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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I might be able to help you here – We have a similar
setup here where we use an ARM+DSP to do our real-time encoding/decoding work
with AV Sync for audio+video (DaVinci platform)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>First of all, let me get the task partitioning here straight,
what are the specific roles of the DSP and your GPP (general purpose processor,
i.e <st1:City w:st="on"><st1:place w:st="on">ur</st1:place></st1:City> embedded
processor)?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>A sensible approach would be to relegate decoding/encoding
activities to the DSP, and control oriented tasks to run on the GPP (i.e
LiveMedia, synchronization, etc)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Does the DSP also take care of outputting the analog stream?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I’m assuming you have a buffered interface between the
GPP and the DSP – that is absolutely required when crossing two clock
domains as you have. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>There should be some feedback from the DSP to the GPP
regarding how fast/slow its decoding samples - this should allow the GPP
to ensure the buffer never under-runs or over-runs<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Compensating using hacky techniques like modifying
gettimeofday() will only yield further problems down the line.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><st1:PersonName w:st="on"><strong><b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Jerry Johns</span></font></b></strong></st1:PersonName><o:p></o:p></p>
<p class=MsoNormal><em><i><font size=1 face=Arial><span style='font-size:7.5pt;
font-family:Arial'>Design Engineer</span></font></i></em><o:p></o:p></p>
<p class=MsoNormal><em><i><font size=1 color=blue face=Arial><span
style='font-size:7.5pt;font-family:Arial;color:blue'>Nuvation Research Corp - <st1:country-region
w:st="on"><st1:place w:st="on">Canada</st1:place></st1:country-region></span></font></i></em><o:p></o:p></p>
<p class=MsoNormal><em><i><font size=1 color=blue face=Arial><span
style='font-size:7.5pt;font-family:Arial;color:blue'>Tel: (519) 746-2304 ext.
225</span></font></i></em><o:p></o:p></p>
<p class=MsoNormal><em><i><font size=1 color=blue face=Arial><span
style='font-size:7.5pt;font-family:Arial;color:blue'><a
href="http://www.nuvation.com"><font face="Times New Roman"><span
style='font-family:"Times New Roman"'>www.nuvation.com</span></font></a></span></font></i></em><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span><o:p></o:p></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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