#include <stdint.h>#include "avcodec.h"Go to the source code of this file.
Data Structures | |
| struct | FilterParams |
| filter data More... | |
| struct | ChannelParams |
| sample data coding information More... | |
Defines | |
| #define | MAX_CHANNELS 16 |
| Maximum number of channels that can be decoded. | |
| #define | MAX_MATRICES 15 |
| 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_SUBSTREAMS 2 |
| Maximum number of substreams that can be decoded. | |
| #define | MAX_SAMPLERATE 192000 |
| maximum sample frequency seen in files | |
| #define | MAX_BLOCKSIZE (40 * (MAX_SAMPLERATE / 48000)) |
| maximum number of audio samples within one access unit | |
| #define | MAX_BLOCKSIZE_POW2 (64 * (MAX_SAMPLERATE / 48000)) |
| next power of two greater than MAX_BLOCKSIZE | |
| #define | NUM_FILTERS 2 |
| number of allowed filters | |
| #define | MAX_FILTER_ORDER 8 |
| The maximum number of taps in either the IIR or FIR filter; I believe MLP actually specifies the maximum order for IIR filters as four, and that the sum of the orders of both filters must be <= 8. | |
| #define | END_OF_STREAM 0xd234d234 |
| Code that signals end of a stream. | |
| #define | FIR 0 |
| #define | IIR 1 |
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. | |
| #define END_OF_STREAM 0xd234d234 |
Code that signals end of a stream.
Definition at line 60 of file mlp.h.
Referenced by read_access_unit().
| #define FIR 0 |
Definition at line 62 of file mlp.h.
Referenced by filter_channel(), read_decoding_params(), read_filter_params(), and read_restart_header().
| #define IIR 1 |
Definition at line 63 of file mlp.h.
Referenced by filter_channel(), read_decoding_params(), and read_restart_header().
| #define MAX_BLOCKSIZE (40 * (MAX_SAMPLERATE / 48000)) |
| #define MAX_BLOCKSIZE_POW2 (64 * (MAX_SAMPLERATE / 48000)) |
next power of two greater than MAX_BLOCKSIZE
Definition at line 48 of file mlp.h.
Referenced by read_major_sync().
| #define MAX_CHANNELS 16 |
| #define MAX_FILTER_ORDER 8 |
The maximum number of taps in either the IIR or FIR filter; I believe MLP actually specifies the maximum order for IIR filters as four, and that the sum of the orders of both filters must be <= 8.
Definition at line 57 of file mlp.h.
Referenced by filter_channel(), and read_filter_params().
| #define MAX_MATRICES 15 |
| #define MAX_SAMPLERATE 192000 |
maximum sample frequency seen in files
Definition at line 43 of file mlp.h.
Referenced by read_major_sync().
| #define MAX_SUBSTREAMS 2 |
Maximum number of substreams that can be decoded.
This could also be set higher, but I haven't seen any examples with more than two.
Definition at line 40 of file mlp.h.
Referenced by mlp_decode_init(), read_access_unit(), and read_major_sync().
| #define NUM_FILTERS 2 |
| 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 94 of file mlp.c.
Referenced by read_access_unit().
| uint16_t ff_mlp_checksum16 | ( | const uint8_t * | buf, | |
| unsigned int | buf_size | |||
| ) |
| 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 68 of file mlp.c.
Referenced by read_access_unit().
| void ff_mlp_init_crc | ( | void | ) |
| 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 75 of file mlp.c.
Referenced by read_restart_header().
| static uint8_t xor_32_to_8 | ( | uint32_t | value | ) | [inline, static] |
XOR four bytes into one.
Definition at line 112 of file mlp.h.
Referenced by ff_mlp_calculate_parity(), and read_restart_header().
| 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().
1.5.8