audio glitching with new aac stream

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audio glitching with new aac stream

Postby dshm_da » Fri Aug 18, 2006 4:23 pm

I just got vlc working with the new stream. Could not get
totem to use an aac codec so switched to vlc.

When using vlc about every 4 to 8 seconds I get this message:
main_debug: audio output is starving (2XXXX), playing silence.

where the XXXX is some number

I have checked many things and dont see the issue. Trying to
increase or decrease the buffer size on vlc does not seem
to change the behavior.

The reception of the new stream seems to be more "bursty"
than the old stream. I can see this both on DSL modem
indicators and while watching the LAN stats.

I don't see this issue with other sources of streaming audio
but not sure I have another 80K source to try.

My LAN RX statistics show about 10K-12KBytes average rate.
Typical CPU usage is between 5 and 20% with vlc taking
about 5%. Pretty sure my DSL connection is good as I can
do ftp downloads at 80KBytes to 150KBytes depending on
the source.

Here's my setup:
I'm physically in Northern CA with a 1.5Mbit SBC DSL connection.

Linux 2.6.12-12mdk #1 Fri Sep 9 18:15:22 CEST 2005 i686 Pentium III (Coppermine) unknown GNU/Linux
1 Ghz CPU, 512Mb PC133 Ram

DSL Statistics:
Datapump HW Rev : ff
Datapump FW Rev : 3.9.16
Datapump Vendor ID : ffff
Current Status : LINK UP
Operating Mode : Ansi T1.413
Data Path : Fast
Downstream Upstream
Current Rate : 1536 Kbps 384 Kbps
Maximum Rate : 2363 Kbps 738 Kbps
Noise Margin : 15.0 dB 16.0 dB
Attenuation : 59.5 dB 31.5 dB
Out Power : 18.5 dB 9.0 dB

Near Far
FEC Counts Fast : 0 0
CRC Counts Fast : 6 1
HEC Counts Fast : 1 0

Any suggestions?


Posts: 6
Joined: Thu May 18, 2006 4:14 pm

re: audio glitching with new aac stream

Postby dshm_da » Fri Aug 18, 2006 7:25 pm

Latest thoughts are that the onboard audio chip
may not have deep enough buffers for the interrupt
latency. Maybe a decent sound card would help.

I found a 160Kbit Ogg stream generated in Northern CA
and it acts similarly.

Here's my audio system for this machine:

Intel 810 + AC97 Audio, version 1.01, 18:11:20 Sep 9 2005
PCI: Setting latency timer of device 0000:00:1f.5 to 64
i810: Intel ICH2 found at IO 0x2400 and 0x2000, MEM 0x0000 and 0x0000, IRQ 17
i810_audio: Audio Controller supports 6 channels.
i810_audio: Defaulting to base 2 channel mode.
i810_audio: Resetting connection 0
ac97_codec: AC97 Audio codec, id: ADS96 (Analog Devices AD1885)
i810_audio: AC'97 codec 0 Unable to map surround DAC's (or DAC's not present), total channels = 2
i810_audio: setting clocking to 41588

I'll try a different machine next week.

Posts: 6
Joined: Thu May 18, 2006 4:14 pm

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