/* * FLAC (Free Lossless Audio Codec) decoder * Copyright (c) 2003 Alex Beregszaszi * * This library 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 of the License, or (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA *//** * @file flac.c * FLAC (Free Lossless Audio Codec) decoder * @author Alex Beregszaszi * * For more information on the FLAC format, visit: *  http://flac.sourceforge.net/ * * This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed * through, starting from the initial 'fLaC' signature; or by passing the * 34-byte streaminfo structure through avctx->extradata[_size] followed * by data starting with the 0xFFF8 marker. */ #include <limits.h> #include "avcodec.h"#include "bitstream.h"#include "golomb.h"#undef NDEBUG#include <assert.h>#define MAX_CHANNELS 8#define MAX_BLOCKSIZE 65535#define FLAC_STREAMINFO_SIZE 34enum decorrelation_type {    INDEPENDENT,    LEFT_SIDE,    RIGHT_SIDE,    MID_SIDE,};typedef struct FLACContext {    AVCodecContext *avctx;    GetBitContext gb;    int min_blocksize, max_blocksize;    int min_framesize, max_framesize;    int samplerate, channels;    int blocksize/*, last_blocksize*/;    int bps, curr_bps;    enum decorrelation_type decorrelation;    int32_t *decoded[MAX_CHANNELS];    uint8_t *bitstream;    int bitstream_size;    int bitstream_index;    int allocated_bitstream_size;} FLACContext;#define METADATA_TYPE_STREAMINFO 0static int sample_rate_table[] ={ 0, 0, 0, 0,  8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,  0, 0, 0, 0 }; static int sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 };static int blocksize_table[] = {     0,    192, 576<<0, 576<<1, 576<<2, 576<<3,      0,      0, 256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7 };static const uint8_t table_crc8[256] = {    0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,    0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d,    0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,    0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d,    0xe0, 0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5,    0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd,    0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85,    0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 0xbd,    0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,    0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea,    0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5, 0xa2,    0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,    0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32,    0x1f, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a,    0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42,    0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a,    0x89, 0x8e, 0x87, 0x80, 0x95, 0x92, 0x9b, 0x9c,    0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4,    0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec,    0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3, 0xd4,    0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,    0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44,    0x19, 0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c,    0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34,    0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b,    0x76, 0x71, 0x78, 0x7f, 0x6a, 0x6d, 0x64, 0x63,    0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b,    0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13,    0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc, 0xbb,    0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,    0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb,    0xe6, 0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3};static int64_t get_utf8(GetBitContext *gb){    uint64_t val;    int ones=0, bytes;        while(get_bits1(gb))        ones++;    if     (ones==0) bytes=0;    else if(ones==1) return -1;    else             bytes= ones - 1;        val= get_bits(gb, 7-ones);    while(bytes--){        const int tmp = get_bits(gb, 8);                if((tmp>>6) != 2)            return -1;        val<<=6;        val|= tmp&0x3F;    }    return val;}#if 0static int skip_utf8(GetBitContext *gb){    int ones=0, bytes;        while(get_bits1(gb))        ones++;    if     (ones==0) bytes=0;    else if(ones==1) return -1;    else             bytes= ones - 1;        skip_bits(gb, 7-ones);    while(bytes--){        const int tmp = get_bits(gb, 8);                if((tmp>>6) != 2)            return -1;    }    return 0;}#endifstatic int get_crc8(const uint8_t *buf, int count){    int crc=0;    int i;        for(i=0; i<count; i++){        crc = table_crc8[crc ^ buf[i]];    }    return crc;}static void metadata_streaminfo(FLACContext *s);static void dump_headers(FLACContext *s);static int flac_decode_init(AVCodecContext * avctx){    FLACContext *s = avctx->priv_data;    s->avctx = avctx;    /* initialize based on the demuxer-supplied streamdata header */    if (avctx->extradata_size == FLAC_STREAMINFO_SIZE) {        init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size*8);        metadata_streaminfo(s);        dump_headers(s);    }    return 0;}static void dump_headers(FLACContext *s){    av_log(s->avctx, AV_LOG_DEBUG, "  Blocksize: %d .. %d (%d)\n", s->min_blocksize, s->max_blocksize, s->blocksize);    av_log(s->avctx, AV_LOG_DEBUG, "  Framesize: %d .. %d\n", s->min_framesize, s->max_framesize);    av_log(s->avctx, AV_LOG_DEBUG, "  Samplerate: %d\n", s->samplerate);    av_log(s->avctx, AV_LOG_DEBUG, "  Channels: %d\n", s->channels);    av_log(s->avctx, AV_LOG_DEBUG, "  Bits: %d\n", s->bps);}static void allocate_buffers(FLACContext *s){    int i;    assert(s->max_blocksize);    if(s->max_framesize == 0 && s->max_blocksize){        s->max_framesize= (s->channels * s->bps * s->max_blocksize + 7)/ 8; //FIXME header overhead    }    for (i = 0; i < s->channels; i++)    {        s->decoded[i] = av_realloc(s->decoded[i], sizeof(int32_t)*s->max_blocksize);    }    s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);}static void metadata_streaminfo(FLACContext *s){    /* mandatory streaminfo */    s->min_blocksize = get_bits(&s->gb, 16);    s->max_blocksize = get_bits(&s->gb, 16);    s->min_framesize = get_bits_long(&s->gb, 24);    s->max_framesize = get_bits_long(&s->gb, 24);        s->samplerate = get_bits_long(&s->gb, 20);    s->channels = get_bits(&s->gb, 3) + 1;    s->bps = get_bits(&s->gb, 5) + 1;        s->avctx->channels = s->channels;    s->avctx->sample_rate = s->samplerate;    skip_bits(&s->gb, 36); /* total num of samples */        skip_bits(&s->gb, 64); /* md5 sum */    skip_bits(&s->gb, 64); /* md5 sum */        allocate_buffers(s);}static int decode_residuals(FLACContext *s, int channel, int pred_order){    int i, tmp, partition, method_type, rice_order;    int sample = 0, samples;    method_type = get_bits(&s->gb, 2);    if (method_type != 0){        av_log(s->avctx, AV_LOG_DEBUG, "illegal residual coding method %d\n", method_type);        return -1;    }        rice_order = get_bits(&s->gb, 4);    samples= s->blocksize >> rice_order;    sample=     i= pred_order;    for (partition = 0; partition < (1 << rice_order); partition++)    {        tmp = get_bits(&s->gb, 4);        if (tmp == 15)        {            av_log(s->avctx, AV_LOG_DEBUG, "fixed len partition\n");            tmp = get_bits(&s->gb, 5);            for (; i < samples; i++, sample++)                s->decoded[channel][sample] = get_sbits(&s->gb, tmp);        }        else        {//            av_log(s->avctx, AV_LOG_DEBUG, "rice coded partition k=%d\n", tmp);            for (; i < samples; i++, sample++){                s->decoded[channel][sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);            }        }        i= 0;    }//    av_log(s->avctx, AV_LOG_DEBUG, "partitions: %d, samples: %d\n", 1 << rice_order, sample);    return 0;}    static int decode_subframe_fixed(FLACContext *s, int channel, int pred_order){    int i;        //    av_log(s->avctx, AV_LOG_DEBUG, "  SUBFRAME FIXED\n");            /* warm up samples *///    av_log(s->avctx, AV_LOG_DEBUG, "   warm up samples: %d\n", pred_order);            for (i = 0; i < pred_order; i++)    {        s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, s->decoded[channel][i]);    }        if (decode_residuals(s, channel, pred_order) < 0)        return -1;    switch(pred_order)    {        case 0:            break;        case 1:            for (i = pred_order; i < s->blocksize; i++)                s->decoded[channel][i] +=   s->decoded[channel][i-1];            break;        case 2:            for (i = pred_order; i < s->blocksize; i++)                s->decoded[channel][i] += 2*s->decoded[channel][i-1]                                          - s->decoded[channel][i-2];            break;        case 3:            for (i = pred_order; i < s->blocksize; i++)                s->decoded[channel][i] += 3*s->decoded[channel][i-1]                                         - 3*s->decoded[channel][i-2]                                        +   s->decoded[channel][i-3];            break;        case 4:            for (i = pred_order; i < s->blocksize; i++)                s->decoded[channel][i] += 4*s->decoded[channel][i-1]                                         - 6*s->decoded[channel][i-2]                                        + 4*s->decoded[channel][i-3]                                        -   s->decoded[channel][i-4];            break;        default:            av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order);            return -1;    }    return 0;}static int decode_subframe_lpc(FLACContext *s, int channel, int pred_order){    int sum, i, j;    int coeff_prec, qlevel;    #if __STDC_VERSION__ >= 199901L    int coeffs[pred_order];    #else    int *coeffs=(int*)_alloca(sizeof(int)*pred_order);    #endif        //    av_log(s->avctx, AV_LOG_DEBUG, "  SUBFRAME LPC\n");            /* warm up samples *///    av_log(s->avctx, AV_LOG_DEBUG, "   warm up samples: %d\n", pred_order);            for (i = 0; i < pred_order; i++)    {        s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps);//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, s->decoded[channel][i]);    }        coeff_prec = get_bits(&s->gb, 4) + 1;    if (coeff_prec == 16)    {        av_log(s->avctx, AV_LOG_DEBUG, "invalid coeff precision\n");        return -1;    }//    av_log(s->avctx, AV_LOG_DEBUG, "   qlp coeff prec: %d\n", coeff_prec);    qlevel = get_sbits(&s->gb, 5);//    av_log(s->avctx, AV_LOG_DEBUG, "   quant level: %d\n", qlevel);    if(qlevel < 0){        av_log(s->avctx, AV_LOG_DEBUG, "qlevel %d not supported, maybe buggy stream\n", qlevel);        return -1;    }    for (i = 0; i < pred_order; i++)    {        coeffs[i] = get_sbits(&s->gb, coeff_prec);//        av_log(s->avctx, AV_LOG_DEBUG, "    %d: %d\n", i, coeffs[i]);    }        if (decode_residuals(s, channel, pred_order) < 0)        return -1;    for (i = pred_order; i < s->blocksize; i++)    {        sum = 0;        for (j = 0; j < pred_order; j++)            sum += coeffs[j] * s->decoded[channel][i-j-1];        s->decoded[channel][i] += sum >> qlevel;    }        return 0;}static inline int decode_subframe(FLACContext *s, int channel){    int type, wasted = 0;    int i, tmp;        s->curr_bps = s->bps;    if(channel == 0){        if(s->decorrelation == RIGHT_SIDE)            s->curr_bps++;    }else{        if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)            s->curr_bps++;    }    if (get_bits1(&s->gb))    {        av_log(s->avctx, AV_LOG_ERROR, "invalid subframe padding\n");        return -1;    }    type = get_bits(&s->gb, 6);