Fast chopping / stuttering in mythmusic after hdaudio merge

[bhuffman@…]

I hear a very fast clipping / stuttering sound in mythmusic now. I see this in the frontend logs (without extra debug) when entering:

2010-05-29 09:08:39.901 AO: Opening audio device 'spdif' ch 2(2) sr 44100 sf signed 16 bit reenc 0 2010-05-29 09:08:39.901 Opening ALSA audio device 'spdif'. 2010-05-29 09:08:39.917 ScreenSaverX11Private: DPMS Deactivated 1 MMX detected. Using fast method !

[bhuffman@…]

mythfrontend -v audio log

[Ken Emerson <kenneth.emerson@…>]

On Sunday, May 30, 2010, Kenneth Emerson <kenneth.emerson@…> wrote:

I have experienced the same results with MythMusic (described in ticket 8509) since upgrading to trunk with the hdaudio merge. Prior to the merge I was using ALSA:plughw,1,0 as my main audio device and "default" in MythMusic setup for the audio device.

After upgrading to 24896, I switched the main audio device from ALSA:plughw,1,0 to ALSA:iec958:CARD=External,DEV=0. If I leave the music audio device at default, I get the choppy,stuttering output described in ticket 8509. When I change the music device to /dev/dsp1 the music plays normally.

If I leave the music device at default and check the PCM Analog box in the general MythTV audio configuration screen, the frontend segfaults (I have a coredump).

Then why not provide a backtrace in the ticket?

The 8509 ticket is unfortunately close to useless.

It does not provide any information that could actually help diagnose the problem.

/dev/dsp is OSS audio

The PCM checkbox is only necessary when using multichannel audio.

What happens if you leave the audio config like it was before? (ALSA:plughw,1,0)

• Show quoted text -

The output from the frontend is:

2010-05-29 14:14:44.166 AO: Opening audio device 'iec958:CARD=External,DEV=0' ch

2(2) sr 44100 sf signed 16 bit reenc 0

2010-05-29 14:14:44.167 Opening ALSA audio device 'iec958:CARD=External,DEV=0'. 2010-05-29 14:14:44.895 ScreenSaverX11Private: DPMS Deactivated 1 2010-05-29 14:15:01.212 ScreenSaverX11Private: DPMS Reactivated 1 2010-05-29 14:15:03.522 Loading menu theme from /usr/local/share/mythtv/music_se ttings.xml

Music stutters.

2010-05-29 14:15:48.166 XMLParse: LoadTheme? using '/usr/local/share/mythtv/theme s/blue-abstract-wide_old/music-ui.xml' 2010-05-29 14:15:48.514 XMLParse, Warning: Unknown: area in repeated image 2010-05-29 14:15:48.515 XMLParse, Warning: Unknown: area in repeated image 2010-05-29 14:15:49.029 AO: Opening audio device '/dev/dsp1' ch 2(2) sr 44100 sf

signed 16 bit reenc 0

Music plays fine.

version info: ken@mythtv:~$ mythfrontend --version Please attach all output as a file in bug reports. MythTV Version : 24896 MythTV Branch : trunk Network Protocol : 57 Library API : 0.23.20100526-2 QT Version : 4.5.0 Options compiled in:

linux debug using_oss using_alsa using_backend using_directfb using_dvb using_f

irewire using_frontend using_hdhomerun using_hdpvr using_iptv using_ivtv using_j oystick_menu using_libfftw3 using_lirc using_mheg using_opengl_video using_openg l_vsync using_qtdbus using_qtwebkit using_v4l using_x11 using_xrandr using_xv us ing_xvmc using_xvmc_vld using_xvmcw using_bindings_perl using_bindings_python us ing_opengl using_vdpau using_ffmpeg_threads using_live using_mheg

Ok. I started on the users list as I didn't want to muddy the waters with what might have been a configuration problem.

/dev/dsp is OSS audio

I realize that. I just wanted to state that this was the only option that produced good audio.

The PCM checkbox is only necessary when using multichannel audio.

I was pretty sure that this was only used when using the individual channel outputs from the sound card (not S/PDIF); however, my nature is to try all possible combinations before giving up in the hope that some information will be useful. what I did get was a segfault from mythfrontend (backtrace attached).

What happens if you leave the audio config like it was before? (ALSA:plughw,1,0)

This was the first option I tried. Recordings and videos sounded fine. I got nothing when I tried playing mp3's through MythMusic; total silence. When I switched to the S/PDIF device for MythMusic, it sounded like it was coming from under water (stuttering/choppy).

This configuration is easy for me to set up, so if there is someway I can provide you with more detailed information, I am at your service.

-- Ken E.

[Ken Emerson <kenneth.emerson@…>]

frontend segfault from mythmusic w/ PCM enabled.

[JYA]

If you are using SPDIF, do *not* use the PCM check box ; I would have thought the help text is rather self-explanatory.. SPDIF does *NOT* support multi-channel PCM, it only supports stereo PCM

The PCM flag was added to be able to differentiate devices that can accept native multi-channel audio (e.g. analog audio card, hdmi) to the one who don't (e.g spdif: coax or optical). We have no way of guessing it, so we ask the user to properly inform with on what it is...

[bhuffman@…]

Thanks for high-jacking my ticket.

Well, I do *not* have PCM checked. I also unchecked the stereo up-mixing (just to remove possible things from the mix). I still have the noise - sounds sort of like clipping. Is there anything else I can provide to assist?

[JYA]

yes. providing a log that actually contains something of use..

use -v audio for a start as well as what audio settings you are using

ALSA:spdif is surely not a device appearing in the list of possible audio device either...

[JYA]

and full log ? You clipped the only bit that would have been of interest

[bhuffman@…]

Did you see the first attachment? That's a -v audio. I added it almost immediately after creating the ticket.

[JYA]

yes... and it contains nothing of interest because it's cut right before it's interesting

[bhuffman@…]

Grr..Ok. I'll try it again. I didn't cut this at all. The only thing I might have done is hit CTRL-C *after* mythmusic was already playing the choppy sound. I'd assumed that the debugging information would at least have been before or during the evidenced sound. But perhaps it outputs debugging after the fact. I'll upload one that is from complete frontend start to stop.

[bhuffman@…]

Uploading new mythfrontend.log that has -v audio and is complete from start to finish. Any debugging output not shown is not being output by mythfrontend -v audio -l mythfrontend.log

[bhuffman@…]

New mythfrontend.log from execute to quit including 13 seconds of playback in mythmusic with -v audio -l mythfrontend.log

[bhuffman@…]

Also switched to one of the default device options. "Default" itself doesn't work, but "ALSA:iec958:CARD=M2496,DEV=0" at least gets me to the same place as before - mythmusic stutters the same, but I'd guess that recordings and TV work fine (I didn't test). Skimming the logging output looks about the same though.

[JYA]

Can you upgrade to svn >= r24901 and report?

The crash reported above should be fixed too

[bhuffman@…]

Upgraded to 24902. Chopping still exists for me.

[JYA]

iis the issue still occurring? is this with all files or only some?

[bhuffman@…]

It is still occurring and it appears to occur with all files that I have. I tested on about 7 different files and it happened on all. However, I have only .flac files that were ripped from CD using mythmusic...so I don't know if it would occur on mp3s or other formats.

[JYA]

I know what's going on then.... But I'll need to see one of the flac file

Original codec was NONE, signed 16 bit, 44 kHz, 2 channels

The codec hasn't been able to be retrieved (hence NONE), as such it tries to play default 16 bits audio. Flac is 24 bits...

Can you post one of the flac file somewhere then .. thank you

[bhuffman@…]

​http://www.graze.net/03-Only_Time.flac

[Ken Emerson <kenneth.emerson@…>]

Combining my observations from the closed ticket #8518: I took a sample mp3 file and played it with "default" as the output device which is set up as "ALSA:iec958:CARD=External,DEV=0" under Setup/General? menu. With the upmix to 5.1 box checked, the music plays very choppy from all five speakers (vocal coming out of center). If I uncheck the 5.1 upmix box, it is still choppy (but less so), but the vocal out of the center speaker sounds almost perfect. My amplifier reads "No digital data" during both of these tests. If I change the music output device from "default" to the OSS device (/dev/dsp1) the music is perfect and the amplifier is happy with the signal. I ran top to see if there was a CPU issue and there wasn't (>97% idle).

I have disabled pulseaudio using this link: ​http://www.jeffsplace.net/node/12. I am running Ubuntu 10.4. I played the same mp3 file using rhythmbox and mediaplayer, both played the file correctly; however, I am not sure whether the system was using ALSA or OSS; with pulseaudio out of the picture, the gdk sound applets were crippled.

MythTV correctly identifies my Sound Blaster Live! USB sound card and all recordings and movies have normal sound. Prior to the sound system re-write I'm pretty sure that I was using "default" as the output for MythMusic having to change to OSS afterwards.

Unfortunately, I cannot test the onboard sound (Intel chip) since it was fried and was not successfully fixed by ASUS RMA process. All testing done using:

MythTV Version : 26118 MythTV Branch : trunk Network Protocol : 61 Library API : 0.23.20100904-1 QT Version : 4.6.2 Options compiled in:

linux debug using_alsa using_oss using_pulse using_pulseoutput using_backend using_bindings_perl using_bindings_python using_directfb using_dvb using_firewire using_frontend using_hdhomerun using_hdpvr using_iptv using_ivtv using_joystick_menu using_libfftw3 using_lirc using_mheg using_opengl_video using_opengl_vsync using_qtdbus using_qtwebkit using_v4l using_x11 using_xrandr using_xv using_xvmc using_xvmc_vld using_xvmcw using_bindings_perl using_bindings_python using_mythtranscode using_opengl using_vdpau using_ffmpeg_threads using_live using_mheg

-- Ken Emerson (kenneth dot emerson at gmail dot com)

[JYA]

This flac sample plays fine with me with all tests.

r26118 as far as I'm concerned is ancient :P

Re-open a ticket if you still have an issue.