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Improve LPC order guess

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The recent compression preset retuning improved upon most material
but it the few tracks that show regression are usually classical
music. This patch improves compression by improving the LPC order
guess, of which classical music benefits most.

Improvement is 0.007% on average but up to 0.1%. I haven't seen
regressions for any of my test samples.

Signed-off-by: Erik de Castro Lopo <erikd@mega-nerd.com>
This commit is contained in:
Martijn van Beurden
2014-12-03 14:59:19 +01:00
committed by Erik de Castro Lopo
parent ac0b4b4cab
commit c97e057ee5
1 changed files with 2 additions and 2 deletions
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4
src/libFLAC/lpc.c
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@@ -1308,7 +1308,7 @@ FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__double lp
FLAC__ASSERT(total_samples > 0);
error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__double)total_samples;
error_scale = 0.5 / (FLAC__double)total_samples;
return FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error, error_scale);
}
@@ -1338,7 +1338,7 @@ unsigned FLAC__lpc_compute_best_order(const FLAC__double lpc_error[], unsigned m
FLAC__ASSERT(max_order > 0);
FLAC__ASSERT(total_samples > 0);
error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__double)total_samples;
error_scale = 0.5 / (FLAC__double)total_samples;
best_index = 0;
best_bits = (unsigned)(-1);