Diffstat (limited to 'core/multimedia/opieplayer/libmad/layer3.c') (more/less context) (show whitespace changes)
| -rw-r--r-- | core/multimedia/opieplayer/libmad/layer3.c | 146 |
1 files changed, 78 insertions, 68 deletions
diff --git a/core/multimedia/opieplayer/libmad/layer3.c b/core/multimedia/opieplayer/libmad/layer3.c index 194fc7e..03f13fe 100644 --- a/core/multimedia/opieplayer/libmad/layer3.c +++ b/core/multimedia/opieplayer/libmad/layer3.c @@ -1,5 +1,5 @@ /* - * mad - MPEG audio decoder + * libmad - MPEG audio decoder library * Copyright (C) 2000-2001 Robert Leslie * * This program is free software; you can redistribute it and/or modify @@ -27,7 +27,10 @@ # include <stdlib.h> # include <string.h> + +# ifdef HAVE_ASSERT_H # include <assert.h> +# endif # ifdef HAVE_LIMITS_H # include <limits.h> @@ -51,6 +54,11 @@ enum { mixed_block_flag = 0x08 }; +enum { + I_STEREO = 0x1, + MS_STEREO = 0x2 +}; + struct sideinfo { unsigned int main_data_begin; unsigned int private_bits; @@ -503,7 +511,7 @@ enum mad_error III_sideinfo(struct mad_bitptr *ptr, unsigned int nch, unsigned int *priv_bitlen) { unsigned int ngr, gr, ch, i; - enum mad_error result = 0; + enum mad_error result = MAD_ERROR_NONE; *data_bitlen = 0; *priv_bitlen = lsf ? ((nch == 1) ? 1 : 2) : ((nch == 1) ? 5 : 3); @@ -602,7 +610,7 @@ unsigned int III_scalefactors_lsf(struct mad_bitptr *ptr, index = (channel->block_type == 2) ? ((channel->flags & mixed_block_flag) ? 2 : 1) : 0; - if (!((mode_extension & 0x1) && gr1ch)) { + if (!((mode_extension & I_STEREO) && gr1ch)) { if (scalefac_compress < 400) { slen[0] = (scalefac_compress >> 4) / 5; slen[1] = (scalefac_compress >> 4) % 5; @@ -643,7 +651,7 @@ unsigned int III_scalefactors_lsf(struct mad_bitptr *ptr, while (n < 39) channel->scalefac[n++] = 0; } - else { /* (mode_extension & 0x1) && gr1ch (i.e. ch == 1) */ + else { /* (mode_extension & I_STEREO) && gr1ch (i.e. ch == 1) */ scalefac_compress >>= 1; if (scalefac_compress < 180) { @@ -775,6 +783,28 @@ unsigned int III_scalefactors(struct mad_bitptr *ptr, struct channel *channel, } /* + * The Layer III formula for requantization and scaling is defined by + * section 2.4.3.4.7.1 of ISO/IEC 11172-3, as follows: + * + * long blocks: + * xr[i] = sign(is[i]) * abs(is[i])^(4/3) * + * 2^((1/4) * (global_gain - 210)) * + * 2^-(scalefac_multiplier * + * (scalefac_l[sfb] + preflag * pretab[sfb])) + * + * short blocks: + * xr[i] = sign(is[i]) * abs(is[i])^(4/3) * + * 2^((1/4) * (global_gain - 210 - 8 * subblock_gain[w])) * + * 2^-(scalefac_multiplier * scalefac_s[sfb][w]) + * + * where: + * scalefac_multiplier = (scalefac_scale + 1) / 2 + * + * The routines III_exponents() and III_requantize() facilitate this + * calculation. + */ + +/* * NAME: III_exponents() * DESCRIPTION: calculate scalefactor exponents */ @@ -856,23 +886,7 @@ mad_fixed_t III_requantize(unsigned int value, signed int exp) signed int frac; struct fixedfloat const *power; - /* - * long blocks: - * xr[i] = sign(is[i]) * abs(is[i])^(4/3) * - * 2^((1/4) * (global_gain - 210)) * - * 2^-(scalefac_multiplier * - * (scalefac_l[sfb] + preflag * pretab[sfb])) - * - * short blocks: - * xr[i] = sign(is[i]) * abs(is[i])^(4/3) * - * 2^((1/4) * (global_gain - 210 - 8 * subblock_gain[w])) * - * 2^-(scalefac_multiplier * scalefac_s[sfb][w]) - * - * where: - * scalefac_multiplier = (scalefac_scale + 1) / 2 - */ - - frac = exp % 4; + frac = exp % 4; /* assumes sign(frac) == sign(exp) */ exp /= 4; power = &rq_table[value]; @@ -884,9 +898,11 @@ mad_fixed_t III_requantize(unsigned int value, signed int exp) /* underflow */ requantized = 0; } - else + else { + requantized += 1L << (-exp - 1); requantized >>= -exp; } + } else { if (exp >= 5) { /* overflow */ @@ -1251,7 +1267,7 @@ enum mad_error III_huffdecode(struct mad_bitptr *ptr, mad_fixed_t xr[576], xrptr += 2; } - return 0; + return MAD_ERROR_NONE; } # undef MASK @@ -1266,37 +1282,39 @@ void III_reorder(mad_fixed_t xr[576], struct channel const *channel, unsigned char const sfbwidth[39]) { mad_fixed_t tmp[32][3][6]; - unsigned int sb, l, sfbi, f, w, sbw[3], sw[3]; + unsigned int sb, l, f, w, sbw[3], sw[3]; /* this is probably wrong for 8000 Hz mixed blocks */ - if (channel->flags & mixed_block_flag) - sb = 2, sfbi = 3 * 3; - else - sb = 0, sfbi = 0; + sb = 0; + if (channel->flags & mixed_block_flag) { + sb = 2; + + l = 0; + while (l < 36) + l += *sfbwidth++; + } for (w = 0; w < 3; ++w) { sbw[w] = sb; sw[w] = 0; } - f = sfbwidth[sfbi]; + f = *sfbwidth++; w = 0; for (l = 18 * sb; l < 576; ++l) { + if (f-- == 0) { + f = *sfbwidth++ - 1; + w = (w + 1) % 3; + } + tmp[sbw[w]][w][sw[w]++] = xr[l]; if (sw[w] == 6) { sw[w] = 0; ++sbw[w]; } - - if (--f == 0) { - if (++w == 3) - w = 0; - - f = sfbwidth[++sfbi]; - } } memcpy(&xr[18 * sb], &tmp[sb], (576 - 18 * sb) * sizeof(mad_fixed_t)); @@ -1315,11 +1333,6 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], short modes[39]; unsigned int sfbi, l, n, i; - enum { - i_stereo = 0x1, - ms_stereo = 0x2 - }; - if (granule->ch[0].block_type != granule->ch[1].block_type || (granule->ch[0].flags & mixed_block_flag) != @@ -1331,7 +1344,7 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], /* intensity stereo */ - if (header->mode_extension & i_stereo) { + if (header->mode_extension & I_STEREO) { struct channel const *right_ch = &granule->ch[1]; mad_fixed_t const *right_xr = xr[1]; unsigned int is_pos; @@ -1387,14 +1400,14 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], /* long blocks */ for (i = 0; i < lower; ++i) - modes[i] = header->mode_extension & ~i_stereo; + modes[i] = header->mode_extension & ~I_STEREO; /* short blocks */ w = 0; for (i = start; i < max; ++i) { if (i < bound[w]) - modes[i] = header->mode_extension & ~i_stereo; + modes[i] = header->mode_extension & ~I_STEREO; w = (w + 1) % 3; } @@ -1417,7 +1430,7 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], } for (i = 0; i < bound; ++i) - modes[i] = header->mode_extension & ~i_stereo; + modes[i] = header->mode_extension & ~I_STEREO; } /* now do the actual processing */ @@ -1432,11 +1445,11 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], for (sfbi = l = 0; l < 576; ++sfbi, l += n) { n = sfbwidth[sfbi]; - if (!(modes[sfbi] & i_stereo)) + if (!(modes[sfbi] & I_STEREO)) continue; if (illegal_pos[sfbi]) { - modes[sfbi] &= ~i_stereo; + modes[sfbi] &= ~I_STEREO; continue; } @@ -1468,13 +1481,13 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], for (sfbi = l = 0; l < 576; ++sfbi, l += n) { n = sfbwidth[sfbi]; - if (!(modes[sfbi] & i_stereo)) + if (!(modes[sfbi] & I_STEREO)) continue; is_pos = right_ch->scalefac[sfbi]; if (is_pos >= 7) { /* illegal intensity position */ - modes[sfbi] &= ~i_stereo; + modes[sfbi] &= ~I_STEREO; continue; } @@ -1492,7 +1505,7 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], /* middle/side stereo */ - if (header->mode_extension & ms_stereo) { + if (header->mode_extension & MS_STEREO) { register mad_fixed_t invsqrt2; header->flags |= MAD_FLAG_MS_STEREO; @@ -1502,7 +1515,7 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], for (sfbi = l = 0; l < 576; ++sfbi, l += n) { n = sfbwidth[sfbi]; - if (modes[sfbi] != ms_stereo) + if (modes[sfbi] != MS_STEREO) continue; for (i = 0; i < n; ++i) { @@ -1517,7 +1530,7 @@ enum mad_error III_stereo(mad_fixed_t xr[2][576], } } - return 0; + return MAD_ERROR_NONE; } /* @@ -1533,15 +1546,12 @@ void III_aliasreduce(mad_fixed_t xr[576], int lines) bound = &xr[lines]; for (xr += 18; xr < bound; xr += 18) { for (i = 0; i < 8; ++i) { - register mad_fixed_t *aptr, *bptr, a, b; + register mad_fixed_t a, b; register mad_fixed64hi_t hi; register mad_fixed64lo_t lo; - aptr = &xr[-1 - i]; - bptr = &xr[ i]; - - a = *aptr; - b = *bptr; + a = xr[-1 - i]; + b = xr[ i]; # if defined(ASO_ZEROCHECK) if (a | b) { @@ -1549,12 +1559,12 @@ void III_aliasreduce(mad_fixed_t xr[576], int lines) MAD_F_ML0(hi, lo, a, cs[i]); MAD_F_MLA(hi, lo, -b, ca[i]); - *aptr = MAD_F_MLZ(hi, lo); + xr[-1 - i] = MAD_F_MLZ(hi, lo); MAD_F_ML0(hi, lo, b, cs[i]); MAD_F_MLA(hi, lo, a, ca[i]); - *bptr = MAD_F_MLZ(hi, lo); + xr[ i] = MAD_F_MLZ(hi, lo); # if defined(ASO_ZEROCHECK) } # endif @@ -2141,7 +2151,7 @@ void III_freqinver(mad_fixed_t sample[18][32], unsigned int sb) * DESCRIPTION: decode frame main_data */ static -int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, +enum mad_error III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, struct sideinfo *si, unsigned int nch) { struct mad_header *header = &frame->header; @@ -2169,7 +2179,7 @@ int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, for (gr = 0; gr < ngr; ++gr) { struct granule *granule = &si->gr[gr]; - unsigned char const *sfbwidth = 0; + unsigned char const *sfbwidth[2]; mad_fixed_t xr[2][576]; unsigned int ch; enum mad_error error; @@ -2178,9 +2188,9 @@ int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, struct channel *channel = &granule->ch[ch]; unsigned int part2_length; - sfbwidth = sfbwidth_table[sfreqi].l; + sfbwidth[ch] = sfbwidth_table[sfreqi].l; if (channel->block_type == 2) { - sfbwidth = (channel->flags & mixed_block_flag) ? + sfbwidth[ch] = (channel->flags & mixed_block_flag) ? sfbwidth_table[sfreqi].m : sfbwidth_table[sfreqi].s; } @@ -2194,7 +2204,7 @@ int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, gr == 0 ? 0 : si->scfsi[ch]); } - error = III_huffdecode(ptr, xr[ch], channel, sfbwidth, part2_length); + error = III_huffdecode(ptr, xr[ch], channel, sfbwidth[ch], part2_length); if (error) return error; } @@ -2202,7 +2212,7 @@ int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, /* joint stereo processing */ if (header->mode == MAD_MODE_JOINT_STEREO && header->mode_extension) { - error = III_stereo(xr, granule, header, sfbwidth); + error = III_stereo(xr, granule, header, sfbwidth[0]); if (error) return error; } @@ -2216,7 +2226,7 @@ int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, mad_fixed_t output[36]; if (channel->block_type == 2) { - III_reorder(xr[ch], channel, sfbwidth_table[sfreqi].s); + III_reorder(xr[ch], channel, sfbwidth[ch]); # if !defined(OPT_STRICT) /* @@ -2300,7 +2310,7 @@ int III_decode(struct mad_bitptr *ptr, struct mad_frame *frame, } } - return 0; + return MAD_ERROR_NONE; } /* |