[mythtv-users] DVB-S Radio and 32KHz Audio issues

Steven Ellis steven at openmedia.co.nz
Sun Dec 24 03:50:48 UTC 2006


First up I'm running MythTV 0.20 fixes with AD1986A sound and a
Technisat SkyStar 2 DVB-S Card.

Now the local DVB-S Radio stations from Optus D1 all appear to be 32KHz
MP2 Audio. These play fine under mplayer as follows with no skips or
playback issues.

mplayer dvb://"Niu FM"
MPlayer 1.0rc1-3.3.5 (C) 2000-2006 MPlayer Team
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 3600+ (Family: 15, Model:
75, Stepping: 2)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx SSE SSE2
/usr/share/fonts/truetype/freefont/FreeMonoBold.ttf doesn't look like a
bitmap font description, ignoring.
Cannot load bitmap font: /usr/share/fonts/truetype/freefont/FreeMonoBold.ttf

Playing dvb://Niu FM.
dvb_tune Freq: 12519000
TS file format detected.
NO VIDEO! AUDIO MPA(pid=1153) NO SUBS (yet)!  PROGRAM N. 0
==========================================================================
Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
AUDIO: 32000 Hz, 2 ch, s16le, 192.0 kbit/18.75% (ratio: 24000->128000)
Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3)
==========================================================================
AO: [oss] 32000Hz 2ch s16le (2 bytes per sample)
Video: no video
Starting playback...


Now I have a couple of issues when playing under MythTV

1. Skips during playback. These show up in the logs as follows. Often
after 5-10 seconds things stablise for a short while, but it does start
happening again.

2006-12-24 16:45:45.942 AFD: Opened codec 0xb0f46fc0, id(MP3) type(Audio)
2006-12-24 16:45:46.412 AFD: Opened codec 0xadc77120, id(MPEG2VIDEO)
type(Video)
2006-12-24 16:45:46.486 Opening OSS audio device '/dev/dsp'.
2006-12-24 16:45:47.067 NVP: prebuffering pause
2006-12-24 16:45:47.748 NVP: prebuffering pause
2006-12-24 16:45:50.072 NVP: prebuffering pause
2006-12-24 16:45:50.646 NVP: prebuffering pause
2006-12-24 16:45:51.141 RingBuf(/myth/tv/4103_20061224164541.mpg):
Waited 1.0 seconds for data to become available...
2006-12-24 16:45:51.141 Checking to see if there's a new livetv program
to switch to..
2006-12-24 16:45:52.151 RingBuf(/myth/tv/4103_20061224164541.mpg):
Waited 2.0 seconds for data to become available...
2006-12-24 16:45:52.151 Checking to see if there's a new livetv program
to switch to..
2006-12-24 16:45:52.267 NVP: Prebuffer wait timed out 10 times.
2006-12-24 16:45:53.888 NVP: Prebuffer wait timed out 10 times.
2006-12-24 16:45:54.169 RingBuf(/myth/tv/4103_20061224164541.mpg):
Waited 4.0 seconds for data to become available...
2006-12-24 16:45:54.169 Checking to see if there's a new livetv program
to switch to..
2006-12-24 16:45:59.031 RingBuf(/myth/tv/4103_20061224164541.mpg):
Taking too long to be allowed to read..
2006-12-24 16:45:59.108 NVP: prebuffering pause
2006-12-24 16:46:03.566 RingBuf(/myth/tv/4103_20061224164541.mpg):
Taking too long to be allowed to read..
2006-12-24 16:46:03.643 NVP: prebuffering pause
2006-12-24 16:46:08.200 RingBuf(/myth/tv/4103_20061224164541.mpg):
Taking too long to be allowed to read..
2006-12-24 16:46:08.277 NVP: prebuffering pause
2006-12-24 16:46:12.781 RingBuf(/myth/tv/4103_20061224164541.mpg):
Taking too long to be allowed to read..
2006-12-24 16:46:17.302 RingBuf(/myth/tv/4103_20061224164541.mpg):
Taking too long to be allowed to read..
2006-12-24 16:46:17.418 NVP: prebuffering pause


2. Playback doesn't work over SPDIF from mplayer.

This is because my AMP doesn't support 32KHz Audio. Now I've played with
.asoundrc files to get this working. Ideally I want both stereo 3.5mm
audio and SPDIF active at the same time so I can feed two different
rooms. My current .asoundrc will do this but won't rate convert 32KHz to
48KHz audio.


So has anyone got working reliable DVB Radio? Any recommendations in
terms of Playback settings, as well as setting up Alsa.

Steve

-- 
Steven Ellis - Technical Director
OpenMedia Limited
email   - steven at openmedia.co.nz
sales   - sales at openmedia.co.nz
support - support at openmedia.co.nz
website - http://www.openmedia.co.nz



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