[MPlayer-users] Revisiting "mplayer and DTS pass-through"

[Sergey Melikhov]

Hello All!

Last summer, Jean-Yves Avenard asked about DTS-WAV
SPDIF pass-through playback (his mail is quoted
below). In the thread, I found an advice on how to
play DVD DTS tracks, but I can't find an answer on the
original question.

http://lists.mplayerhq.hu/pipermail/mplayer-users/2006-July/061383.html

May I kindly ask to revisit this issue...

AFAIK, the sampling rate of DTS-WAV files differ from
DVD soundtracks, and maybe other encoding parameters
differ as well. I guess that has something to do with
the problem, as mplayer switches to incorrect sampling
rate, according to its output (see session listing
below).

Currently, I  play these files with aplay from ALSA.
It's OK as a short-term solution, but if mplayer could
do it would be just perfect. 

Again, this question is about pass-trough. mplayer can
decode this file to stereo PCM no problem, but that's
not what other people and I are looking for.

Thanks!

   Sergey

----------- Listing --------------
[root at fedora tmp]# mplayer -ac hwdts -ao alsa   
./diatonis_dts_secret-universe.wav 
MPlayer 1.0rc1-4.1.1 (C) 2000-2006 MPlayer Team
CPU: Intel Celeron 2/Pentium III
Coppermine,Geyserville (Family: 6, Model: 8, Stepping:
6)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1
SSE2: 0
Compiled with runtime CPU detection.
Can't open joystick device /dev/input/js0: No such
file or directory
Can't init input joystick
mplayer: could not open config files /root/.lircrc and
/etc/lircrc
mplayer: No such file or directory
Failed to read LIRC config file ~/.lircrc.

Playing ./diatonis_dts_secret-universe.wav.
Audio file file format detected.
==========================================================================
Forced audio codec: hwdts
Opening audio decoder: [hwac3] AC3/DTS pass-through
S/PDIF
No accelerated IMDCT transform found
hwac3: switched to AC3, 32000 bps, 48000 Hz
a52: CRC check failed!  
AUDIO: 48000 Hz, 2 ch, ac3, 32.0 kbit/2.08% (ratio:
4000->192000)
Selected audio codec: [hwdts] afm: hwac3 (DTS through
S/PDIF)
==========================================================================
AO: [alsa] 48000Hz 2ch ac3 (1 bytes per sample)
Video: no video
Starting playback...
a52: CRC check failed!  
a52: CRC check failed!  
a52: CRC check failed!  
a52: CRC check failed!  
a5


------------ Original Request --------------




Jean-Yves Avenard jyavenard at gmail.com
Sat Jul 8 11:20:44 CEST 2006

ello

I'm trying to play a DTS encoded .wav file with
mplayer, however I
haven't found a way to play it with pass-through my
DTS decoder over
the S/PDIF output.

I can play the dts file just fine using mplayer
decoder, with something like:
mplayer  -ao alsa:device=spdif 
dts_diatonis_io_afos.dts
Playing dts_diatonis_io_afos.dts.
Audio file file format detected.
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec
audio decoders
AUDIO: 44100 Hz, 2 ch, s16le, 1411.2 kbit/100.00%
(ratio: 176400->176400)
Selected audio codec: [ffdts] afm: ffmpeg (DTS)
==========================================================================
alsa-init: using device spdif
alsa: 48000 Hz/2 channels/4 bpf/65536 bytes
buffer/Signed 16 bit Little Endian
AO: [alsa] 48000Hz 2ch s16le (2 bytes per sample)
Video: no video
Starting playback...
A:   5.8 (05.8) of 517.0 (08:37.0)  7.6%

However, when I try the pass-through option:
mplayer -afm hwac3 -ao alsa:device=spdif 
dts_diatonis_io_afos.dts

I get :
Trying to force audio codec driver family hwac3...
Opening audio decoder: [hwac3] AC3/DTS pass-through
S/PDIF
No accelerated IMDCT transform found
hwac3: switched to AC3, 80000 bps, 48000 Hz
a52: CRC check failed!
AUDIO: 48000 Hz, 2 ch, ac3, 80.0 kbit/5.21% (ratio:
10000->192000)
Selected audio codec: [hwdts] afm: hwac3 (DTS through
S/PDIF)
==========================================================================
alsa-init: using device spdif
alsa: 48000 Hz/2 channels/4 bpf/65536 bytes
buffer/Signed 16 bit Little Endian
AO: [alsa] 48000Hz 2ch ac3 (1 bytes per sample)
Video: no video
Starting playback...
a52: CRC check failed!
a52: CRC check failed!


 
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