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apedec.c
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apedec.c
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/*
* Monkey's Audio lossless audio decoder
* Copyright (c) 2007 Benjamin Zores <[email protected]>
* based upon libdemac from Dave Chapman.
*
* 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 <inttypes.h>
#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/crc.h"
#include "libavutil/opt.h"
#include "lossless_audiodsp.h"
#include "avcodec.h"
#include "bswapdsp.h"
#include "bytestream.h"
#include "internal.h"
#include "get_bits.h"
#include "unary.h"
/**
* @file
* Monkey's Audio lossless audio decoder
*/
#define MAX_CHANNELS 2
#define MAX_BYTESPERSAMPLE 3
#define APE_FRAMECODE_MONO_SILENCE 1
#define APE_FRAMECODE_STEREO_SILENCE 3
#define APE_FRAMECODE_PSEUDO_STEREO 4
#define HISTORY_SIZE 512
#define PREDICTOR_ORDER 8
/** Total size of all predictor histories */
#define PREDICTOR_SIZE 50
#define YDELAYA (18 + PREDICTOR_ORDER*4)
#define YDELAYB (18 + PREDICTOR_ORDER*3)
#define XDELAYA (18 + PREDICTOR_ORDER*2)
#define XDELAYB (18 + PREDICTOR_ORDER)
#define YADAPTCOEFFSA 18
#define XADAPTCOEFFSA 14
#define YADAPTCOEFFSB 10
#define XADAPTCOEFFSB 5
/**
* Possible compression levels
* @{
*/
enum APECompressionLevel {
COMPRESSION_LEVEL_FAST = 1000,
COMPRESSION_LEVEL_NORMAL = 2000,
COMPRESSION_LEVEL_HIGH = 3000,
COMPRESSION_LEVEL_EXTRA_HIGH = 4000,
COMPRESSION_LEVEL_INSANE = 5000
};
/** @} */
#define APE_FILTER_LEVELS 3
/** Filter orders depending on compression level */
static const uint16_t ape_filter_orders[5][APE_FILTER_LEVELS] = {
{ 0, 0, 0 },
{ 16, 0, 0 },
{ 64, 0, 0 },
{ 32, 256, 0 },
{ 16, 256, 1280 }
};
/** Filter fraction bits depending on compression level */
static const uint8_t ape_filter_fracbits[5][APE_FILTER_LEVELS] = {
{ 0, 0, 0 },
{ 11, 0, 0 },
{ 11, 0, 0 },
{ 10, 13, 0 },
{ 11, 13, 15 }
};
/** Filters applied to the decoded data */
typedef struct APEFilter {
int16_t *coeffs; ///< actual coefficients used in filtering
int16_t *adaptcoeffs; ///< adaptive filter coefficients used for correcting of actual filter coefficients
int16_t *historybuffer; ///< filter memory
int16_t *delay; ///< filtered values
uint32_t avg;
} APEFilter;
typedef struct APERice {
uint32_t k;
uint32_t ksum;
} APERice;
typedef struct APERangecoder {
uint32_t low; ///< low end of interval
uint32_t range; ///< length of interval
uint32_t help; ///< bytes_to_follow resp. intermediate value
unsigned int buffer; ///< buffer for input/output
} APERangecoder;
/** Filter histories */
typedef struct APEPredictor {
int32_t *buf;
int32_t lastA[2];
int32_t filterA[2];
int32_t filterB[2];
uint32_t coeffsA[2][4]; ///< adaption coefficients
uint32_t coeffsB[2][5]; ///< adaption coefficients
int32_t historybuffer[HISTORY_SIZE + PREDICTOR_SIZE];
unsigned int sample_pos;
} APEPredictor;
/** Decoder context */
typedef struct APEContext {
AVClass *class; ///< class for AVOptions
AVCodecContext *avctx;
BswapDSPContext bdsp;
LLAudDSPContext adsp;
int channels;
int samples; ///< samples left to decode in current frame
int bps;
int fileversion; ///< codec version, very important in decoding process
int compression_level; ///< compression levels
int fset; ///< which filter set to use (calculated from compression level)
int flags; ///< global decoder flags
uint32_t CRC; ///< signalled frame CRC
uint32_t CRC_state; ///< accumulated CRC
int frameflags; ///< frame flags
APEPredictor predictor; ///< predictor used for final reconstruction
int32_t *decoded_buffer;
int decoded_size;
int32_t *decoded[MAX_CHANNELS]; ///< decoded data for each channel
int blocks_per_loop; ///< maximum number of samples to decode for each call
int16_t* filterbuf[APE_FILTER_LEVELS]; ///< filter memory
APERangecoder rc; ///< rangecoder used to decode actual values
APERice riceX; ///< rice code parameters for the second channel
APERice riceY; ///< rice code parameters for the first channel
APEFilter filters[APE_FILTER_LEVELS][2]; ///< filters used for reconstruction
GetBitContext gb;
uint8_t *data; ///< current frame data
uint8_t *data_end; ///< frame data end
int data_size; ///< frame data allocated size
const uint8_t *ptr; ///< current position in frame data
int error;
void (*entropy_decode_mono)(struct APEContext *ctx, int blockstodecode);
void (*entropy_decode_stereo)(struct APEContext *ctx, int blockstodecode);
void (*predictor_decode_mono)(struct APEContext *ctx, int count);
void (*predictor_decode_stereo)(struct APEContext *ctx, int count);
} APEContext;
static void ape_apply_filters(APEContext *ctx, int32_t *decoded0,
int32_t *decoded1, int count);
static void entropy_decode_mono_0000(APEContext *ctx, int blockstodecode);
static void entropy_decode_stereo_0000(APEContext *ctx, int blockstodecode);
static void entropy_decode_mono_3860(APEContext *ctx, int blockstodecode);
static void entropy_decode_stereo_3860(APEContext *ctx, int blockstodecode);
static void entropy_decode_mono_3900(APEContext *ctx, int blockstodecode);
static void entropy_decode_stereo_3900(APEContext *ctx, int blockstodecode);
static void entropy_decode_stereo_3930(APEContext *ctx, int blockstodecode);
static void entropy_decode_mono_3990(APEContext *ctx, int blockstodecode);
static void entropy_decode_stereo_3990(APEContext *ctx, int blockstodecode);
static void predictor_decode_mono_3800(APEContext *ctx, int count);
static void predictor_decode_stereo_3800(APEContext *ctx, int count);
static void predictor_decode_mono_3930(APEContext *ctx, int count);
static void predictor_decode_stereo_3930(APEContext *ctx, int count);
static void predictor_decode_mono_3950(APEContext *ctx, int count);
static void predictor_decode_stereo_3950(APEContext *ctx, int count);
static av_cold int ape_decode_close(AVCodecContext *avctx)
{
APEContext *s = avctx->priv_data;
int i;
for (i = 0; i < APE_FILTER_LEVELS; i++)
av_freep(&s->filterbuf[i]);
av_freep(&s->decoded_buffer);
av_freep(&s->data);
s->decoded_size = s->data_size = 0;
return 0;
}
static av_cold int ape_decode_init(AVCodecContext *avctx)
{
APEContext *s = avctx->priv_data;
int i;
if (avctx->extradata_size != 6) {
av_log(avctx, AV_LOG_ERROR, "Incorrect extradata\n");
return AVERROR(EINVAL);
}
if (avctx->channels > 2) {
av_log(avctx, AV_LOG_ERROR, "Only mono and stereo is supported\n");
return AVERROR(EINVAL);
}
s->bps = avctx->bits_per_coded_sample;
switch (s->bps) {
case 8:
avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
break;
case 16:
avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
break;
case 24:
avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
break;
default:
avpriv_request_sample(avctx,
"%d bits per coded sample", s->bps);
return AVERROR_PATCHWELCOME;
}
s->avctx = avctx;
s->channels = avctx->channels;
s->fileversion = AV_RL16(avctx->extradata);
s->compression_level = AV_RL16(avctx->extradata + 2);
s->flags = AV_RL16(avctx->extradata + 4);
av_log(avctx, AV_LOG_VERBOSE, "Compression Level: %d - Flags: %d\n",
s->compression_level, s->flags);
if (s->compression_level % 1000 || s->compression_level > COMPRESSION_LEVEL_INSANE ||
!s->compression_level ||
(s->fileversion < 3930 && s->compression_level == COMPRESSION_LEVEL_INSANE)) {
av_log(avctx, AV_LOG_ERROR, "Incorrect compression level %d\n",
s->compression_level);
return AVERROR_INVALIDDATA;
}
s->fset = s->compression_level / 1000 - 1;
for (i = 0; i < APE_FILTER_LEVELS; i++) {
if (!ape_filter_orders[s->fset][i])
break;
FF_ALLOC_OR_GOTO(avctx, s->filterbuf[i],
(ape_filter_orders[s->fset][i] * 3 + HISTORY_SIZE) * 4,
filter_alloc_fail);
}
if (s->fileversion < 3860) {
s->entropy_decode_mono = entropy_decode_mono_0000;
s->entropy_decode_stereo = entropy_decode_stereo_0000;
} else if (s->fileversion < 3900) {
s->entropy_decode_mono = entropy_decode_mono_3860;
s->entropy_decode_stereo = entropy_decode_stereo_3860;
} else if (s->fileversion < 3930) {
s->entropy_decode_mono = entropy_decode_mono_3900;
s->entropy_decode_stereo = entropy_decode_stereo_3900;
} else if (s->fileversion < 3990) {
s->entropy_decode_mono = entropy_decode_mono_3900;
s->entropy_decode_stereo = entropy_decode_stereo_3930;
} else {
s->entropy_decode_mono = entropy_decode_mono_3990;
s->entropy_decode_stereo = entropy_decode_stereo_3990;
}
if (s->fileversion < 3930) {
s->predictor_decode_mono = predictor_decode_mono_3800;
s->predictor_decode_stereo = predictor_decode_stereo_3800;
} else if (s->fileversion < 3950) {
s->predictor_decode_mono = predictor_decode_mono_3930;
s->predictor_decode_stereo = predictor_decode_stereo_3930;
} else {
s->predictor_decode_mono = predictor_decode_mono_3950;
s->predictor_decode_stereo = predictor_decode_stereo_3950;
}
ff_bswapdsp_init(&s->bdsp);
ff_llauddsp_init(&s->adsp);
avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
return 0;
filter_alloc_fail:
ape_decode_close(avctx);
return AVERROR(ENOMEM);
}
/**
* @name APE range decoding functions
* @{
*/
#define CODE_BITS 32
#define TOP_VALUE ((unsigned int)1 << (CODE_BITS-1))
#define SHIFT_BITS (CODE_BITS - 9)
#define EXTRA_BITS ((CODE_BITS-2) % 8 + 1)
#define BOTTOM_VALUE (TOP_VALUE >> 8)
/** Start the decoder */
static inline void range_start_decoding(APEContext *ctx)
{
ctx->rc.buffer = bytestream_get_byte(&ctx->ptr);
ctx->rc.low = ctx->rc.buffer >> (8 - EXTRA_BITS);
ctx->rc.range = (uint32_t) 1 << EXTRA_BITS;
}
/** Perform normalization */
static inline void range_dec_normalize(APEContext *ctx)
{
while (ctx->rc.range <= BOTTOM_VALUE) {
ctx->rc.buffer <<= 8;
if(ctx->ptr < ctx->data_end) {
ctx->rc.buffer += *ctx->ptr;
ctx->ptr++;
} else {
ctx->error = 1;
}
ctx->rc.low = (ctx->rc.low << 8) | ((ctx->rc.buffer >> 1) & 0xFF);
ctx->rc.range <<= 8;
}
}
/**
* Calculate cumulative frequency for next symbol. Does NO update!
* @param ctx decoder context
* @param tot_f is the total frequency or (code_value)1<<shift
* @return the cumulative frequency
*/
static inline int range_decode_culfreq(APEContext *ctx, int tot_f)
{
range_dec_normalize(ctx);
ctx->rc.help = ctx->rc.range / tot_f;
return ctx->rc.low / ctx->rc.help;
}
/**
* Decode value with given size in bits
* @param ctx decoder context
* @param shift number of bits to decode
*/
static inline int range_decode_culshift(APEContext *ctx, int shift)
{
range_dec_normalize(ctx);
ctx->rc.help = ctx->rc.range >> shift;
return ctx->rc.low / ctx->rc.help;
}
/**
* Update decoding state
* @param ctx decoder context
* @param sy_f the interval length (frequency of the symbol)
* @param lt_f the lower end (frequency sum of < symbols)
*/
static inline void range_decode_update(APEContext *ctx, int sy_f, int lt_f)
{
ctx->rc.low -= ctx->rc.help * lt_f;
ctx->rc.range = ctx->rc.help * sy_f;
}
/** Decode n bits (n <= 16) without modelling */
static inline int range_decode_bits(APEContext *ctx, int n)
{
int sym = range_decode_culshift(ctx, n);
range_decode_update(ctx, 1, sym);
return sym;
}
#define MODEL_ELEMENTS 64
/**
* Fixed probabilities for symbols in Monkey Audio version 3.97
*/
static const uint16_t counts_3970[22] = {
0, 14824, 28224, 39348, 47855, 53994, 58171, 60926,
62682, 63786, 64463, 64878, 65126, 65276, 65365, 65419,
65450, 65469, 65480, 65487, 65491, 65493,
};
/**
* Probability ranges for symbols in Monkey Audio version 3.97
*/
static const uint16_t counts_diff_3970[21] = {
14824, 13400, 11124, 8507, 6139, 4177, 2755, 1756,
1104, 677, 415, 248, 150, 89, 54, 31,
19, 11, 7, 4, 2,
};
/**
* Fixed probabilities for symbols in Monkey Audio version 3.98
*/
static const uint16_t counts_3980[22] = {
0, 19578, 36160, 48417, 56323, 60899, 63265, 64435,
64971, 65232, 65351, 65416, 65447, 65466, 65476, 65482,
65485, 65488, 65490, 65491, 65492, 65493,
};
/**
* Probability ranges for symbols in Monkey Audio version 3.98
*/
static const uint16_t counts_diff_3980[21] = {
19578, 16582, 12257, 7906, 4576, 2366, 1170, 536,
261, 119, 65, 31, 19, 10, 6, 3,
3, 2, 1, 1, 1,
};
/**
* Decode symbol
* @param ctx decoder context
* @param counts probability range start position
* @param counts_diff probability range widths
*/
static inline int range_get_symbol(APEContext *ctx,
const uint16_t counts[],
const uint16_t counts_diff[])
{
int symbol, cf;
cf = range_decode_culshift(ctx, 16);
if(cf > 65492){
symbol= cf - 65535 + 63;
range_decode_update(ctx, 1, cf);
if(cf > 65535)
ctx->error=1;
return symbol;
}
/* figure out the symbol inefficiently; a binary search would be much better */
for (symbol = 0; counts[symbol + 1] <= cf; symbol++);
range_decode_update(ctx, counts_diff[symbol], counts[symbol]);
return symbol;
}
/** @} */ // group rangecoder
static inline void update_rice(APERice *rice, unsigned int x)
{
int lim = rice->k ? (1 << (rice->k + 4)) : 0;
rice->ksum += ((x + 1) / 2) - ((rice->ksum + 16) >> 5);
if (rice->ksum < lim)
rice->k--;
else if (rice->ksum >= (1 << (rice->k + 5)) && rice->k < 24)
rice->k++;
}
static inline int get_rice_ook(GetBitContext *gb, int k)
{
unsigned int x;
x = get_unary(gb, 1, get_bits_left(gb));
if (k)
x = (x << k) | get_bits(gb, k);
return x;
}
static inline int ape_decode_value_3860(APEContext *ctx, GetBitContext *gb,
APERice *rice)
{
unsigned int x, overflow;
overflow = get_unary(gb, 1, get_bits_left(gb));
if (ctx->fileversion > 3880) {
while (overflow >= 16) {
overflow -= 16;
rice->k += 4;
}
}
if (!rice->k)
x = overflow;
else if(rice->k <= MIN_CACHE_BITS) {
x = (overflow << rice->k) + get_bits(gb, rice->k);
} else {
av_log(ctx->avctx, AV_LOG_ERROR, "Too many bits: %"PRIu32"\n", rice->k);
ctx->error = 1;
return AVERROR_INVALIDDATA;
}
rice->ksum += x - (rice->ksum + 8 >> 4);
if (rice->ksum < (rice->k ? 1 << (rice->k + 4) : 0))
rice->k--;
else if (rice->ksum >= (1 << (rice->k + 5)) && rice->k < 24)
rice->k++;
/* Convert to signed */
return ((x >> 1) ^ ((x & 1) - 1)) + 1;
}
static inline int ape_decode_value_3900(APEContext *ctx, APERice *rice)
{
unsigned int x, overflow;
int tmpk;
overflow = range_get_symbol(ctx, counts_3970, counts_diff_3970);
if (overflow == (MODEL_ELEMENTS - 1)) {
tmpk = range_decode_bits(ctx, 5);
overflow = 0;
} else
tmpk = (rice->k < 1) ? 0 : rice->k - 1;
if (tmpk <= 16 || ctx->fileversion < 3910) {
if (tmpk > 23) {
av_log(ctx->avctx, AV_LOG_ERROR, "Too many bits: %d\n", tmpk);
return AVERROR_INVALIDDATA;
}
x = range_decode_bits(ctx, tmpk);
} else if (tmpk <= 31) {
x = range_decode_bits(ctx, 16);
x |= (range_decode_bits(ctx, tmpk - 16) << 16);
} else {
av_log(ctx->avctx, AV_LOG_ERROR, "Too many bits: %d\n", tmpk);
return AVERROR_INVALIDDATA;
}
x += overflow << tmpk;
update_rice(rice, x);
/* Convert to signed */
return ((x >> 1) ^ ((x & 1) - 1)) + 1;
}
static inline int ape_decode_value_3990(APEContext *ctx, APERice *rice)
{
unsigned int x, overflow;
int base, pivot;
pivot = rice->ksum >> 5;
if (pivot == 0)
pivot = 1;
overflow = range_get_symbol(ctx, counts_3980, counts_diff_3980);
if (overflow == (MODEL_ELEMENTS - 1)) {
overflow = (unsigned)range_decode_bits(ctx, 16) << 16;
overflow |= range_decode_bits(ctx, 16);
}
if (pivot < 0x10000) {
base = range_decode_culfreq(ctx, pivot);
range_decode_update(ctx, 1, base);
} else {
int base_hi = pivot, base_lo;
int bbits = 0;
while (base_hi & ~0xFFFF) {
base_hi >>= 1;
bbits++;
}
base_hi = range_decode_culfreq(ctx, base_hi + 1);
range_decode_update(ctx, 1, base_hi);
base_lo = range_decode_culfreq(ctx, 1 << bbits);
range_decode_update(ctx, 1, base_lo);
base = (base_hi << bbits) + base_lo;
}
x = base + overflow * pivot;
update_rice(rice, x);
/* Convert to signed */
return ((x >> 1) ^ ((x & 1) - 1)) + 1;
}
static int get_k(int ksum)
{
return av_log2(ksum) + !!ksum;
}
static void decode_array_0000(APEContext *ctx, GetBitContext *gb,
int32_t *out, APERice *rice, int blockstodecode)
{
int i;
unsigned ksummax, ksummin;
rice->ksum = 0;
for (i = 0; i < FFMIN(blockstodecode, 5); i++) {
out[i] = get_rice_ook(&ctx->gb, 10);
rice->ksum += out[i];
}
if (blockstodecode <= 5)
goto end;
rice->k = get_k(rice->ksum / 10);
if (rice->k >= 24)
return;
for (; i < FFMIN(blockstodecode, 64); i++) {
out[i] = get_rice_ook(&ctx->gb, rice->k);
rice->ksum += out[i];
rice->k = get_k(rice->ksum / ((i + 1) * 2));
if (rice->k >= 24)
return;
}
if (blockstodecode <= 64)
goto end;
rice->k = get_k(rice->ksum >> 7);
ksummax = 1 << rice->k + 7;
ksummin = rice->k ? (1 << rice->k + 6) : 0;
for (; i < blockstodecode; i++) {
if (get_bits_left(&ctx->gb) < 1) {
ctx->error = 1;
return;
}
out[i] = get_rice_ook(&ctx->gb, rice->k);
rice->ksum += out[i] - (unsigned)out[i - 64];
while (rice->ksum < ksummin) {
rice->k--;
ksummin = rice->k ? ksummin >> 1 : 0;
ksummax >>= 1;
}
while (rice->ksum >= ksummax) {
rice->k++;
if (rice->k > 24)
return;
ksummax <<= 1;
ksummin = ksummin ? ksummin << 1 : 128;
}
}
end:
for (i = 0; i < blockstodecode; i++)
out[i] = ((out[i] >> 1) ^ ((out[i] & 1) - 1)) + 1;
}
static void entropy_decode_mono_0000(APEContext *ctx, int blockstodecode)
{
decode_array_0000(ctx, &ctx->gb, ctx->decoded[0], &ctx->riceY,
blockstodecode);
}
static void entropy_decode_stereo_0000(APEContext *ctx, int blockstodecode)
{
decode_array_0000(ctx, &ctx->gb, ctx->decoded[0], &ctx->riceY,
blockstodecode);
decode_array_0000(ctx, &ctx->gb, ctx->decoded[1], &ctx->riceX,
blockstodecode);
}
static void entropy_decode_mono_3860(APEContext *ctx, int blockstodecode)
{
int32_t *decoded0 = ctx->decoded[0];
while (blockstodecode--)
*decoded0++ = ape_decode_value_3860(ctx, &ctx->gb, &ctx->riceY);
}
static void entropy_decode_stereo_3860(APEContext *ctx, int blockstodecode)
{
int32_t *decoded0 = ctx->decoded[0];
int32_t *decoded1 = ctx->decoded[1];
int blocks = blockstodecode;
while (blockstodecode--)
*decoded0++ = ape_decode_value_3860(ctx, &ctx->gb, &ctx->riceY);
while (blocks--)
*decoded1++ = ape_decode_value_3860(ctx, &ctx->gb, &ctx->riceX);
}
static void entropy_decode_mono_3900(APEContext *ctx, int blockstodecode)
{
int32_t *decoded0 = ctx->decoded[0];
while (blockstodecode--)
*decoded0++ = ape_decode_value_3900(ctx, &ctx->riceY);
}
static void entropy_decode_stereo_3900(APEContext *ctx, int blockstodecode)
{
int32_t *decoded0 = ctx->decoded[0];
int32_t *decoded1 = ctx->decoded[1];
int blocks = blockstodecode;
while (blockstodecode--)
*decoded0++ = ape_decode_value_3900(ctx, &ctx->riceY);
range_dec_normalize(ctx);
// because of some implementation peculiarities we need to backpedal here
ctx->ptr -= 1;
range_start_decoding(ctx);
while (blocks--)
*decoded1++ = ape_decode_value_3900(ctx, &ctx->riceX);
}
static void entropy_decode_stereo_3930(APEContext *ctx, int blockstodecode)
{
int32_t *decoded0 = ctx->decoded[0];
int32_t *decoded1 = ctx->decoded[1];
while (blockstodecode--) {
*decoded0++ = ape_decode_value_3900(ctx, &ctx->riceY);
*decoded1++ = ape_decode_value_3900(ctx, &ctx->riceX);
}
}
static void entropy_decode_mono_3990(APEContext *ctx, int blockstodecode)
{
int32_t *decoded0 = ctx->decoded[0];
while (blockstodecode--)
*decoded0++ = ape_decode_value_3990(ctx, &ctx->riceY);
}
static void entropy_decode_stereo_3990(APEContext *ctx, int blockstodecode)
{
int32_t *decoded0 = ctx->decoded[0];
int32_t *decoded1 = ctx->decoded[1];
while (blockstodecode--) {
*decoded0++ = ape_decode_value_3990(ctx, &ctx->riceY);
*decoded1++ = ape_decode_value_3990(ctx, &ctx->riceX);
}
}
static int init_entropy_decoder(APEContext *ctx)
{
/* Read the CRC */
if (ctx->fileversion >= 3900) {
if (ctx->data_end - ctx->ptr < 6)
return AVERROR_INVALIDDATA;
ctx->CRC = bytestream_get_be32(&ctx->ptr);
} else {
ctx->CRC = get_bits_long(&ctx->gb, 32);
}
/* Read the frame flags if they exist */
ctx->frameflags = 0;
ctx->CRC_state = UINT32_MAX;
if ((ctx->fileversion > 3820) && (ctx->CRC & 0x80000000)) {
ctx->CRC &= ~0x80000000;
if (ctx->data_end - ctx->ptr < 6)
return AVERROR_INVALIDDATA;
ctx->frameflags = bytestream_get_be32(&ctx->ptr);
}
/* Initialize the rice structs */
ctx->riceX.k = 10;
ctx->riceX.ksum = (1 << ctx->riceX.k) * 16;
ctx->riceY.k = 10;
ctx->riceY.ksum = (1 << ctx->riceY.k) * 16;
if (ctx->fileversion >= 3900) {
/* The first 8 bits of input are ignored. */
ctx->ptr++;
range_start_decoding(ctx);
}
return 0;
}
static const int32_t initial_coeffs_fast_3320[1] = {
375,
};
static const int32_t initial_coeffs_a_3800[3] = {
64, 115, 64,
};
static const int32_t initial_coeffs_b_3800[2] = {
740, 0
};
static const int32_t initial_coeffs_3930[4] = {
360, 317, -109, 98
};
static void init_predictor_decoder(APEContext *ctx)
{
APEPredictor *p = &ctx->predictor;
/* Zero the history buffers */
memset(p->historybuffer, 0, PREDICTOR_SIZE * sizeof(*p->historybuffer));
p->buf = p->historybuffer;
/* Initialize and zero the coefficients */
if (ctx->fileversion < 3930) {
if (ctx->compression_level == COMPRESSION_LEVEL_FAST) {
memcpy(p->coeffsA[0], initial_coeffs_fast_3320,
sizeof(initial_coeffs_fast_3320));
memcpy(p->coeffsA[1], initial_coeffs_fast_3320,
sizeof(initial_coeffs_fast_3320));
} else {
memcpy(p->coeffsA[0], initial_coeffs_a_3800,
sizeof(initial_coeffs_a_3800));
memcpy(p->coeffsA[1], initial_coeffs_a_3800,
sizeof(initial_coeffs_a_3800));
}
} else {
memcpy(p->coeffsA[0], initial_coeffs_3930, sizeof(initial_coeffs_3930));
memcpy(p->coeffsA[1], initial_coeffs_3930, sizeof(initial_coeffs_3930));
}
memset(p->coeffsB, 0, sizeof(p->coeffsB));
if (ctx->fileversion < 3930) {
memcpy(p->coeffsB[0], initial_coeffs_b_3800,
sizeof(initial_coeffs_b_3800));
memcpy(p->coeffsB[1], initial_coeffs_b_3800,
sizeof(initial_coeffs_b_3800));
}
p->filterA[0] = p->filterA[1] = 0;
p->filterB[0] = p->filterB[1] = 0;
p->lastA[0] = p->lastA[1] = 0;
p->sample_pos = 0;
}
/** Get inverse sign of integer (-1 for positive, 1 for negative and 0 for zero) */
static inline int APESIGN(int32_t x) {
return (x < 0) - (x > 0);
}
static av_always_inline int filter_fast_3320(APEPredictor *p,
const int decoded, const int filter,
const int delayA)
{
int32_t predictionA;
p->buf[delayA] = p->lastA[filter];
if (p->sample_pos < 3) {
p->lastA[filter] = decoded;
p->filterA[filter] = decoded;
return decoded;
}
predictionA = p->buf[delayA] * 2U - p->buf[delayA - 1];
p->lastA[filter] = decoded + (unsigned)((int32_t)(predictionA * p->coeffsA[filter][0]) >> 9);
if ((decoded ^ predictionA) > 0)
p->coeffsA[filter][0]++;
else
p->coeffsA[filter][0]--;
p->filterA[filter] += (unsigned)p->lastA[filter];
return p->filterA[filter];
}
static av_always_inline int filter_3800(APEPredictor *p,
const unsigned decoded, const int filter,
const int delayA, const int delayB,
const int start, const int shift)
{
int32_t predictionA, predictionB, sign;
int32_t d0, d1, d2, d3, d4;
p->buf[delayA] = p->lastA[filter];
p->buf[delayB] = p->filterB[filter];
if (p->sample_pos < start) {
predictionA = decoded + p->filterA[filter];
p->lastA[filter] = decoded;
p->filterB[filter] = decoded;
p->filterA[filter] = predictionA;
return predictionA;
}
d2 = p->buf[delayA];
d1 = (p->buf[delayA] - (unsigned)p->buf[delayA - 1]) * 2;
d0 = p->buf[delayA] + ((p->buf[delayA - 2] - (unsigned)p->buf[delayA - 1]) * 8);
d3 = p->buf[delayB] * 2U - p->buf[delayB - 1];
d4 = p->buf[delayB];
predictionA = d0 * p->coeffsA[filter][0] +
d1 * p->coeffsA[filter][1] +
d2 * p->coeffsA[filter][2];
sign = APESIGN(decoded);
p->coeffsA[filter][0] += (((d0 >> 30) & 2) - 1) * sign;
p->coeffsA[filter][1] += (((d1 >> 28) & 8) - 4) * sign;
p->coeffsA[filter][2] += (((d2 >> 28) & 8) - 4) * sign;
predictionB = d3 * p->coeffsB[filter][0] -
d4 * p->coeffsB[filter][1];
p->lastA[filter] = decoded + (predictionA >> 11);
sign = APESIGN(p->lastA[filter]);
p->coeffsB[filter][0] += (((d3 >> 29) & 4) - 2) * sign;
p->coeffsB[filter][1] -= (((d4 >> 30) & 2) - 1) * sign;
p->filterB[filter] = p->lastA[filter] + (unsigned)(predictionB >> shift);
p->filterA[filter] = p->filterB[filter] + (unsigned)((int)(p->filterA[filter] * 31U) >> 5);
return p->filterA[filter];
}
static void long_filter_high_3800(int32_t *buffer, int order, int shift, int length)
{
int i, j;
int32_t dotprod, sign;
int32_t coeffs[256], delay[256];
if (order >= length)
return;
memset(coeffs, 0, order * sizeof(*coeffs));
for (i = 0; i < order; i++)
delay[i] = buffer[i];
for (i = order; i < length; i++) {
dotprod = 0;
sign = APESIGN(buffer[i]);
for (j = 0; j < order; j++) {
dotprod += delay[j] * (unsigned)coeffs[j];
coeffs[j] += ((delay[j] >> 31) | 1) * sign;
}
buffer[i] -= (unsigned)(dotprod >> shift);
for (j = 0; j < order - 1; j++)
delay[j] = delay[j + 1];
delay[order - 1] = buffer[i];
}
}
static void long_filter_ehigh_3830(int32_t *buffer, int length)
{
int i, j;
int32_t dotprod, sign;
int32_t delay[8] = { 0 };
uint32_t coeffs[8] = { 0 };
for (i = 0; i < length; i++) {
dotprod = 0;
sign = APESIGN(buffer[i]);
for (j = 7; j >= 0; j--) {
dotprod += delay[j] * coeffs[j];
coeffs[j] += ((delay[j] >> 31) | 1) * sign;
}
for (j = 7; j > 0; j--)
delay[j] = delay[j - 1];
delay[0] = buffer[i];
buffer[i] -= (unsigned)(dotprod >> 9);
}
}
static void predictor_decode_stereo_3800(APEContext *ctx, int count)
{
APEPredictor *p = &ctx->predictor;
int32_t *decoded0 = ctx->decoded[0];
int32_t *decoded1 = ctx->decoded[1];
int start = 4, shift = 10;
if (ctx->compression_level == COMPRESSION_LEVEL_HIGH) {
start = 16;
long_filter_high_3800(decoded0, 16, 9, count);
long_filter_high_3800(decoded1, 16, 9, count);
} else if (ctx->compression_level == COMPRESSION_LEVEL_EXTRA_HIGH) {
int order = 128, shift2 = 11;
if (ctx->fileversion >= 3830) {
order <<= 1;
shift++;
shift2++;
long_filter_ehigh_3830(decoded0 + order, count - order);
long_filter_ehigh_3830(decoded1 + order, count - order);
}
start = order;
long_filter_high_3800(decoded0, order, shift2, count);
long_filter_high_3800(decoded1, order, shift2, count);
}
while (count--) {
int X = *decoded0, Y = *decoded1;
if (ctx->compression_level == COMPRESSION_LEVEL_FAST) {
*decoded0 = filter_fast_3320(p, Y, 0, YDELAYA);
decoded0++;
*decoded1 = filter_fast_3320(p, X, 1, XDELAYA);
decoded1++;
} else {
*decoded0 = filter_3800(p, Y, 0, YDELAYA, YDELAYB,
start, shift);
decoded0++;
*decoded1 = filter_3800(p, X, 1, XDELAYA, XDELAYB,
start, shift);
decoded1++;
}