[flac-dev] [PATCH] stream_encoder : Improve selection of residual accumulator width

Erik de Castro Lopo mle+la at mega-nerd.com
Fri Jun 27 17:22:14 PDT 2014

Miroslav Lichvar wrote:

> In the precompute_partition_info_sums_ function, instead of selecting
> 64-bit accumulator when the signal bps is larger than 16, revert to the
> original approach based on partition size, but make room for few extra
> bits to not overflow with unusual signals where the average residual
> magnitude may be larger than bps.
> It slightly improves the performance with standard encoding levels and
> 16-bit files as the 17-bit side channel can still be processed with the
> 32-bit accumulator and correctly selects the 64-bit accumulator with
> very large 16-bit partitions.
> This is related to commits 6f7ec60c and 187e596e.

Sorry I wasn't able to deal with this patch when it came in because I
was busy with $day_job.

There was a lot of discussion about this patch but I can't really 
figure out from the thread what the conclusion was.

The patch still applies, and the test suite passes. If there is a 
problem with this patch that the test suite doesn't catch, we should
write a test that does catch it.

If there is no problem with the patch I'll push it.

Erik de Castro Lopo

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