PROCESSOR-SDK-AM57X: AIR interlaced video issue

Manu Iyengar

Part Number: PROCESSOR-SDK-AM57X
Other Parts Discussed in Thread: AM5728

Hi,

I have an AM5728 based encoder system which captures live video, encodes it using H.264 encoder and streams over network.

We have turned on Adaptive Intra Refresh (AIR) encoder toolset with a refresh interval of 2 seconds. With this, we expect a decoder receiving the bit-stream from our encoder to be able to refresh the whole image gradually even if an I/IDR frame is not received.

On analysis of the encoder output using a standard decoder, I see that the image is getting refreshed correctly for progressive video formats.
However, for interlaced video formats, the image is not getting completely refreshed. Encoder settings w.r.t AIR is same for both progressive and interlaced formats.
Please find the attached file for a comparison between the behavior of AIR in case of interlaced and progressive video.
If you observe carefully, for interlaced video, some macroblocks are never getting refreshed.
Is there any specific configuration for interlaced video to avoid this?

AIR-1080p-vs-1080i.zip

Regards,
Manu

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

Hi,

Which SDK are you using?

0 Manu Iyengar over 6 years ago in reply to Biser Gatchev-XID

Intellectual 590 points

I'm using Processor SDK Linux v2.00.00.00

Regards,
Manu

0 Biser Gatchev-XID over 6 years ago in reply to Manu Iyengar

TI__Guru**** 393215 points

Have you checked with a newer version of the SDK? v2.00 is quite old.

0 Manu Iyengar over 6 years ago in reply to Biser Gatchev-XID

Intellectual 590 points

Biser,

I have not checked the behavior with latest SDK yet. I understand that v2.00 is old but migrating to newer SDK is difficult.

I believe the issue is specific to H.264 encoder. The version of H.264 encoder in v2.00 PSDK is 02.00.09.
Is there a newer version of H.264 encoder in the latest SDK? If so, can you please let me know if there are any fixes related to AIR in the new encoder?

Regards,
Manu

0 Manu Iyengar over 6 years ago in reply to Manu Iyengar

Intellectual 590 points

Hi Biser,

I checked for H.264 encoder version in the latest PSDK. It looks like the encoder version (02.00.09) is same as the one in PSDK v2.00. Please confirm if this is correct. If so, I believe the issue is expected with latest SDK also.

Regards,
Manu

0 Rogerio Almeida over 6 years ago in reply to Manu Iyengar

TI__Mastermind 26025 points

Manu,
the team working on Codecs are actively looking into this...sorry for the delay...

0 Prashanth Kumar15 over 6 years ago in reply to Rogerio Almeida

Mastermind 8775 points

Hi Manu,
We regret the delayed response.

The latest H.264 Encoder version is 02.00.09.01(which you are using).
Can you please share the encoder parameters for Progressive & Interlaced settings.

0 Rogerio Almeida over 6 years ago in reply to Prashanth Kumar15

TI__Mastermind 26025 points

Prashanth, please contact me offline.

0 Prashanth Kumar15 over 6 years ago in reply to Rogerio Almeida

Mastermind 8775 points

Hi Rogerio,

I have received the config. I will look in to it. Thanks.

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

Thanks for looking into this issue. Hope the config file has all the details you were looking for.
Do you see any issue with the configuration?

Regards,
Manu

0 Prashanth Kumar15 over 6 years ago in reply to Manu Iyengar

Mastermind 8775 points

Hi Manu,

Yes, I have below questions for you 7 a suggestion for interlaced setting.

1. After analysing the shared stream for interlaced & progressive the refresh rate are different.

Interlaced refresh rate is @ 60 and Progressive refresh rate is @120.

Can you try this below setting(If you have not tried this)?

intraRefreshMethod = 1 (IH264_INTRAREFRESH_CYCLIC_MBS)

gdrOverlapRowsBtwFrames = 0

constrainedIntraPredEnable = 0

intraCodingBias = 0

intraRefreshRate = 120

2. There are 2 slices in Progressive case and 4 in Interlaced. Are you looking form same?

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

Prashanth Kumar15 said:

1. After analysing the shared stream for interlaced & progressive the refresh rate are different.

Interlaced refresh rate is @ 60 and Progressive refresh rate is @120.

Can you try this below setting(If you have not tried this)?

intraRefreshMethod = 1 (IH264_INTRAREFRESH_CYCLIC_MBS)

gdrOverlapRowsBtwFrames = 0

constrainedIntraPredEnable = 0

intraCodingBias = 0

intraRefreshRate = 120

Thanks for the suggestions. I tried the changes but did not see any improvement.

Prashanth Kumar15 said:

2. There are 2 slices in Progressive case and 4 in Interlaced. Are you looking form same?

This is correct. We configure 2 slices for progressive and 4 slices for interlaced video formats.

Regards,

Manu

0 Prashanth Kumar15 over 6 years ago in reply to Manu Iyengar

Mastermind 8775 points

Hi Manish,

Thanks for the details. Can you try with these configs? This is our standalone config file where intra-refresh is working fine. intra_refresh_interlaced.cfg

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

Thanks for sharing the encoder configurations. I will try these configurations and get back.
In the meanwhile, can you also please share the encoded file (.264) where AIR is working for interlaced video?

Regards,
Manu

0 Prashanth Kumar15 over 6 years ago in reply to Manu Iyengar

Mastermind 8775 points

Hi Manu,

PFA for the encoded stream, rename it as .264. Also use interlaceCodingType = 2(MRF)

sample.264.txt

0 Prashanth Kumar15 over 6 years ago in reply to Prashanth Kumar15

Mastermind 8775 points

Hi Manu,
Did that work? If yes can you please close this thread?

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

Sorry for the delay. I'm still working on this.
I will get back as soon as I have the results.

Regards,
Manu

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

After reviewing the config file you had shared earlier, I did not see any key differences w.r.t AIR from our configurations.
I noticed differences in the following parameters - dataLayout, bottomFieldIntra and interlaceCodingType.
Our use-case requires only one field (either TOP or BOTTOM) to be provided to encoder. Hence we cannot change the dataLayout parameter.
As for the other two (bottomFieldIntra and interlaceCodingType), I did not see any difference in the behavior even after changing the values.

I was able to see AIR working in the encoded file you had shared. But the file has been encoded for 480i (720x480) video.
So, I tried encoding 480i video with our configurations itself and found AIR to be working!
However, the video gets refreshed very slowly. Only one column of macroblocks gets refreshed in every refresh cycle (1 cycle = 60 frames ~= 2 sec) instead of all macroblocks.
I see the same behavior in the clip shared by you also.

The difference in AIR behavior between 1080i and 480i seems to be a result of the number of macroblocks per row.
480i video contains odd number (45) of macroblocks per row and 1080i video contains even number of macroblocks (120).
When the no. of macroblocks per row is even, I observe that some macroblocks are refreshed either in TOP field or in BOTTOM field but not in both.
Please confirm if my observation is correct.

In summary, we are still seeing the following issues –
1. AIR works for 480i video but does not work for 1080i video with same configurations
2. AIR refresh time is very high for 480i video

Can you please look into the above and help me resolve them?

Once again, apologies for the delay in my response

Regards,
Manu

0 Prashanth Kumar15 over 6 years ago in reply to Manu Iyengar

Mastermind 8775 points

Hi Manu,
Did you try setting interlaceCodingType = 2(MRF)? Please try this and it should work for interlaced input too.
I had shared an sample video of smaller resolution just to show that AIR is taking effect.

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

I tried encoding with the suggested value (MRF) for interlaceCodingType and AIR is working! The refresh rate is also good!!
I had tried SPF and ARF earlier but not MRF. Sorry I missed it when you had suggested the same earlier.

However, I see another issue with MRF (and ARF). When the video has a complex scene (e.g. lot of text), the quality of encoded video when interlaceCodingType is set to MRF/ARF is not as good as when configured to SPF, which I believe is expected behavior. This is the reason why I had originally configured interlaceCodingType to SPF. Is it not possible to make AIR working with SPF configuration? or is there an alternate way to make AIR work and have good video quality?

Regards,
Manu

0 Prashanth Kumar15 over 6 years ago in reply to Manu Iyengar

Mastermind 8775 points

Hi Manu,
For interlaced intraRefereshRate works with MRF. When SPF is used, every alternate line refreshing will be missed.

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

Prashanth Kumar15 said:
Hi Manu,
For interlaced intraRefereshRate works with MRF. When SPF is used, every alternate line refreshing will be missed.

Thanks for confirming this. So, is this a bug in the encoder?

Regards,

Manu

0 Prashanth Kumar15 over 6 years ago in reply to Manu Iyengar

Mastermind 8775 points

Hi Manu,

Its not a bug in the Encoder, instead this feature is not supported for interlaced content. So, AIR wont take effect if you use other types than MRF. In other words for interlaced content intraRefresh takes effect only with MRF.

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

As I had mentioned in my earlier post, I see a problem when we configure interlaceCodingType to MRF.
The problem is that video quality is poor even at sufficiently high bitrates for contents like static input with lot of text.
I have attached two clips, one encoded with MRF and another encoded with SPF configuration. As you can see, video quality for MRF configuration is not good.
This video quality is not acceptable for our use-case. On the other hand, if I use SPF configuration, video quality is acceptable but I cannot use AIR feature which is also a problem.

Ideally I would like AIR feature to be supported with SPF configuration. I understand that this is not feasible with the current version of encoder.
So, can you please suggest a solution to achieve good video quality and get AIR to work simultaneously?

MRF-vs-SPF.zip

Regards,
Manu

0 Prashanth Kumar15 over 6 years ago in reply to Manu Iyengar

Mastermind 8775 points

Hi Manu,
Thanks for the streams.
For normal videos scenes the TF & BF will have close relation and the codec will give the better quality when used MRF for interlaced video. But here this input sequence is created video which has less correlation with TF & BF. That's the reason quality is not that good compared to SPF.
This is the best what encoder can do.

0 Prashanth Kumar15 over 6 years ago in reply to Prashanth Kumar15

Mastermind 8775 points

Hi Manu,
Can we close this query? If its resolved?

0 Manu Iyengar over 6 years ago in reply to Prashanth Kumar15

Intellectual 590 points

Hi Prashanth,

Yes, you can consider this thread closed. I have no further queries.

Thank you very much for your continuous support in resolving this issue.

Regards,
Manu

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PROCESSOR-SDK-AM57X: AIR interlaced video issue