question about ENC_LINK_CMD_SET_CODEC_SNAPSHOT

OYE

Dear all:

I am using DVRRDK3.0 with DM8168EVM.

I create a chain to archive dual stream and JPEG encoding.And I have these three streams saved to 3 files.

I found the stream about the JPEG is always output. The following is my JPEG Coding parameters：

pLinkChPrm = &encPrm.chCreateParams[1];
pLinkDynPrm = &pLinkChPrm->defaultDynamicParams;

pLinkChPrm->format = IVIDEO_MJPEG;
pLinkChPrm->profile = 0;
pLinkChPrm->dataLayout = IVIDEO_FIELD_SEPARATED;
pLinkChPrm->fieldMergeEncodeEnable = FALSE;
pLinkChPrm->enableAnalyticinfo = 0;
pLinkChPrm->enableWaterMarking = 0;
pLinkChPrm->maxBitRate = 0;
pLinkChPrm->encodingPreset = XDM_DEFAULT;
pLinkChPrm->rateControlPreset = 0;
pLinkChPrm->enableHighSpeed = 0;

pLinkDynPrm->intraFrameInterval = 0;
pLinkDynPrm->targetBitRate = (100*1000);
pLinkDynPrm->interFrameInterval = 0;
pLinkDynPrm->mvAccuracy = 0;
pLinkDynPrm->inputFrameRate = 1;
pLinkDynPrm->targetFrameRate = 0;
pLinkDynPrm->qpMin = 0;
pLinkDynPrm->qpMax = 0;
pLinkDynPrm->qpInit = -1;
pLinkDynPrm->vbrDuration = 0;
pLinkDynPrm->vbrSensitivity = 0;

Then I saw this post：http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/717/t/270659.aspx

According to this post, I use Venc_disableChn and Venc_enableChn to disable and enable the JPEG encoder channel with out invoke Venc_snapshotDump, I was able to successfully get a frame JPEG stream.

I want to know what is the role about the cmd "ENC_LINK_CMD_SET_CODEC_SNAPSHOT", and when I save a JPEG picture I need to use it?

over 12 years ago

0 Badri Narayanan over 12 years ago

TI__Guru 59700 points

You are right just doing Venc_enable and Venc_disable is sufficient. Calling cmd "ENC_LINK_CMD_SET_CODEC_SNAPSHOT" ensures the next frame received by the encLink is encoded and not dropped so that snapshot frame is encoded as soon as possible. Not invoking SNAPSHOT CMD will be an issue if fps of encoding is very low like 1 fps in which case frame may be encoded only after 1 sec.

0 OYE over 12 years ago in reply to Badri Narayanan

Intellectual 400 points

Hi Badri,

Thanks for you reply.

I have another question to consult.

If I invoke the Venc_enable and the cmd "ENC_LINK_CMD_SET_CODEC_SNAPSHOT", Can I able to get the stream immediately? Is there have any delay?

And the inputFrameRate and targetFrameRate I must set to 1 and 0? If not ,what value I also can set.

0 Badri Narayanan over 12 years ago in reply to OYE

TI__Guru 59700 points

Yes if you send ENC_LINK_CMD_SET_CODEC_SNAPSHOT you will get the encoded stream immediately (first frame received after snapshot cmd will be encoded). If you are doing Venc_enable and Venc_disable then set inputFrameRate = targetFrameRate = 30.

0 OYE over 12 years ago in reply to Badri Narayanan

Intellectual 400 points

Badri,

Thanks for you quick reply.I have already got it.

0 user4343658 over 9 years ago

Prodigy 30 points

Hello OYE:
I also want to take a jpeg picture from video streams. But I really don't kown how to use the function Venc_snapshotDump(). Can you tell me where is the function should be called ? And How to use the cmd "ENC_LINK_CMD_SET_CODEC_SNAPSHOT"?
I'm looking forward your reply ,Thank you very much !

0 Margarita Gashova over 9 years ago in reply to user4343658

TI__Guru* 80190 points

Hello,

What is the software release that you are using here?
Is it DVRRDK or else?

BR
Margarita

0 user4343658 over 9 years ago in reply to Margarita Gashova

Prodigy 30 points

Thank you for your reply!

I am using DVRRDK4.0 on DM8168.

0 Margarita Gashova over 9 years ago in reply to user4343658

TI__Guru* 80190 points

Hello,

Please check these threads also:
e2e.ti.com/.../1181824
e2e.ti.com/.../889580

BR
Margarita

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question about ENC_LINK_CMD_SET_CODEC_SNAPSHOT