Rob's right, the Link details are intentionally hidden under Codec Engine. But it's often useful to know what's going on underneath.
There are more details about CE and DSP Link interaction during DSP start/stop in section 2's "Opening an Engine" and "Closing an Engine" here: http://tiexpressdsp.com/index.php/Codec_Engine_Application_Developers_Guide ------------------------- I couldn't find an article that describes the internal MSGQ usage under the VISA APIs, but you can get a good feel for what's going on under by studying the trace output when setting CE_DEBUG=3 (http://tiexpressdsp.com/index.php/CE_DEBUG). Here's a [very trimmed] excerpt of trace from a single VIDENC_process() call with CE_DEBUG=3 set. The ARM-side is in red, the DSP side is in green, and I've underlined the lines where Codec Engine internally calls MSGQ_alloc()/put()/get()/free() on the ARM side, as well as MSGQ_get()/put() on the DSP side: @1,454,227us: [+0 T:0x4001f000 S:0x03874944] ti.sdo.ce.video.VIDENC - VIDENC_process> Enter (handle=0x44c90, inBufs=0x3874a74, outBufs=0x3874a68, inArgs=0x443c8, outArgs=0x443e0) @1,454,428us: [+5 T:0x4001f000 S:0x038748dc] CV - VISA_allocMsg> Allocating message for messageId=0x00026700 @1,458,639us: [+0 T:0x4001f000 S:0x038748e4] CV - VISA_call(visa=0x44c90, msg=0x41169c80): messageId=0x00026700, command=0x0 @1,458,807us: [+0 T:0x4001f000 S:0x038748ac] OC - Comm_put> Enter(queue=0x2, msg=0x41169c80) @1,459,039us: [+0 T:0x4001f000 S:0x038748ac] OC - Comm_put> return (0) @1,459,221us: [+0 T:0x4001f000 S:0x038748a4] OC - Comm_get> Enter(queue=0x10001, msg=0x387495c, timeout=-1) @1,507,703us: [+0 T:0x4001f000 S:0x038748a4] OC - Comm_get> MSGQ_get() status=0x8000, return (0) [DSP] @0,511,501tk: [+5 T:0x8b9fb21c S:0x8b9fd1e4] CN - NODE> 0x8fa82398(xavsc_ateme#0) call(algHandle=0x8fa82450, msg=0x8fe06c80); messageId=0x00026700 [DSP] @0,512,933tk: [+0 T:0x8b9fb21c S:0x8b9fd14c] ti.sdo.ce.video.VIDENC - VIDENC_process> Enter (handle=0x8fa82450, inBufs=0x8b9fd1ec, outBufs=0x8b9fd1f8, inArgs=0x8fe06db8, outArgs=0x8fe06dc8) [DSP] @0,513,035tk: [+5 T:0x8b9fb21c S:0x8b9fd12c] CV - VISA_enter(visa=0x8fa82450): algHandle = 0x8fa82480 [DSP] @0,513,095tk: [+0 T:0x8b9fb21c S:0x8b9fd10c] ti.sdo.ce.alg.Algorithm - Algorithm_activate> Enter(alg=0x8fa82480) [DSP] @0,513,157tk: [+0 T:0x8b9fb21c S:0x8b9fd10c] ti.sdo.ce.alg.Algorithm - Algorithm_activate> Exit [DSP] @0,622,199tk: [+5 T:0x8b9fb21c S:0x8b9fd12c] CV - VISA_exit(visa=0x8fa82450): algHandle = 0x8fa82480 [DSP] @0,622,282tk: [+0 T:0x8b9fb21c S:0x8b9fd10c] ti.sdo.ce.alg.Algorithm - Algorithm_deactivate> Enter(alg=0x8fa82480) [DSP] @0,622,371tk: [+0 T:0x8b9fb21c S:0x8b9fd10c] ti.sdo.ce.alg.Algorithm - Algorithm_deactivate> Exit [DSP] @0,622,424tk: [+0 T:0x8b9fb21c S:0x8b9fd14c] ti.sdo.ce.video.VIDENC - VIDENC_process> Exit (handle=0x8fa82450, retVal=0x0) [DSP] @0,623,888tk: [+5 T:0x8b9fb21c S:0x8b9fd1e4] CN - NODE> returned from call(algHandle=0x8fa82450, msg=0x8fe06c80); messageId=0x00026700 @1,518,966us: [+0 T:0x4001f000 S:0x038748e4] CV - VISA_call Completed: messageId=0x00026700, command=0x0, return(status=0) @1,522,687us: [+5 T:0x4001f000 S:0x038748bc] CV - VISA_freeMsg(0x44c90, 0x41169c80): Freeing message with messageId=0x00026700 @1,522,855us: [+0 T:0x4001f000 S:0x03874944] ti.sdo.ce.video.VIDENC - VIDENC_process> Exit (handle=0x44c90, retVal=0x0) Chris ________________________________ From: davinci-linux-open-source-boun...@linux.davincidsp.com [mailto:davinci-linux-open-source-boun...@linux.davincidsp.com] On Behalf Of Tivy, Robert Sent: Wednesday, April 07, 2010 10:39 AM To: liuyue18301; davinci-linux-open-source@linux.davincidsp.com Subject: RE: how Codec_engine call the dsplink ________________________________ From: davinci-linux-open-source-boun...@linux.davincidsp.com [mailto:davinci-linux-open-source-boun...@linux.davincidsp.com] On Behalf Of liuyue18301 Sent: Tuesday, April 06, 2010 6:56 PM To: davinci-linux-open-source@linux.davincidsp.com Subject: how Codec_engine call the dsplink hello everybody: well in the video_copy demos of the codec_engine i think i call the api of dsplink to implement the communication between arm and dsp. but i can't find out that in the code who can help me it confused me so long time. what is the relationship codec_engine and dsplink and the relationship of calling thank you very much. DSPLink is used internally by Codec Engine. You do not call any DSPLink APIs, which is the whole point of Codec Engine, to insulate the user from the details of the implementation. You just call Codec Engine APIs, as the video_copy demo does, or any of the Codec Engine example apps. DSPLink is used by Codec Engine when there is a remote server configured into the system, so you need to configure a remote server but you don't need to configure the use of DSPLink, since Codec Engine does that for you. If you're just doing a "local" codec then you won't specify a server and DSPLink is not needed in this case. - Rob
_______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
