Viewing 6 posts - 1 through 6 (of 6 total)
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  • caver01
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    Post count: 31

    I just setup the latest retropie image (3.4) on my Pi2. I have a USB audio adapter from Adafruit (https://www.adafruit.com/products/1475). Mine is the “CM-Headphone Type”. The setup for this is pretty straightforward on Jessie–you merely add /etc/asound.conf and put in:

    pcm.!default  {
     type hw card 1
    }
    ctl.!default {
     type hw card 1
    }

    That done, I get sound as expected using speakertest both white noise tests and wave tests. I also get audio in Emulation Station scrolling through roms. NES emulator for example works fine.

    Then, I loaded roms for AdvanceMAME and configured the default to launch 1.4. It works, but the audio is delayed about 5 seconds! It sounds great, but seriously, this is ridiculous latency leading me to think I have something configured wrong. Advmame .94 is better, but there is still latency. What’s going on here?

    On my PiPlay SD card, AdvanceMAME 1.2 works fine–no latency. I would consider other MAME builds, but I want to be able to run Vector games at my display’s full resolution (1280×1024) and I want to be able to have shader/scanline flexibility for the other games (so probably running at higher, doubled etc. resolutions). Does anyone have any thoughts or recommendations? HDMI audio is not possible with my display setup.

    caver01
    Participant
    Post count: 31
    blanka
    Participant
    Post count: 3

    I am really curious how the link helped you fix the delay. I have the USB card as default (achieved in another way, by disabling the broadcom module in /boot/config.txt), yet I still have a 5 second delay in AdvMame.

    caver01
    Participant
    Post count: 31

    blanka, I think you answered your own question. I was getting sound to work at first using another method too. In fact, I have used four or five different methods to get usb sound working in some capacity, but it wasn’t until I reversed my other attempts and followed the instructions in the link to create /etc/modprobe.d/alsa-base.conf that the delay went away.

    Right now, however, I have the broadcom audio enabled again going to the built-in 3.5mm jack and my USB dongle is unplugged. I discovered that the NORMALIZE audio setting in advancemame was the cause of crackling. Once I turned off normalization in the GUI, and permanently with this line in advmame.rc: “sound_normalize no” the crackling stops. I am testing whether or not I even need USB audio.

    Anyway, try the technique outlined in the link above and see if that works better.

    andrewsi
    Participant
    Post count: 10

    Hey, I’d like to reactivate this thread. I’ve been working on migrating an earlier 3.x setup to a Raspberry Pi 3 with the latest Jessie bits, and I pretty much have everything working, except I am hitting exactly this same 5-second delay thing in Advmame. This occurs even on the Pi 2 using the same SD card, so it’s not a Pi 3 specific problem.

    I notice that the delay occurs in both Advmame 1.2 and 1.4, and not so much in 0.9, as was described above. However, I got exactly nowhere in terms of curing it via any of the steps above. I can even blacklist snd-bcm2835 so that the built-in sound driver never loads and the _only_ ALSA sound adapter is the USB one, but I still get the big delay. However, I also noticed that it seems to somehow be related to emulator startup – sounds that occur right after boot (for example in the btime ROM) play at a lower pitch than they should. This gave me an idea, and I started playing around with the various latency and sound sync options in the .rc file, but I still didn’t get anywhere, until…

    If I use “debug_rawsound yes” option in the advmame .rc files, then yes, the problem seems to go away. However, as this disables the sound sync code altogether, I suspect that the sound will start to drift over time, so I wasn’t thrilled with this being the actual solution. Finally, I just changed the sound option to use SDL instead of ALSA, and that seemed to fix it as well.

    caver01
    Participant
    Post count: 31

    Hmm. That’s pretty interesting. I don’t think I have mentioned this anywhere above, but the default value for sound_latency was something like 0.2, which is really strange and noticeably long. I don’t think you can set it to zero, but .05 is fine, and you can definitely hear the difference. I don’t understand how a 5th of a second audio lag could be acceptable as a default. It won’t fix the 5-second problem, but don’t ignore it.

    I wish I knew exactly what steps I took while troubleshooting my USB audio besides landing on the settings linked above. It’s possible that I have some residual ALSA file somewhere after trying so many different things. I am really disappointed in the way my USB card is supported. Commands to the channel name PCM don’t work at all.

    I had hoped to find a way to use an ALSA “clone” plugin so that I could leave the PCM channel (built-in Broadcom) enabled and setup my config to mimic everything to the USB hardware. I had a few aspects of this working at one point, but not every had sound. Perhaps some of them bypassed ALSA settings. In any case, I switched to the built-in jack for now. I may come back to USB, but it’s so frustrating.

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