From 24c2c15f9f40dae48b6ee8bfcf6c527669482acc Mon Sep 17 00:00:00 2001 From: Seppo Ingalsuo Date: Wed, 30 Sep 2020 11:31:09 +0300 Subject: [PATCH] Tools: Test: Fix for dBFS level measure for muted audio The log() function returns -Inf for level measure for stream of digital zeros. It is correct but requires extra handling in the upper level functions to avoid unnecessary tests fails. Adding of offset 1e-20 results to -196.99 dBFS be the smallest possible reported value. The function remains sufficient for all audio measurements with 16 - 32 bit formats. The license text is also updated to current version. Signed-off-by: Seppo Ingalsuo --- tools/test/audio/std_utils/level_dbfs.m | 32 +++---------------------- 1 file changed, 3 insertions(+), 29 deletions(-) diff --git a/tools/test/audio/std_utils/level_dbfs.m b/tools/test/audio/std_utils/level_dbfs.m index 73cddedb4..8bca99664 100644 --- a/tools/test/audio/std_utils/level_dbfs.m +++ b/tools/test/audio/std_utils/level_dbfs.m @@ -9,38 +9,12 @@ function dbfs = level_dbfs(x) % dbfs - sigmal level in dBFS % -%% -% Copyright (c) 2017, Intel Corporation -% All rights reserved. -% -% Redistribution and use in source and binary forms, with or without -% modification, are permitted provided that the following conditions are met: -% * Redistributions of source code must retain the above copyright -% notice, this list of conditions and the following disclaimer. -% * Redistributions in binary form must reproduce the above copyright -% notice, this list of conditions and the following disclaimer in the -% documentation and/or other materials provided with the distribution. -% * Neither the name of the Intel Corporation nor the -% names of its contributors may be used to endorse or promote products -% derived from this software without specific prior written permission. -% -% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" -% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE -% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR -% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF -% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS -% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN -% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) -% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -% POSSIBILITY OF SUCH DAMAGE. -% +% SPDX-License-Identifier: BSD-3-Clause +% Copyright(c) 2017 Intel Corporation. All rights reserved. % Author: Seppo Ingalsuo -% %% Reference AES 17 3.12.3 level_ms = mean(x.^2); -dbfs = 10*log10(level_ms) + 20*log10(sqrt(2)); +dbfs = 10*log10(level_ms + 1e-20) + 20*log10(sqrt(2)); end