Class VbiParse

Namespace

CHDSharp.Encoder

Assembly

CHDSharpLib.dll

Port of MAME's vbiparse (src/lib/util/vbiparse.cpp): parses Philips codes and the "white flag" from laserdisc VBI lines, and packs the per-frame results into the 16-byte form stored in 'AVLD' metadata. Input is a YUY2 frame in serialized byte order; each 16-bit pixel is read little-endian and shifted right by sourceShift (= 8 selects the luma byte), exactly like MAME reading its native bitmap.

public static class VbiParse

Inheritance

object

VbiParse

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Fields

PackedBytes

Size of one packed VBI record (VBI_PACKED_BYTES).

public const int PackedBytes = 16

Field Value

int

Methods

MetadataPack(Span<byte>, uint, VbiMetadata)

Packs the VBI data down into the 16-byte storage form (MAME's vbi_metadata_pack): u24be frame number, white flag, then four u24be codes.

public static void MetadataPack(Span<byte> dest, uint frameNum, VbiMetadata vbi)

Parameters

dest Span<byte>

frameNum uint

vbi VbiMetadata

ParseAll(byte[], int, int, int)

Parses everything from a video frame (MAME's vbi_parse_all): the white flag from line 11 and Manchester codes from lines 16/17/18, then reconciles lines 17/18.

public static VbiMetadata ParseAll(byte[] source, int sourceRowPixels, int sourceWidth, int sourceShift)

Parameters

source byte[]

Frame bytes (YUY2 order).

sourceRowPixels int

Row stride in pixels.

sourceWidth int

Visible width in pixels.

sourceShift int

Right-shift selecting the sample byte within each 16-bit pixel.

Returns

VbiMetadata

ParseManchesterCode(byte[], int, int, int, int, uint[])

Parses a Manchester code from a line of video data (MAME's vbi_parse_manchester_code). Returns the number of bits extracted (0 on failure); each result entry holds (confidence << 1) | bit.

public static int ParseManchesterCode(byte[] source, int sourceOffsetBytes, int sourceWidth, int sourceShift, int expectedBits, uint[] result)

Parameters

source byte[]

sourceOffsetBytes int

sourceWidth int

sourceShift int

expectedBits int

result uint[]

Returns

int

ParseWhiteFlag(byte[], int, int, int)

Computes the "white flag" from a line of video data (MAME's vbi_parse_white_flag): true when the histogram peak sits above 90% of the noise-trimmed dynamic range.

public static bool ParseWhiteFlag(byte[] source, int sourceOffsetBytes, int sourceWidth, int sourceShift)

Parameters

source byte[]

sourceOffsetBytes int

sourceWidth int

sourceShift int

Returns

bool