The legacy scaler is no longer implicitly used to generate a reference
to perform comparisons for every conversion. It is now up to the user
to generate a reference file and use it as input for a separate run to
perform comparisons.
It is now possible to compare against previous runs of the graph-based
scaler, for example to test for newer optimizations.
This reduces the overall time necessary to obtain speedup numbers from
the legacy scaler to the graph-based scaler (or any other comparison,
for that matter) since the reference must only be run once.
For example, to check the speedup between the legacy scaler and the
graph-based scaler:
./libswscale/tests/swscale [...] -bench 50 -legacy 1 > legacy_ref.txt
./libswscale/tests/swscale [...] -bench 50 -ref legacy_ref.txt
If no -ref file is specified, we are assuming that we are generating a
reference file, and therefore all information is printed (including
ssim/loss, and benchmarks if -bench is used).
If a -ref file is specified, the output printed depends on whether we
are testing for correctness (ssim/loss only) or benchmarking (time/
speedup only, along with overall speedup).
Sponsored-by: Sovereign Tech Fund
Signed-off-by: Ramiro Polla <ramiro.polla@gmail.com>
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