Originally committed as revision 14733 to svn://svn.ffmpeg.org/ffmpeg/trunkpull/126/head
Ramiro Polla
17 years ago
parent
e7327dbba7
commit
ce15710f55
5 changed files with 247 additions and 180 deletions
@ -0,0 +1,120 @@ |
||||
/*
|
||||
* MLP codec common code |
||||
* 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 |
||||
*/ |
||||
|
||||
#include <stdint.h> |
||||
|
||||
#include "libavutil/crc.h" |
||||
#include "mlp.h" |
||||
|
||||
const uint8_t ff_mlp_huffman_tables[3][18][2] = { |
||||
{ /* Huffman table 0, -7 - +10 */ |
||||
{0x01, 9}, {0x01, 8}, {0x01, 7}, {0x01, 6}, {0x01, 5}, {0x01, 4}, {0x01, 3}, |
||||
{0x04, 3}, {0x05, 3}, {0x06, 3}, {0x07, 3}, |
||||
{0x03, 3}, {0x05, 4}, {0x09, 5}, {0x11, 6}, {0x21, 7}, {0x41, 8}, {0x81, 9}, |
||||
}, { /* Huffman table 1, -7 - +8 */ |
||||
{0x01, 9}, {0x01, 8}, {0x01, 7}, {0x01, 6}, {0x01, 5}, {0x01, 4}, {0x01, 3}, |
||||
{0x02, 2}, {0x03, 2}, |
||||
{0x03, 3}, {0x05, 4}, {0x09, 5}, {0x11, 6}, {0x21, 7}, {0x41, 8}, {0x81, 9}, |
||||
}, { /* Huffman table 2, -7 - +7 */ |
||||
{0x01, 9}, {0x01, 8}, {0x01, 7}, {0x01, 6}, {0x01, 5}, {0x01, 4}, {0x01, 3}, |
||||
{0x01, 1}, |
||||
{0x03, 3}, {0x05, 4}, {0x09, 5}, {0x11, 6}, {0x21, 7}, {0x41, 8}, {0x81, 9}, |
||||
} |
||||
}; |
||||
|
||||
static int crc_init = 0; |
||||
static AVCRC crc_63[1024]; |
||||
static AVCRC crc_1D[1024]; |
||||
|
||||
|
||||
static int crc_init_2D = 0; |
||||
static AVCRC crc_2D[1024]; |
||||
|
||||
int av_cold ff_mlp_init_crc2D(AVCodecParserContext *s) |
||||
{ |
||||
if (!crc_init_2D) { |
||||
av_crc_init(crc_2D, 0, 16, 0x002D, sizeof(crc_2D)); |
||||
crc_init_2D = 1; |
||||
} |
||||
|
||||
return 0; |
||||
} |
||||
|
||||
void av_cold ff_mlp_init_crc() |
||||
{ |
||||
if (!crc_init) { |
||||
av_crc_init(crc_63, 0, 8, 0x63, sizeof(crc_63)); |
||||
av_crc_init(crc_1D, 0, 8, 0x1D, sizeof(crc_1D)); |
||||
crc_init = 1; |
||||
} |
||||
} |
||||
|
||||
uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_size) |
||||
{ |
||||
uint16_t crc; |
||||
|
||||
crc = av_crc(crc_2D, 0, buf, buf_size - 2); |
||||
crc ^= AV_RL16(buf + buf_size - 2); |
||||
return crc; |
||||
} |
||||
|
||||
uint8_t ff_mlp_checksum8(const uint8_t *buf, unsigned int buf_size) |
||||
{ |
||||
uint8_t checksum = av_crc(crc_63, 0x3c, buf, buf_size - 1); // crc_63[0xa2] == 0x3c
|
||||
checksum ^= buf[buf_size-1]; |
||||
return checksum; |
||||
} |
||||
|
||||
uint8_t ff_mlp_restart_checksum(const uint8_t *buf, unsigned int bit_size) |
||||
{ |
||||
int i; |
||||
int num_bytes = (bit_size + 2) / 8; |
||||
|
||||
int crc = crc_1D[buf[0] & 0x3f]; |
||||
crc = av_crc(crc_1D, crc, buf + 1, num_bytes - 2); |
||||
crc ^= buf[num_bytes - 1]; |
||||
|
||||
for (i = 0; i < ((bit_size + 2) & 7); i++) { |
||||
crc <<= 1; |
||||
if (crc & 0x100) |
||||
crc ^= 0x11D; |
||||
crc ^= (buf[num_bytes] >> (7 - i)) & 1; |
||||
} |
||||
|
||||
return crc; |
||||
} |
||||
|
||||
uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size) |
||||
{ |
||||
uint32_t scratch = 0; |
||||
const uint8_t *buf_end = buf + buf_size; |
||||
|
||||
for (; buf < buf_end - 3; buf += 4) |
||||
scratch ^= *((const uint32_t*)buf); |
||||
|
||||
scratch ^= scratch >> 16; |
||||
scratch ^= scratch >> 8; |
||||
|
||||
for (; buf < buf_end; buf++) |
||||
scratch ^= *buf; |
||||
|
||||
return scratch; |
||||
} |
||||
@ -0,0 +1,109 @@ |
||||
/*
|
||||
* 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 FFMPEG_MLP_H |
||||
#define FFMPEG_MLP_H |
||||
|
||||
#include <stdint.h> |
||||
|
||||
#include "avcodec.h" |
||||
|
||||
/** Maximum number of channels that can be decoded. */ |
||||
#define MAX_CHANNELS 16 |
||||
|
||||
/** 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 15 |
||||
|
||||
/** 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. */ |
||||
#define MAX_SUBSTREAMS 2 |
||||
|
||||
/** maximum sample frequency seen in files */ |
||||
#define MAX_SAMPLERATE 192000 |
||||
|
||||
/** maximum number of audio samples within one access unit */ |
||||
#define MAX_BLOCKSIZE (40 * (MAX_SAMPLERATE / 48000)) |
||||
/** next power of two greater than MAX_BLOCKSIZE */ |
||||
#define MAX_BLOCKSIZE_POW2 (64 * (MAX_SAMPLERATE / 48000)) |
||||
|
||||
/** number of allowed filters */ |
||||
#define NUM_FILTERS 2 |
||||
|
||||
/** 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 MAX_FILTER_ORDER 8 |
||||
|
||||
#define FIR 0 |
||||
#define IIR 1 |
||||
|
||||
/** filter data */ |
||||
typedef struct { |
||||
uint8_t order; ///< number of taps in filter
|
||||
uint8_t shift; ///< Right shift to apply to output of filter.
|
||||
|
||||
int32_t coeff[MAX_FILTER_ORDER]; |
||||
int32_t state[MAX_FILTER_ORDER]; |
||||
} FilterParams; |
||||
|
||||
/** sample data coding information */ |
||||
typedef struct { |
||||
FilterParams filter_params[NUM_FILTERS]; |
||||
|
||||
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); |
||||
|
||||
int ff_mlp_init_crc2D(AVCodecParserContext *s); |
||||
|
||||
void ff_mlp_init_crc(); |
||||
|
||||
#endif /* FFMPEG_MLP_H */ |
||||
Loading…
Reference in new issue