/* * 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 */ #include "libavutil/avassert.h" #include "libavutil/channel_layout.h" #include "libavutil/opt.h" #include "avcodec.h" #include "dsputil.h" #include "bytestream.h" #include "internal.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 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 { AVClass *class; ///< class for AVOptions AVCodecContext *avctx; AVFrame frame; DSPContext dsp; 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; ///< frame 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 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; } APEContext; // TODO: dsputilize 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: av_log_ask_for_sample(avctx, "Unsupported bits per coded sample %d\n", 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_DEBUG, "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) { 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); } ff_dsputil_init(&s->dsp, avctx); avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO; avcodec_get_frame_defaults(&s->frame); avctx->coded_frame = &s->frame; 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 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, 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++; } static inline int ape_decode_value(APEContext *ctx, APERice *rice) { unsigned 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 if (tmpk <= 32) { 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; } 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); } 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 */ 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->decoded[0]; int32_t *decoded1 = ctx->decoded[1]; while (blockstodecode--) { *decoded0++ = ape_decode_value(ctx, &ctx->riceY); if (stereo) *decoded1++ = ape_decode_value(ctx, &ctx->riceX); } } static int init_entropy_decoder(APEContext *ctx) { /* Read the CRC */ if (ctx->data_end - ctx->ptr < 6) return AVERROR_INVALIDDATA; 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; 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; /* The first 8 bits of input are ignored. */ ctx->ptr++; range_start_decoding(ctx); return 0; } 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(*p->historybuffer)); 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 av_always_inline 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, sign; 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); sign = APESIGN(decoded); p->coeffsA[filter][0] += p->buf[adaptA ] * sign; p->coeffsA[filter][1] += p->buf[adaptA - 1] * sign; p->coeffsA[filter][2] += p->buf[adaptA - 2] * sign; p->coeffsA[filter][3] += p->buf[adaptA - 3] * sign; p->coeffsB[filter][0] += p->buf[adaptB ] * sign; p->coeffsB[filter][1] += p->buf[adaptB - 1] * sign; p->coeffsB[filter][2] += p->buf[adaptB - 2] * sign; p->coeffsB[filter][3] += p->buf[adaptB - 3] * sign; p->coeffsB[filter][4] += p->buf[adaptB - 4] * sign; return p->filterA[filter]; } static void predictor_decode_stereo(APEContext *ctx, int count) { APEPredictor *p = &ctx->predictor; int32_t *decoded0 = ctx->decoded[0]; int32_t *decoded1 = ctx->decoded[1]; while (count--) { /* Predictor Y */ *decoded0 = predictor_update_filter(p, *decoded0, 0, YDELAYA, YDELAYB, YADAPTCOEFFSA, YADAPTCOEFFSB); decoded0++; *decoded1 = predictor_update_filter(p, *decoded1, 1, XDELAYA, XDELAYB, XADAPTCOEFFSA, XADAPTCOEFFSB); decoded1++; /* Combined */ p->buf++; /* Have we filled the history buffer? */ if (p->buf == p->historybuffer + HISTORY_SIZE) { memmove(p->historybuffer, p->buf, PREDICTOR_SIZE * sizeof(*p->historybuffer)); p->buf = p->historybuffer; } } } static void predictor_decode_mono(APEContext *ctx, int count) { APEPredictor *p = &ctx->predictor; int32_t *decoded0 = ctx->decoded[0]; int32_t predictionA, currentA, A, sign; 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]); sign = APESIGN(A); p->coeffsA[0][0] += p->buf[YADAPTCOEFFSA ] * sign; p->coeffsA[0][1] += p->buf[YADAPTCOEFFSA - 1] * sign; p->coeffsA[0][2] += p->buf[YADAPTCOEFFSA - 2] * sign; p->coeffsA[0][3] += p->buf[YADAPTCOEFFSA - 3] * sign; p->buf++; /* Have we filled the history buffer? */ if (p->buf == p->historybuffer + HISTORY_SIZE) { memmove(p->historybuffer, p->buf, PREDICTOR_SIZE * sizeof(*p->historybuffer)); 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(*f->historybuffer)); memset(f->coeffs, 0, order * sizeof(*f->coeffs)); 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 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_and_madd_int16(f->coeffs, f->delay - order, f->adaptcoeffs - order, order, APESIGN(*data)); res = (res + (1 << (fracbits - 1))) >> fracbits; 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 = FFABS(res); if (absres) *f->adaptcoeffs = ((res & (-1<<31)) ^ (-1<<30)) >> (25 + (absres <= f->avg*3) + (absres <= f->avg*4/3)); 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(*f->historybuffer)); 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 int init_frame_decoder(APEContext *ctx) { int i, ret; if ((ret = init_entropy_decoder(ctx)) < 0) return ret; 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]); } return 0; } static void ape_unpack_mono(APEContext *ctx, int count) { if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) { /* 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, ctx->decoded[0], 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) { memcpy(ctx->decoded[1], ctx->decoded[0], count * sizeof(*ctx->decoded[1])); } } static void ape_unpack_stereo(APEContext *ctx, int count) { int32_t left, right; int32_t *decoded0 = ctx->decoded[0]; int32_t *decoded1 = ctx->decoded[1]; 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 *got_frame_ptr, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; APEContext *s = avctx->priv_data; uint8_t *sample8; int16_t *sample16; int32_t *sample24; int i, ch, ret; int blockstodecode; /* this should never be negative, but bad things will happen if it is, so check it just to make sure. */ av_assert0(s->samples >= 0); if(!s->samples){ uint32_t nblocks, offset; int buf_size; if (!avpkt->size) { *got_frame_ptr = 0; return 0; } if (avpkt->size < 8) { av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); return AVERROR_INVALIDDATA; } buf_size = avpkt->size & ~3; if (buf_size != avpkt->size) { av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. " "extra bytes at the end will be skipped.\n"); } av_fast_malloc(&s->data, &s->data_size, buf_size); if (!s->data) return AVERROR(ENOMEM); s->dsp.bswap_buf((uint32_t*)s->data, (const uint32_t*)buf, buf_size >> 2); s->ptr = s->data; s->data_end = s->data + buf_size; nblocks = bytestream_get_be32(&s->ptr); offset = bytestream_get_be32(&s->ptr); if (offset > 3) { av_log(avctx, AV_LOG_ERROR, "Incorrect offset passed\n"); s->data = NULL; return AVERROR_INVALIDDATA; } if (s->data_end - s->ptr < offset) { av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); return AVERROR_INVALIDDATA; } s->ptr += offset; if (!nblocks || nblocks > INT_MAX) { av_log(avctx, AV_LOG_ERROR, "Invalid sample count: %u.\n", nblocks); return AVERROR_INVALIDDATA; } s->samples = nblocks; /* Initialize the frame decoder */ if (init_frame_decoder(s) < 0) { av_log(avctx, AV_LOG_ERROR, "Error reading frame header\n"); return AVERROR_INVALIDDATA; } } if (!s->data) { *got_frame_ptr = 0; return avpkt->size; } blockstodecode = FFMIN(s->blocks_per_loop, s->samples); /* reallocate decoded sample buffer if needed */ av_fast_malloc(&s->decoded_buffer, &s->decoded_size, 2 * FFALIGN(blockstodecode, 8) * sizeof(*s->decoded_buffer)); if (!s->decoded_buffer) return AVERROR(ENOMEM); memset(s->decoded_buffer, 0, s->decoded_size); s->decoded[0] = s->decoded_buffer; s->decoded[1] = s->decoded_buffer + FFALIGN(blockstodecode, 8); /* get output buffer */ s->frame.nb_samples = blockstodecode; if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } s->error=0; if ((s->channels == 1) || (s->frameflags & APE_FRAMECODE_PSEUDO_STEREO)) ape_unpack_mono(s, blockstodecode); else ape_unpack_stereo(s, blockstodecode); emms_c(); if (s->error) { s->samples=0; av_log(avctx, AV_LOG_ERROR, "Error decoding frame\n"); return AVERROR_INVALIDDATA; } switch (s->bps) { case 8: for (ch = 0; ch < s->channels; ch++) { sample8 = (uint8_t *)s->frame.data[ch]; for (i = 0; i < blockstodecode; i++) *sample8++ = (s->decoded[ch][i] + 0x80) & 0xff; } break; case 16: for (ch = 0; ch < s->channels; ch++) { sample16 = (int16_t *)s->frame.data[ch]; for (i = 0; i < blockstodecode; i++) *sample16++ = s->decoded[ch][i]; } break; case 24: for (ch = 0; ch < s->channels; ch++) { sample24 = (int32_t *)s->frame.data[ch]; for (i = 0; i < blockstodecode; i++) *sample24++ = s->decoded[ch][i] << 8; } break; } s->samples -= blockstodecode; *got_frame_ptr = 1; *(AVFrame *)data = s->frame; return !s->samples ? avpkt->size : 0; } static void ape_flush(AVCodecContext *avctx) { APEContext *s = avctx->priv_data; s->samples= 0; } #define OFFSET(x) offsetof(APEContext, x) #define PAR (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM) static const AVOption options[] = { { "max_samples", "maximum number of samples decoded per call", OFFSET(blocks_per_loop), AV_OPT_TYPE_INT, { .i64 = 4608 }, 1, INT_MAX, PAR, "max_samples" }, { "all", "no maximum. decode all samples for each packet at once", 0, AV_OPT_TYPE_CONST, { .i64 = INT_MAX }, INT_MIN, INT_MAX, PAR, "max_samples" }, { NULL}, }; static const AVClass ape_decoder_class = { .class_name = "APE decoder", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; AVCodec ff_ape_decoder = { .name = "ape", .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_APE, .priv_data_size = sizeof(APEContext), .init = ape_decode_init, .close = ape_decode_close, .decode = ape_decode_frame, .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DELAY | CODEC_CAP_DR1, .flush = ape_flush, .long_name = NULL_IF_CONFIG_SMALL("Monkey's Audio"), .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P, AV_SAMPLE_FMT_S16P, AV_SAMPLE_FMT_S32P, AV_SAMPLE_FMT_NONE }, .priv_class = &ape_decoder_class, };