Date: Fri, 17 Oct 2003 12:50:36 -0400 From: Andriy Gapon <agapon@cv-nj.com> To: freebsd-multimedia@freebsd.org Subject: full duplex problem Message-ID: <3F901DDC.8010809@cv-nj.com>
next in thread | raw e-mail | index | archive | help
Maybe I misunderstand how full duplex is supposed to work, but I observe the following problem - when one application writes to /dev/dsp and then I start reading from the device with another application the playback becomes much slower, it's hard to say how much exactly, but definetly slower than half-speed. Another strange thing is that if I start the recording application first (it reads from the device in blocking mode) and then I start the playback application, the recording application would get EAGAIN (Resource temporarily unavailable) error, which is very surprising. A recording application can be as simple as `cat` in this case. My system/hardware/config: FreeBSD 4.8-RELEASE sbc0: <Creative SB AWE64 Gold> at port 0x220-0x22f,0x330-0x331,0x388-0x38b irq 5 drq 1,5 on isa0 sbc0: setting card to irq 5, drq 1, 5 pcm0: <SB16 DSP 4.16> on sbc0 FreeBSD Audio Driver (newpcm) Installed devices: pcm0: <SB16 DSP 4.16> at io 0x220 irq 5 drq 1:5 bufsz 4096d (1p/1r/6v channels duplex) hw.snd.targetirqrate: 32 hw.snd.report_soft_formats: 1 hw.snd.verbose: 1 hw.snd.maxautovchans: 0 hw.snd.pcm0.buffersize: 4096 hw.snd.pcm0.vchans: 6 I can not find any reports of problems with full duplex with SB hardware and FreeBSD since after circa 97, so I am a little bit puzzled. I will apprecite any ideas at what I might try to do or what I should read. -- Andriy Gapon
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3F901DDC.8010809>