forked from len0rd/rockbox
Initial attept at supporting Line Spectral Pairs. Various issues remain, and the ffmpeg decoder itself often fails on certain valid LSP files. Expect some issues.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14134 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Michael Giacomelli
parent
66029a58ae
commit
206e883e78
4 changed files with 125 additions and 83 deletions
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@ -286,10 +286,9 @@ int ff_mdct_init(MDCTContext *s, int nbits, int inverse)
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s->tsin[i] = - fsincos(ip<<16, &(s->tcos[i])); //I can't remember why this works, but it seems to agree for ~24 bits, maybe more!
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s->tcos[i] *=-1;
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}
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s->fft.nbits = s->nbits - 2;
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(&s->fft)->nbits = nbits-2;
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s->fft.inverse = inverse;
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(&s->fft)->inverse = inverse;
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return 0;
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@ -733,8 +732,10 @@ int wma_decode_init(WMADecodeContext* s, asf_waveformatex_t *wfx)
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s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
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/* high freq computation */
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fixed32 tmp = high_freq*2;
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s->high_band_start[k] = fixtoi32(fixdiv32(tmp, itofix32(s->sample_rate)) *block_len +0x8000);
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fixed32 tmp1 = high_freq*2; /* high_freq is a fixed32!*/
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fixed32 tmp2=itofix32(s->sample_rate>>1);
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s->high_band_start[k] = fixtoi32( fixdiv32(tmp1, tmp2) * (block_len>>1) +0x8000);
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/*
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s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
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s->sample_rate + 0.5);*/
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@ -935,48 +936,57 @@ int wma_decode_init(WMADecodeContext* s, asf_waveformatex_t *wfx)
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static inline fixed32 pow_m1_4(WMADecodeContext *s, fixed32 x)
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{
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union {
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fixed64 f;
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float f;
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unsigned int v;
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} u, t;
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unsigned int e, m;
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fixed64 a, b;
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fixed32 a, b;
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u.f = x;
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u.f = fixtof64(x);
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e = u.v >> 23;
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m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
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/* build interpolation scale: 1 <= t < 2. */
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t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
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a = s->lsp_pow_m_table1[m];
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b = s->lsp_pow_m_table2[m];
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return lsp_pow_e_table[e] * (a + b * t.f);
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/*lsp_pow_e_table contains 32.32 format */
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/*TODO: Since we're unlikely have value that cover the whole
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* IEEE754 range, we probably don't need to have all possible exponents*/
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return (lsp_pow_e_table[e] * (a + fixmul32(b, ftofix32(t.f))) >>32);
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}
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static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
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{
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fixed32 wdel, a, b;
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fixed32 wdel, a, b, temp, temp2;
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int i, m;
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wdel = fixdiv32(M_PI_F, itofix32(frame_len));
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temp = fixdiv32(itofix32(1), itofix32(frame_len));
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for (i=0; i<frame_len; ++i)
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{
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s->lsp_cos_table[i] = 0x20000 * fixcos32(wdel * i); //wdel*i between 0 and pi
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/*TODO: can probably reuse the trig_init values here */
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fsincos((temp*i)<<15, &temp2);
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/*get 3 bits headroom + 1 bit from not doubleing the values*/
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s->lsp_cos_table[i] = temp2>>3;
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}
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/* NOTE: these two tables are needed to avoid two operations in
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pow_m1_4 */
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b = itofix32(1);
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int ix = 0;
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/*double check this later*/
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for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--)
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{
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m = (1 << LSP_POW_BITS) + i;
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a = m * (0x8000 / (1 << LSP_POW_BITS)); //PJJ
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a = pow_a_table[ix++]; // PJJ : further refinement
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a = pow_a_table[ix++]<<4;
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s->lsp_pow_m_table1[i] = 2 * a - b;
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s->lsp_pow_m_table2[i] = b - a;
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b = a;
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}
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}
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/* NOTE: We use the same code as Vorbis here */
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@ -988,27 +998,42 @@ static void wma_lsp_to_curve(WMADecodeContext *s,
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fixed32 *lsp)
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{
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int i, j;
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fixed32 p, q, w, v, val_max;
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fixed32 p, q, w, v, val_max, temp, temp2;
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val_max = 0;
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for(i=0;i<n;++i)
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{
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p = 0x8000;
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q = 0x8000;
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/* shift by 2 now to reduce rounding error,
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* we can renormalize right before pow_m1_4
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*/
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p = 0x8000<<5;
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q = 0x8000<<5;
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w = s->lsp_cos_table[i];
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for (j=1;j<NB_LSP_COEFS;j+=2)
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{
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q *= w - lsp[j - 1];
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p *= w - lsp[j];
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/*w is 5.27 format, lsp is in 16.16, temp2 becomes 5.27 format*/
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temp2 = ((w - (lsp[j - 1]<<11)));
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temp = q;
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/*q is 16.16 format, temp2 is 5.27, q becomes 16.16 */
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q = fixmul32b(q, temp2 )<<4;
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p = fixmul32b(p, (w - (lsp[j]<<11)))<<4;
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}
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p *= p * (0x20000 - w);
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q *= q * (0x20000 + w);
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v = p + q;
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v = pow_m1_4(s, v); // PJJ
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/* 2 in 5.27 format is 0x10000000 */
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p = fixmul32(p, fixmul32b(p, (0x10000000 - w)))<<3;
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q = fixmul32(q, fixmul32b(q, (0x10000000 + w)))<<3;
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v = (p + q) >>9; /* p/q end up as 16.16 */
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v = pow_m1_4(s, v);
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if (v > val_max)
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val_max = v;
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out[i] = v;
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}
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*val_max_ptr = val_max;
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}
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@ -1392,13 +1417,11 @@ static int wma_decode_block(WMADecodeContext *s)
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coefs1 = s->coefs1[ch];
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exponents = s->exponents[ch];
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esize = s->exponents_bsize[ch];
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mult = fixdiv64(pow_table[total_gain],Fixed32To64(s->max_exponent[ch]));
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// mul = fixtof64(pow_table[total_gain])/(s->block_len/2)/fixtof64(s->max_exponent[ch]);
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mult = fixdiv64(pow_table[total_gain+20],Fixed32To64(s->max_exponent[ch]));
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mult = fixmul64byfixed(mult, mdct_norm); //what the hell? This is actually fixed64*2^16!
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coefs = (*(s->coefs))[ch]; //VLC exponenents are used to get MDCT coef here!
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coefs = (*(s->coefs))[ch];
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n=0;
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n=0;
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if (s->use_noise_coding)
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{
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@ -1428,8 +1451,9 @@ static int wma_decode_block(WMADecodeContext *s)
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e2 = 0;
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for(i = 0;i < n; ++i)
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{
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v = exp_ptr[i]>>5; /*v is noramlized later on so its fixed format is irrelevant*/
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e2 += fixmul32(v, v);
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/*v is noramlized later on so its fixed format is irrelevant*/
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v = exp_ptr[i]>>4;
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e2 += fixmul32(v, v)>>3;
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}
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exp_power[j] = e2/n; /*n is an int...*/
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last_high_band = j;
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@ -1456,7 +1480,8 @@ static int wma_decode_block(WMADecodeContext *s)
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fixed32 tmp = fixdiv32(exp_power[j],exp_power[last_high_band]);
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mult1 = (fixed64)fixsqrt32(tmp);
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/* XXX: use a table */
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mult1 = mult1 * pow_table[s->high_band_values[ch][j]] >> PRECISION;
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/*mult1 is 48.16, pow_table is 48.16*/
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mult1 = mult1 * pow_table[s->high_band_values[ch][j]+20] >> PRECISION;
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/*this step has a fairly high degree of error for some reason*/
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mult1 = fixdiv64(mult1,fixmul32(s->max_exponent[ch],s->noise_mult));
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@ -1481,9 +1506,9 @@ static int wma_decode_block(WMADecodeContext *s)
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/*don't forget to renormalize the noise*/
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temp1 = (((int32_t)*coefs1++)<<16) + (noise>>4);
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temp2 = fixmul32(*exponents, mult>>16);
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*coefs++ = fixmul32(temp1, temp2)>>1;
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++exponents;
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temp2 = fixmul32(*exponents, mult>>17);
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*coefs++ = fixmul32(temp1, temp2);
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++exponents;
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}
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}
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}
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@ -1637,10 +1662,8 @@ static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
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for (i=0;i<n;++i)
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{
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a = fixtoi32(*iptr++)<<1; //ugly but good enough for now
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a = fixtoi32(*iptr++)<<1; //ugly but good enough for now
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if (a > 32767)
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