Hi,
The following item is mentionned in the list of issue fixed in IPP 7 update 2.
DPD200137548
H.264 Decompression on x64 is significantly slower compared to x32.
It sounds like a serious issue but there is no detail about the fix or situation in which the problem happen.
-Is this a sample fix, a library fix or both ?
-Is this an issue in IPP 6.1 or was this a bug introduced in IPP 7 ?
-Is this an issue with any H.264 stream or only specific profiles ?
Thanks
Hello,
this issue was related to the level of optimization for primitive functions. No H.264 sample code changes involved.
Regards,
Vladimir
Great thanks, and I suspect that the less optimized code was also in IPP 6.1.
Yes, the optimization problems also existed in the 6.1 code.
I have run several tests using sample version 6.1 and IPP 6.1 vs 7.02 and can't find any difference in term of speed.
Have you compared performance on IA32 vs Intel64 architectures?
Vladimir
No I just tested the two versions on 64bits expecting to see an improvment (no 32 bits system on hands).
Emmanuel
Hi Emmanuel,
a lot of factors may affect performance comparison. But for this particular issue we have a confirmation that it was fixed from customer who has intially reported about it. Below are performance data on IPP functions
IPP 6.1 IPP 7.0.2 intel64 intel64 ia32 ippiReconstructLumaIntra8x8_H264High_32s16u_IP1R 2.56 0.385 0.574 ippiReconstructChroma422Inter4x4_H264High_32s16u_IP2R 0.897 0.158 0.19 ippiDecodeCAVLCCoeffs_H264_1u32s 0.528 0.467 0.445 ippiReconstructChroma422Intra4x4_H264High_32s16u_IP2R 0.14 0.079 0.061Regards,
Vladimir
Thanks Vladimir,
I didn't use 8x8 transform or 422 sampling in my tests so that makes sence ;)
Emmanuel