Hi, I just checked with our system verification guys and they have had a DM355 (running this kernel) playing out audio since Friday without issue (so that would be >48 hours) so it can be made to work. We incorporated some advice given to us by a MV engineer into our framework, which may be the reason we don't see any issue. This included..
* Write to device only in fragment sized chunks. * Read from device only in fragment sized chunks and empty input if possible. * Choose fragment size to match data rate. In OSS, fragments are a 'power of 2' - we need to read/write in 10 or 20 msec chunks for VOIP speech codecs. Fragment size needs to be as close to 10msec @ whatever speed/channels/sample size is used, typically 256 bytes for 16 bit, 8kHz mono. Some drivers default to 4k, which is fine for 44.1kHz half duplex playback. However it adds a huge delay when used full duplex @ 8khz. * When in full duplex mode you need to treat input & output as seperate items. * Avoid 'blocking' read/write functions as you may 'starve' the other operation. Use the input/output space OSS ioctls to see if the driver has space for output or samples for input - this avoids blocking as you skip the read or write if there is no output space or input data available. Regards Phil Q Regards Phil Q Phil Quiney, Principal 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 amingaming Sent: 13 October 2008 06:01 To: davinci-linux-open-source@linux.davincidsp.com Subject: mvl_4_0_1_demo_lsp_setuplinux_01_20_00_014.bin for DM355 ? hi all: I dowanLoad mvl_4_0_1_demo_lsp_setuplinux_01_20_00_014.bin form www.TI.com for DM355. start run DM355 OK,after some times,no Sound! why ? thx ________________________________ 用MSN有问题?客服机器人小美帮你忙! 立刻和小美聊天! <http://im.live.cn/xiaom/>
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