Hi, AFAIK there is no ALSA driver for the DM355/DM6446. I don't think there is a requirement on an OSS audio driver for mono operation - from memory the OSS document does not make any suggestions about what number of channels is mandatory (or sample rates either come to that). In practise on the various targets we have used, we have found the ALSA drivers to offer poorer performance than the OSS ones. We almost always use the so called 'OSS emulation' mode and continue to use the OSS API via /dev/dsp. If we do not do that and go via the user space 'libasound' we get all kinds of audio artifacts (clicks/pops). Bear in mind though that our VOIP application drives the audio interface hard. We have to use full duplex and also play with fragment size to reduce latancy and read/write in 'audio codec' sized chunks (10 or 20 msec worth of data typically). If your application is playing out a file then you will probably not notice this. Regards Phil Q Phil Quiney, Senior Software Engineer Trinity Convergence Cambridge Business Park Cowley Road Cambridge CB4 0WZ, UK T: +44(0)1223-435536 F: +44(0)1223-435560 www.trinityconvergence.com <http://www.trinityconvergence.com/>
________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of amr ali Sent: 23 September 2008 11:22 To: davinci forum Subject: FW: OSS Device Driver Hi, I have tested capabilities of the OSS driver. Here are my findings: ***************************************************************************** *High Performance MPEG 1.0/2.0/2.5 Audio Player for Layers 1, 2 and 3 * version 1.5.1; written and copyright by Michael Hipp and others * free software (LGPL/GPL) without any warranty but with best wishes *[format.c:188] error: Unable to set up output format! Constraints: mono, 44100, 22050 or 11025Hz. *[mpg123.c:956] error: Initial seek failed: Unable to set up output format! (code 1) *So, you have trouble getting an output format... this is the matrix of currently possible formats: *Audio driver: oss *Audio device: /dev/dsp *Audio capabilities: *(matrix of [S]tereo or [M]ono support for sample format and rate in Hz) * | s16 | u16 | u8 | s8 | ulaw | alaw | * -------------------------------------------------------- * 8000 | S | | | | | | * 11025 | S | | | | | | * 12000 | S | | | | | | * 16000 | S | | | | | | * 22050 | S | | | | | | * 24000 | S | | | | | | * 32000 | S | | | | | | * 44100 | S | | | | | | * 48000 | S | | | | | | *Somehow the input data and your choices don't allow one of these. *Tried enabling resampling with a forced rate (only 2to1 and 4to1 downsampling is tried automatically)? *Tried allowing mono/stereo? ***************************************************************************** BTW, Is there any ALSA device driver for the board? It may be implemented better than the ALSA device driver and has the mono working? I am using kernel 2.6.1_mvl. BR, Amr Ali. ________________________________ Get news, entertainment and everything you care about at Live.com. Check it out! <http://www.live.com/getstarted.aspx> ________________________________ Explore the seven wonders of the world Learn more! <http://search.msn.com/results.aspx?q=7+wonders+world&mkt=en-US&form=QBRE>
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