HD-PVR Recordings Have Low Audio Volume

[SkierHiker]

I just got my HD-PVR (HDPVR) installed with a Comcast RNG110 STB and have noticed that all recordings have very low audio volume. I'm comparing it against my PVR-350 recordings. The volume is so low that I have to turn up my TV to almost max volume to hear anything. I looked through the STB settings and didn't find any output volume adjustments. This is in the recording as it sounds the same whether you're using SageTV, VLC, or WMP. Would this be a HD-PVR issue or SageTV? I'm using the latest HD-PVR (Windows 7) drivers on my Win2008 Server.

Also, I'm a little confused as to what parts the HD-PVR and SageTV play in the recording. I understand that the HD-PVR encodes the video. Does it also encodes the audio and then passes the data off to SageTV for recording to disk?

[toricred]

What type of audio connection are you using (digital/spdif or analog)?

[Spectrum]

The PVR-350 is probably encoding the audio to mp2 and the HDPVR encodes to the audio to AC3. AC3 has a lower reference level. If you are using client for playback you could adjust the gain in AC3 filter to level things out some. AFAIK there isn't a way to do this on an extender though.

As far as the interaction, sage just tells the HDPVR when to record and the HDPVR encodes the video to an h264 stream and the audio to an AC3 stream and muxes them into a .TS container.

[SkierHiker]

Originally Posted by toricred

What type of audio connection are you using (digital/spdif or analog)?

Sorry, forgot to mention that. It's SPDIF.

Originally Posted by Spectrum

The PVR-350 is probably encoding the audio to mp2 and the HDPVR encodes to the audio to AC3. AC3 has a lower reference level. If you are using client for playback you could adjust the gain in AC3 filter to level things out some. AFAIK there isn't a way to do this on an extender though.

As far as the interaction, sage just tells the HDPVR when to record and the HDPVR encodes the video to an h264 stream and the audio to an AC3 stream and muxes them into a .TS container.

I'm new to this whole H.264 and AC3. Where do I adjust the gain in the AC3 filter? - Thanks.

Edit 10:00 PM - Ok, I found AC3Filter Config. Going over to the Software forum to try to figure out how to use it.

[ericscottf]

I'm having this same problem (using regular SD video and RCA audio in on my pvrs).
It is annoying because i watch things recorded off the PVRs, the HDHR and downloaded video, and if i don't remember to turn the volume down when i switch to something not recorded by the PVR, the audio is LOUD.
With PVR recordings, i have to turn the volume all the way up and I still can't hear over the A/C.

I'm only using HD200s to view, so i'm looking for a software fix where i can pass video to some piece of software and have it bump up the audio. Haven't found anything good yet. Ideally, it would be very fast and not touch the video track or cause any audio/video shift (i'm very intolerant of audio/video unsyncing. )

[Taddeusz]

You say you're using optical. Are you getting 5.1 audio or is it strictly stereo? The reason I ask is because if the STB is sending out PCM stereo the HDPVR will automatically convert the audio to stereo AC3. Many STB's have their own volume control in this case which is usually set low. If you're just doing stereo you want to make sure the volume on your STB is up all the way.

If you're using the original audio (i.e. 5.1 or stereo depending on the source) then keep trying to adjust AC3Filter. You might also give ffmpeg a try. It has normalization options for AC3.

I will tell you that volume can vary pretty widely between channels. For the most part most channels are about the same volume but there is the odd channel that has more quiet audio. The SyFy channel I've noticed has audio that is a little more quiet than the norm. I always have to turn the volume up a little more on that channel than on the rest. But I've not noticed anything really extreme unless my cable box is messing up and has decided to start sending out PCM stereo rather than AC3. Those recordings tend to be fairly quiet.

[SkierHiker]

Got it working with AC3Filter. My week of going to HD and SageTV 7 is over at http://forums.sagetv.com/forums/showthread.php?t=50986