eden-emu/opus
19
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Simplified flags encoding

Browse source
This commit is contained in:
Jean-Marc Valin 2010-08-05 15:42:50 -04:00
parent 8cbea177ba
commit 017001a512
1 changed files with 10 additions and 70 deletions
Download patch file Download diff file Expand all files Collapse all files

80
libcelt/celt.c
View file

@ -400,74 +400,6 @@ static void compute_inv_mdcts(const CELTMode *mode, int shortBlocks, celt_sig *X
} }
} }
#define FLAG_NONE 0
#define FLAG_INTRA (1U<<13)
#define FLAG_PITCH (1U<<12)
#define FLAG_SHORT (1U<<11)
#define FLAG_FOLD (1U<<10)
#define FLAG_MASK (FLAG_INTRA|FLAG_PITCH|FLAG_SHORT|FLAG_FOLD)
static const int flaglist[8] = {
0 /*00 */ | FLAG_FOLD,
1 /*01 */ | FLAG_PITCH|FLAG_FOLD,
8 /*1000*/ | FLAG_NONE,
9 /*1001*/ | FLAG_SHORT|FLAG_FOLD,
10 /*1010*/ | FLAG_PITCH,
11 /*1011*/ | FLAG_INTRA,
6 /*110 */ | FLAG_INTRA|FLAG_FOLD,
7 /*111 */ | FLAG_INTRA|FLAG_SHORT|FLAG_FOLD
};
static void encode_flags(ec_enc *enc, int intra_ener, int shortBlocks, int has_fold)
{
int i;
int flags=FLAG_NONE;
int flag_bits;
flags |= intra_ener ? FLAG_INTRA : 0;
flags |= shortBlocks ? FLAG_SHORT : 0;
flags |= has_fold ? FLAG_FOLD : 0;
for (i=0;i<8;i++)
{
if (flags == (flaglist[i]&FLAG_MASK))
{
flag_bits = flaglist[i]&0xf;
break;
}
}
celt_assert(i<8);
/*printf ("enc %d: %d %d %d %d\n", flag_bits, intra_ener, has_pitch, shortBlocks, has_fold);*/
if (i<2)
ec_enc_uint(enc, flag_bits, 4);
else if (i<6)
{
ec_enc_uint(enc, flag_bits>>2, 4);
ec_enc_uint(enc, flag_bits&0x3, 4);
} else {
ec_enc_uint(enc, flag_bits>>1, 4);
ec_enc_uint(enc, flag_bits&0x1, 2);
}
}
static void decode_flags(ec_dec *dec, int *intra_ener, int *shortBlocks, int *has_fold)
{
int i;
int flag_bits;
flag_bits = ec_dec_uint(dec, 4);
/*printf ("(%d) ", flag_bits);*/
if (flag_bits==2)
flag_bits = (flag_bits<<2) | ec_dec_uint(dec, 4);
else if (flag_bits==3)
flag_bits = (flag_bits<<1) | ec_dec_uint(dec, 2);
for (i=0;i<8;i++)
if (flag_bits == (flaglist[i]&0xf))
break;
celt_assert(i<8);
*intra_ener = (flaglist[i]&FLAG_INTRA) != 0;
*shortBlocks = (flaglist[i]&FLAG_SHORT) != 0;
*has_fold = (flaglist[i]&FLAG_FOLD ) != 0;
/*printf ("dec %d: %d %d %d %d\n", flag_bits, *intra_ener, *has_pitch, *shortBlocks, *has_fold);*/
}
static void deemphasis(celt_sig *in, celt_word16 *pcm, int N, int _C, const celt_word16 *coef, celt_sig *mem) static void deemphasis(celt_sig *in, celt_word16 *pcm, int N, int _C, const celt_word16 *coef, celt_sig *mem)
{ {
const int C = CHANNELS(_C); const int C = CHANNELS(_C);
@ -877,8 +809,12 @@ int celt_encode_with_ec_float(CELTEncoder * restrict st, const celt_sig * pcm, c
mdct_shape(st->mode, X, mdct_weight_pos+1, M, N, mdct_weight_shift, effEnd, C, 0, M); mdct_shape(st->mode, X, mdct_weight_pos+1, M, N, mdct_weight_shift, effEnd, C, 0, M);
} }
/* Encode the global flags using a simple probability model
(first symbols in the stream) */
ec_enc_bit_prob(enc, intra_ener, 8192);
ec_enc_bit_prob(enc, shortBlocks!=0, 8192);
ec_enc_bit_prob(enc, has_fold, 57344);
encode_flags(enc, intra_ener, shortBlocks, has_fold);
if (shortBlocks) if (shortBlocks)
{ {
if (transient_shift) if (transient_shift)
@ -1676,7 +1612,11 @@ int celt_decode_with_ec_float(CELTDecoder * restrict st, const unsigned char *da
} }
nbAvailableBytes = len-nbFilledBytes; nbAvailableBytes = len-nbFilledBytes;
decode_flags(dec, &intra_ener, &isTransient, &has_fold); /* Decode the global flags (first symbols in the stream) */
intra_ener = ec_dec_bit_prob(dec, 8192);
isTransient = ec_dec_bit_prob(dec, 8192);
has_fold = ec_dec_bit_prob(dec, 57344);
if (isTransient) if (isTransient)
shortBlocks = M; shortBlocks = M;
else else