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| − | == To send sound to both DVI and HDMI via ALSA ==
| + | Documents in this category are HOWTO documents explaining a specific scenario or task. You'll often find that they're more specific than you need, or that they pertain to a slightly different environment than you have, but you can often generalize about what they say to help you, anyway. |
| − | eg. to TV and Amplifier simultaneously you can use an .asoundrc file in your home directory.
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| − | Firstly a note or two -
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| − | # Sound CAN be sent over DVI, if you sound card supports it. Preferably use a DVI to HDMI connector / cobale (often cheaper than an HDMI to HDMI cable)
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| − | # Your sound device (presumably a graphics card with built in sound eg. NVidia GT430 as used here) needs to treat DVI and HDMI connectors similarly
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| − | # The sound device (graphics card) needs to support sound
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| − | Secondly, Pulse is probably easier if that is what you use, but this is useful for those of us using ALSA
| + | [[Category:Knowledge Base]] |
| − | | |
| − | ===The asoundrc file===
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| − | | |
| − | <pre>
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| − | # .asoundrc
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| − | # Add to your home directory
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| − | # works with NVidia GT430 ... once the video card itself is set to work correctly
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| − | #
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| − | # Default ALSA to send to both DVI and HDMI
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| − | pcm.!default {
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| − | type plug
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| − | slave {
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| − | # The following line actually does the work
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| − | pcm "hdmi_dvi_both"
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| − | }
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| − | }
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| − | # DVI connection on GT430
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| − | pcm.!hdmi3 {
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| − | type hw
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| − | card 0
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| − | device 3
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| − | channels 2
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| − | }
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| − | # Doesn't seem to be necessary, just for completeness
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| − | ctl.!hdmi3 {
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| − | type hw
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| − | card 0
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| − | device 3
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| − | channels 2
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| − | }
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| − | pcm.!hdmi7 {
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| − | type hw
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| − | card 0
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| − | device 7
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| − | channels 2
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| − | }
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| − | pcm.!hdmi8 {
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| − | type hw
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| − | card 0
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| − | device 8
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| − | channels 2
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| − | }
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| − | # HDMI Connection on GT430
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| − | pcm.!hdmi9 {
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| − | type hw
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| − | card 0
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| − | device 9
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| − | channels 2
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| − | }
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| − | # Doesn't seem to be necessary, just for completeness
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| − | ctl.!hdmi9 {
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| − | type hw
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| − | card 0
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| − | device 9
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| − | channels 2
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| − | }
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| − | | |
| − | pcm.multi_dig {
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| − | type multi
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| − | # Define DVI slave
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| − | slaves.a {
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| − | pcm "hdmi3"
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| − | # In this version, only pass 2 channels (like SPDIF)
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| − | channels 2
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| − | }
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| − | # Define HDMI slave
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| − | slaves.b {
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| − | pcm "hdmi9"
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| − | # In this version, only pass 2 channels (like SPDIF)
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| − | channels 2
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| − | }
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| − | # Bind the 2 DVI channels to a name ie "a"
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| − | bindings.0.slave a
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| − | bindings.0.channel 0
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| − | bindings.1.slave a
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| − | bindings.1.channel 1
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| − | | |
| − | # Bind the 2 HDMI channels to a name ie "b"
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| − | bindings.2.slave b
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| − | bindings.2.channel 0
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| − | bindings.3.slave b
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| − | bindings.3.channel 1
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| − | }
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| − | # Define the routing which actually send s the signal to both DVI and HDMI
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| − | pcm.hdmi_dvi_both {
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| − | type route
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| − | slave {
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| − | pcm "multi_dig"
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| − | # The channels definition is critical to define the total number of channels out (2 sets of 2)
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| − | channels 4
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| − | }
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| − | # The first dot after "ttable" defines the channel out
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| − | # The second dot defines the channel as bound above in the "multi-dig" definition
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| − | # Define 4 channels out in total, 2 each for DVI and HDMI
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| − | ttable.0.0 1
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| − | ttable.1.1 1
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| − | ttable.0.2 1
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| − | ttable.1.3 1
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| − | }
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| − | # You may have to mess around with your TV and amp depending on what they support
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| − | # My curent setup is MythTv v 0.23
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| − | # my amp supports Dolby, DTS and AC3
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| − | # my TV support DTS and AC# ... but NOT Dolby (just get nasty "noise" if "dolby" selected in MythTv)
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| − | # I sent HDMI to TV because of default colour space etc
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| − | # and DVI to amp cause its not sensitive to colour etc. (just used for sound)
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| − | # BUT need to tell NVidia Config to send video to both (default is DVI only)
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| − | | |
| − | </pre>
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| − | | |
| − | Paste the above file into your home directory as ".asoundrc"
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| − | | |
| − | === MythTv Setup ===
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| − | Go to MythTv Setup / General / Audio System and set the "Audio output device" to ALSA:default or ALSA:hdmi_dvi_both
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| − | | |
| − | === Other Notes ===
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| − | Depending on your TV and Amp you may also need to change the settings for 5.1 sound. Your devices may or may not support
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| − | # AC3 (nothing else selected)
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| − | # Dolby
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| − | # DTS
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| − | In my case,
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| − | # TV supports AC3 and DTS but NOT Dolby
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| − | # Amp supports all the above (but not 7.1 bitstream)
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| − | Now I can use either TV sound or Amp sound or both
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| − | | |
| − | [[Category:HOWTO]] | |
Documents in this category are HOWTO documents explaining a specific scenario or task. You'll often find that they're more specific than you need, or that they pertain to a slightly different environment than you have, but you can often generalize about what they say to help you, anyway.
