CDVDDemuxUtils Class Reference

#include <DVDDemuxUtils.h>

Static Public Member Functions
static void	FreeDemuxPacket (DemuxPacket *pPacket)
static DemuxPacket *	AllocateDemuxPacket (int iDataSize=0)
static DemuxPacket *	AllocateDemuxPacket (unsigned int iDataSize, unsigned int encryptedSubsampleCount)
static void	StoreSideData (DemuxPacket *pkt, AVPacket *src)
static std::vector< ChapterFFmpeg >	LoadChapters (std::span< AVChapter * > chapters)
static bool	SnapMsQuantisedFrameRate (int &fpsRate, int &fpsScale, double hintFps)
	Snap a container-declared frame rate that is exactly 1000/N fps (a whole number of milliseconds N per frame) to a standard rate whose millisecond-rounded duration equals N and agrees with the statistics.
static double	FrameRateFromStatistics (const std::string &frames, const std::string &duration)
	Average rate from Matroska NUMBER_OF_FRAMES and DURATION tags, or 0 if invalid.

Static Public Attributes
static constexpr std::chrono::milliseconds	KEYFRAME_OFFSET_LIMIT {1000}

Member Function Documentation

AllocateDemuxPacket() [1/2]

DemuxPacket * CDVDDemuxUtils::AllocateDemuxPacket ( int iDataSize = 0 )

static

Required number of additionally allocated bytes at the end of the input bitstream for decoding. this is mainly needed because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
Note, if the first 23 bits of the additional bytes are not 0 then damaged MPEG bitstreams could cause overread and segfault

AllocateDemuxPacket() [2/2]

DemuxPacket * CDVDDemuxUtils::AllocateDemuxPacket ( unsigned int iDataSize, unsigned int encryptedSubsampleCount )

static

FrameRateFromStatistics()

double CDVDDemuxUtils::FrameRateFromStatistics ( const std::string & frames, const std::string & duration )

static

Average rate from Matroska NUMBER_OF_FRAMES and DURATION tags, or 0 if invalid.

FreeDemuxPacket()

void CDVDDemuxUtils::FreeDemuxPacket ( DemuxPacket * pPacket )

static

Todo

: properly handle avpkt side_data. this works around our improper use of the side_data

LoadChapters()

std::vector< ChapterFFmpeg > CDVDDemuxUtils::LoadChapters ( std::span< AVChapter * > chapters )

static

SnapMsQuantisedFrameRate()

bool CDVDDemuxUtils::SnapMsQuantisedFrameRate ( int & fpsRate, int & fpsScale, double hintFps )

static

Snap a container-declared frame rate that is exactly 1000/N fps (a whole number of milliseconds N per frame) to a standard rate whose millisecond-rounded duration equals N and agrees with the statistics.

Parameters

[in,out]	fpsRate	frame rate numerator, rewritten on success
[in,out]	fpsScale	frame rate denominator, rewritten on success
	hintFps	measured rate from container statistics (frame count / duration) used to resolve rates that quantise to the same duration (23.976 vs 24). Missing or ambiguous statistics leave the rate unchanged.

Returns

true when the rate was rewritten

StoreSideData()

void CDVDDemuxUtils::StoreSideData ( DemuxPacket * pkt, AVPacket * src )

static

Todo

: properly handle avpkt side_data. this works around our improper use of the side_data

Member Data Documentation

KEYFRAME_OFFSET_LIMIT

std::chrono::milliseconds CDVDDemuxUtils::KEYFRAME_OFFSET_LIMIT {1000}

staticconstexpr

How far in a first chapter may start and still count as starting at zero: longer than a keyframe interval, shorter than anything worth seeking to.

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The documentation for this class was generated from the following files:

• DVDDemuxUtils.h
• DVDDemuxUtils.cpp