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aptx: simplify by pre-calculating factor_max

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This commit is contained in:
Aurelien Jacobs 2018-01-06 00:23:43 +01:00
parent 81d6501be7
commit b7915f8a14
1 changed files with 7 additions and 9 deletions
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16
libavcodec/aptx.c
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@ -188,7 +188,7 @@ typedef const struct {
const int32_t *quantize_dither_factors;
const int16_t *quantize_factor_select_offset;
int tables_size;
int32_t quantized_bits;
int32_t factor_max;
int32_t prediction_order;
} ConstTables;
@ -198,25 +198,25 @@ static ConstTables tables[NB_SUBBANDS] = {
quantize_dither_factors_LF,
quantize_factor_select_offset_LF,
FF_ARRAY_ELEMS(quantize_intervals_LF),
7, 24 },
0x11FF, 24 },
[MLF] = { quantize_intervals_MLF,
invert_quantize_dither_factors_MLF,
quantize_dither_factors_MLF,
quantize_factor_select_offset_MLF,
FF_ARRAY_ELEMS(quantize_intervals_MLF),
4, 12 },
0x14FF, 12 },
[MHF] = { quantize_intervals_MHF,
invert_quantize_dither_factors_MHF,
quantize_dither_factors_MHF,
quantize_factor_select_offset_MHF,
FF_ARRAY_ELEMS(quantize_intervals_MHF),
2, 6 },
0x16FF, 6 },
[HF] = { quantize_intervals_HF,
invert_quantize_dither_factors_HF,
quantize_dither_factors_HF,
quantize_factor_select_offset_HF,
FF_ARRAY_ELEMS(quantize_intervals_HF),
3, 12 },
0x15FF, 12 },
};
static const int16_t quantization_factors[32] = {
@ -530,16 +530,14 @@ static void aptx_invert_quantization(InvertQuantize *invert_quantize,
qr = rshift64_clip24(((int64_t)qr<<32) + MUL64(dither, tables->invert_quantize_dither_factors[idx]), 32);
invert_quantize->reconstructed_difference = MUL64(invert_quantize->quantization_factor, qr) >> 19;
shift = 24 - tables->quantized_bits;
/* update factor_select */
factor_select = 32620 * invert_quantize->factor_select;
factor_select = rshift32(factor_select + (tables->quantize_factor_select_offset[idx] << 15), 15);
invert_quantize->factor_select = av_clip(factor_select, 0, (shift << 8) | 0xFF);
invert_quantize->factor_select = av_clip(factor_select, 0, tables->factor_max);
/* update quantization factor */
idx = (invert_quantize->factor_select & 0xFF) >> 3;
shift -= invert_quantize->factor_select >> 8;
shift = (tables->factor_max - invert_quantize->factor_select) >> 8;
invert_quantize->quantization_factor = (quantization_factors[idx] << 11) >> shift;
}