Zero latency VPU h264 encoder with periodic intra frame support?

[moire59]

The documentation is vague about it and there are no previous questions I could find.

Is this encoder profile supported from the imx6 platform?

Thank you.

[gavingreenwalt]

If you find a solution please let me know.

[moire59]

Well, from this question: https://community.freescale.com/thread/311299

and this quote from the manual:

intraRefresh where 0 = Intra MB refresh is not used. Otherwise = At least N MB's in every P-frame are encoded as intra MB's.

It should be possible to have intra refresh P frames, while having maybe 1 I frame every few hours? Depending on how that number is declared? Even if it's a 16 bit one it should still be quite a lot of frames before an I one.

But maybe my understanding of it is completely wrong.

[jamesbone · Accepted solution]

Giovanni,

You are correct the intraRefresh parameter  is the latency and  you can control the I-frames and P-frames in the EncOpenParam structure, modifing the Gobsize

typedef struct {

CodStd bitstreamFormat;

PhysicalAddress bitstreamBuffer;

Uint32 bitstreamBufferSize;

Uint8 *virt_bitstreamBuffer;

int streamBufResetEnable;

int picWidth;

int picHeight;

Uint32 frameRateInfo;

int bitRate;

int initialDelay;

int vbvBufferSize;

int enableAutoSkip;

int gopSize;

int sliceMode;

int sliceSizeMode;

int sliceSize;

int intraRefresh;

int sliceReport;

int mbReport;

int mbQpReport;

union {

EncMp4Param mp4Param;

EncH263Param h263Param;

EncAvcParam avcParam;

} EncStdParam;

} EncOpenParam;

Gobsize

0 – Only first picture is I, 1 – all I pictures, 2 – IPIP…, 3 – IPPIPP…

The maximum value is limited by 60.

[moire59]

Hi, and thank you for the answer.

Can you also confirm that the encoder doesn't support slice based encoding (or rather it does, but it can't output/input slices instead of full frames, so I need to wait for the full frame during the encoding and during the decoding, and I add 2 frames of latency to my application without considering anything else?

Thank you.