shaka::media::NaluReader Class Reference

#include <nalu_reader.h>

Public Types
enum	Result { kOk , kInvalidStream , kEOStream }

Public Member Functions
	NaluReader (Nalu::CodecType type, uint8_t nal_length_size, const uint8_t *stream, uint64_t stream_size)
	NaluReader (Nalu::CodecType type, uint8_t nal_length_size, const uint8_t *stream, uint64_t stream_size, const std::vector< SubsampleEntry > &subsamples)
Result	Advance (Nalu *nalu)
bool	StartsWithStartCode ()

Static Public Member Functions
static bool	FindStartCode (const uint8_t *data, uint64_t data_size, uint64_t *offset, uint8_t *start_code_size)
static bool	FindStartCodeInClearRange (const uint8_t *data, uint64_t data_size, uint64_t *offset, uint8_t *start_code_size, const std::vector< SubsampleEntry > &subsamples)

Detailed Description

Helper class used to read NAL units based on several formats:

• Annex B H.264/h.265
• NAL Unit Stream

Definition at line 149 of file nalu_reader.h.

Constructor & Destructor Documentation

NaluReader() [1/2]

shaka::media::NaluReader::NaluReader	(	Nalu::CodecType	type,
		uint8_t	nal_length_size,
		const uint8_t *	stream,
		uint64_t	stream_size
	)

Parameters

nalu_length_size

should be set to 0 for AnnexB byte streams; otherwise, it indicates the size of NAL unit length for the NAL unit stream.

Definition at line 214 of file nalu_reader.cc.

NaluReader() [2/2]

shaka::media::NaluReader::NaluReader	(	Nalu::CodecType	type,
		uint8_t	nal_length_size,
		const uint8_t *	stream,
		uint64_t	stream_size,
		const std::vector< SubsampleEntry > &	subsamples
	)

Parameters

type	is the codec type of the NALU unit.
nalu_length_size	should be set to 0 for AnnexB byte streams; otherwise, it indicates the size of NAL unit length for the NAL unit stream.
stream	is the input stream.
stream_size	is the size of stream.
subsamples	specifies the clear and encrypted sections of the stream starting from the beginning of the stream. If subsamples doesn't cover the entire stream, then the rest is assumed to be in the clear.

Definition at line 224 of file nalu_reader.cc.

Member Function Documentation

Advance()

NaluReader::Result shaka::media::NaluReader::Advance

(

Nalu *

nalu

)

Reads a NALU from the stream into |*nalu|, if one exists, and then advances to the next NALU.

Parameters

nalu	contains the NALU read if it exists.

Returns

kOk if a NALU is read; kEOStream if the stream is at the end-of-stream; kInvalidStream on error.

Definition at line 241 of file nalu_reader.cc.

FindStartCodeInClearRange()

bool shaka::media::NaluReader::FindStartCodeInClearRange ( const uint8_t *  data, uint64_t  data_size, uint64_t *  offset, uint8_t *  start_code_size, const std::vector< SubsampleEntry > &  subsamples  )

static

Same as FindStartCode() but also specify the subsamples. This searches for start codes in the clear section and will not scan for start codes in the encrypted section. Even if there is a real NALU start code in the encrypted section, this will skip them.

Parameters

subsamples

starting from the start of data. If subsamples does not cover the whole data, the rest is assumed to be in the clear.

Returns

true if it finds a NALU. false otherwise.

Definition at line 346 of file nalu_reader.cc.

StartsWithStartCode()

bool shaka::media::NaluReader::StartsWithStartCode

(

)

Returns

true if the current position points to a start code.

Definition at line 299 of file nalu_reader.cc.

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

• packager/media/codecs/nalu_reader.h
• packager/media/codecs/nalu_reader.cc