Runtime IALG_alloc dynamic memory allocation

Are you the codec producer?

If so, it's true that your IALG_Fxns->algNumAlloc() must return an Int with the worst case number of memTabs your codec may require.  But the IVIDENC_Params (passed to your IALG_Fxns->algAlloc()) could/should indicate which mode your codec will run in - and the actual memory required, in the memTabs returned by IALG_Fxns->algAlloc(), can be less than the Int returned by IALG_Fxns->algNumAlloc().  Finally, the memory should only be allocated by the framework after IALG_Fxns->algAlloc() reports what the _actual_ needs are (not the worst case needs), and the memory is provided to the codec via IALG_Fxns->algInit().

So you really should only be requesting the memory you need for the mode indicated in the create params.

Is that what you're asking?

Chris

Thanks for the response, Chris.

We produce the codec.

We have implemented:

• IALG_Fxns->algNumAlloc();
• IALG_Fxns->algAlloc();
• IALG_Fxns->algInit();

So from dskt2crea.c:

numRecs = fxns->algNumAlloc();
sizeofMemTab = numRecs * sizeof(IALG_MemRec);
memTab = MEM_calloc(_DSKT2_heapID, sizeofMemTab, 0);
numRecs = fxns->algAlloc((IALG_Params *)params, &fxnsPtr, memTab);
for (i = 0; i < numRecs; i++) {
    _DSKT2_assignInstanceMemory(scratchId, memTab, numRecs, extHeapId)    
}
status = fxns->algInit(alg, memTab, NULL, (IALG_Params *)params) ;

We have currently introduced a new feature in our application that can take up 5MB of memory.  When running four codecs on the DM6467 this extra 20MB is a major problem.

So for example:

• IALG_Fxns->algNumAlloc() has been increase from 20 to 21
• IALG_Fxns->algAlloc() returns worst case 5MB (for Megapixel) for that new memTab
• IALG_Fxns->algInit() uses 1MB for D1 leaving 4MB of allocated memory space free.

As you can see when VIDENC_Create is called DSKT2 allocated 5MB but we only really need 1MB.

Is there anyway to change the size of the memTab at VIDENC_create:

Int MY_CODEC_alloc(const IALG_Params *algParams, IALG_Fxns **pf, IALG_MemRec memTab[])
{
    memTab[ MEM_SEGMENT_NEW_MEM_TAB ].size = MEGA_PIXEL_MEMORY_SIZE_NEEDED;
    memTab[ MEM_SEGMENT_NEW_MEM_TAB ].alignment = 128;
    memTab[ MEM_SEGMENT_NEW_MEM_TAB ].space = IALG_EXTERNAL;
    memTab[ MEM_SEGMENT_NEW_MEM_TAB ].attrs = IALG_PERSIST;
}

Can I use the IALG_Params to specify the size, instead of using a #define MEGA_PIXEL_MEMORY_SIZE_NEEDED? (Only just noticed that input variable, will look into it now)

Are those IALG_Params the input parameters from the VIDENC_create?

Thanks, Chris, you're right, I'd pretty much landed the answer.  Just traced back the IALG_Params through the framework to the VIDENC_create.

I'll have a look over the params and will post again with what i work out.

Cheers, for all your help, in the last thread as well ;)