Audio with Colossus issue

[Zeb]

At least not on channel 519 ACMAXHD, and yet i3c says good recordings show "Track 1 [AC3]" and bad recordings show no audio stream at all.

Martin, there are three errors in the very long NRecord log that I don't remember seeing before. The first two errors happen every time, the third only a couple of times:

2013-10-23 00:39:03.553 [ERROR][9] Failed to set Latency
2013-10-23 00:39:03.553 [ERROR][9] Failed to set B-frames per GOP to 3
2013-10-23 00:39:03.678 [ERROR][9] Failed to set requested peak bitrate

@i3c: The very long NRecord log shows that NPVR Service hasn't been restarted in a week. Did you set <ForceSPDIF>true<ForceSPDIF>? I would restart NPVR Service after a change like that. Did you have these audio problems when you were using RCA cables? If you have more than one STB in your home, maybe try switching to another one. Oh, AC3Filter is a free decoder that I happen to use, but I haven't heard any complaints about the Hauppauge AC3 decoder that you're using. Even without a decoder, you should be able to identify the audio stream via the right-click menu.

[Edit] The channel in your previous NPVR log (post #6) where AAC audio was reported was 509 HBOZHD, another premium HD movie channel. Maybe this is a form of HDCP? If your audio problems only occur on this type of channel, maybe you should reconnect the RCA cables. On Settings->Devices, you could update only those channels to RCA input and leave the other channels set for SPDIF if you wish. I'm not sure how <ForceSPDIF> should be set in that case.

[i3c]

At least not on channel 519 ACMAXHD, and yet i3c says good recordings show "Track 1 [AC3]" and bad recordings show no audio stream at all.

Martin, there are three errors in the very long NRecord log that I don't remember seeing before. The first two errors happen every time, the third only a couple of times:

2013-10-23 00:39:03.553 [ERROR][9] Failed to set Latency
2013-10-23 00:39:03.553 [ERROR][9] Failed to set B-frames per GOP to 3
2013-10-23 00:39:03.678 [ERROR][9] Failed to set requested peak bitrate

@i3c: The very long NRecord log shows that NPVR Service hasn't been restarted in a week. Did you set <ForceSPDIF>true<ForceSPDIF>? I would restart NPVR Service after a change like that. Did you have these audio problems when you were using RCA cables? If you have more than one STB in your home, maybe try switching to another one. Oh, AC3Filter is a free decoder that I happen to use, but I haven't heard any complaints about the Hauppauge AC3 decoder that you're using. Even without a decoder, you should be able to identify the audio stream via the right-click menu.

[Edit] The channel in your previous NPVR log (post #6) where AAC audio was reported was 509 HBOZHD, another premium HD movie channel. Maybe this is a form of HDCP? If your audio problems only occur on this type of channel, maybe you should reconnect the RCA cables. On Settings->Devices, you could update only those channels to RCA input and leave the other channels set for SPDIF if you wish. I'm not sure how <ForceSPDIF> should be set in that case.

I can't believe the computer have been running for a week. I seem to restart it quite often. but you never know. I on;y ran with RCA cables briefly and with a faulty board (replaced with the current, good one). The only other STB I have is an old low-def model without AC-3 or any of that stuff. Of all the decoders listed only Hauppauge one works with the collosus, though I could give AC3Filter a try. I didn't have the impression that the audio problems were limitted to certain channels but i havn't been keeping very good records. I'll start a diary, see if i can identify bad channels, the relegate them to RCA land.

[jghanisco]

Not sure if you're still around, but this seems like an issue that I also have with recording the Colossus with digital audio. If not, maybe it's just me, but I wanted to put this out there.

What I believe is happening is that the NPVR is sending the signal to change the channel to what you want to record. The channel changes, or maybe it stays on the same channel, and no audio is being "recorded". I say "recorded" as in being written down, as if I try to play one of these recordings in VLC player, there is sound. If you're around and could confirm that this is your scenario, I'd appreciate it.

Currently, I convert the recording with handbrake into an mp4, change the database to point to the mp4, and the audio plays on my popcorn hour client. Of course that utilizes the popcorn hour and doesn't do the skip and commercial breaks, but at least I can get a working recording.

Now, this happens in live tv also, and I have noticed that if I change the channel, audio works fine. I have also noticed that if the STB had been actively recording to the colossus in the previous few minutes (I think up to 30-60 minutes, but don't hold me to that), and then the recording starts, the audio is fine. I can play it in VLC player, I can play it in NPVR. It's almost like something is sleeping and not waking up in time. I don't know if it's the STB or the Colossus, but I think that it has to be one of those two. There is a setting in the colossus device setting for "wait longer before starting recording capture" that I am just now trying, but I don't know if that is helping matters.

Anyway, I don't know if there can be a tweak for this if it is also what you are dealing with. I have debated adding a channel change to some random channel, and then having the channel blaster point to the proper channel, but I have no idea if that is even possible or just goofy. I have just used the RCA cables, which record with no problems, but one RCA connector went bad on me, so I'm living with the spdif right now.

[ScaryBox]

I'll chime in here too. I have the same problem. Happens on any channel any time. Usually after the system has been "resting" for a while. I have noticed that both live-tv and recordings will start/finish with video no problem but the audio does not play in Npvr or XBMC. For live TV simply changing the channel or stopping and starting corrects the issue. For recordings, I also have found that the file will play fine in VLC. At first I suspected a codec/decoder issue. Eventually I found that the resulting files (both recordings and live-tv buffer files) seem to have the sound type wrong in the file header. For example (and it is always the same), the file will have the sound header marking 6Kbps AAC sound when in fact the cable box and the resulting file are actually using AC3 sound. (In fact, up here in Canada, Cogeco cable passes all HD sound as AC3 I belive).

At any rate, I have managed to improve the situation by increasing the channel change time in XBMC and the amount of time XBMC waits to start playback/recording after a channel change has been requested. It has not solved the problem completely.

If I were a betting man, and I have to be because you folks have a way better grip on this stuff than me, I would guess that when the audio stream begins the npvr is misidentifying the audio stream. It could have something to do with HDCP but Cogeco assures me that it does not exist with HDMI output from the cablebox and consequently with the SPDIF/optical out. (could also lay somewhere in the Colussus card capture as well).

Let me know if you would like to see some logs and sample files.

Cheers
Ken

[mvallevand]

Eventually I found that the resulting files (both recordings and live-tv buffer files) seem to have the sound type wrong in the file header. For example (and it is always the same), the file will have the sound header marking 6Kbps AAC sound when in fact the cable box and the resulting file are actually using AC3 sound. (In fact, up here in Canada, Cogeco cable passes all HD sound as AC3 I belive).

If I were a betting man, I'd say the Colossus is recording audio silence as AAC because your STB Is not passing through anything while it tunes, You might even be able to notice the red light go off. I wouldn't mid seeing a 100 MB sample that plays in VLC.

Martin

[jghanisco]

Exactly what I have experienced, also from Cogeco (Hamilton ON). I'm using a Pace DC-550 box with the Colossus just for for information's sake.

I'll chime in here too. I have the same problem. Happens on any channel any time. Usually after the system has been "resting" for a while. I have noticed that both live-tv and recordings will start/finish with video no problem but the audio does not play in Npvr or XBMC. For live TV simply changing the channel or stopping and starting corrects the issue. For recordings, I also have found that the file will play fine in VLC. At first I suspected a codec/decoder issue. Eventually I found that the resulting files (both recordings and live-tv buffer files) seem to have the sound type wrong in the file header. For example (and it is always the same), the file will have the sound header marking 6Kbps AAC sound when in fact the cable box and the resulting file are actually using AC3 sound. (In fact, up here in Canada, Cogeco cable passes all HD sound as AC3 I belive).

At any rate, I have managed to improve the situation by increasing the channel change time in XBMC and the amount of time XBMC waits to start playback/recording after a channel change has been requested. It has not solved the problem completely.

If I were a betting man, and I have to be because you folks have a way better grip on this stuff than me, I would guess that when the audio stream begins the npvr is misidentifying the audio stream. It could have something to do with HDCP but Cogeco assures me that it does not exist with HDMI output from the cablebox and consequently with the SPDIF/optical out. (could also lay somewhere in the Colussus card capture as well).

Let me know if you would like to see some logs and sample files.

Cheers
Ken

[ScaryBox]

I would like to upload a 100MB sample but the forum will not allow greater than 25mb. Is there a way around this??

KEn

[sub]

I would like to upload a 100MB sample but the forum will not allow greater than 25mb. Is there a way around this?

For large attachments you need to use external sites for hosting the file, like dropbox etc, and just post the link here.

[ScaryBox]

Thanks Sub. I'll figure that out after work today.

Ken