On Thu, Mar 24, 2011 at 10:50 AM, Anssi Hannula <anssi.hannula at iki.fi> wrote: > On 24.03.2011 16:18, pl bossart wrote: >>> It seems that 384k sample rates aren't supported directly in alsa, I did >>> some patching to no avail yet. >>> >>> In any case if the channel count can be specified with passthrough the >>> following should work. >>> >>> paplay --raw --channels=2 --rate=192000 --passthrough File.dts.spdif192khz ( >>> this works). >>> >>> paplay --raw --channels=4 --rate=192000 --passthrough File.dts.spdif384khz ( >>> this fails). >>> >>> To passthrough dolby true-hd it looks like it'll be necessary for more than >>> two channels to work. >> >> There was a thread on dts-hd in alsa-devel at some point. Anssi >> (cc:ed) contributed some patches for HDMI and provided the information >> below on ffmpeg configurations. >> You may want to try at the alsa level before trying with pulseaudio to >> make sure your setup is correct. I tend to believe you have to go for >> 8ch @ 192kHz to make this work based on my limited understanding of >> HBR. > > Indeed for HBR you need to always specify 8 channels and use rate to > control the final rate (i.e. you either use "normal" 2 channel > passthrough or HBR 8 channel passthrough). > > For example to passthrough the abovementioned 384 kHz stream you need to > use 8 channels and rate of 96000. However, I think 384kHz DTS bitstream > is generally *not* supported by A/V receivers, so you probably want to > use 768kHz (8 channels, 192kHz). > > (note: I haven't tested whether HBR works with pulseaudio or not) > > >> The DTS-HD part is not merged yet (patch is in ffmpeg-devel@), but the >> TrueHD and E-AC-3 support is already there in ffmpeg trunk. >> >> The ffmpeg commandline to use is: >> ffmpeg -i input.file -f spdif output.spdif >> >> For DTS-HD files, to get full passthrough (i.e. not only core), a >> -dtshd_rate parameter is needed, which sets the output IEC958 rate. >> ffmpeg -i input.file -f spdif -dtshd_rate 192000 output.spdif >> ffmpeg -i input.file -f spdif -dtshd_rate 768000 output.spdif >> 192000Hz is enough for streams that have a bitrate below 6.144Mbps, which >> means all DTS-HD High Resolution Audio files and even many of the DTS-HD >> Master Audio (the latter are lossless VBR). >> >> To play the spdif files back, I use >> aplay -D hdmi:CARD=$CARDNAME,DEV=$DEVICENUM,AES0=0x06 -c $CHANCOUNT -r >> $RATE file.spdif >> >> - replacing $CARDNAME with the card name >> - replacing $DEVICENUM with 0..3 depending on card and hdmi port (for >> non-zero DEVICENUM you'll need a patch from alsa git: >> http://git.alsa-project.org/?p=alsa-lib.git;a=commitdiff;h=e6d5dcf1f625984605d362338d71162de45a6c60 >> ) >> - set $CHANCOUNT and $RATE as per below >> ?- rate 192000 and channels 2 for IEC958 rate 192 kHz (for e.g. 48 kHz >> E-AC-3, and DTS-HD when the IEC958 rate was set to 192000 in ffmpeg) >> ?- rate 192000 and channels 8 for IEC958 rate 768 kHz (for most TrueHD >> files, and for DTS-HD when the rate was set to 768000) >> - note that having the 0x02 bit (non-pcm) set in AES0 is mandatory when >> $CHANCOUNT is larger than 2, as ALSA uses it to determine whether to use >> HBR or not. The additional 0x04 (non-copyright) I use above is not >> mandatory, but is the alsa default so I kept it. > > > -- > Anssi Hannula > _______________________________________________ > pulseaudio-discuss mailing list > pulseaudio-discuss at mail.0pointer.de > https://tango.0pointer.de/mailman/listinfo/pulseaudio-discuss > Would anyone know where I could get a hold of some DTS-HD samples in 192Khz and 384kHz for testing?
