<div class="gmail_quote">On Thu, Feb 28, 2008 at 10:27 AM, Robert Jones <<a href="mailto:kaosfere@gmail.com">kaosfere@gmail.com</a>> wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Hi, everyone.<br><br>I decided yesterday that I was going to do away with my standalone DVD<br>player and allow myth to take over that role in my entertainment<br>
center. However, I ran into some bizarre issues getting audio to<br>passthrough to my home theater receiver.<br><br>I'm currently running Ubuntu Gutsy, tracking the Mythbuntu weekly<br>builds of the svn trunk. My system has MCP51 onboard audio, using the<br>
hda-intel drivers manually updated to the latest ALSA beta (although<br>this also occured with earlier versions).<br>I'm pulling digital out via S/PDIF.<br><br>My audio out and digital passthrough are both currently set to ALSA:iec958.<br>
<br>I can get full dolby digital to my amp using mplayer, by routing sound<br>to ALSA:iec958 and forcing hwac3. However, when I try to play the<br>same DVD through myth, the audio I get is raw digital noise. It's<br>
almost as though the bitstream is being sent down the wire as plain<br>PCM audio.<br><br>I have tried jiggering the output devices. using ALSA:plug:iec958<br>doesn't change anything. Nor do any of the AESx hex incantations that<br>
I have seen scattered about -- they either break audio entirely, or do<br>nothing to change the presentation of raw digital noise. Accessing<br>hw:0,1 doesn't help, either.<br><br>(And, yes, I'm set to AC3 and DTS passthrough, and "use video as<br>
timebase" is off.)<br><br>For reference, here's the output of aplay -l:<br><br>**** List of PLAYBACK Hardware Devices ****<br>card 0: NVidia [HDA NVidia], device 0: AD198x Analog [AD198x Analog]<br> Subdevices: 1/1<br>
Subdevice #0: subdevice #0<br>card 0: NVidia [HDA NVidia], device 1: AD198x Digital [AD198x Digital]<br> Subdevices: 1/1<br> Subdevice #0: subdevice #0<br><br><br><br><br><br>Here's aplay -L:<br><br>default:CARD=NVidia<br>
HDA NVidia, AD198x Analog<br> Default Audio Device<br>front:CARD=NVidia,DEV=0<br> HDA NVidia, AD198x Analog<br> Front speakers<br>surround40:CARD=NVidia,DEV=0<br> HDA NVidia, AD198x Analog<br> 4.0 Surround output to Front and Rear speakers<br>
surround41:CARD=NVidia,DEV=0<br> HDA NVidia, AD198x Analog<br> 4.1 Surround output to Front, Rear and Subwoofer speakers<br>surround50:CARD=NVidia,DEV=0<br> HDA NVidia, AD198x Analog<br> 5.0 Surround output to Front, Center and Rear speakers<br>
surround51:CARD=NVidia,DEV=0<br> HDA NVidia, AD198x Analog<br> 5.1 Surround output to Front, Center, Rear and Subwoofer speakers<br>surround71:CARD=NVidia,DEV=0<br> HDA NVidia, AD198x Analog<br> 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers<br>
iec958:CARD=NVidia,DEV=0<br> HDA NVidia, AD198x Digital<br> IEC958 (S/PDIF) Digital Audio Output<br>null<br> Discard all samples (playback) or generate zero samples (capture)<br><br><br><br><br>And here's a portion of my frontend log (from a title screen, so it's<br>
only 2-channel AC3, but 6-channel looks similar, and both sound the<br>same), with -v audio turned on.:<br><br><br><br>2008-02-28 02:45:40.997 AFD: Opened codec 0xaa6ef030, id(AC3) type(Audio)<br>2008-02-28 02:45:40.998 AFD: Audio Track #1 is A/V stream #1 and has 0<br>
channels in the Undetermined language(7695972).<br>2008-02-28 02:45:41.007 AFD: Selected track 1: Undetermined LIBA52 2ch<br>(A/V Stream #1)<br>2008-02-28 02:45:41.008 AFD: Initializing audio parms from audio track #1<br>
2008-02-28 02:45:41.008 AFD: Audio format changed digital passthrough<br>id( AC3) 48000Hz 2ch 16bps pt<br> from id(NONE) -1Hz -1ch 0bps ;<br>id(NONE) -1Hz -1ch 0bps<br> to id( AC3) 48000Hz 2ch 16bps pt ; id(<br>
AC3) 48000Hz 2ch 16bps pt<br>2008-02-28 02:45:41.019 AO: Needs upmix<br>2008-02-28 02:45:41.019 AO: Killing AudioOutputDSP<br>2008-02-28 02:45:41.019 Opening audio device 'plug:iec958'. ch 6(2) sr 48000<br>2008-02-28 02:45:41.020 Opening ALSA audio device 'plug:iec958'.<br>
2008-02-28 02:45:41.032 in SetParameters(format=2, channels=6,<br>rate=48000, buffer_time=100000, period_time=25000)<br>2008-02-28 02:45:41.034 get_buffer_size returned 4800<br>2008-02-28 02:45:41.034 set_period_time_near returned 20000<br>
2008-02-28 02:45:41.034 get_period_size returned 960<br>2008-02-28 02:45:41.050 AO: Audio fragment size: 19200<br>2008-02-28 02:45:41.052 AO: create upmixer<br>2008-02-28 02:45:42.135 AO: create upmixer done with surround mode 2<br>
2008-02-28 02:45:42.136 AO: Audio Stretch Factor: 1<br>2008-02-28 02:45:42.136 Audio Codec Used: not set<br>2008-02-28 02:45:42.136 AO: Ending reconfigure<br>2008-02-28 02:45:42.136 NVP: Enabling Audio<br>2008-02-28 02:45:42.136 AO: Killing AudioOutputDSP<br>
2008-02-28 02:45:42.136 AO: kickoffOutputAudioLoop: pid = 16227<br>2008-02-28 02:45:42.136 AO: OutputAudioLoop: Stop Event<br>2008-02-28 02:45:42.136 AO: kickoffOutputAudioLoop exiting<br><br><br><br>I can provide more extensive logs if necessary, but I feel as though<br>
I'm missing something glaringly obvious. :(</blockquote>
<div> </div>
<div>I *think* since you are seeing upmixer notes in your logs that you are running a very recent SVN version? If this is the case, I think you need to set your upmix settings to passthrough or something like that (I haven't updated but I saw some messages regarding this). See if you can find that setting.</div>
<div> </div>
<div>Kevin</div></div>