Why is happened the difference during H264 encoding?

nrson — Wed, 14 Nov 2012 06:07:07 GMT

Hi, All

I have a meet the problems during tesing H264 fielding coding on IPP(Ver.7.0.5.059).

I set the parameter for fielding as following:

coding_type = 1;

But there is the difference a generated bitstream according to image.

one(A) is general H264 bitstream, other(B) is strange H264 bitstream.

The decoing result of A is good, but B's bitstream is as following and not decoding.

00 00 00 01 21 B8 04 07 4B ED 4B 1D FF 9C 6F FC 16 B3 A1 AB C4 AB F9 9D EA BB 6E 39 48 56 F8 A4 C5 3B 3D 08 65 C9 75 00 F1 B1 18 0B 71 A2 80 8E 39 B9 E9 F9 96 4A B1 30 A4 83 59 A9 8C 60 63 5A 4E 2F 14 A0 5B 77 94 AA B3 A1 03 51 5A 2D A2 97~~~~

I think that SPS and PPS of B is wrong or fielding coding is incompletely.

How do I solve the problem or advice?

Best regards,

nrson

Good day.

Pavel_V_Intel — Wed, 14 Nov 2012 12:03:43 GMT

Good day. There was a problem with missing SPS headers in field encoding. It was fixed in 7.1 However I must warn you what we have a bug in motion estimation in filed mode which can cause significant artifacts on P frames. Here is a fix for 7.0.5: umc_h264_gen_enc_tmpl.cpp.h line 593, add firstFieldClass variable [cpp] Status H264ENC_MAKE_NAME(H264CoreEncoder_CompressFrame)( void* state, EnumPicCodType& ePictureType, EnumPicClass& ePic_Class, MediaData* dst) { ... EnumPicClass firstFieldClass; [/cpp] line 618, store picture type for first field in firstFieldClass [cpp] // reencode frame loop for (;;) { brcRecode = false; core_enc->m_is_cur_pic_afrm = (Ipp32s)(core_enc->m_pCurrentFrame->m_PictureStructureForDec==AFRM_STRUCTURE); firstFieldClass = ePic_Class; [/cpp] line 953, replace this condition: [cpp] if (ePic_Class == IDR_PIC && (!core_enc->m_field_index)) { core_enc->m_SliceHeader.idr_pic_id--; core_enc->m_SliceHeader.idr_pic_id &= 0xff; //Restrict to 255 to reduce number of bits(max value 65535 in standard) } [/cpp] with this: [cpp] if(core_enc->m_field_index) { if(firstFieldClass == IDR_PIC) // restore IDR flag or SPS header will be lost { core_enc->m_SliceHeader.idr_pic_id--; ePic_Class = IDR_PIC; } core_enc->m_HeightInMBs <<= 1; } else { if(ePic_Class == IDR_PIC) { core_enc->m_SliceHeader.idr_pic_id--; core_enc->m_SliceHeader.idr_pic_id &= 0xff; //Restrict to 255 to reduce number of bits(max value 65535 in standard) } } [/cpp]

topic Why is happened the difference during H264 encoding? in Intel® Integrated Performance Primitives

Why is happened the difference during H264 encoding?

Good day.