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da4e02cdd3
Some assembly routines don't work on Thumb as-is. For now just disable these so the codecs compile. Affected codecs: - libflac - libmad - libspeex - libtta - libwavpack A few DSP routines need to be disabled for the same reason: - crossfeed_process - crossfeed_meier_process - resample_hermite - filter_process - sample_output_stereo Change-Id: I277e0719652096745a19a7e2b597eff32d8e1553
692 lines
21 KiB
C
692 lines
21 KiB
C
/*
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* FLAC (Free Lossless Audio Codec) decoder
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* Copyright (c) 2003 Alex Beregszaszi
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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/**
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* @file flac.c
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* FLAC (Free Lossless Audio Codec) decoder
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* @author Alex Beregszaszi
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*
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* For more information on the FLAC format, visit:
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* http://flac.sourceforge.net/
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*
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* This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
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* through, starting from the initial 'fLaC' signature; or by passing the
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* 34-byte streaminfo structure through avctx->extradata[_size] followed
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* by data starting with the 0xFFF8 marker.
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*/
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#include <inttypes.h>
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#include <stdbool.h>
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#ifndef BUILD_STANDALONE
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#include "codeclib.h"
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#endif
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#include "bitstream.h"
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#include "golomb.h"
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#include "decoder.h"
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#if defined(CPU_COLDFIRE)
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#include "coldfire.h"
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#elif defined(CPU_ARM)
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#include "arm.h"
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#endif
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static const int sample_rate_table[] ICONST_ATTR =
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{ 0, 88200, 176400, 192000,
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8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
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0, 0, 0, 0 };
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static const int sample_size_table[] ICONST_ATTR =
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{ 0, 8, 12, 0, 16, 20, 24, 0 };
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static const int blocksize_table[] ICONST_ATTR = {
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0, 192, 576<<0, 576<<1, 576<<2, 576<<3, 0, 0,
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256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
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};
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static const uint8_t table_crc8[256] ICONST_ATTR = {
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0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,
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0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d,
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0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,
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0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d,
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0xe0, 0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5,
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0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd,
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0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85,
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0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 0xbd,
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0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,
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0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea,
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0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5, 0xa2,
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0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,
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0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32,
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0x1f, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a,
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0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42,
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0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a,
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0x89, 0x8e, 0x87, 0x80, 0x95, 0x92, 0x9b, 0x9c,
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0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4,
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0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec,
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0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3, 0xd4,
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0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,
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0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44,
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0x19, 0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c,
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0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34,
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0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b,
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0x76, 0x71, 0x78, 0x7f, 0x6a, 0x6d, 0x64, 0x63,
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0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b,
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0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13,
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0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc, 0xbb,
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0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,
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0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb,
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0xe6, 0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3
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};
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static int64_t get_utf8(GetBitContext *gb) ICODE_ATTR_FLAC;
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static int64_t get_utf8(GetBitContext *gb)
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{
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uint64_t val;
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int ones=0, bytes;
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while(get_bits1(gb))
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ones++;
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if (ones==0) bytes=0;
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else if(ones==1) return -1;
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else bytes= ones - 1;
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val= get_bits(gb, 7-ones);
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while(bytes--){
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const int tmp = get_bits(gb, 8);
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if((tmp>>6) != 2)
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return -2;
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val<<=6;
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val|= tmp&0x3F;
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}
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return val;
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}
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static int get_crc8(const uint8_t *buf, int count) ICODE_ATTR_FLAC;
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static int get_crc8(const uint8_t *buf, int count)
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{
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int crc=0;
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int i;
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for(i=0; i<count; i++){
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crc = table_crc8[crc ^ buf[i]];
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}
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return crc;
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}
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static int decode_residuals(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
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static int decode_residuals(FLACContext *s, int32_t *decoded, int pred_order)
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{
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GetBitContext gb = s->gb;
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int i, tmp, partition, method_type, rice_order;
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int rice_bits, rice_esc;
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int samples;
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method_type = get_bits(&gb, 2);
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rice_order = get_bits(&gb, 4);
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samples = s->blocksize >> rice_order;
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rice_bits = 4 + method_type;
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rice_esc = (1 << rice_bits) - 1;
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decoded += pred_order;
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i = pred_order;
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if (method_type > 1 || (samples << rice_order != s->blocksize) || pred_order > samples)
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{
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return -3;
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}
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for (partition = 0; partition < (1 << rice_order); partition++) {
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tmp = get_bits(&gb, rice_bits);
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if (tmp == rice_esc) {
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tmp = get_bits(&gb, 5);
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for (; i < samples; i++)
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*decoded++ = get_sbits(&gb, tmp);
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} else {
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int real_limit = tmp ? (INT_MAX >> tmp) + 2 : INT_MAX;
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for (; i < samples; i++) {
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int v = get_sr_golomb_flac(&gb, tmp, real_limit, 0);
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if ((unsigned) v == 0x80000000){
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return -3;
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}
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*decoded++ = v;
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}
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}
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i= 0;
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}
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s->gb = gb;
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return 0;
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}
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//static int decode_subframe_fixed(FLACContext *s, int32_t* decoded, int pred_order, int bps) ICODE_ATTR_FLAC;
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int decode_subframe_fixed(FLACContext *s, int32_t* decoded, int pred_order, int bps)
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{
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const int blocksize = s->blocksize;
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unsigned a, b, c, d;
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int i;
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/* warm up samples */
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for (i = 0; i < pred_order; i++)
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{
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decoded[i] = get_sbits(&s->gb, bps);
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}
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if (decode_residuals(s, decoded, pred_order) < 0)
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return -4;
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switch(pred_order)
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{
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case 0:
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break;
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case 1:
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a = decoded[pred_order-1];
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for (i = pred_order; i < blocksize; i++)
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decoded[i] = a += decoded[i];
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break;
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case 2:
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a = decoded[pred_order-1];
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b = a - decoded[pred_order-2];
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for (i = pred_order; i < blocksize; i++)
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decoded[i] = a += b += decoded[i];
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break;
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case 3:
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a = decoded[pred_order-1];
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b = a - decoded[pred_order-2];
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c = b - decoded[pred_order-2] + decoded[pred_order-3];
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for (i = pred_order; i < blocksize; i++)
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decoded[i] = a += b += c += decoded[i];
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break;
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case 4:
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a = decoded[pred_order-1];
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b = a - decoded[pred_order-2];
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c = b - decoded[pred_order-2] + decoded[pred_order-3];
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d = c - decoded[pred_order-2] + 2U*decoded[pred_order-3] - decoded[pred_order-4];
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for (i = pred_order; i < blocksize; i++)
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decoded[i] = a += b += c += d += decoded[i];
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break;
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default:
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return -5;
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}
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return 0;
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}
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#if !defined(CPU_COLDFIRE)
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static void flac_lpc_32_c(int32_t *decoded, int coeffs[],
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int pred_order, int qlevel, int len) ICODE_ATTR_FLAC;
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static void flac_lpc_32_c(int32_t *decoded, int coeffs[],
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int pred_order, int qlevel, int len)
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{
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int i, j;
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/*NOTE coeffs[] is in reverse order compared to upstream*/
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for (i = pred_order; i < len; i++, decoded++) {
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int64_t sum = 0;
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for (j = 0; j < pred_order; j++)
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sum += (int64_t)coeffs[pred_order-j-1] * decoded[j];
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decoded[j] += sum >> qlevel;
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}
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}
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static void lpc_analyze_remodulate(int32_t *decoded, int coeffs[],
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int order, int qlevel, int len, int bps)
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{
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/*NOTE coeffs[] is in reverse order compared to upstream*/
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int i, j;
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int ebps = 1 << (bps-1);
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unsigned sigma = 0;
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for (i = order; i < len; i++)
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sigma |= decoded[i] + ebps;
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if (sigma < 2U*ebps)
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return;
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for (i = len - 1; i >= order; i--) {
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int64_t p = 0;
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for (j = 0; j < order; j++)
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p += coeffs[order-j-1] * (int64_t)(int32_t)decoded[i-order+j];
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decoded[i] -= p >> qlevel;
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}
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for (i = order; i < len; i++, decoded++) {
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int32_t p = 0;
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for (j = 0; j < order; j++)
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p += coeffs[order-j-1] * (uint32_t)decoded[j];
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decoded[j] += p >> qlevel;
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}
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}
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#endif
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static int decode_subframe_lpc(FLACContext *s, int32_t* decoded, int pred_order, int bps) ICODE_ATTR_FLAC;
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static int decode_subframe_lpc(FLACContext *s, int32_t* decoded, int pred_order, int bps)
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{
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int sum, i, j;
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int coeff_prec, qlevel;
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int coeffs[pred_order];
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/* warm up samples */
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for (i = 0; i < pred_order; i++)
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{
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decoded[i] = get_sbits(&s->gb, bps);
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}
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coeff_prec = get_bits(&s->gb, 4) + 1;
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if (coeff_prec == 16)
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{
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//fprintf(stderr,"invalid coeff precision\n");
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return -6;
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}
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qlevel = get_sbits(&s->gb, 5);
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if (qlevel < 0)
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{
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//fprintf(stderr,"qlevel %d not supported, maybe buggy stream\n", qlevel);
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return -7;
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}
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for (j = 0; j < pred_order; j++)
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{
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coeffs[j] = get_sbits(&s->gb, coeff_prec);
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}
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if (decode_residuals(s, decoded, pred_order) < 0)
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return -8;
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if ((s->bps + coeff_prec + av_log2(pred_order)) <= 32) {
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#if defined(CPU_COLDFIRE)
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(void)sum;
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lpc_decode_emac(s->blocksize - pred_order, qlevel, pred_order,
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decoded + pred_order, coeffs);
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#elif defined(CPU_ARM_CLASSIC)
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(void)sum;
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lpc_decode_arm(s->blocksize - pred_order, qlevel, pred_order,
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decoded + pred_order, coeffs);
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#else
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for (i = pred_order; i < s->blocksize; i++)
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{
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sum = 0;
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for (j = 0; j < pred_order; j++)
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sum += coeffs[j] * decoded[i-j-1];
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decoded[i] += sum >> qlevel;
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}
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#endif
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} else {
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#if defined(CPU_COLDFIRE)
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lpc_decode_emac_wide(s->blocksize - pred_order, qlevel, pred_order,
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decoded + pred_order, coeffs);
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#else
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flac_lpc_32_c(decoded, coeffs, pred_order, qlevel, s->blocksize);
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if (bps <= 16)
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lpc_analyze_remodulate(decoded, coeffs, pred_order, qlevel, s->blocksize, bps);
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#endif
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}
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return 0;
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}
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static inline int decode_subframe(FLACContext *s, int channel, int32_t* decoded)
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{
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int type, wasted = 0;
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int i, tmp;
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int bps = s->bps;
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if(channel == 0){
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if(s->ch_mode == RIGHT_SIDE)
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bps++;
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}else{
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if(s->ch_mode == LEFT_SIDE || s->ch_mode == MID_SIDE)
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bps++;
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}
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if (get_bits1(&s->gb))
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{
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//fprintf(stderr,"invalid subframe padding\n");
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return -9;
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}
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type = get_bits(&s->gb, 6);
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if (get_bits1(&s->gb))
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{
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wasted = 1;
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while (!get_bits1(&s->gb))
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wasted++;
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bps -= wasted;
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//fprintf(stderr,"%d wasted bits\n", wasted);
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}
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//FIXME use av_log2 for types
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if (type == 0)
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{
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//fprintf(stderr,"coding type: constant\n");
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tmp = get_sbits(&s->gb, bps);
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for (i = 0; i < s->blocksize; i++)
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decoded[i] = tmp;
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}
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else if (type == 1)
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{
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//fprintf(stderr,"coding type: verbatim\n");
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for (i = 0; i < s->blocksize; i++)
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decoded[i] = get_sbits(&s->gb, bps);
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}
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else if ((type >= 8) && (type <= 12))
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{
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//fprintf(stderr,"coding type: fixed\n");
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if (decode_subframe_fixed(s, decoded, type & ~0x8, bps) < 0)
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return -10;
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}
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else if (type >= 32)
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{
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//fprintf(stderr,"coding type: lpc\n");
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if (decode_subframe_lpc(s, decoded, (type & ~0x20)+1, bps) < 0)
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return -11;
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}
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else
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{
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//fprintf(stderr,"Unknown coding type: %d\n",type);
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return -12;
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}
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if (wasted && wasted < 32)
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{
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int i;
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for (i = 0; i < s->blocksize; i++)
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decoded[i] = (unsigned)decoded[i] << wasted;
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}
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return 0;
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}
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static int decode_frame(FLACContext *s,
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void (*yield)(void)) ICODE_ATTR_FLAC;
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static int decode_frame(FLACContext *s,
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void (*yield)(void))
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{
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int blocksize_code, sample_rate_code, sample_size_code, crc8;
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int ch_mode, bps, blocksize, samplerate;
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int res, ch;
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GetBitContext *gb = &s->gb;
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blocksize_code = get_bits(gb, 4);
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sample_rate_code = get_bits(gb, 4);
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ch_mode = get_bits(gb, 4); /* channel assignment */
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if (ch_mode < 8 && s->channels == ch_mode+1)
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ch_mode = INDEPENDENT;
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else if (ch_mode >=8 && ch_mode < 11 && s->channels == 2)
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ch_mode = LEFT_SIDE + ch_mode - 8;
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else
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{
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return -13;
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}
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sample_size_code = get_bits(gb, 3);
|
|
if(sample_size_code == 0)
|
|
bps= s->bps;
|
|
else if((sample_size_code != 3) && (sample_size_code != 7))
|
|
bps = sample_size_table[sample_size_code];
|
|
else
|
|
{
|
|
return -14;
|
|
}
|
|
|
|
if (get_bits1(gb))
|
|
{
|
|
return -15;
|
|
}
|
|
|
|
/* Get the samplenumber of the first sample in this block */
|
|
s->samplenumber=get_utf8(gb);
|
|
|
|
/* samplenumber actually contains the frame number for streams
|
|
with a constant block size - so we multiply by blocksize to
|
|
get the actual sample number */
|
|
if (s->min_blocksize == s->max_blocksize) {
|
|
s->samplenumber*=s->min_blocksize;
|
|
}
|
|
|
|
#if 0
|
|
if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/
|
|
(s->min_blocksize != s->max_blocksize)){
|
|
}else{
|
|
}
|
|
#endif
|
|
|
|
if (blocksize_code == 0)
|
|
blocksize = s->min_blocksize;
|
|
else if (blocksize_code == 6)
|
|
blocksize = get_bits(gb, 8)+1;
|
|
else if (blocksize_code == 7)
|
|
blocksize = get_bits(gb, 16)+1;
|
|
else
|
|
blocksize = blocksize_table[blocksize_code];
|
|
|
|
if(blocksize > s->max_blocksize){
|
|
return -16;
|
|
}
|
|
|
|
if (sample_rate_code == 0){
|
|
samplerate= s->samplerate;
|
|
}else if ((sample_rate_code < 12))
|
|
samplerate = sample_rate_table[sample_rate_code];
|
|
else if (sample_rate_code == 12)
|
|
samplerate = get_bits(gb, 8) * 1000;
|
|
else if (sample_rate_code == 13)
|
|
samplerate = get_bits(gb, 16);
|
|
else if (sample_rate_code == 14)
|
|
samplerate = get_bits(gb, 16) * 10;
|
|
else{
|
|
return -17;
|
|
}
|
|
|
|
skip_bits(gb, 8);
|
|
crc8= get_crc8(s->gb.buffer, get_bits_count(gb)/8);
|
|
if(crc8){
|
|
return -18;
|
|
}
|
|
|
|
s->blocksize = blocksize;
|
|
s->samplerate = samplerate;
|
|
s->bps = bps;
|
|
s->ch_mode = ch_mode;
|
|
|
|
for (ch=0; ch<s->channels; ++ch) {
|
|
yield();
|
|
if ((res=decode_subframe(s, ch, s->decoded[ch])) < 0)
|
|
return res-100;
|
|
}
|
|
|
|
yield();
|
|
align_get_bits(gb);
|
|
|
|
/* frame footer */
|
|
skip_bits(gb, 16); /* data crc */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int flac_downmix(FLACContext *s) ICODE_ATTR_FLAC;
|
|
static int flac_downmix(FLACContext *s)
|
|
{
|
|
int32_t *FL, *FR, *FC, *SB, *RL, *RR, *RC;
|
|
int32_t *outL = s->decoded[0];
|
|
int32_t *outR = s->decoded[1];
|
|
int i, scale=FLAC_OUTPUT_DEPTH-s->bps;
|
|
|
|
switch(s->channels)
|
|
{
|
|
case 3: /* 3.0 channel order: FL FR FC */
|
|
FL = s->decoded[0];
|
|
FR = s->decoded[1];
|
|
FC = s->decoded[2];
|
|
/* LF = 0.66 LF + 0.33 FC
|
|
LR = 0.66 LR + 0.33 FC */
|
|
for (i=0; i<s->blocksize; ++i) {
|
|
int32_t a = *(FL)*2 + *(FC);
|
|
int32_t b = *(FR)*2 + *(FC);
|
|
*outL++ = ((a + (a<<2))>>4) << scale; /* 1/3 ~= 5>>4 */
|
|
*outR++ = ((b + (b<<2))>>4) << scale; /* 1/3 ~= 5>>4 */
|
|
FL++; FR++; FC++;
|
|
}
|
|
break;
|
|
case 4: /* 4.0 channel order: FL FR RL RR */
|
|
FL = s->decoded[0];
|
|
FR = s->decoded[1];
|
|
RL = s->decoded[2];
|
|
RR = s->decoded[3];
|
|
/* LF = 0.50 LF + 0.50 RL + 0.00 RR
|
|
LR = 0.50 LR + 0.00 RL + 0.50 RR */
|
|
for (i=0; i<s->blocksize; ++i) {
|
|
int32_t a = *(FL) + *(RL);
|
|
int32_t b = *(FR) + *(RR);
|
|
*outL++ = (a>>1) << scale;
|
|
*outR++ = (b>>1) << scale;
|
|
FL++; FR++; RL++; RR++;
|
|
}
|
|
break;
|
|
case 5: /* 5.0 channel order: FL FR FC RL RR */
|
|
FL = s->decoded[0];
|
|
FR = s->decoded[1];
|
|
FC = s->decoded[2];
|
|
RL = s->decoded[3];
|
|
RR = s->decoded[4];
|
|
/* LF = 0.40 LF + 0.20 FC + 0.40 RL + 0.00 RR
|
|
LR = 0.40 LR + 0.20 FC + 0.00 RL + 0.40 RR */
|
|
for (i=0; i<s->blocksize; ++i) {
|
|
int32_t a = *(FL)*2 + *(FC) + *(RL)*2;
|
|
int32_t b = *(FR)*2 + *(FC) + *(RR)*2;
|
|
*outL++ = ((a + (a<<1))>>4) << scale; /* 3>>4 ~= 1/5 */
|
|
*outR++ = ((b + (b<<1))>>4) << scale; /* 3>>4 ~= 1/5 */
|
|
FL++; FR++; FC++; RL++; RR++;
|
|
}
|
|
break;
|
|
case 6: /* 5.1 channel order: FL FR FC SUB RL RR */
|
|
FL = s->decoded[0];
|
|
FR = s->decoded[1];
|
|
FC = s->decoded[2];
|
|
SB = s->decoded[3];
|
|
RL = s->decoded[4];
|
|
RR = s->decoded[5];
|
|
/* LF = 0.33 LF + 0.16 SUB + 0.16 FC + 0.33 RL + 0.00 RR
|
|
LR = 0.33 LR + 0.16 SUB + 0.16 FC + 0.00 RL + 0.33 RR */
|
|
for (i=0; i<s->blocksize; ++i) {
|
|
int32_t a = *(FL)*2 + *(SB) + *(FC) + *(RL)*2;
|
|
int32_t b = *(FR)*2 + *(SB) + *(FC) + *(RR)*2;
|
|
*outL++ = ((a + (a<<2))>>5) << scale; /* 5>>5 ~= 1/6 */
|
|
*outR++ = ((b + (b<<2))>>5) << scale; /* 5>>5 ~= 1/6 */
|
|
FL++; FR++; SB++; FC++; RL++; RR++;
|
|
}
|
|
break;
|
|
case 7: /* 6.1 channel order: FL FR FC SUB RL RR RC */
|
|
FL = s->decoded[0];
|
|
FR = s->decoded[1];
|
|
FC = s->decoded[2];
|
|
SB = s->decoded[3];
|
|
RL = s->decoded[4];
|
|
RR = s->decoded[5];
|
|
RC = s->decoded[6];
|
|
/* LF = 0.28 LF + 0.14 SUB + 0.14 FC + 0.28 RL + 0.00 RR + 0.14 CR
|
|
LR = 0.28 LR + 0.14 SUB + 0.14 FC + 0.00 RL + 0.28 RR + 0.14 CR */
|
|
for (i=0; i<s->blocksize; ++i) {
|
|
int32_t a = *(FL)*2 + *(SB) + *(FC) + *(RL)*2 + *(RC);
|
|
int32_t b = *(FR)*2 + *(SB) + *(FC) + *(RR)*2 + *(RC);
|
|
*outL++ = ((a + (a<<4))>>6) << scale; /* 9>>6 ~= 1/7 */
|
|
*outR++ = ((b + (b<<4))>>6) << scale; /* 9>>6 ~= 1/7 */
|
|
FL++; FR++; SB++; FC++; RL++; RR++; RC++;
|
|
}
|
|
break;
|
|
default: /* 1.0 and 2.0 do not need downmix, other formats unknown. */
|
|
return -501;
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int flac_decode_frame(FLACContext *s,
|
|
uint8_t *buf, int buf_size,
|
|
void (*yield)(void))
|
|
{
|
|
int tmp;
|
|
int i;
|
|
int framesize;
|
|
int scale;
|
|
|
|
/* check that there is at least the smallest decodable amount of data.
|
|
this amount corresponds to the smallest valid FLAC frame possible.
|
|
this amount corresponds to the smallest valid FLAC frame possible.
|
|
FF F8 69 02 00 00 9A 00 00 34 46 */
|
|
if (buf_size < MIN_FRAME_SIZE)
|
|
return buf_size;
|
|
|
|
init_get_bits(&s->gb, buf, buf_size*8);
|
|
|
|
tmp = get_bits(&s->gb, 16);
|
|
if ((tmp & 0xFFFE) != 0xFFF8){
|
|
return -41;
|
|
}
|
|
|
|
if ((framesize=decode_frame(s,yield)) < 0){
|
|
s->bitstream_size=0;
|
|
s->bitstream_index=0;
|
|
return framesize;
|
|
}
|
|
|
|
yield();
|
|
|
|
#define DECORRELATE(left, right)\
|
|
for (i = 0; i < s->blocksize; i++) {\
|
|
int32_t a = s->decoded[0][i];\
|
|
int32_t b = s->decoded[1][i];\
|
|
s->decoded[0][i] = (left) << scale;\
|
|
s->decoded[1][i] = (right) << scale;\
|
|
}\
|
|
|
|
scale=FLAC_OUTPUT_DEPTH-s->bps;
|
|
switch(s->ch_mode)
|
|
{
|
|
case INDEPENDENT:
|
|
if (s->channels <= 2) {
|
|
DECORRELATE(a, b) /* Always decorrelate exactly the two supported channels. */
|
|
} else {
|
|
if ((tmp=flac_downmix(s)) != 0)
|
|
return tmp;
|
|
}
|
|
break;
|
|
case LEFT_SIDE:
|
|
DECORRELATE(a, a-b)
|
|
break;
|
|
case RIGHT_SIDE:
|
|
DECORRELATE(a+b, b)
|
|
break;
|
|
case MID_SIDE:
|
|
DECORRELATE( (a-=b>>1) + b, a)
|
|
break;
|
|
}
|
|
|
|
s->framesize = (get_bits_count(&s->gb)+7)>>3;
|
|
|
|
return 0;
|
|
}
|