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Diffstat (limited to 'ffmpeg/libavcodec/mlp.h')
| -rw-r--r-- | ffmpeg/libavcodec/mlp.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/mlp.h b/ffmpeg/libavcodec/mlp.h new file mode 100644 index 0000000..d8d1292 --- /dev/null +++ b/ffmpeg/libavcodec/mlp.h @@ -0,0 +1,127 @@ +/* + * MLP codec common header file + * Copyright (c) 2007-2008 Ian Caulfield + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVCODEC_MLP_H +#define AVCODEC_MLP_H + +#include <stdint.h> + +#include "avcodec.h" + +/** Last possible matrix channel for each codec */ +#define MAX_MATRIX_CHANNEL_MLP 5 +#define MAX_MATRIX_CHANNEL_TRUEHD 7 +/** Maximum number of channels in a valid stream. + * MLP : 5.1 + 2 noise channels -> 8 channels + * TrueHD: 7.1 -> 8 channels + */ +#define MAX_CHANNELS 8 + +/** 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_MLP 6 +#define MAX_MATRICES_TRUEHD 8 +#define MAX_MATRICES 8 + +/** Maximum number of substreams that can be decoded. + * MLP's limit is 2. TrueHD supports at least up to 3. + */ +#define MAX_SUBSTREAMS 3 + +/** which multiple of 48000 the maximum sample rate is */ +#define MAX_RATEFACTOR 4 +/** maximum sample frequency seen in files */ +#define MAX_SAMPLERATE (MAX_RATEFACTOR * 48000) + +/** maximum number of audio samples within one access unit */ +#define MAX_BLOCKSIZE (40 * MAX_RATEFACTOR) +/** next power of two greater than MAX_BLOCKSIZE */ +#define MAX_BLOCKSIZE_POW2 (64 * MAX_RATEFACTOR) + +/** number of allowed filters */ +#define NUM_FILTERS 2 + +/** The maximum number of taps in IIR and FIR filters. */ +#define MAX_FIR_ORDER 8 +#define MAX_IIR_ORDER 4 + +/** Code that signals end of a stream. */ +#define END_OF_STREAM 0xd234d234 + +#define FIR 0 +#define IIR 1 + +/** filter data */ +typedef struct FilterParams { + uint8_t order; ///< number of taps in filter + uint8_t shift; ///< Right shift to apply to output of filter. + + int32_t state[MAX_FIR_ORDER]; +} FilterParams; + +/** sample data coding information */ +typedef struct ChannelParams { + FilterParams filter_params[NUM_FILTERS]; + int32_t coeff[NUM_FILTERS][MAX_FIR_ORDER]; + + int16_t huff_offset; ///< Offset to apply to residual values. + int32_t sign_huff_offset; ///< sign/rounding-corrected version of huff_offset + uint8_t codebook; ///< Which VLC codebook to use to read residuals. + uint8_t huff_lsbs; ///< Size of residual suffix not encoded using VLC. +} ChannelParams; + +/** 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. + */ +extern const uint8_t ff_mlp_huffman_tables[3][18][2]; + +/** 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. + */ +uint8_t ff_mlp_checksum8 (const uint8_t *buf, unsigned int buf_size); +uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_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_restart_checksum(const uint8_t *buf, unsigned int bit_size); + +/** XOR together all the bytes of a buffer. + * Does this belong in dspcontext? + */ +uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size); + +void ff_mlp_init_crc(void); + +/** XOR four bytes into one. */ +static inline uint8_t xor_32_to_8(uint32_t value) +{ + value ^= value >> 16; + value ^= value >> 8; + return value; +} + +#endif /* AVCODEC_MLP_H */ |
