[MPlayer-users] No sound in TV output

[dion king]

I use the bellow command to watch TV:

mplayer -tv on:device=/dev/video0:driver=v4l
:width=640:height=480:input=0:forcechan=2

but there is no sound output.
____________________________________________________________________
Playing TV
TV detected! ;-)
Selected driver: v4l
 name: Video 4 Linux input
 author: Alex Beregszaszi <alex at naxine.org>
 comment: under development
Selected device: BT878(Leadtek WinFast 2000)
 Capabilites: capture tuner overlay clipping frameram scales 
 Device type: 235
 Supported sizes: 48x32 => 924x576
 Inputs: 3
  0: Television: tuner audio tv camera  (tuner:1, norm:pal)
  1: Composite1: audio camera  (tuner:0, norm:pal)
  2: S-Video: audio camera  (tuner:0, norm:pal)
Card reports an unknown audio mode !
Trying two channel audio. Use forcechan to override.
Using input 'Television'
vo: X11 running at 1024x768 with depth 24 and 32 bpp (":0.0" => local display)
Disabling DPMS
==========================================================================
Opening video decoder: [raw] RAW Uncompressed Video
VDec: vo config request - 640 x 480 (preferred csp: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is undefined - no prescaling applied.
VO: [xv] 640x480 => 640x480 Planar YV12 
Selected video codec: [rawyv12] vfm:raw (RAW YV12)
==========================================================================
Audio: no sound
Starting playback...
Successfully enabled DPMS.0% 0 0 0%
________________________________________________________________________

I have tried forcechan=1 and forcechan=2, but it doesn't work.
However my tv card (Leadtek WinFast 2000) run well under xawtv:

xawtv -debug 1
________________________________________________________________________
v4l: open: /dev/video0 (BT878(Leadtek WinFast 2000))
capabilities:  capture tuner overlay clipping frameram scales
  size    : 48x32 => 924x576
  channels: 3
  Television: 1 tuner audio  tv 
  composite1: 0 audio  camera 
     S-Video: 0 audio  camera 
audios  : 1
 3 (TV): muted=no 
tuner   : Television 0-4294967295 PAL NTSC SECAM
v4l: bttv version 0.7.91
fbuffer : base=0x0xd4000000 size=1024x768 depth=32 bpl=4096
picture : brightness=30801 hue=30801 colour=30146 contrast=26214
picture : whiteness=0 depth=12 palette=yuv420p
mbuf: size=4259840 frames=2
v4l: using mapped buffers for capture
vid-open: ok: v4l
__________________________________________________________________________

xawtv can get video and audio,
Then what shall I do for mplayer ???

Thanks

dion