find no combination of trickplay buttons that affect this problem. If anybody knows a trickplay combo that works, I'd love to hear it.


The fix I was referring to is only for when this problem causes the audio to get out of sync and be delayed by a second or so. For that particular sync problem, just about any stop/pause/play or other trickplay combination will get the audio back in sync. Unfortunately there are other unrelated sync problems that can't be fixed with any combination of stop/start or trickplay, and it doesn't do anything to fix the "long delay to play" problem.

Luckily for me, my home theater amp doesn't often get confused by the bad digital audio data coming out of the HR20 and it rarely exhibits the "long delay to play" problem, but the bad data does more often cause the "out of sync" problem.


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## cartrivision (Jul 25, 2007)

TigerDriver said:


> I have no doubt the bug will get fixed sooner or later--but not by D*. Upon reflection, I feel that it's unlikely that the fault lies in D*'s application code, which has very little to do with this kind of thing. It's far more likely that DSP code--either external or internal--is at fault; if internal, it will get fixed on the next die production; if external it will be fixed in the next rev of the DSP firmware. For all I know, that's already happened...maybe I've got old DSP parts in my HR20.


Someone once stated somewhere in these forums that it was the application code's fault in that they should never stop delivering a valid DD stream, and instead just continue putting out a valid "silent" DD signal when actual program audio is not being output. I don't know if that is correct, but it seems to make sense that if you never stop outputting a good DD data stream, there's not going to be any issues with the receiver/amp having to re-sync with a stopped and restarted digital stream.


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## TigerDriver (Jul 27, 2007)

cartrivision said:


> Luckily for me, my home theater amp doesn't often get confused by the bad digital audio data coming out of the HR20 and it rarely exhibits the "long delay to play" problem, but the bad data does more often cause the "out of sync" problem.


There's neither a theoretical nor observed reason to suspect that the audio/video sync problem is related to the garbage in the Dolby Digital stream that causes the "long delay to play" problem. Some people have one problem or the other; some have both. To those who have both: correlation does not prove causality.


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## TigerDriver (Jul 27, 2007)

cartrivision said:


> Someone once stated somewhere in these forums that it was the application code's fault in that they should never stop delivering a valid DD stream, and instead just continue putting out a valid "silent" DD signal when actual program audio is not being output. I don't know if that is correct, but it seems to make sense that if you never stop outputting a good DD data stream, there's not going to be any issues with the receiver/amp having to re-sync with a stopped and restarted digital stream.


Please read the testing report that begins this thread. It not only quotes the document that requires "pause data" during interruptions, but explains why it's necessary. It also provides empirical proof that my HR20-100 sends garbage instead of pause data after a stream interruption (i.e., FF/RW/SLIP).

As for it being the application code's fault, read the last two paragraphs of my report.


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## TigerDriver (Jul 27, 2007)

cartrivision said:


> Someone once stated somewhere in these forums that it was the application code's fault in that they should never stop delivering a valid DD stream, and instead just continue putting out a valid "silent" DD signal when actual program audio is not being output. I don't know if that is correct, but it seems to make sense that if you never stop outputting a good DD data stream, there's not going to be any issues with the receiver/amp having to re-sync with a stopped and restarted digital stream.


The bug is actually fairly subtle: the (offending) HR20's behave correctly--i.e., send Pause Data during the interruption--until it's time to resume sending real audio content again, at which they instead send garbage for several seconds.


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## cartrivision (Jul 25, 2007)

TigerDriver said:


> There's neither a theoretical nor observed reason to suspect that the audio/video sync problem is related to the garbage in the Dolby Digital stream that causes the "long delay to play" problem. Some people have one problem or the other; some have both. To those who have both: correlation does not prove causality.


There is every reason to suspect that the sync problem is caused by the garbage data because it only happens immediately following events that cause the garbage data to be put out. Of course that's no proof that it's the cause, but it's illogical to say that there is no reason to suspect that it's the cause.

I'm not saying that it's the cause of every sync problem that people are seeing on the HR20, because there are other sync problems that that have nothing to do with the digital audio outputs, but I have not seen that one particular sync problem happen at any other time than under the conditions which you described when you observed that garbage DD data was being output.


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## tonyd79 (Jul 24, 2006)

How odd.

My HR20/DG1000 setup gives me full audio immediately after a pause or any other trick play and the DG1000 seems to decode it properly. In fact, that is quickest way to check what type of signal I am seeing, a pause and play to make my DG1000 display the audio type.

Nor do I have any audio problems with my second HR20 connected via HDMI directly to a Visio LCD.

Are you sure it is not a handshake error you are seeing?


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## TigerDriver (Jul 27, 2007)

cartrivision said:


> There is every reason to suspect that the sync problem is caused by the garbage data because it only happens immediately following events that cause the garbage data to be put out. Of course that's no proof that it's the cause, but it's illogical to say that there is no reason to suspect that it's the cause.
> 
> I'm not saying that it's the cause of every sync problem that people are seeing on the HR20, because there are other sync problems that that have nothing to do with the digital audio outputs, but I have not seen that one particular sync problem happen at any other time than under the conditions which you described when you observed that garbage DD data was being output.


Sorry, I can't understand what you're saying. For the purpose of clarity, would you please repost your message using the following terms in place of "it" or "its."


*D-SYNC*: the sync between the Dolby Digial streams on the DVR and AVR--the topic of my study.

*L-SYNC*: lip sync, the sync between video and audio streams.


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## TigerDriver (Jul 27, 2007)

tonyd79 said:


> How odd.
> 
> My HR20/DG1000 setup gives me full audio immediately after a pause or any other trick play and the DG1000 seems to decode it properly. In fact, that is quickest way to check what type of signal I am seeing, a pause and play to make my DG1000 display the audio type.
> 
> ...


The number of folks with the Dolby-Delay problem (D-sync) seems relatively small compared to the number of folks with the lip-sync (L-sync) problems. You are fortunate to have neither.

I don't know what handshaking you're referring to.


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## cadet502 (Jun 17, 2005)

Has anyone seen this on an HR20-700? I'm running my HR20-700 to the TV over HDMI and to my Onkyo 670 with optical. I've got DD on, and with any kind of trick play, I have no delay in audio returning through the TV or the AVR. Watching the DD indicator on the AVR, it never flickers on return.


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## cartrivision (Jul 25, 2007)

TigerDriver said:


> Sorry, I can't understand what you're saying. For the purpose of clarity, would you please repost your message using the following terms in place of "it" or "its."
> 
> 
> *D-SYNC*: the sync between the Dolby Digial streams on the DVR and AVR--the topic of my study.
> ...


It's not that simple because with this sync problem, although the observed video and audio are out of sync, the data streams are not.... something is causing the audio output of the AVR to be behind by about one second when it is playing the digital audio stream. The digital audio stream isn't out of sync, the AVR is just playing it out of sync, and you can get the sound back in sync with the video without touching anything on the HR20.

Since this particular problem with sync between audio and video only happens when I do things that cause the "D-SYNC" problem on the HR20 (but never when I do the same thing with non-HR20 DVRs, and other devices that output Dolby digital audio streams), there is a good reason to suspect that the D-SYNC problem is sometimes the cause of the audio being out of sync with the video.


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## cartrivision (Jul 25, 2007)

tonyd79 said:


> How odd.
> 
> My HR20/DG1000 setup gives me full audio immediately after a pause or any other trick play and the DG1000 seems to decode it properly. In fact, that is quickest way to check what type of signal I am seeing, a pause and play to make my DG1000 display the audio type.
> 
> ...


Is there even any handshaking involved in the protocol used to deliver the audio data stream? I thought that it was just one way.


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## TigerDriver (Jul 27, 2007)

cartrivision said:


> It's not that simple because with this sync problem, although the observed video and audio are out of sync, the data streams are not.... something is causing the audio output of the AVR to be behind by about one second when it is playing the digital audio stream. The digital audio stream isn't out of sync, the AVR is just playing it out of sync, and you can get the sound back in sync with the video without touching anything on the HR20.


You're the first person on this thread who's mentioned that he has both L-SYNC and D-SYNC problems.  Except when several mpeg4 stations (e.g., USA, Bravo, Discovery) were unwatchable, I've never had an L-SYNC problems.



cartrivision said:


> Since this particular problem with sync between audio and video only happens when I do things that cause the "D-SYNC" problem on the HR20 (but never when I do the same thing with non-HR20 DVRs, and other devices that output Dolby digital audio streams), there is a good reason to suspect that the D-SYNC problem is sometimes the cause of the audio being out of sync with the video.


You may observe that they happen at the same time, but it doesn't follow that one caused the other. It's just as likely (far more likely, actually) that there's a common underlying bug for both behaviors, and fixing it will fix both the L-SYNC and D-SYNC problems.


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## cartrivision (Jul 25, 2007)

TigerDriver said:


> You may observe that they happen at the same time, but it doesn't follow that one caused the other. It's just as likely (far more likely, actually) that there's a common underlying bug for both behaviors, and fixing it will fix both the L-SYNC and D-SYNC problems.


Since you seem to be quite familiar with the subject, what is your theory on why the L-SYNC problem is happening?


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## flipptyfloppity (Aug 20, 2007)

I have to say I find this odd only because my HR10-250 drove my amplifier up a wall. It would drop out for 10 seconds or more on DD 2.0 signals upon resume. After a few weeks of doing this, the amp would just plain stop playing non-PCM audio and I'd have to reboot it.

While with the HR20 and the same amp, everything works swimmingly.

Did you do any tests with DD 2.0 (OTA digital audio) or just 5.1?


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## TigerDriver (Jul 27, 2007)

cartrivision said:


> Since you seem to be quite familiar with the subject, what is your theory on why the L-SYNC problem is happening?


I don't have a theory about the lip-sync problem because I know next to nothing about the mpeg4 format (e.g., whether it contain sync bursts/markers). I also don't know anything about the the mpeg4 decoder in the receiver, or how the two streams are handled once they've been "demuxed."


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## cartrivision (Jul 25, 2007)

TigerDriver said:


> I don't have a theory about the lip-sync problem because I know next to nothing about the mpeg4 format (e.g., whether it contain sync bursts/markers). I also don't know anything about the the mpeg4 decoder in the receiver, or how the two streams are handled once they've been "demuxed."


I was asking about issues with out of sync decoding and playing of the digital audio stream coming from the HR20, not MPEG4 issues.

Although I suspect that the majority of the lip-sync issues are indeed related the MPEG encoding and decoding process, that's not the issue that I was discussing this thread&#8230;. which was specifically the lip-sync issues which are caused by improper (late/out of sync) decoding of the digital audio stream that comes from an HR 20.

That lip-sync issue has nothing to do with the MPEG encoding/decoding process but is strictly a problem with the external TV or other audio receiver device decoding and outputting it's sound out of sync with the picture despite the fact that the digital audio stream coming from the HR20 is in sync with the picture... which I still believe is likely caused by the error/garbage digital audio data that comes out of the HR20 for a few seconds after it exits pause mode.


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## TigerDriver (Jul 27, 2007)

cartrivision said:


> I was asking about issues with out of sync decoding and playing of the digital audio stream coming from the HR20, not MPEG4 issues.
> 
> That lip-sync issue has nothing to do with the MPEG encoding/decoding process but is strictly a problem with the external TV or other audio receiver device decoding and outputting it's sound out of sync with the picture despite the fact that the digital audio stream coming from the HR20 is in sync with the picture... which I still believe is likely caused by the error/garbage digital audio data that comes out of the HR20 for a few seconds after it exits pause mode.


As I've said, these may be symptoms with an underlying common cause, but there's no evidence that one is an artifact of the other. Without additional facts, I don't care to discuss it further.


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## mridan (Nov 15, 2006)

The problem with this audio delay or lag on DD after trickplay or when changing channels is the new Onkyo receivers.I had the new Onkyo 805 for one week and exchanged it for a Pioneer VSX-92-TXH.My wife and I couldn't stand the audio lag when changing channels or during trickplay of programs in DD.I was told there is a slight pause of audio because I have everything hooked up thru HDMI in on receiver and HDMI out to plasma.But when I hooked up HR20 using optical cable to Onkyo I still had that annoying lag,IMHO I think the problem is in the Onkyo DD processor.My new Pioneer does not have this audio lag nor did my old Denon 2105.I wanted to upgrade my old denon with a new receiver that decodes the Dolby True hd and DTS Master hd and one with HDMI ,I read great reviews on the Onkyo ,But with this audio lag problem I would not recommend it,the Onkyo also runs very hot(mine was in an open cabinet without glass door).Also when playing a dvd if you go into dvd menu while watching movie ,there is that same annoying audio lag.(going from dolby digital soundtrack to stereo for movie menu).


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## mridan (Nov 15, 2006)

cadet502 said:


> Has anyone seen this on an HR20-700? I'm running my HR20-700 to the TV over HDMI and to my Onkyo 670 with optical. I've got DD on, and with any kind of trick play, I have no delay in audio returning through the TV or the AVR. Watching the DD indicator on the AVR, it never flickers on return.


I think you don't have this problem because you have an older model.The new Onkyo's 605,705,805's are the ones with the audio delay/lag.


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## keith_benedict (Jan 12, 2007)

I have severe audio lag at times with the HR20. I have an older Onkyo TX-DS676. I do not have audio lag with any other Dolby Digital sources. I did not have audio lag when I had the DirecTivo box hooked up to the same receiver.


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## TigerDriver (Jul 27, 2007)

mridan said:


> The problem with this audio delay or lag on DD after trickplay or when changing channels is the new Onkyo receivers.I had the new Onkyo 805 for one week and exchanged it for a Pioneer VSX-92-TXH.My wife and I couldn't stand the audio lag when changing channels or during trickplay of programs in DD.I was told there is a slight pause of audio because I have everything hooked up thru HDMI in on receiver and HDMI out to plasma.But when I hooked up HR20 using optical cable to Onkyo I still had that annoying lag,IMHO I think the problem is in the Onkyo DD processor.My new Pioneer does not have this audio lag nor did my old Denon 2105.I wanted to upgrade my old denon with a new receiver that decodes the Dolby True hd and DTS Master hd and one with HDMI ,I read great reviews on the Onkyo ,But with this audio lag problem I would not recommend it,the Onkyo also runs very hot(mine was in an open cabinet without glass door).


Did you read my test report? It shows that the HR20-(mine is a 100) outputs garbage that exactly corresponds to the delay. My recently acquired HR21 exhibits the same behavior. My HR10 doesn't show any such delay.

Before a decoder chip can make claims about Dolby Digital, the manufacturer has to submit it to Dolby Labs for certification. The D* receivers, by contrast, don't decode the Dolby stream, they just reroute it and therefore require no DL certification. So Onkyo has Dolby Labs' blessing, and D* doesn't need it. Hummmmmm.


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## cartrivision (Jul 25, 2007)

keith_benedict said:


> I have severe audio lag at times with the HR20. I have an older Onkyo TX-DS676. I do not have audio lag with any other Dolby Digital sources. I did not have audio lag when I had the DirecTivo box hooked up to the same receiver.


For you and other people who are getting this type of lag when passing the audio to a home theater system.....

If you also pass the audio to the TV via the HDMI port, is that audio still in sync?

If you unplug and reconnect the optical audio cable from the home theater receiver without doing anything on the HR20, does the audio coming from the home theater receiver return to proper sync?


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## mridan (Nov 15, 2006)

TigerDriver said:


> Did you read my test report? It shows that the HR20-(mine is a 100) outputs garbage that exactly corresponds to the delay. My recently acquired HR21 exhibits the same behavior. My HR10 doesn't show any such delay.
> 
> Before a decoder chip can make claims about Dolby Digital, the manufacturer has to submit it to Dolby Labs for certification. The D* receivers, by contrast, don't decode the Dolby stream, they just reroute it and therefore require no DL certification. So Onkyo has Dolby Labs' blessing, and D* doesn't need it. Hummmmmm.


I did read it but to me it's like reading a foreign languge I'm not no where near as knowledgeable as you are on the subject,and I'm not saying your findings are incorrect.When I bought the Onkyo I couldn't stand the audio lag so I went to a couple of forums and discovered that people who have an HR20 and one of the new Onkyos are having these audio delay issues.I spoke with service at Abt Electronics they told me this was a normal delay with the HDMI.So I changed to an optical cable ,still the same lag problem which lead me to believe it was the Onkyo. So I exchanged it for the Pioneer,and now I have no audio lag.I recommend anybody on this forum ,not to purchase one of the new Okyo receivers because of this problem.Just a quick note this is not a lipsync issue,when you change channels or do any trick play ,you will not hear any audio for a couple of seconds very annoying.


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## DBordello (Dec 16, 2006)

Has there been any update on this? I was considering purchasing a Onkyo TX-SR705 or TX-SR805 soon to be used with an HR20. 

Has any response been received from either party? 

Although it is likely an issue with the HR20, I am not sure the Onkyo isn't completely innocent. Since it is the only receiver to have issues, it's DD capabilities clearly aren't as robust. Perhaps the error correction is subpar. Bad DD streams exist, it is the responsibility of the certified device to deal with these the best it can. I am curious to what Onkyo's response to this would be. I imagine a firmware update would be able to fix it.

-Dan


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## w3syt (Feb 17, 2006)

I have to hit an extra pause on my Onkyo 304 to get sync..


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## cartrivision (Jul 25, 2007)

DBordello said:


> Has there been any update on this? I was considering purchasing a Onkyo TX-SR705 or TX-SR805 soon to be used with an HR20.
> 
> Has any response been received from either party?
> 
> ...


The Onkyo isn't the only receiver to be affected by this issue, although different DD receivers seem to be affected differently that others by the bad DD data being dilevered by the HR20, there are cases of that bad data causing both the "long delay to resume playing" problem and the "out of sync audio" problem on receivers other than Onkyos.


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## gully_foyle (Jan 18, 2007)

Very interesting thread. Being a comm engineer, I do understand where the OP is coming from, but I somewhat disagree with his conclusions regarding "blame", mostly at a practical level. I also have more data points.

I have just received an Onkyo 875 and connected an HR20-700 via straight HDMI and an HR10-250 via component and optical. Both are set for Dolby Digital. Both exhibit a 3-5 second audio muting after pause (rew/ff/etc) about 60-70% of the time.

This replaces a Denon 3803 which never exhibited this problem with either DVR, with all audio inputs optical (no HDMI on Denon 3803). Both DVRs have always been set for Dolby Digital output.

With the Onkyo, the DD indicator remains lit during pause, as the OP observes. If it remains lit at the end of pause (less than half the time), then there is no audio mute. Otherwise there is. My HR10 and HR20 do this approximately the same percentage of times, and for the same 3-5 second duration. I see no difference in operation between the two.

The following devices never have this issue: Oppo 971 (DVD), Panasonic RP-56 (DVD), Panasonic Blu-ray BD30K, Toshiba HD-A35 HDDVD. This holds true for all audio formats, including TrueHD bitstream and DTS-MA bitstream.

*Now, for my difference of opinion: I think that the Onkyo is also in error, and should be corrected at the earliest opportunity, if possible.*

The HR10/20 should be providing synchronous null packets so that the Onkyo can easily maintain timing, and should resume audio while maintaining framing. HOWEVER, the Onkyo should never rely on such a silly expectation. There is nothing in any spec that says that it cannot detect an error condition and correct it quickly, and good engineering suggests that fault tolerance is a virtue. Other AVRs manage this.

I suspect that what happens is that the appropriate null packets are sent by the HR20, and when the pause is released (and play resumes) a new valid audio packet is begun ABORTING AN IN PROGRESS NULL PACKET. In some cases the alignment of this new packet is within the Onkyo's ability to detect, and in others it isn't. This may vary among Onkyo receivers.

Now, the OP's test equipment correctly detects this error condition and flags it. Test equipment is supposed to be rigid in this regard. It reports this framing error as "junk" as it has no reason to attempt to find meaning in such an event.

Actual real-world devices that interact with a multitude of untested partner devices need to be more tolerant. The Onkyo isn't. A more proper design would have either a much faster resynch loop, or a secondary synchronizer scanning for just such framing errors.

Yes, the HR20 should do better (as should my HR10), but it is still a very valid response to return an Onkyo because it won't work with the HR20 and get something that will.


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## TigerDriver (Jul 27, 2007)

kcmurphy88 said:


> Very interesting thread. Being a comm engineer, I do understand where the OP is coming from, but I somewhat disagree with his conclusions regarding "blame", mostly at a practical level. I also have more data points.
> 
> I have just received an Onkyo 875 and connected an HR20-700 via straight HDMI and an HR10-250 via component and optical. Both are set for Dolby Digital. Both exhibit a 3-5 second audio muting after pause (rew/ff/etc) about 60-70% of the time.
> 
> ...


You make some excellent points. And I'm sure you and I could compare our state diagrams for reacquiring synchronization in an HDLC-style stream.

The one point I wish to stress is that very few (perhaps none) A/V manufacturers engineer their Dolby Digital DSP chips, but rather purchase them them from a vendor whose chips have been certified by Dolby Labs. Without such certification, none of the Dolby trademark terms can be used.

Dolby's certification test requires that the decoder be able to re-establish synchronization within 10ms, and must buffer up to 10 consecutive frames to assure that sync is not re-lost. After 10 frames, the 10 buffered fames are discarded and packet payload can be passed to the DSP for decoding. The differential scrambler algorithm for testing this ability is specified in order to guarantee that a valid packet can be plucked out of what amounts to random noise.

So I'm convince that Dolby certification demonstrates that any encoding or decoding device bearing the Dolby Digital logo doesn't have "silly" expectations.

Now consider the amount of certification required for pass-through vendors such as DirecTV, Dish, etc. Because their devices do not decode or encode the DD stream, but merely redirect it, no certification is necessary.

So Dolby certification tells me that the Onkyo receiver should be able to handle anything thrown at it, and I've proved empirically that the HR20 outputs defective data for several seconds after any sort of interruption-of-play. Had DirecTV shown even rudimentary engineering diligence (i.e., rent from Dolby Labs the same test apparatus that I employed), the multi-second blob of garbage in their data stream would have been obvious. (It's never to late...)

My HR20 is connected to the Onkyo in my family room. The HR21 is connect to a Sony STR-DG810 (a current model) in my "office" in the basement, and it exhibits the identical problem. (Now, Sony may make its own chips.)

I'm a practical guy. If you (kcmurphy88) find a replacement for your Onkyo (with all the same bells and whistles, of course) that fixes this problem, I'll immediately purchase one my self.

Until then, and mainly because this problem is apparently not wide-spread, and because it has an odd signature (e.g., you HR10 sometimes fails), I'm running a background task in the back of my mind whose job it is to come up with a Eureka! moment. Should this happen, I'll...pause for 5 seconds...then post the insight here.


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## gully_foyle (Jan 18, 2007)

Joe--

You're not wrong either. The problem I have is threefold: I will grow old waiting for DirecTV to correct something in the HR2x; there may be other devices that behave the same way, since DiirecTV also does not make their own chips (pretty sure it's Broadcom); and there is no alternative to the HR2x.

I'm also not happy about the Onkyo's (pretty much undisclosed) 6-video-source limit, which is ridiculous in a $1500 device with 7 HD video inputs, so it doesn't get the benefit of my doubt. I have 7 video sources and this number seems to be increasing....

Not to rant on Onkyo, though -- there are many things the AVR does well, such as setup and deep control of audio modes -- but it looks like it doesn't match my particular needs.


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## TigerDriver (Jul 27, 2007)

kcmurphy88 said:


> Joe--
> 
> Not to rant on Onkyo, though -- there are many things the AVR does well, such as setup and deep control of audio modes -- but it looks like it doesn't match my particular needs.


Agreed. Please PM me when you've found something you like...I'm always looking for a better gadget.


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## myrison (Oct 14, 2007)

Is there anyone with this combination (newer Onkyo receiver & HR20) who is *NOT* having this problem? I'd just decided on the TX-SR875 as the perfect receiver, but this looks like a deal killer...


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## steve053 (May 11, 2007)

Interesting read. Thanks to the OP for taking the time to research and post.

FWIW

I have the Onkyo 674, and the HR20-100 with DD on. The HR20-100 was new out of the box in August 2007. I realize that this is an Onkyo xx5 reveiw, but I do not experience any long delays in audio when using trick play, and rarely have synch problems.

I don't know if I'm "lucky" with a "newer" HR20-100, or if there is less of a problem w/ the "older" 674 receiver. Or, that I just have an internal 5 second processing delay that makes it all seem hunky-dory.

I do know that I have been coveting the 875, and now have a logical reason to wait unitl the 876? is released and vetted.


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## Maruuk (Dec 5, 2007)

I have the same problem with my HR21. D* acknowledges the common problem and claims they will fix it in a future firmware update.


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## brianp6621 (Jun 13, 2007)

I have the 805 and the HR20 and have the same issue. However unlike others I have found another device that causes the 805 to do the same thing. The Vudu VOD box exhibits identical symptoms.

I don't think it is a coincidence that the only devices that do it are from non-name brand electronics manufacturers.


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## TigerDriver (Jul 27, 2007)

brianp6621 said:


> I have the 805 and the HR20 and have the same issue. However unlike others I have found another device that causes the 805 to do the same thing. The Vudu VOD box exhibits identical symptoms.
> 
> I don't think it is a coincidence that the only devices that do it are from non-name brand electronics manufacturers.


One _might _argue that Onkyo is not a name brand, but as I mentioned earlier, the current-model Sony (<prefix>-810) in my office exhibits the same problem.


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## brianp6621 (Jun 13, 2007)

TigerDriver said:


> One _might _argue that Onkyo is not a name brand, but as I mentioned earlier, the current-model Sony (<prefix>-810) in my office exhibits the same problem.


It is good to see that the Onkyos are not the only ones that suffer. However I would like to see whomever wouldn't consider Onkyo a name brand suffer though 

Edit..
I just realized I think you may have missed my point. DTV and Vudu aren't exactly top tier consumer electronics manufacturers with strong quality control methods which lead me to believe that something was missed in the design/testing of these devices.


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## gully_foyle (Jan 18, 2007)

brianp6621 said:


> It is good to see that the Onkyos are not the only ones that suffer. However I would like to see whomever wouldn't consider Onkyo a name brand suffer though
> 
> Edit..
> I just realized I think you may have missed my point. DTV and Vudu aren't exactly top tier consumer electronics manufacturers with strong quality control methods which lead me to believe that something was missed in the design/testing of these devices.


Or, it may be that they use the same drivers from the same chip manufacturer. Obviously something goes discontinuous when the HR20 switches from idle packets back to audio packets. Since some receivers can deal with it, it seems that the data is there, but out of spec in some way. I'd bet that some receiver makers caught the error and took pains to correct for it. I saw a note on another forum by a Denon rep that basically said the HR20 was an ongoing problem for them.


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## brianp6621 (Jun 13, 2007)

I have posted this thread over at the Vudu forums and their engineer states they have similar problems (static in audio after unpause) on Marantz receivers and they have a solution in place for the next software release which they think may fix our problem as well. They are going to test it with an Onkyo receiver soon.

If only we could get the DTV engineers on board like that.


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## techntrek (Apr 26, 2007)

I almost bought the Onkyo 875 last month... except it wouldn't fit in the space where it had to go. We have a low cabinet from Ikea and the equipment "cubbies" are only 6" high (and the wife won't allow the receiver to sit on top). So I moved down the line to the first one that would fit, the 575, which is about 5.8 inches high. After reading this I'm a little happier with my forced downgrade!

Oh, yes I knew they ran hot from my research so I installed a fan in the back of the cabinet. It forces a good fresh-air flow over the top and bottom of the receiver. Don't want someone to worry about the small 0.2" top clearance. So far even after driving it hard with a good action movie the air that comes off the top is only a little warm.


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## TigerDriver (Jul 27, 2007)

See my posting on the HR21-700 CE forum.


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## ub1934 (Dec 30, 2005)

cartrivision said:


> Now, good luck getting DirecTV to fix this bug instead of just telling their customers to "fix" it themselves by using some combination of the trick play buttons.


Also now have this audio bug but only since the Fri. nights CE , have to change Ch up or down to get audio back


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## TigerDriver (Jul 27, 2007)

ub1934 said:


> Also now have this audio bug but only since the Fri. nights CE , have to change Ch up or down to get audio back


If the sound doesn't return after a few seconds, it's not, by definition, the same bug.

Did you post your bug in the appropriate CE forum?


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## TigerDriver (Jul 27, 2007)

The problem described has been fixed on HR21-700 and HR20-100 in CE releases. Details are given near the top of the original post of this thread.

If you have noticed fixes in other models, please post here. Be certain to give the complete model and CE release numbers.


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## George Be (Apr 1, 2008)

Just thought I should let someone know that the audio-delay problems are NOT fixed in NR 0x0206!

I personally have 2 HR21-700s with 0x206 (installed early February), and they both exhibit the problems described here when returning from FF/RW/Pause. Admittedly, I am using the RCA outputs (whereas TigerDriver Joe discusses only the DD aspects of the issue), but I have seen many recent postings from people who also have it on HDMI, DD, optical, etc.

There are many people on the AVS Forum entitled "DIRECTV HR20/HR21 Master Topic". at www dot avsforum dot com (I can't post an external link yet due to the admin's rules that I have to make 5 postings before I can do that. Nuts!),

...and there are many people on this Forum:

( *HR21-700: 0x0206 Issues / Discussion* )

&#8230; who are expressing widespread problems over a broad spectrum of connection types. (PM me if you want links, I guess...!)

DirecTV, PLEASE get on this immediately, and issue a fix for it ASAP! Apparently it WAS fixed in CE edition 0x0206, but then broken before they could get it out the door as an NR. And, D*, would it kill you to post an update here from time to time, to let us know what's going on?

Thanks,
George


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## brianp6621 (Jun 13, 2007)

As I mentioned earlier in this thread, the Vudu boxes when used with Onkyo receivers suffered the same issue. The difference however is that Vudu fixed this quite quickly with the very next software update.

I really wish we could get DTV to resolve this issue. I obviously watch DTV much more than my other devices and it is the only one now that suffers from this issue.


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## TigerDriver (Jul 27, 2007)

brianp6621 said:


> As I mentioned earlier in this thread, the Vudu boxes when used with Onkyo receivers suffered the same issue. The difference however is that Vudu fixed this quite quickly with the very next software update.
> 
> I really wish we could get DTV to resolve this issue. I obviously watch DTV much more than my other devices and it is the only one now that suffers from this issue.


Did you read the notes I added to the top of my article?

What model/software are you using?


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## brianp6621 (Jun 13, 2007)

TigerDriver said:


> Did you read the notes I added to the top of my article?
> 
> What model/software are you using?


HR20-700. Any ETA on a fix on that box?


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