topic Re: H.264 Decoder Problems in Intel® Integrated Performance Primitives

H.264 Decoder Problems

dchris — Mon, 15 Oct 2007 21:43:13 GMT

Hello again,

I have been doing some testing of the H.264 decoder with a stream that is being received over an unreliable medium, which can cause the stream to have a high bit error rate. In my testing I have found that this can lead to crash the H.264 decoder. I have stepped through the code to try to fix the problem and have found that most often the decoder is trying to access a reference picture that is outside the bounds of the reference picture array. I have made some modifications to do some bounds checking and some other initializations that have caused problems. After my modifications I do not experience the crash, but it sends the decoder into an infinite loop. I have attached a zip file which contains diff files for the modifications I made as well as a sample H.264 stream that will cause the errors I'm seeing. Can you suggest any better modifications to help resolve this problem? Thanks,

Derek

Note:
I'm using IPP 5.2 on WinXP SP2 and the problem can be reproduced using the sample umc_h264_dec included with IPP 5.2.

Re: H.264 Decoder Problems

Vladimir_Dudnik — Wed, 17 Oct 2007 20:06:32 GMT

Hi Derek,

there is comment from our expert:

It seems that this H.264 stream is corrupted. So, if you use MSVC compiler I recommend to recompile the h264_dec project with EHa option (instead of -EHsc) and fexception option for gcc. In this case IPP H.264 decoder could catch all possible exceptions and work stable.

Regards,
Vladimir

Re: H.264 Decoder Problems

dchris — Wed, 17 Oct 2007 20:35:35 GMT

Vladimir,

Thank you for your reply,

I am using MSVC and I am compiling with the -EHa option. In fact I can see in the output window that there are several other exceptions being caught, but I am still seeing the decoder crash. Were you able to play the stream without it crashing? Thanks,

Derek

Re: H.264 Decoder Problems

dchris — Fri, 26 Oct 2007 13:51:17 GMT

Vladimir,

As I said before, I have tried recompiling with the -EHa flag, but i continue to have errors. Have you been able to play the stream without problems? Are there are other recommendations as to how solve this problem? Thanks again,

Derek

Re: H.264 Decoder Problems

Vladimir_Dudnik — Mon, 05 Nov 2007 10:57:24 GMT

Hi Derek,

it seems that the best solution will be updating to IPP 5.3 version, which is coming soon. We've added additional handling of exceptional situations into H.264 decoder based on our internal testing and input from you.

Regards,
Vladimir

Re: H.264 Decoder Problems

dchris — Mon, 05 Nov 2007 15:01:53 GMT

Vladimir,

Thank you for the reply and the suggestion to upgrade to 5.3 I look forward to the new version. When can we expect to see IPP 5.3?

Derek

Re: H.264 Decoder Problems

Vladimir_Dudnik — Tue, 06 Nov 2007 02:55:00 GMT

Hi Derek,

IPP 5.3 should be available at Q4'07, so it comes soon.

Regards,
Vladimir