Pi B+ and HiFiBerry DAC+ = Stuttering video

Do not know exectly when this started but it must have been an update :wink: Anyway, I recently noticed that video playback from tvheadend (4.0.7) was uneven, jerky. Noticeable when the camera was panning. Anyway, I did try all the suggestions I could find, ie the “adjust refresh display” and “sync playback to display”, with limited success. It was either good audio and choppy display or smooth display with audio dropouts. Watching a programme and hitting “o” showed skipped frames

Stumbles across a post that suggested removing dtoverlay from config.txt, which I did (dtoverlay=hifiberry-dacplus-overlay) and lo and behold, smooth audio and video, but no output from the DAC card. So, is there any way to have both? Ie smooth video and the HiFiBerry card active?

Linux pi 4.4.8-3-osmc #1 PREEMPT Sun May 1 22:11:11 UTC 2016 armv6l GNU/Linux
Kodi (16.1).

OK. I have been trying to wrap my head around this… Reason I bought the HiFiBerry was to get a decent DAC. The audio quality from the 3.5mm jack is not that stellar…

OTOH, is the audio that goes over HDMI digital. I could just as well route the audio through the TV to the Stereo, but I do not want to have the TV on at all times.

What I could do is to get one of those cheap HDMI-to Analogue extractors that sell for under 10$ on ebay. As an added bonus I would get audio on both TV and Stereo. Chances are that the DAC in such an unit is not that stellar, but it is worth investigating.

What I do not understand is why the HiFiBerry has suddenly started dragging down the Pi? From what I have learned is that it is just receiving an I2S stream from the Pi, right? No need to interrupt the Pi? Is it a driver issue? Whose responsibility is the HifiBerry driver? Raspberry or HiFiberry?

If you want better quality analogue output, then adding:
to config.txt may be worth a try. See here for more information.
It’s still an experimental feature, so may have some issues, but it seems to be working well for some users.

I can try, but I’d still like to have digital, either the HifiBerry or through HDMI. Any thoughts on the HiFiBerry issue?

Does this only occur with live TV and not with recordings?

I will have to check tomorrow.

OK. Sorry. It was kind of late yesterday. Anyway, this is what I did today:

  1. Edited config.txt and put back: dtoverlay=hifiberry-dacplus-overlay
  2. Rebooted
  3. Set the HiFiBerry as output
  4. Played two films. One stored on my NFS share, one a recording from TVHeadend
  5. Set HDMI as output
  6. Played the same two films

    The ones with the skips and drops are with HiFiBerry active

Nudge… Should I upload logs or is the info in the pictures enough?

OK. Solved this is a roundabout way: Removed the HiFiBerry card and installed a cheap HDMI splitter that drops out the audio on a separate output. Cannot judge the quality of the DAC as all IC markings are scraped off… sigh… But the unit seems solid, metal case and there was nothing to complain about when looking at the PCB fab quality.

Have the same setup pi3 + hifiberry - but works like a charm. I used a standard osmc install and simply added the hifiberry overlay in config.txt. Did remove lirc and had some hardware acceleration issues at first (disabled omxplayer in guisettings.xml).

OK. Could it be that code bloat has made the OSMC/HiFiBerry cobo unuseable on older PI’s? Perhaps I should bet a Pi 3 and try? The DAC+ will fit on a PI3 as well, does it not?

I can confirm that the DAC+ fits on a PI3, however I can also confirm jerky video playback with that setup.

I am running osmc on a PI3 with Hifiberry DAC+, and I get stuttering video playback on some (not all) videos. Strangely enough, from several videos generated from one DVD containing several episodes of a series using the same settings for each single episode, some are jerky, most are not. Jerkiness is reproducible. When playing back the relevant videos with other systems, no jerkiness occurs.

If I can help by providing any sort of log or other information, just ask.

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Can you confirm if you get stuttering on Pi3 with HDMI as the output with the problematic DVD rips?
Have you tested with June OSMC release? There were some kernel fixes for I2S audio.

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I will have a look. I already updated to 4.4.13-5-osmc, will post results later (as soon as I manage to test it).

Thank you for the hint - indeed the update that I installed today seems to have fixed the stuttering video playback for me. I can now confirm fluent video playback on PI3 with Hifiberry DAC+.

@halogene Thanks for reporting. Good to know.