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Old 11-21-10, 08:08 AM   #1
FFmpeg developer
Join Date: Jan 2009
Location: Vienna, Austria
Posts: 467
Default Call for testers: HDMI pass-through

Anssi Hannula has provided patches for FFmpeg that should allow to use HDMI pass-through on Linux for TrueHD and DTS-HD.
Since they do not work for me on a G210 and KRF-V7300D, I would like to ask people to test two files (that were made using his patches) on HDMI and suitable receiver hardware.
You can find the two testfiles in
To produce such files yourself, use:
ffmpeg -i input -acodec copy output.spdif

Add the following to ~/.asoundrc:
## begin custom stuff
pcm.hdmihdtest {
        @args [ DEVICE CTLINDEX ]
        @args.DEVICE {
                type integer
        @args.CTLINDEX {
                type integer
        type hooks
        slave.pcm {
                type hw
                card NVidia
                device $DEVICE
        hooks.0 {
                type ctl_elems
                hook_args [
                        name "IEC958 Playback Default"
                        index $CTLINDEX
                        lock true
                        preserve true
                        value [ 0x06 0x82 0x00 0x01 ]
                        name "IEC958 Playback Switch"
                        index $CTLINDEX
                        lock true
                        preserve true
                        value true
pcm.hdmihdtest0 { @func refer name "pcm.hdmihdtest:DEVICE=3,CTLINDEX=0" }
pcm.hdmihdtest1 { @func refer name "pcm.hdmihdtest:DEVICE=7,CTLINDEX=1" }
pcm.hdmihdtest2 { @func refer name "pcm.hdmihdtest:DEVICE=8,CTLINDEX=2" }
pcm.hdmihdtest3 { @func refer name "pcm.hdmihdtest:DEVICE=9,CTLINDEX=3" }
## end custom stuff
Make sure alsa is not muted with
alsamixer -cNVidia
To test them, use:
aplay -D hdmihdtest0 -c8 -fs16_le -r192000 file.spdif
aplay -D hdmihdtest1 -c8 -fs16_le -r192000 file.spdif
aplay -D hdmihdtest2 -c8 -fs16_le -r192000 file.spdif
aplay -D hdmihdtest3 -c8 -fs16_le -r192000 file.spdif
You either need Linux kernel 2.6.36 or an older kernel with latest alsa drivers installed (and you should preferably confirm that aplay works on wav files over hdmi before downloading the test files).

Please provide the following information:
  • Card and GPU type (you find this information for example in the third line of qvdpautest output)
  • Driver version
  • Kernel (and ALSA) version
  • Receiver
  • If none, one or both files work for you (they only contain short noise, the question is if the receiver correctly recognizes them)
Some information and the patches are here:

Thank you, Carl Eugen

Last edited by cehoyos; 03-06-11 at 10:55 AM. Reason: Rm wrong info about Anssi's hw and add kernel version requirement
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