#include <stdint.h>
#include "avcodec.h"

Data Structures
struct	FilterParams
	filter data More...

struct	ChannelParams
	sample data coding information More...

Macros
#define	MAX_MATRIX_CHANNEL_MLP 5
	Last possible matrix channel for each codec.

#define	MAX_MATRIX_CHANNEL_TRUEHD 7

#define	MAX_CHANNELS 8
	Maximum number of channels in a valid stream.

#define	MAX_MATRICES_MLP 6
	Maximum number of matrices used in decoding; most streams have one matrix per output channel, but some rematrix a channel (usually 0) more than once.

#define	MAX_MATRICES_TRUEHD 8

#define	MAX_MATRICES 8

#define	MAX_SUBSTREAMS 3
	Maximum number of substreams that can be decoded.

#define	MAX_RATEFACTOR 4
	which multiple of 48000 the maximum sample rate is

#define	MAX_SAMPLERATE (MAX_RATEFACTOR * 48000)
	maximum sample frequency seen in files

#define	MAX_BLOCKSIZE (40 * MAX_RATEFACTOR)
	maximum number of audio samples within one access unit

#define	MAX_BLOCKSIZE_POW2 (64 * MAX_RATEFACTOR)
	next power of two greater than MAX_BLOCKSIZE

#define	NUM_FILTERS 2
	number of allowed filters

#define	MAX_FIR_ORDER 8
	The maximum number of taps in IIR and FIR filters.

#define	MAX_IIR_ORDER 4

#define	END_OF_STREAM 0xd234d234
	Code that signals end of a stream.

#define	FIR 0

#define	IIR 1

Enumerations
enum	THDChannelModifier { THD_CH_MODIFIER_NOTINDICATED = 0x0, THD_CH_MODIFIER_STEREO = 0x0, THD_CH_MODIFIER_LTRT = 0x1, THD_CH_MODIFIER_LBINRBIN = 0x2, THD_CH_MODIFIER_MONO = 0x3, THD_CH_MODIFIER_NOTSURROUNDEX = 0x1, THD_CH_MODIFIER_SURROUNDEX = 0x2 }

Functions
uint8_t	ff_mlp_checksum8 (const uint8_t *buf, unsigned int buf_size)
	MLP uses checksums that seem to be based on the standard CRC algorithm, but are not (in implementation terms, the table lookup and XOR are reversed).

uint16_t	ff_mlp_checksum16 (const uint8_t *buf, unsigned int buf_size)

uint8_t	ff_mlp_restart_checksum (const uint8_t *buf, unsigned int bit_size)
	Calculate an 8-bit checksum over a restart header – a non-multiple-of-8 number of bits, starting two bits into the first byte of buf.

uint8_t	ff_mlp_calculate_parity (const uint8_t *buf, unsigned int buf_size)
	XOR together all the bytes of a buffer.

void	ff_mlp_init_crc (void)

static uint8_t	xor_32_to_8 (uint32_t value)
	XOR four bytes into one.

Variables
const uint8_t	ff_mlp_huffman_tables [3][18][2]
	Tables defining the Huffman codes.

Macro Definition Documentation

#define MAX_MATRIX_CHANNEL_MLP 5

Last possible matrix channel for each codec.

Definition at line 30 of file mlp.h.

Referenced by read_restart_header().

#define MAX_MATRIX_CHANNEL_TRUEHD 7

Definition at line 31 of file mlp.h.

Referenced by read_restart_header().

#define MAX_CHANNELS 8

Maximum number of channels in a valid stream.

MLP : 5.1 + 2 noise channels -> 8 channels TrueHD: 7.1 -> 8 channels

Definition at line 36 of file mlp.h.

#define MAX_MATRICES_MLP 6

Maximum number of matrices used in decoding; most streams have one matrix per output channel, but some rematrix a channel (usually 0) more than once.

Definition at line 41 of file mlp.h.

Referenced by read_matrix_params().

#define MAX_MATRICES_TRUEHD 8

Definition at line 42 of file mlp.h.

Referenced by read_matrix_params().

#define MAX_MATRICES 8

Definition at line 43 of file mlp.h.

#define MAX_SUBSTREAMS 3

Maximum number of substreams that can be decoded.

MLP's limit is 2. TrueHD supports at least up to 3.

Definition at line 48 of file mlp.h.

Referenced by mlp_decode_init(), read_access_unit(), and read_major_sync().

#define MAX_RATEFACTOR 4

which multiple of 48000 the maximum sample rate is

Definition at line 51 of file mlp.h.

#define MAX_SAMPLERATE (MAX_RATEFACTOR * 48000)

maximum sample frequency seen in files

Definition at line 53 of file mlp.h.

Referenced by read_major_sync().

#define MAX_BLOCKSIZE (40 * MAX_RATEFACTOR)

maximum number of audio samples within one access unit

Definition at line 56 of file mlp.h.

#define MAX_BLOCKSIZE_POW2 (64 * MAX_RATEFACTOR)

next power of two greater than MAX_BLOCKSIZE

Definition at line 58 of file mlp.h.

Referenced by read_major_sync().

#define NUM_FILTERS 2

number of allowed filters

Definition at line 61 of file mlp.h.

Referenced by filter_channel().

#define MAX_FIR_ORDER 8

The maximum number of taps in IIR and FIR filters.

Definition at line 64 of file mlp.h.

Referenced by filter_channel(), mlp_filter_channel(), and read_filter_params().

#define MAX_IIR_ORDER 4

Definition at line 65 of file mlp.h.

Referenced by filter_channel(), and read_filter_params().

#define END_OF_STREAM 0xd234d234

Code that signals end of a stream.

Definition at line 68 of file mlp.h.

#define FIR 0

Definition at line 70 of file mlp.h.

Referenced by filter_channel(), read_channel_params(), read_filter_params(), and read_restart_header().

#define IIR 1

Definition at line 71 of file mlp.h.

Referenced by filter_channel(), read_channel_params(), and read_restart_header().

Enumeration Type Documentation

enum THDChannelModifier

Enumerator:

THD_CH_MODIFIER_NOTINDICATED
THD_CH_MODIFIER_STEREO
THD_CH_MODIFIER_LTRT
THD_CH_MODIFIER_LBINRBIN
THD_CH_MODIFIER_MONO
THD_CH_MODIFIER_NOTSURROUNDEX
THD_CH_MODIFIER_SURROUNDEX

Definition at line 127 of file mlp.h.

Function Documentation

uint8_t ff_mlp_checksum8	(	const uint8_t *	buf,
		unsigned int	buf_size
	)

MLP uses checksums that seem to be based on the standard CRC algorithm, but are not (in implementation terms, the table lookup and XOR are reversed).

We can implement this behavior using a standard av_crc on all but the last element, then XOR that with the last element.

Definition at line 73 of file mlp.c.

Referenced by read_access_unit().

uint16_t ff_mlp_checksum16	(	const uint8_t *	buf,
		unsigned int	buf_size
	)

Definition at line 64 of file mlp.c.

Referenced by ff_mlp_read_major_sync().

uint8_t ff_mlp_restart_checksum	(	const uint8_t *	buf,
		unsigned int	bit_size
	)

Calculate an 8-bit checksum over a restart header – a non-multiple-of-8 number of bits, starting two bits into the first byte of buf.

Definition at line 80 of file mlp.c.

Referenced by read_restart_header().

uint8_t ff_mlp_calculate_parity	(	const uint8_t *	buf,
		unsigned int	buf_size
	)

XOR together all the bytes of a buffer.

Does this belong in dspcontext?

Definition at line 99 of file mlp.c.

Referenced by read_access_unit().

void ff_mlp_init_crc ( void )

Definition at line 54 of file mlp.c.

Referenced by init_static(), and mlp_init().

static uint8_t xor_32_to_8 ( uint32_t value )

inlinestatic

XOR four bytes into one.

Definition at line 120 of file mlp.h.

Referenced by ff_mlp_calculate_parity(), and read_restart_header().

Variable Documentation

const uint8_t ff_mlp_huffman_tables[3][18][2]

Tables defining the Huffman codes.

There are three entropy coding methods used in MLP (four if you count "none" as a method). These use the same sequences for codes starting with 00 or 01, but have different codes starting with 1.

Definition at line 28 of file mlp.c.

Referenced by init_static().

Data Structures

Macros

Enumerations

Functions

Variables

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation

Variable Documentation