Class TAvcPictureHeader

class TAvcPictureHeader;

Description

AVC Picture Header.

Members

Defined in TAvcPictureHeader:
iAspectRatioDenom, iAspectRatioNum, iBaselineProfileConstraintSet, iBottomFieldOrderCount, iClockTimestamp, iExtendedProfileConstraintSet, iFrame, iFrameCropRect, iIdrPicture, iLongTermPicture, iMainProfileConstraintSet, iOverscanInfo, iPictureStructure, iPictureType, iQPY, iTopField, iTopFieldOrderCount, iVideoFormat

TBool iBaselineProfileConstraintSet;

Description

Equal to ETrue indicates that the bitstream obeys all constraints specified in subclause A.2.1 of the AVC specification, equal to EFalse indicates that the bitstream may or may not obey the constraints. The value is equal to ETrue (EFalse) if the syntax element constraint_set0_flag is equal to 1 (0).

TBool iMainProfileConstraintSet;

Description

Equal to ETrue indicates that the bitstream obeys all constraints specified in subclause A.2.2 of the AVC specification, equal to EFalse indicates that the bitstream may or may not obey the constraints. The value is equal to ETrue (EFalse) if the syntax element constraint_set1_flag is equal to 1 (0).

TBool iExtendedProfileConstraintSet;

Description

Equal to ETrue indicates that the bitstream obeys all constraints specified in subclause A.2.3 of the AVC specification, equal to EFalse indicates that the bitstream may or may not obey the constraints. The value is equal to ETrue (EFalse) if the syntax element constraint_set2_flag is equal to 1 (0).

TAvcPictureType iPictureType;

Description

Indicates the picture type. iPictureType is set as one of the values defined in TAvcPictureType.

TBool iLongTermPicture;

Description

iLongTermPicture equal to ETrue indicates that the picture is a long-term picture, i.e., it has been marked as "used for long-term reference" according to the decoded reference picture marking process as specified in subclause 8.2.5 of the AVC specification. Otherwise the picture is not a long-term picture.

TBool iFrame;

Description

Indicates whether the picture is a frame or a field. iFrame is equal to ETrue if the picture is a frame (field_pic_flag is equal to 0), EFalse if the picture is a field (field_pic_flag is equal to 1).

TBool iTopField;

Description

Valid only if iFrame is equal to EFalse. Indicates whether the field picture is a top field or a bottom field. iTopField is equal to ETrue if the picture is a top field (bottom_field_flag is equal to 0), EFalse if the picture is a bottom field (bottom_field_flag is equal to 0).

TUint iTopFieldOrderCount;

Description

Indicates the picture order count of the top field of a frame, the top field of a complementary field pair, or a top field. iTopFieldOrderCount is equal to the value of TopFieldOrderCnt as specified in subclause 8.2.1 of the AVC specification.

TUint iBottomFieldOrderCount;

Description

Indicates the picture order count of the bottom field of a frame, the bottom field of a complementary field pair, or a bottom field. iBottomFieldOrderCount is equal to the value of BottomFieldOrderCnt as specified in subclause 8.2.1 of the AVC specification.

TBool iIdrPicture;

Description

Equal to ETrue indicates that the picture is an Instantaneous Decoding Refresh (IDR) picture; otherwise the picture is not an IDR picture. The value of nal_unit_type of all the Video Coding Layer (VCL) NAL units of the primary coded picture of an IDR picture shall be equal to 5.

TUint iQPY;

Description

Indicates the initial value of the quantization parameter. If iPictureType is equal to EAvcPictureTypeSI or EavcPictureTypeSP, iPQY is equal to pic_init_qs_minus26 + 26; otherwise iPQY is equal to pic_init_qp_minus26 + 26.

TUint iAspectRatioNum;

Description

Pixel aspect ratio numerator. The pixel aspect ratio is defined as iAspectRatioNum/iAspectRatioDenom, where the values are positive integers and relatively prime. When aspect_ratio_idc is equal to 0 or sar_width is equal to 0 or sar_height is equal to 0, the sample aspect ratio shall be considered unspecified, and iAspectRatioNum and iAspectRationDenom are set to 0. When aspect_ratio_idc is equal to any of the value from 1 to 13, inclusive, iAspectRatioNum and iAspectRatioDenom are set according to Table E-1 of the AVC specification. When aspect_ratio_idc is equal to 255 (Extended_SAR), iAspectRatioNum is set to sar_width and iAspectRatioDenom is set to sar_height.

TUint iAspectRatioDenom;

Description

Pixel aspect ratio denominator. The pixel aspect ratio is defined as iAspectRatioNum/iAspectRatioDenom, where the values are positive integers and relatively prime. When aspect_ratio_idc is equal to 0 or sar_width is equal to 0 or sar_height is equal to 0, the sample aspect ratio shall be considered unspecified, and iAspectRatioNum and iAspectRationDenom are set to 0. When aspect_ratio_idc is equal to any of the value from 1 to 13, inclusive, iAspectRatioNum and iAspectRatioDenom are set according to Table E-1 of the AVC specification. When aspect_ratio_idc is equal to 255 (Extended_SAR), iAspectRatioNum is set to sar_width and iAspectRatioDenom is set to sar_height.

TRect iFrameCropRect;

Description

Indicates the frame cropping rectangle as specified in subclause 7.4.2.1 of the AVC specification.

TUint iOverscanInfo;

Description

Equal to 0 indicates that the cropped (according to the frame cropping rectangle) decoded pictures output contain visually important information in the entire region out to the edges of the cropping rectangle of the picture, such that the cropped decoded pictures output should not be displayed using overscan. Instead, they should be displayed using either an exact match between the display area and the cropping rectangle, or using underscan. Equal to 1 indicates that the cropped decoded picture output is suitable for display using overscan. Otherwise, it is unspecified whether the cropped decoded picture output is suitable for display using overscan or not.

TUint iVideoFormat;

Description

Indicates the representation of the pictures as specified in Table E-2 of the AVC specification, before being coded.

TUint iPictureStructure;

Description

Indicates whether a picture should be displayed as a frame or one or more fields, according to Table D-1. iPictureStructure is equal to the syntax element pic_struct.

TTimeIntervalMicroSeconds iClockTimestamp;

Description

Each picture has up to NumClockTS sets of clock timestamp information. The value of NumClockTS is as specified in Table D-1 of the AVC specification, with a maximum value equal to 3. Each instance of iClockTimestamp[i] indicates a time of origin, capture, or alternative ideal display, in units of microseconds. iClockTimestamp[i] is equal to (clockTimestamp[i] / time_scale * 1000000), where clockTimestamp[i] is the i-th set of clock timestamp information as specified in subclause D.2.2 of the AVC specification. iClockTimestamp[i] where i is larger than NumClockTS-1 is invalid. When picture timing information is not available, NumClockTS is set to zero.