[mythtv] Clicky/jittery audio

Dave Smith dave at nobodynet.net
Mon Jan 27 10:18:19 EST 2003

Firstly, the Myth project looks really awesome - very excited about it.

I'm having a few problems though - my current main problem being with 
audio.  All audio recorded and played-back (both seperatly recorded, and 
when "Watching Live") suffers from very bad, constant clicking/jittering.

I have tried compressed and uncompressed audio, both with the same 
problem.  I've tried different sample rates, all have the clicking, but 
anything other than 48000 also has some bad quantisation-like square-ness 
sound.  48000 however _only_ has the clicking problem.

I've tried recording audio directly using "rec", which works fine.

I've tried both RTJPeg and Mpeg, both the same.

I'm using ALSA 0.9rc6.  The soundcard is (I think) Intel8x0 / AC97 type, 
on the motherboard.  I'm grabbing from my cable/DTT boxes, so sound is 
plugged directly in to the soundcard line-in.

Video wise, I'm using a Matrox G450 for capture, which seems to be 
capturing really well.

If anyone can offer me any help, it'd be great.  I'm just now going round 
in circles now.  There's more info on my system below.


MythTV Diagnosis script v0.0.1

OS and Version Info
Linux edmonds.nobody 2.4.20 #6 Fri Jan 10 20:44:30 GMT 2003 i686 unknown 
unknown GNU/Linux
Mandrake Linux release 9.0 (dolphin) for i586
Mandrake Linux release 9.0 (dolphin) for i586

Hardware Info
processor	: 0
vendor_id	: AuthenticAMD
cpu family	: 6
model		: 4
model name	: AMD Athlon(tm) Processor
stepping	: 4
cpu MHz		: 1394.099
cache size	: 256 KB
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
fpu		: yes
fpu_exception	: yes
cpuid level	: 1
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca 
cmov pat pse36 mmx fxsr syscall mmxext 3dnowext 3dnow
bogomips	: 2785.28

reg00: base=0x00000000 (   0MB), size=1024MB: write-back, count=1
reg01: base=0xcc000000 (3264MB), size=  32MB: write-combining, count=4096
reg07: base=0xd0000000 (3328MB), size=  64MB: write-combining, count=1
PCI devices found:
  Bus  0, device   0, function  0:
    Host bridge: Silicon Integrated Systems [SiS] 735 Host (rev 1).
      Master Capable.  Latency=32.  
      Non-prefetchable 32 bit memory at 0xd0000000 [0xd3ffffff].
  Bus  0, device   1, function  0:
    PCI bridge: Silicon Integrated Systems [SiS] 5591/5592 AGP (rev 0).
      Master Capable.  Latency=64.  Min Gnt=10.
  Bus  0, device   2, function  0:
    ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513 (rev 0).
  Bus  0, device   2, function  3:
    USB Controller: Silicon Integrated Systems [SiS] 7001 (#2) (rev 7).
      IRQ 5.
      Master Capable.  Latency=64.  Max Lat=80.
      Non-prefetchable 32 bit memory at 0xcffff000 [0xcfffffff].
  Bus  0, device   2, function  2:
    USB Controller: Silicon Integrated Systems [SiS] 7001 (rev 7).
      IRQ 11.
      Master Capable.  Latency=64.  Max Lat=80.
      Non-prefetchable 32 bit memory at 0xcfffe000 [0xcfffefff].
  Bus  0, device   2, function  5:
    IDE interface: Silicon Integrated Systems [SiS] 5513 [IDE] (rev 208).
      Master Capable.  Latency=128.  
      I/O at 0xff00 [0xff0f].
  Bus  0, device   2, function  7:
    Multimedia audio controller: Silicon Integrated Systems [SiS] SiS7012 
PCI Audio Accelerator (rev 160).
      IRQ 10.
      Master Capable.  Latency=64.  Min Gnt=52.Max Lat=11.
      I/O at 0xdc00 [0xdcff].
      I/O at 0xd800 [0xd83f].
  Bus  0, device  17, function  0:
    Ethernet controller: Realtek Semiconductor Co., Ltd. 
RTL-8139/8139C/8139C+ (rev 16).
      IRQ 11.
      Master Capable.  Latency=64.  Min Gnt=32.Max Lat=64.
      I/O at 0xd400 [0xd4ff].
      Non-prefetchable 32 bit memory at 0xcfffdf00 [0xcfffdfff].
  Bus  1, device   0, function  0:
    VGA compatible controller: Matrox Graphics, Inc. MGA G400 AGP (rev 
      IRQ 11.
      Master Capable.  Latency=64.  Min Gnt=16.Max Lat=32.
      Prefetchable 32 bit memory at 0xcc000000 [0xcdffffff].
      Non-prefetchable 32 bit memory at 0xcfefc000 [0xcfefffff].
      Non-prefetchable 32 bit memory at 0xcf000000 [0xcf7fffff].

             total       used       free     shared    buffers     cached
Mem:       1033576     176416     857160          0      11256      68436
-/+ buffers/cache:      96724     936852
Swap:       257000      13376     243624

Filesystem Info
/dev/hda5 on / type ext3 (rw)
/dev/hda7 on /mnt/maxdor_data type ext3 (rw)


 Model=Maxtor 6Y080P0, FwRev=YAR41VW0, SerialNo=Y30CQC5E
 Config={ Fixed }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
 BuffType=DualPortCache, BuffSize=7936kB, MaxMultSect=16, MultSect=16
 CurCHS=4047/16/255, CurSects=16511760, LBA=yes, LBAsects=160086528
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4 
 DMA modes:  mdma0 mdma1 mdma2 
 UDMA modes: udma0 udma1 *udma2 udma3 udma4 udma5 udma6 
 AdvancedPM=yes: disabled (255) WriteCache=enabled
 Drive conforms to: (null):  1 2 3 4 5 6 7

/dev/hda elevator ID		0
	read_latency:		2048
	write_latency:		8192
	max_bomb_segments:	0

 Timing buffer-cache reads:   128 MB in  0.60 seconds =213.33 MB/sec
 Timing buffered disk reads:  64 MB in  2.15 seconds = 29.77 MB/sec

Version Info
Reading specs from /usr/lib/gcc-lib/i586-mandrake-linux-gnu/3.2/specs
Configured with: ../configure --prefix=/usr --libdir=/usr/lib 
--with-slibdir=/lib --mandir=/usr/share/man --infodir=/usr/share/info 
--enable-shared --enable-threads=posix --disable-checking 
--enable-long-long --enable-__cxa_atexit 
--enable-languages=c,c++,ada,f77,objc,java --host=i586-mandrake-linux-gnu 
Thread model: posix
gcc version 3.2 (Mandrake Linux 9.0 3.2-1mdk)

XFree86 Version 4.2.1 / X Window System
(protocol Version 11, revision 0, vendor release 6600)
Release Date: 3 September 2002
	If the server is older than 6-12 months, or if your card is
	newer than the above date, look for a newer version before
	reporting problems.  (See http://www.XFree86.Org/)
Build Operating System: Linux 2.4.18-23mdkenterprise i686 [ELF] 
Module Loader present
snd-pcm-oss            47460   0  (autoclean)
snd-mixer-oss          14680   0  (autoclean) [snd-pcm-oss]
snd-intel8x0           21632   0 
snd-pcm                71392   0  [snd-pcm-oss snd-intel8x0]
snd-timer              12968   0  [snd-pcm]
snd-ac97-codec         31620   0  [snd-intel8x0]
snd-mpu401-uart         3824   0  [snd-intel8x0]
snd-rawmidi            15744   0  [snd-mpu401-uart]
snd-seq-device          4700   0  [snd-rawmidi]



Dave Smith
dave   nobodynet net

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