[MPlayer-users] hwac3 not working

Jean-Pierre Gygax jpgygax at swissonline.ch
Wed Apr 23 16:17:43 CEST 2003

Hi MPlayer makers,

[first off: a salute to you - this is a BIG piece of software]

I cannot seem to get the AC3 passthrough codec working. I have an SS51G
barebone, which uses the SiS 7012 chip for its audio. The SS51G has an
optical SP/DIF (TOSLINK) output, which of course I would like to use to get
surround sound when watching DVD movies.

I have tried both ALSA (I compiled myself a 2.5.67 kernel in order to get a
recent and well-supported version) and OSS (I didn't try OSS/Free, though).
OSS brought me a bit farther in the sense that I can get sound from the
SP/DIF output, where I never could get ALSA to play anything through that.

The basic symptom however is the same on both OSS and ALSA: instead of
surround sound, I get a horrible noise that threatens to tear to pieces the
cloth of my speakers. In the case of ALSA, I can only get that noise through
the normal outputs; with OSS, I can get it to "play" through SP/DIF.

What seems strange to me is that MPlayer talks about building an "audio
filter chain" (see output below). Since hwac3 is a passthrough, shouldn't
the filter chain be muted out/bypassed/something?

Would very much appreciate some help on this one!

-- Jean-Pierre gygax

gpc:~# mplayer -ao oss -ac hwac3 -dvd 1 -
Using GNU internationalization
Original domain: messages
Original dirname: /usr/share/locale
Current domain: mplayer
Current dirname: /usr/local/share/locale

MPlayer 0.90rc5-2.95.4 (C) 2000-2003 Arpad Gereoffy (see DOCS)

CPU: Intel Pentium 4 Xeon Foster (Family: 8, Stepping: 3)
Detected cache-line size is 64 bytes
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 SSE SSE2

Reading config file /usr/local/etc/mplayer/mplayer.conf: No such file or
Reading config file /root/.mplayer/config
Reading /root/.mplayer/codecs.conf: can't open '/root/.mplayer/codecs.conf':
No such file or directory
Reading /usr/local/etc/mplayer/codecs.conf: 50 audio & 136 video codecs
font: can't open file: /root/.mplayer/font/font.desc
font: can't open file: /usr/local/share/mplayer/font/font.desc
Using Linux hardware RTC timing (1024Hz).
Can't open input config file /root/.mplayer/input.conf : No such file or
Can't open input config file /usr/local/etc/mplayer/input.conf : No such
file or directory
Falling back on default (hardcoded) input config

Playing DVD title 1
Reading disc structure, please wait...
There are 37 titles on this DVD.
There are 38 chapters in this DVD title.
There are 1 angles in this DVD title.
DVD successfully opened.
MPEG-PS file format detected.
VIDEO:  MPEG2  720x576  (aspect 3)  25.00 fps  6800.0 kbps (850.0 kbyte/s)
Forced audio codec: hwac3
Opening audio decoder: [hwac3] AC3 pass-through SP/DIF
No accelerated IMDCT transform found
AUDIO: 48000 Hz, 2 ch, 16 bit (0x400), ratio: 48000->192000 (384.0 kbit)
Selected audio codec: [hwac3] afm:hwac3 (AC3 through SPDIF)
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 720 x 576 (preferred csp: Mpeg PES)
Could not find matching colorspace - retrying with -vop scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
VDecoder init failed :(
Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder v2.0
libmpeg2: Using MMXEXT for IDCT transform
libmpeg2: Using MMXEXT for motion compensation
VDec: vo config request - 720 x 576 (preferred csp: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [fbdev] 720x576 => 1024x576 Planar YV12
Using MMX2 for colorspace transform
Selected video codec: [mpeg12] vfm:libmpeg2 (MPEG 1 or 2 (libmpeg2))
Checking audio filter chain for 48000Hz/2ch/16bit -> 48000Hz/2ch/8bit...
AF_pre: af format: 2 bps, 2 ch, 48000 hz, big endian AC3
AF_pre: 48000Hz 2ch AC3
Can't set audio device /dev/dsp to AC3 output, trying S16...
AO: [oss] 48000Hz 2ch Signed 16-bit (Little-Endian) (2 bps)
Building audio filter chain for 48000Hz/2ch/16bit -> 48000Hz/2ch/16bit...
[format] Sample format big endian AC3  not yet supported
[libaf] Reinitialization did not work, audio filter 'format' returned error
code -2
Couldn't find matching filter / ao format!
Starting playback...
A:   1.9 V:   1.9 A-V:  0.005 ct:  0.043   48/ 48  14%  7%  7.4% 0 0 0%

More information about the MPlayer-users mailing list