MCFW question on DSP releasing frames

This is obviously incorrect.You are holding current frame at DSP while encoder is allowed to process future frames. 

E.g., you are holding one frame which is of timestamp  T and then your are f/wing frames of timestamp T+1,2..N to encoder.

When your DSP processing is done, you would release frame of timestamp T but encoder has already processed frames T+1,2..N. In this case you would see rolling back (as you are encoding frame from past).

Another issue (not serous though) could be high bitrate  (or quality compromise) when you have scene change just around the frame which you are holding. Let us say, you are holding frame of previous static scene and the next frame has scene change which you can't process in DSP hence f/w to encoder. Encoder will use more bits to encode as this is scene change. Now when you release frame of DSP (which is of previous static scene) encoder would again see this as scene change and consume more bits.

To avoid this problem, you can have frame copy mechanism as it is done in existing DSP algorithm SCD. In SCD link of RDK framework, there is logic of two thread which takes care of this scenario. DMA is used to copy Luma content.

Check below link for more details.

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/717/p/291128/1015314.aspx#1015314

Thanks for the quick reply.

I thought before when a frame at timestamp T is passed from dup_link to enc_link and dsp, they could handle it at the same time, instead of procesed by dsp first and then enc_link? So I thought enc_link is processing all T, T+1, T+2...frame, except that a frame at T is not released to dup_link or previous link?

Is that I understand it wrongly? Thanks

I will try following the SCD algorithm for frame copying using DMA. But I remember I tried before while compilation it said  there is not enough memory to allocate buffer for 16D1 + 16CIF using 

Utils_memAlloc(
pChObj->scdProcessObj.processFrameSize,
SharedRegion_getCacheLineSize(SYSTEM_IPC_SR_CACHED)

as in SCD algorithm?

But anyway, I will try it again.

Thanks.

Below is the IPC link setting for VPSS to Encoder

IpcLink_CreateParams* ipc_para_p;

// set IPC link in VPSS for passing frame to VICP
ipc_para_p = &_this->link.ipc_vpss_out.param;
IpcLink_CreateParams_Init(ipc_para_p);
ipc_para_p->inQueParams.prevLinkId = src_link_id;
ipc_para_p->inQueParams.prevLinkQueId = src_que_id;
ipc_para_p->numOutQue = 1;
ipc_para_p->outQueParams[0].nextLink = _this->link.ipc_video_in.id;
ipc_para_p->noNotifyMode = TRUE;
ipc_para_p->notifyPrevLink = TRUE;
ipc_para_p->notifyNextLink = FALSE;

// set IPC link in VICP for getting frame from VPSS
ipc_para_p = &_this->link.ipc_video_in.param;
IpcLink_CreateParams_Init(ipc_para_p);
ipc_para_p->inQueParams.prevLinkId = _this->link.ipc_vpss_out.id;
ipc_para_p->inQueParams.prevLinkQueId = 0;
ipc_para_p->numOutQue = 1;
ipc_para_p->outQueParams[0].nextLink = _this->link.enc.id;
ipc_para_p->noNotifyMode = TRUE;
ipc_para_p->notifyPrevLink = FALSE;
ipc_para_p->notifyNextLink = TRUE;

Below is the IPC link setting for VPSS to DSP

// set IPC link in M3-VPSS for passing frame to C6-DSP
IpcFramesOutLinkRTOS_CreateParams_Init(&_this->link.ipc_m3_out.param);
ipc_para_p = &_this->link.ipc_m3_out.param.baseCreateParams;
ipc_para_p->inQueParams.prevLinkId = src_link_id;
ipc_para_p->inQueParams.prevLinkQueId = src_que_id;
ipc_para_p->numOutQue = 1;
ipc_para_p->outQueParams[0].nextLink = _this->link.ipc_dsp_in.id;
ipc_para_p->noNotifyMode = FALSE;
ipc_para_p->notifyPrevLink = TRUE;
ipc_para_p->notifyNextLink = TRUE;
ipc_para_p->processLink = SYSTEM_LINK_ID_INVALID;
ipc_para_p->notifyProcessLink = FALSE;
ipc_para_p->inputFrameRate = 30;
ipc_para_p->outputFrameRate = 30;

// set IPC link in C6-DSP for getting frame from M3-VPSS
IpcFramesInLinkRTOS_CreateParams_Init(&_this->link.ipc_dsp_in.param);
ipc_para_p = &_this->link.ipc_dsp_in.param.baseCreateParams;
ipc_para_p->inQueParams.prevLinkId = _this->link.ipc_m3_out.id;
ipc_para_p->inQueParams.prevLinkQueId = 0;
ipc_para_p->numOutQue = 1;
ipc_para_p->outQueParams[0].nextLink = _this->link.dsp.id;
ipc_para_p->noNotifyMode = FALSE;
ipc_para_p->notifyPrevLink = TRUE;
ipc_para_p->notifyNextLink = TRUE;

Thanks

And I am actually connecting the links a little more complicate as below.

                 CAP

                    |     

                 DEI (420 output)

                     |

              DUP (16D1 + 16CIF)

                      |

        |-------------------------------------|

     DUP                                        DSP   (16D1 + 16CIF)

         |   (16D1 + 16CIF)

|-----------------| 

|                 SELECT

|                       |     (16CIF for JPEG)

|-- MERGE----|

            |                 (16D1 + 16CIF + 16CIF)

        ENC

what do you mean the SystemFrameInfo will get corrupted?

and for encLink part, I will try that. Thanks

You don't have to understand what SystemFrameInfo corruption means. Just dont use 2 dupLink. A frame cannot pass thru 2 dupLink. You have to remove one.

I have found the bug in my program.

Thanks for the help, board closed