fixed.c

tcpmp.src.0.72RC1 优秀的多媒体播放器TCPMP的源代码

	else
		return rbps;
}
#endif

#ifndef FLAC__INTEGER_ONLY_LIBRARY
unsigned FLAC__fixed_compute_best_predictor(const FLAC__int32 data[], unsigned data_len, FLAC__float residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
#else
unsigned FLAC__fixed_compute_best_predictor(const FLAC__int32 data[], unsigned data_len, FLAC__fixedpoint residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
#endif
{
	FLAC__int32 last_error_0 = data[-1];
	FLAC__int32 last_error_1 = data[-1] - data[-2];
	FLAC__int32 last_error_2 = last_error_1 - (data[-2] - data[-3]);
	FLAC__int32 last_error_3 = last_error_2 - (data[-2] - 2*data[-3] + data[-4]);
	FLAC__int32 error, save;
	FLAC__uint32 total_error_0 = 0, total_error_1 = 0, total_error_2 = 0, total_error_3 = 0, total_error_4 = 0;
	unsigned i, order;

	for(i = 0; i < data_len; i++) {
		error  = data[i]     ; total_error_0 += local_abs(error);                      save = error;
		error -= last_error_0; total_error_1 += local_abs(error); last_error_0 = save; save = error;
		error -= last_error_1; total_error_2 += local_abs(error); last_error_1 = save; save = error;
		error -= last_error_2; total_error_3 += local_abs(error); last_error_2 = save; save = error;
		error -= last_error_3; total_error_4 += local_abs(error); last_error_3 = save;
	}

	if(total_error_0 < min(min(min(total_error_1, total_error_2), total_error_3), total_error_4))
		order = 0;
	else if(total_error_1 < min(min(total_error_2, total_error_3), total_error_4))
		order = 1;
	else if(total_error_2 < min(total_error_3, total_error_4))
		order = 2;
	else if(total_error_3 < total_error_4)
		order = 3;
	else
		order = 4;

	/* Estimate the expected number of bits per residual signal sample. */
	/* 'total_error*' is linearly related to the variance of the residual */
	/* signal, so we use it directly to compute E(|x|) */
	FLAC__ASSERT(data_len > 0 || total_error_0 == 0);
	FLAC__ASSERT(data_len > 0 || total_error_1 == 0);
	FLAC__ASSERT(data_len > 0 || total_error_2 == 0);
	FLAC__ASSERT(data_len > 0 || total_error_3 == 0);
	FLAC__ASSERT(data_len > 0 || total_error_4 == 0);
#ifndef FLAC__INTEGER_ONLY_LIBRARY
	residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ? log(M_LN2 * (FLAC__double)total_error_0 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[1] = (FLAC__float)((total_error_1 > 0) ? log(M_LN2 * (FLAC__double)total_error_1 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[2] = (FLAC__float)((total_error_2 > 0) ? log(M_LN2 * (FLAC__double)total_error_2 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[3] = (FLAC__float)((total_error_3 > 0) ? log(M_LN2 * (FLAC__double)total_error_3 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[4] = (FLAC__float)((total_error_4 > 0) ? log(M_LN2 * (FLAC__double)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0);
#else
	residual_bits_per_sample[0] = (total_error_0 > 0) ? local__compute_rbps_integerized(total_error_0, data_len) : 0;
	residual_bits_per_sample[1] = (total_error_1 > 0) ? local__compute_rbps_integerized(total_error_1, data_len) : 0;
	residual_bits_per_sample[2] = (total_error_2 > 0) ? local__compute_rbps_integerized(total_error_2, data_len) : 0;
	residual_bits_per_sample[3] = (total_error_3 > 0) ? local__compute_rbps_integerized(total_error_3, data_len) : 0;
	residual_bits_per_sample[4] = (total_error_4 > 0) ? local__compute_rbps_integerized(total_error_4, data_len) : 0;
#endif

	return order;
}

#ifndef FLAC__INTEGER_ONLY_LIBRARY
unsigned FLAC__fixed_compute_best_predictor_wide(const FLAC__int32 data[], unsigned data_len, FLAC__float residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
#else
unsigned FLAC__fixed_compute_best_predictor_wide(const FLAC__int32 data[], unsigned data_len, FLAC__fixedpoint residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
#endif
{
	FLAC__int32 last_error_0 = data[-1];
	FLAC__int32 last_error_1 = data[-1] - data[-2];
	FLAC__int32 last_error_2 = last_error_1 - (data[-2] - data[-3]);
	FLAC__int32 last_error_3 = last_error_2 - (data[-2] - 2*data[-3] + data[-4]);
	FLAC__int32 error, save;
	/* total_error_* are 64-bits to avoid overflow when encoding
	 * erratic signals when the bits-per-sample and blocksize are
	 * large.
	 */
	FLAC__uint64 total_error_0 = 0, total_error_1 = 0, total_error_2 = 0, total_error_3 = 0, total_error_4 = 0;
	unsigned i, order;

	for(i = 0; i < data_len; i++) {
		error  = data[i]     ; total_error_0 += local_abs(error);                      save = error;
		error -= last_error_0; total_error_1 += local_abs(error); last_error_0 = save; save = error;
		error -= last_error_1; total_error_2 += local_abs(error); last_error_1 = save; save = error;
		error -= last_error_2; total_error_3 += local_abs(error); last_error_2 = save; save = error;
		error -= last_error_3; total_error_4 += local_abs(error); last_error_3 = save;
	}

	if(total_error_0 < min(min(min(total_error_1, total_error_2), total_error_3), total_error_4))
		order = 0;
	else if(total_error_1 < min(min(total_error_2, total_error_3), total_error_4))
		order = 1;
	else if(total_error_2 < min(total_error_3, total_error_4))
		order = 2;
	else if(total_error_3 < total_error_4)
		order = 3;
	else
		order = 4;

	/* Estimate the expected number of bits per residual signal sample. */
	/* 'total_error*' is linearly related to the variance of the residual */
	/* signal, so we use it directly to compute E(|x|) */
	FLAC__ASSERT(data_len > 0 || total_error_0 == 0);
	FLAC__ASSERT(data_len > 0 || total_error_1 == 0);
	FLAC__ASSERT(data_len > 0 || total_error_2 == 0);
	FLAC__ASSERT(data_len > 0 || total_error_3 == 0);
	FLAC__ASSERT(data_len > 0 || total_error_4 == 0);
#ifndef FLAC__INTEGER_ONLY_LIBRARY
#if defined _MSC_VER || defined __MINGW32__
	/* with MSVC you have to spoon feed it the casting */
	residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_0 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[1] = (FLAC__float)((total_error_1 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_1 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[2] = (FLAC__float)((total_error_2 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_2 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[3] = (FLAC__float)((total_error_3 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_3 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[4] = (FLAC__float)((total_error_4 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0);
#else
	residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ? log(M_LN2 * (FLAC__double)total_error_0 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[1] = (FLAC__float)((total_error_1 > 0) ? log(M_LN2 * (FLAC__double)total_error_1 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[2] = (FLAC__float)((total_error_2 > 0) ? log(M_LN2 * (FLAC__double)total_error_2 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[3] = (FLAC__float)((total_error_3 > 0) ? log(M_LN2 * (FLAC__double)total_error_3 / (FLAC__double)data_len) / M_LN2 : 0.0);
	residual_bits_per_sample[4] = (FLAC__float)((total_error_4 > 0) ? log(M_LN2 * (FLAC__double)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0);
#endif
#else
	residual_bits_per_sample[0] = (total_error_0 > 0) ? local__compute_rbps_wide_integerized(total_error_0, data_len) : 0;
	residual_bits_per_sample[1] = (total_error_1 > 0) ? local__compute_rbps_wide_integerized(total_error_1, data_len) : 0;
	residual_bits_per_sample[2] = (total_error_2 > 0) ? local__compute_rbps_wide_integerized(total_error_2, data_len) : 0;
	residual_bits_per_sample[3] = (total_error_3 > 0) ? local__compute_rbps_wide_integerized(total_error_3, data_len) : 0;
	residual_bits_per_sample[4] = (total_error_4 > 0) ? local__compute_rbps_wide_integerized(total_error_4, data_len) : 0;
#endif

	return order;
}

void FLAC__fixed_compute_residual(const FLAC__int32 data[], unsigned data_len, unsigned order, FLAC__int32 residual[])
{
	const int idata_len = (int)data_len;
	int i;

	switch(order) {
		case 0:
			for(i = 0; i < idata_len; i++) {
				residual[i] = data[i];
			}
			break;
		case 1:
			for(i = 0; i < idata_len; i++) {
				residual[i] = data[i] - data[i-1];
			}
			break;
		case 2:
			for(i = 0; i < idata_len; i++) {
				/* == data[i] - 2*data[i-1] + data[i-2] */
				residual[i] = data[i] - (data[i-1] << 1) + data[i-2];
			}
			break;
		case 3:
			for(i = 0; i < idata_len; i++) {
				/* == data[i] - 3*data[i-1] + 3*data[i-2] - data[i-3] */
				residual[i] = data[i] - (((data[i-1]-data[i-2])<<1) + (data[i-1]-data[i-2])) - data[i-3];
			}
			break;
		case 4:
			for(i = 0; i < idata_len; i++) {
				/* == data[i] - 4*data[i-1] + 6*data[i-2] - 4*data[i-3] + data[i-4] */
				residual[i] = data[i] - ((data[i-1]+data[i-3])<<2) + ((data[i-2]<<2) + (data[i-2]<<1)) + data[i-4];
			}
			break;
		default:
			FLAC__ASSERT(0);
	}
}

void FLAC__fixed_restore_signal(const FLAC__int32 residual[], unsigned data_len, unsigned order, FLAC__int32 data[])
{
	int i, idata_len = (int)data_len;

	switch(order) {
		case 0:
			for(i = 0; i < idata_len; i++) {
				data[i] = residual[i];
			}
			break;
		case 1:
			for(i = 0; i < idata_len; i++) {
				data[i] = residual[i] + data[i-1];
			}
			break;
		case 2:
			for(i = 0; i < idata_len; i++) {
				/* == residual[i] + 2*data[i-1] - data[i-2] */
				data[i] = residual[i] + (data[i-1]<<1) - data[i-2];
			}
			break;
		case 3:
			for(i = 0; i < idata_len; i++) {
				/* residual[i] + 3*data[i-1] - 3*data[i-2]) + data[i-3] */
				data[i] = residual[i] + (((data[i-1]-data[i-2])<<1) + (data[i-1]-data[i-2])) + data[i-3];
			}
			break;
		case 4:
			for(i = 0; i < idata_len; i++) {
				/* == residual[i] + 4*data[i-1] - 6*data[i-2] + 4*data[i-3] - data[i-4] */
				data[i] = residual[i] + ((data[i-1]+data[i-3])<<2) - ((data[i-2]<<2) + (data[i-2]<<1)) - data[i-4];
			}
			break;
		default:
			FLAC__ASSERT(0);
	}
}