Hello,
According to SPRS488E it should be possible to do MPEG4 encoding at D1
resolution (720x480) at around 9ms for an I-frame. I am unable to get
this to happen. I have tried changing the params.encodingPreset value
from XDM_DEFAULT to XDM_HIGH_SPEED, and
IMP4VENC_LOW_QUALITY_HIGHEST_PERFORMANCE, however it doesn't seem to
make any difference. When I compress these frames, it takes at least
12ms/frame, and more like 14 on average. In fact, no amount of fiddling
with these parameters seems to make any difference at all.
Has anyone had numbers in line with what this document suggests, or am I
misunderstanding what I can expect from it?
This is the configuration I'm using to set up the encoder:
retval->params.size = sizeof(VIDENC1_Params);
retval->params.encodingPreset = XDM_HIGH_SPEED;
retval->params.rateControlPreset = IVIDEO_STORAGE;
retval->params.maxHeight = height;
retval->params.maxWidth = width;
retval->params.maxFrameRate = (50 * 1000);
retval->params.maxBitRate = 10 * 1000 * 1000;
retval->params.dataEndianness = XDM_BYTE;
retval->params.maxInterFrameInterval = XDM_DEFAULT;
retval->params.inputChromaFormat = XDM_YUV_422ILE; // pixelFormat;
retval->params.inputContentType = IVIDEO_PROGRESSIVE;
retval->params.reconChromaFormat = XDM_DEFAULT;
retval->dynParams.size = sizeof(VIDENC1_DynamicParams);
retval->dynParams.inputHeight = height;
retval->dynParams.inputWidth = width;
retval->dynParams.refFrameRate = retval->params.maxFrameRate;
retval->dynParams.targetFrameRate = retval->params.maxFrameRate;
retval->dynParams.targetBitRate = 2 * 1000 * 1000;
retval->dynParams.intraFrameInterval = 1;
retval->dynParams.generateHeader = XDM_DEFAULT;
retval->dynParams.captureWidth = XDM_DEFAULT;
retval->dynParams.forceFrame = XDM_DEFAULT;
retval->dynParams.interFrameInterval = XDM_DEFAULT;
retval->dynParams.mbDataFlag = XDM_DEFAULT;
Thanks,
Andre Renaud
--
Bluewater Systems Ltd - ARM Technology Solution Centre
Andre Renaud Unit 5, Amuri Park
Phone: +64 3 3779127 404 Barbadoes St
Fax: +64 3 3779135 PO Box 13 889
Email: [email protected] Christchurch, 8013
Web: http://www.bluewatersys.com New Zealand
Freecall Australia 1800 148 751 USA 1800 261 2934
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