Media (Intel® oneAPI Video Processing Library, Intel Media SDK)
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Decode without repeat first field

BMart1
New Contributor II
234 Views

How can I get the progressive samples from the decoder before it applies repeat first field and similar flags? I don't want to deinterlace originally interlaced frames.

 

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10 Replies
Mark_L_Intel1
Moderator
234 Views

Hi Bruno,

Try to understand your request, do you want to use decode only, input an interlaced stream and output a output stream with the same frame rate but each frame has a double line number? (duplicate each line as the next line to it in output)

You might use the argument "-di <bob or adi>" for sample_decode to do this. Refer to the following document about how to use sample_decode:

 https://github.com/Intel-Media-SDK/samples/blob/master/samples/sample_decode/readme-decode_linux.pdf

Mark 

BMart1
New Contributor II
234 Views

Some DVD are encoded as 23.976 progressive and special flags inserted so decoders do telecine to generate 29.97 interlaced frames. Does the mfx encoder support this? Can the mfx decoder ignore the flags and return the original 23.976 progressive frames?

BMart1
New Contributor II
234 Views

I think you can feed the encoder fields marked with MFX_PICSTRUCT_FIELD_REPEATED and get soft telecine, but I still cannot find how to get it from the decoder.

Mark_L_Intel1
Moderator
234 Views

Hi Martinez,

So you want this special video of progressive with interlaced flag set in the stream? In this case, your app should prefer not to do deinterlacing.

Normally the configuration sequence in the decode app is:

1. Set the initial parameters

2. Read the stream header and overwrite the parameters in #1 with the new parameters from stream.

3. Decoding

I think you might to check you code to make sure, the progressive parameter is set between #2 and #3.

Mark

BMart1
New Contributor II
234 Views

So which initial parameters do I use to prevent the decoder from assembling interlaced frames from source progressive frames?

Mark_L_Intel1
Moderator
234 Views

You can download our tutorial 0.0.4 at the following page:

https://software.intel.com/en-us/media-sdk/training

You can get the initial parameters example from simple_decode project. In general, any parameter is fine because they will be overwrite by the input from the stream header.

Mark 

BMart1
New Contributor II
234 Views

Sorry Mark, I don't understand. What configuration disables interlacing in the decoder?

BMart1
New Contributor II
234 Views

Let me answer my own question: With mfxInfoMFX::ExtendedPicStruct decoding gives you raw encoded frames without repeats.

Mark_L_Intel1
Moderator
234 Views

Hi Bruno,

Sorry I missed your question, did you find the solution yet?

Mark

BMart1
New Contributor II
234 Views

Yes, thanks Mark.

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