MPEG4 has terrible scene change.

John Anderson

I just switched from using the MPEG4 (MJCP) to the MPEG4 (HDVICP) encoder and my scene changes look really bad and take a while to clean up. Is there a parameter that might help with this? I'm using a intra interval of 30 frames. I imagine that lowering that number would help. But thought there might be something more efficient.

JohnA

over 14 years ago

0 Yashwant Dutt over 14 years ago

TI__Genius 17215 points

John,

Any reason why you are choosing HDVICP based encoder ? Can you pls send the parameter details, specially rcAlgo, maxDelay, Min/MaxQP.

regards

Yashwant

0 John Anderson over 14 years ago in reply to Yashwant Dutt

Genius 5240 points

I changed because the MJCP version doesn't support captureWidth. So I end up with a 736 wide image that has a extra 16 pixels of junk on the right (which is black because I clear the capture buffers). Also I'm unsure about which is best to use. I need to be able to support encoding H264, MPEG4, MPEG2, and MJPEG all at the same time. I don't know if using the MJCP or HDVICP is better.

I'm not using the extended parameters at this time so whatever the default in the codec is what's used.

JohnA

0 John Anderson over 14 years ago in reply to John Anderson

Genius 5240 points

So nobody has any comments on the MJCP vs HDVCIP version of the MPEG-4 encoders? I'm using the default settings. Perhaps there are some parameters that might make a difference?

JohnA

0 Yashwant Dutt over 14 years ago in reply to John Anderson

TI__Genius 17215 points

Hi John,

The MJCP codec indeed supports capture width. You can use subWindowHeight, subWindowWidth for this purpose.

Please keep -

inputWidth = stride or capture width

subwindowWidth = actual width to be encoded

The start location of subwindow is always from the top left of the image.

I suggest you use MJCP encoder for your purpose.

regards

Yashwant

0 John Anderson over 14 years ago in reply to Yashwant Dutt

Genius 5240 points

Thanks Yashwant, I will give this a try and verify your answer if it works.

JohnA

0 John Anderson over 14 years ago in reply to Yashwant Dutt

Genius 5240 points

It worked.

JohnA

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MPEG4 has terrible scene change.