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- /*
- * Monkey's Audio lossless audio decoder
- * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>
- * 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
- */
- #define ALT_BITSTREAM_READER_LE
- #include "avcodec.h"
- #include "dsputil.h"
- #include "bitstream.h"
- #include "bytestream.h"
- /**
- * @file libavcodec/apedec.c
- * Monkey's Audio lossless audio decoder
- */
- #define BLOCKS_PER_LOOP 4608
- #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
- int 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];
- int32_t coeffsA[2][4]; ///< adaption coefficients
- int32_t coeffsB[2][5]; ///< adaption coefficients
- int32_t historybuffer[HISTORY_SIZE + PREDICTOR_SIZE];
- } APEPredictor;
- /** Decoder context */
- typedef struct APEContext {
- AVCodecContext *avctx;
- DSPContext dsp;
- int channels;
- int samples; ///< samples left to decode in current frame
- 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; ///< frame CRC
- int frameflags; ///< frame flags
- int currentframeblocks; ///< samples (per channel) in current frame
- int blocksdecoded; ///< count of decoded samples in current frame
- APEPredictor predictor; ///< predictor used for final reconstruction
- int32_t decoded0[BLOCKS_PER_LOOP]; ///< decoded data for the first channel
- int32_t decoded1[BLOCKS_PER_LOOP]; ///< decoded data for the second channel
- 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
- uint8_t *data; ///< current frame data
- uint8_t *data_end; ///< frame data end
- const uint8_t *ptr; ///< current position in frame data
- const uint8_t *last_ptr; ///< position where last 4608-sample block ended
- int error;
- } APEContext;
- // TODO: dsputilize
- 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 -1;
- }
- if (avctx->bits_per_coded_sample != 16) {
- av_log(avctx, AV_LOG_ERROR, "Only 16-bit samples are supported\n");
- return -1;
- }
- if (avctx->channels > 2) {
- av_log(avctx, AV_LOG_ERROR, "Only mono and stereo is supported\n");
- return -1;
- }
- 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_DEBUG, "Compression Level: %d - Flags: %d\n", s->compression_level, s->flags);
- if (s->compression_level % 1000 || s->compression_level > COMPRESSION_LEVEL_INSANE) {
- av_log(avctx, AV_LOG_ERROR, "Incorrect compression level %d\n", s->compression_level);
- return -1;
- }
- s->fset = s->compression_level / 1000 - 1;
- for (i = 0; i < APE_FILTER_LEVELS; i++) {
- if (!ape_filter_orders[s->fset][i])
- break;
- s->filterbuf[i] = av_malloc((ape_filter_orders[s->fset][i] * 3 + HISTORY_SIZE) * 4);
- }
- dsputil_init(&s->dsp, avctx);
- avctx->sample_fmt = SAMPLE_FMT_S16;
- avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
- return 0;
- }
- 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]);
- return 0;
- }
- /**
- * @defgroup rangecoder APE range decoder
- * @{
- */
- #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++;
- ctx->rc.low = (ctx->rc.low << 8) | ((ctx->rc.buffer >> 1) & 0xFF);
- ctx->rc.range <<= 8;
- }
- }
- /**
- * Calculate culmulative 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 culmulative 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, 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++;
- }
- static inline int ape_decode_value(APEContext * ctx, APERice *rice)
- {
- int x, overflow;
- if (ctx->fileversion < 3990) {
- 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)
- x = range_decode_bits(ctx, tmpk);
- else {
- x = range_decode_bits(ctx, 16);
- x |= (range_decode_bits(ctx, tmpk - 16) << 16);
- }
- x += overflow << tmpk;
- } else {
- 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 = range_decode_bits(ctx, 16) << 16;
- overflow |= range_decode_bits(ctx, 16);
- }
- base = range_decode_culfreq(ctx, pivot);
- range_decode_update(ctx, 1, base);
- x = base + overflow * pivot;
- }
- update_rice(rice, x);
- /* Convert to signed */
- if (x & 1)
- return (x >> 1) + 1;
- else
- return -(x >> 1);
- }
- static void entropy_decode(APEContext * ctx, int blockstodecode, int stereo)
- {
- int32_t *decoded0 = ctx->decoded0;
- int32_t *decoded1 = ctx->decoded1;
- ctx->blocksdecoded = blockstodecode;
- if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) {
- /* We are pure silence, just memset the output buffer. */
- memset(decoded0, 0, blockstodecode * sizeof(int32_t));
- memset(decoded1, 0, blockstodecode * sizeof(int32_t));
- } else {
- while (blockstodecode--) {
- *decoded0++ = ape_decode_value(ctx, &ctx->riceY);
- if (stereo)
- *decoded1++ = ape_decode_value(ctx, &ctx->riceX);
- }
- }
- if (ctx->blocksdecoded == ctx->currentframeblocks)
- range_dec_normalize(ctx); /* normalize to use up all bytes */
- }
- static void init_entropy_decoder(APEContext * ctx)
- {
- /* Read the CRC */
- ctx->CRC = bytestream_get_be32(&ctx->ptr);
- /* Read the frame flags if they exist */
- ctx->frameflags = 0;
- if ((ctx->fileversion > 3820) && (ctx->CRC & 0x80000000)) {
- ctx->CRC &= ~0x80000000;
- ctx->frameflags = bytestream_get_be32(&ctx->ptr);
- }
- /* Keep a count of the blocks decoded in this frame */
- ctx->blocksdecoded = 0;
- /* 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;
- /* The first 8 bits of input are ignored. */
- ctx->ptr++;
- range_start_decoding(ctx);
- }
- static const int32_t initial_coeffs[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(int32_t));
- p->buf = p->historybuffer;
- /* Initialize and zero the coefficients */
- memcpy(p->coeffsA[0], initial_coeffs, sizeof(initial_coeffs));
- memcpy(p->coeffsA[1], initial_coeffs, sizeof(initial_coeffs));
- memset(p->coeffsB, 0, sizeof(p->coeffsB));
- p->filterA[0] = p->filterA[1] = 0;
- p->filterB[0] = p->filterB[1] = 0;
- p->lastA[0] = p->lastA[1] = 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 int predictor_update_filter(APEPredictor *p, const int decoded, const int filter, const int delayA, const int delayB, const int adaptA, const int adaptB)
- {
- int32_t predictionA, predictionB;
- p->buf[delayA] = p->lastA[filter];
- p->buf[adaptA] = APESIGN(p->buf[delayA]);
- p->buf[delayA - 1] = p->buf[delayA] - p->buf[delayA - 1];
- p->buf[adaptA - 1] = APESIGN(p->buf[delayA - 1]);
- predictionA = p->buf[delayA ] * p->coeffsA[filter][0] +
- p->buf[delayA - 1] * p->coeffsA[filter][1] +
- p->buf[delayA - 2] * p->coeffsA[filter][2] +
- p->buf[delayA - 3] * p->coeffsA[filter][3];
- /* Apply a scaled first-order filter compression */
- p->buf[delayB] = p->filterA[filter ^ 1] - ((p->filterB[filter] * 31) >> 5);
- p->buf[adaptB] = APESIGN(p->buf[delayB]);
- p->buf[delayB - 1] = p->buf[delayB] - p->buf[delayB - 1];
- p->buf[adaptB - 1] = APESIGN(p->buf[delayB - 1]);
- p->filterB[filter] = p->filterA[filter ^ 1];
- predictionB = p->buf[delayB ] * p->coeffsB[filter][0] +
- p->buf[delayB - 1] * p->coeffsB[filter][1] +
- p->buf[delayB - 2] * p->coeffsB[filter][2] +
- p->buf[delayB - 3] * p->coeffsB[filter][3] +
- p->buf[delayB - 4] * p->coeffsB[filter][4];
- p->lastA[filter] = decoded + ((predictionA + (predictionB >> 1)) >> 10);
- p->filterA[filter] = p->lastA[filter] + ((p->filterA[filter] * 31) >> 5);
- if (!decoded) // no need updating filter coefficients
- return p->filterA[filter];
- if (decoded > 0) {
- p->coeffsA[filter][0] -= p->buf[adaptA ];
- p->coeffsA[filter][1] -= p->buf[adaptA - 1];
- p->coeffsA[filter][2] -= p->buf[adaptA - 2];
- p->coeffsA[filter][3] -= p->buf[adaptA - 3];
- p->coeffsB[filter][0] -= p->buf[adaptB ];
- p->coeffsB[filter][1] -= p->buf[adaptB - 1];
- p->coeffsB[filter][2] -= p->buf[adaptB - 2];
- p->coeffsB[filter][3] -= p->buf[adaptB - 3];
- p->coeffsB[filter][4] -= p->buf[adaptB - 4];
- } else {
- p->coeffsA[filter][0] += p->buf[adaptA ];
- p->coeffsA[filter][1] += p->buf[adaptA - 1];
- p->coeffsA[filter][2] += p->buf[adaptA - 2];
- p->coeffsA[filter][3] += p->buf[adaptA - 3];
- p->coeffsB[filter][0] += p->buf[adaptB ];
- p->coeffsB[filter][1] += p->buf[adaptB - 1];
- p->coeffsB[filter][2] += p->buf[adaptB - 2];
- p->coeffsB[filter][3] += p->buf[adaptB - 3];
- p->coeffsB[filter][4] += p->buf[adaptB - 4];
- }
- return p->filterA[filter];
- }
- static void predictor_decode_stereo(APEContext * ctx, int count)
- {
- int32_t predictionA, predictionB;
- APEPredictor *p = &ctx->predictor;
- int32_t *decoded0 = ctx->decoded0;
- int32_t *decoded1 = ctx->decoded1;
- while (count--) {
- /* Predictor Y */
- predictionA = predictor_update_filter(p, *decoded0, 0, YDELAYA, YDELAYB, YADAPTCOEFFSA, YADAPTCOEFFSB);
- predictionB = predictor_update_filter(p, *decoded1, 1, XDELAYA, XDELAYB, XADAPTCOEFFSA, XADAPTCOEFFSB);
- *(decoded0++) = predictionA;
- *(decoded1++) = predictionB;
- /* Combined */
- p->buf++;
- /* Have we filled the history buffer? */
- if (p->buf == p->historybuffer + HISTORY_SIZE) {
- memmove(p->historybuffer, p->buf, PREDICTOR_SIZE * sizeof(int32_t));
- p->buf = p->historybuffer;
- }
- }
- }
- static void predictor_decode_mono(APEContext * ctx, int count)
- {
- APEPredictor *p = &ctx->predictor;
- int32_t *decoded0 = ctx->decoded0;
- int32_t predictionA, currentA, A;
- currentA = p->lastA[0];
- while (count--) {
- A = *decoded0;
- p->buf[YDELAYA] = currentA;
- p->buf[YDELAYA - 1] = p->buf[YDELAYA] - p->buf[YDELAYA - 1];
- predictionA = p->buf[YDELAYA ] * p->coeffsA[0][0] +
- p->buf[YDELAYA - 1] * p->coeffsA[0][1] +
- p->buf[YDELAYA - 2] * p->coeffsA[0][2] +
- p->buf[YDELAYA - 3] * p->coeffsA[0][3];
- currentA = A + (predictionA >> 10);
- p->buf[YADAPTCOEFFSA] = APESIGN(p->buf[YDELAYA ]);
- p->buf[YADAPTCOEFFSA - 1] = APESIGN(p->buf[YDELAYA - 1]);
- if (A > 0) {
- p->coeffsA[0][0] -= p->buf[YADAPTCOEFFSA ];
- p->coeffsA[0][1] -= p->buf[YADAPTCOEFFSA - 1];
- p->coeffsA[0][2] -= p->buf[YADAPTCOEFFSA - 2];
- p->coeffsA[0][3] -= p->buf[YADAPTCOEFFSA - 3];
- } else if (A < 0) {
- p->coeffsA[0][0] += p->buf[YADAPTCOEFFSA ];
- p->coeffsA[0][1] += p->buf[YADAPTCOEFFSA - 1];
- p->coeffsA[0][2] += p->buf[YADAPTCOEFFSA - 2];
- p->coeffsA[0][3] += p->buf[YADAPTCOEFFSA - 3];
- }
- p->buf++;
- /* Have we filled the history buffer? */
- if (p->buf == p->historybuffer + HISTORY_SIZE) {
- memmove(p->historybuffer, p->buf, PREDICTOR_SIZE * sizeof(int32_t));
- p->buf = p->historybuffer;
- }
- p->filterA[0] = currentA + ((p->filterA[0] * 31) >> 5);
- *(decoded0++) = p->filterA[0];
- }
- p->lastA[0] = currentA;
- }
- static void do_init_filter(APEFilter *f, int16_t * buf, int order)
- {
- f->coeffs = buf;
- f->historybuffer = buf + order;
- f->delay = f->historybuffer + order * 2;
- f->adaptcoeffs = f->historybuffer + order;
- memset(f->historybuffer, 0, (order * 2) * sizeof(int16_t));
- memset(f->coeffs, 0, order * sizeof(int16_t));
- f->avg = 0;
- }
- static void init_filter(APEContext * ctx, APEFilter *f, int16_t * buf, int order)
- {
- do_init_filter(&f[0], buf, order);
- do_init_filter(&f[1], buf + order * 3 + HISTORY_SIZE, order);
- }
- static inline void do_apply_filter(APEContext * ctx, int version, APEFilter *f, int32_t *data, int count, int order, int fracbits)
- {
- int res;
- int absres;
- while (count--) {
- /* round fixedpoint scalar product */
- res = (ctx->dsp.scalarproduct_int16(f->delay - order, f->coeffs, order, 0) + (1 << (fracbits - 1))) >> fracbits;
- if (*data < 0)
- ctx->dsp.add_int16(f->coeffs, f->adaptcoeffs - order, order);
- else if (*data > 0)
- ctx->dsp.sub_int16(f->coeffs, f->adaptcoeffs - order, order);
- res += *data;
- *data++ = res;
- /* Update the output history */
- *f->delay++ = av_clip_int16(res);
- if (version < 3980) {
- /* Version ??? to < 3.98 files (untested) */
- f->adaptcoeffs[0] = (res == 0) ? 0 : ((res >> 28) & 8) - 4;
- f->adaptcoeffs[-4] >>= 1;
- f->adaptcoeffs[-8] >>= 1;
- } else {
- /* Version 3.98 and later files */
- /* Update the adaption coefficients */
- absres = (res < 0 ? -res : res);
- if (absres > (f->avg * 3))
- *f->adaptcoeffs = ((res >> 25) & 64) - 32;
- else if (absres > (f->avg * 4) / 3)
- *f->adaptcoeffs = ((res >> 26) & 32) - 16;
- else if (absres > 0)
- *f->adaptcoeffs = ((res >> 27) & 16) - 8;
- else
- *f->adaptcoeffs = 0;
- f->avg += (absres - f->avg) / 16;
- f->adaptcoeffs[-1] >>= 1;
- f->adaptcoeffs[-2] >>= 1;
- f->adaptcoeffs[-8] >>= 1;
- }
- f->adaptcoeffs++;
- /* Have we filled the history buffer? */
- if (f->delay == f->historybuffer + HISTORY_SIZE + (order * 2)) {
- memmove(f->historybuffer, f->delay - (order * 2),
- (order * 2) * sizeof(int16_t));
- f->delay = f->historybuffer + order * 2;
- f->adaptcoeffs = f->historybuffer + order;
- }
- }
- }
- static void apply_filter(APEContext * ctx, APEFilter *f,
- int32_t * data0, int32_t * data1,
- int count, int order, int fracbits)
- {
- do_apply_filter(ctx, ctx->fileversion, &f[0], data0, count, order, fracbits);
- if (data1)
- do_apply_filter(ctx, ctx->fileversion, &f[1], data1, count, order, fracbits);
- }
- static void ape_apply_filters(APEContext * ctx, int32_t * decoded0,
- int32_t * decoded1, int count)
- {
- int i;
- for (i = 0; i < APE_FILTER_LEVELS; i++) {
- if (!ape_filter_orders[ctx->fset][i])
- break;
- apply_filter(ctx, ctx->filters[i], decoded0, decoded1, count, ape_filter_orders[ctx->fset][i], ape_filter_fracbits[ctx->fset][i]);
- }
- }
- static void init_frame_decoder(APEContext * ctx)
- {
- int i;
- init_entropy_decoder(ctx);
- init_predictor_decoder(ctx);
- for (i = 0; i < APE_FILTER_LEVELS; i++) {
- if (!ape_filter_orders[ctx->fset][i])
- break;
- init_filter(ctx, ctx->filters[i], ctx->filterbuf[i], ape_filter_orders[ctx->fset][i]);
- }
- }
- static void ape_unpack_mono(APEContext * ctx, int count)
- {
- int32_t left;
- int32_t *decoded0 = ctx->decoded0;
- int32_t *decoded1 = ctx->decoded1;
- if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) {
- entropy_decode(ctx, count, 0);
- /* We are pure silence, so we're done. */
- av_log(ctx->avctx, AV_LOG_DEBUG, "pure silence mono\n");
- return;
- }
- entropy_decode(ctx, count, 0);
- ape_apply_filters(ctx, decoded0, NULL, count);
- /* Now apply the predictor decoding */
- predictor_decode_mono(ctx, count);
- /* Pseudo-stereo - just copy left channel to right channel */
- if (ctx->channels == 2) {
- while (count--) {
- left = *decoded0;
- *(decoded1++) = *(decoded0++) = left;
- }
- }
- }
- static void ape_unpack_stereo(APEContext * ctx, int count)
- {
- int32_t left, right;
- int32_t *decoded0 = ctx->decoded0;
- int32_t *decoded1 = ctx->decoded1;
- if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) {
- /* We are pure silence, so we're done. */
- av_log(ctx->avctx, AV_LOG_DEBUG, "pure silence stereo\n");
- return;
- }
- entropy_decode(ctx, count, 1);
- ape_apply_filters(ctx, decoded0, decoded1, count);
- /* Now apply the predictor decoding */
- predictor_decode_stereo(ctx, count);
- /* Decorrelate and scale to output depth */
- while (count--) {
- left = *decoded1 - (*decoded0 / 2);
- right = left + *decoded0;
- *(decoded0++) = left;
- *(decoded1++) = right;
- }
- }
- static int ape_decode_frame(AVCodecContext * avctx,
- void *data, int *data_size,
- const uint8_t * buf, int buf_size)
- {
- APEContext *s = avctx->priv_data;
- int16_t *samples = data;
- int nblocks;
- int i, n;
- int blockstodecode;
- int bytes_used;
- if (buf_size == 0 && !s->samples) {
- *data_size = 0;
- return 0;
- }
- /* should not happen but who knows */
- if (BLOCKS_PER_LOOP * 2 * avctx->channels > *data_size) {
- av_log (avctx, AV_LOG_ERROR, "Packet size is too big to be handled in lavc! (max is %d where you have %d)\n", *data_size, s->samples * 2 * avctx->channels);
- return -1;
- }
- if(!s->samples){
- s->data = av_realloc(s->data, (buf_size + 3) & ~3);
- s->dsp.bswap_buf((uint32_t*)s->data, (const uint32_t*)buf, buf_size >> 2);
- s->ptr = s->last_ptr = s->data;
- s->data_end = s->data + buf_size;
- nblocks = s->samples = bytestream_get_be32(&s->ptr);
- n = bytestream_get_be32(&s->ptr);
- if(n < 0 || n > 3){
- av_log(avctx, AV_LOG_ERROR, "Incorrect offset passed\n");
- s->data = NULL;
- return -1;
- }
- s->ptr += n;
- s->currentframeblocks = nblocks;
- buf += 4;
- if (s->samples <= 0) {
- *data_size = 0;
- return buf_size;
- }
- memset(s->decoded0, 0, sizeof(s->decoded0));
- memset(s->decoded1, 0, sizeof(s->decoded1));
- /* Initialize the frame decoder */
- init_frame_decoder(s);
- }
- if (!s->data) {
- *data_size = 0;
- return buf_size;
- }
- nblocks = s->samples;
- blockstodecode = FFMIN(BLOCKS_PER_LOOP, nblocks);
- s->error=0;
- if ((s->channels == 1) || (s->frameflags & APE_FRAMECODE_PSEUDO_STEREO))
- ape_unpack_mono(s, blockstodecode);
- else
- ape_unpack_stereo(s, blockstodecode);
- if(s->error || s->ptr > s->data_end){
- s->samples=0;
- av_log(avctx, AV_LOG_ERROR, "Error decoding frame\n");
- return -1;
- }
- for (i = 0; i < blockstodecode; i++) {
- *samples++ = s->decoded0[i];
- if(s->channels == 2)
- *samples++ = s->decoded1[i];
- }
- s->samples -= blockstodecode;
- *data_size = blockstodecode * 2 * s->channels;
- bytes_used = s->samples ? s->ptr - s->last_ptr : buf_size;
- s->last_ptr = s->ptr;
- return bytes_used;
- }
- AVCodec ape_decoder = {
- "ape",
- CODEC_TYPE_AUDIO,
- CODEC_ID_APE,
- sizeof(APEContext),
- ape_decode_init,
- NULL,
- ape_decode_close,
- ape_decode_frame,
- .long_name = NULL_IF_CONFIG_SMALL("Monkey's Audio"),
- };
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