Audio: MFCC: Refactor run_mfcc.sh and add decode_all.m

Refactor run_mfcc.sh into functions for input conversion and testbench
execution to reduce code duplication. Add Xtensa testbench support when
XTENSA_PATH environment variable is set, producing xt_ prefixed output
files.

Add decode_all.m Octave script to decode and plot all MFCC cepstral
and Mel spectrogram output files from run_mfcc.sh, including Xtensa
variants.

Update README.txt to document the current run_mfcc.sh output files,
Xtensa support, and decode_all.m usage.

Export XTENSA_PATH in rebuild-testbench.sh so that run_mfcc.sh can
find the Xtensa toolchain path for the testbench build.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

Author: singalsu

scripts/rebuild-testbench.sh

@@ -97,7 +97,7 @@ export_xtensa_setup()
     cat <<EOFSETUP > "$export_script"
 export XTENSA_TOOLS_ROOT=$XTENSA_TOOLS_ROOT
 export XTENSA_CORE=$XTENSA_CORE
-XTENSA_PATH=$tools_bin
+export XTENSA_PATH=$tools_bin
 EOFSETUP
 }
 

src/audio/mfcc/tune/README.txt

@@ -8,28 +8,45 @@ need to be created with "scripts/build-tools.sh -t". Next the testbench
 is build with "scripts/rebuild-testbench.sh".
 
 Once the previous steps are done, a sample wav file can be processed
-into stream of cepstral coefficients with script run_mfcc.sh. E.g.
-next command processes an ALSA test file with speech clip "front center".
-The output file is hard-coded to mfcc.raw.
+with script run_mfcc.sh. The script converts the input to raw 16 kHz
+stereo format and runs the testbench for S16, S24, and S32 bit depths,
+producing both cepstral coefficient (MFCC) and Mel spectrogram outputs.
 
 ./run_mfcc.sh /usr/share/sounds/alsa/Front_Center.wav
 
-The output can be plotted and retrieved with Matlab or Octave command:
+Output files from host testbench:
+  mfcc_s16.raw, mfcc_s24.raw, mfcc_s32.raw   - cepstral coefficients
+  mel_s16.raw, mel_s24.raw, mel_s32.raw       - Mel spectrogram
+
+If the XTENSA_PATH environment variable is set, the script also runs
+the Xtensa build of the testbench (via xt-run) and produces additional
+output files prefixed with "xt_":
+  xt_mfcc_s16.raw, xt_mfcc_s24.raw, xt_mfcc_s32.raw
+  xt_mel_s16.raw, xt_mel_s24.raw, xt_mel_s32.raw
+
+All output files can be decoded and plotted at once in Matlab or Octave
+with the decode_all.m script:
+
+decode_all
+
+This calls decode_ceps for each MFCC file (13 cepstral coefficients) and
+decode_mel for each Mel file (80 Mel bins), plotting spectrograms for all
+files that exist including the Xtensa variants.
+
+Individual files can also be decoded manually:
 
 [ceps, t, n] = decode_ceps('mfcc_s16.raw', 13);
 
 In the above it's known from configuration script that MFCC was set up to
 output 13 cepstral coefficients from each FFT -> Mel -> DCT -> Cepstral
 coefficients computation run.
 
+The 80 bands Mel output can be visualized with command:
+
+[mel, t, n] = decode_mel('mel_s16.raw', 80);
+
 Other kind of signals have quite big visual difference in audio features. Try
 e.g. other sound files found in computer.
 
 ./run_mfcc.sh /usr/share/sounds/gnome/default/alerts/bark.ogg
 ./run_mfcc.sh /usr/share/sounds/gnome/default/alerts/sonar.ogg
-
-The script runs the same input sample with s16/24/32 formats for
-cepstral coefficients data output and Mel frequency spectrogram
-output. The 80 bands Mel output can be visualized with command:
-
-[ceps, t, n] = decode_mel('mel_s16.raw', 80);

src/audio/mfcc/tune/decode_all.m

@@ -0,0 +1,39 @@
+% decode_all.m - Decode all MFCC and Mel raw output files from run_mfcc.sh
+%
+% SPDX-License-Identifier: BSD-3-Clause
+% Copyright(c) 2026 Intel Corporation.
+
+num_ceps = 13;
+num_mel = 80;
+
+% MFCC cepstral output files
+ceps_files = {'mfcc_s16.raw', 'mfcc_s24.raw', 'mfcc_s32.raw'};
+
+% Mel output files with corresponding format
+mel_files = {'mel_s16.raw', 'mel_s24.raw', 'mel_s32.raw'};
+mel_fmts  = {'s16',         's24',          's32'};
+
+% Xtensa prefixed variants
+xt_ceps_files = {'xt_mfcc_s16.raw', 'xt_mfcc_s24.raw', 'xt_mfcc_s32.raw'};
+xt_mel_files  = {'xt_mel_s16.raw',  'xt_mel_s24.raw',  'xt_mel_s32.raw'};
+
+all_ceps_files = [ceps_files, xt_ceps_files];
+all_mel_files  = [mel_files, xt_mel_files];
+all_mel_fmts   = [mel_fmts, mel_fmts];
+
+for i = 1:length(all_ceps_files)
+	fn = all_ceps_files{i};
+	if exist(fn, 'file')
+		fprintf('Decoding MFCC ceps: %s\n', fn);
+		[ceps, t, n] = decode_ceps(fn, num_ceps);
+	end
+end
+
+for i = 1:length(all_mel_files)
+	fn = all_mel_files{i};
+	fmt = all_mel_fmts{i};
+	if exist(fn, 'file')
+		fprintf('Decoding Mel: %s\n', fn);
+		[mel, t, n] = decode_mel(fn, num_mel, fmt);
+	end
+end

src/audio/mfcc/tune/run_mfcc.sh

@@ -7,50 +7,49 @@ set -e
 RAW_INPUT_S16=in_s16.raw
 RAW_INPUT_S24=in_s24.raw
 RAW_INPUT_S32=in_s32.raw
-RAW_OUTPUT_S16=mfcc_s16.raw
-RAW_OUTPUT_S24=mfcc_s24.raw
-RAW_OUTPUT_S32=mfcc_s32.raw
 
 VALGRIND="valgrind --leak-check=full"
+#VALGRIND=""
 TESTBENCH=$SOF_WORKSPACE/sof/tools/testbench/build_testbench/install/bin/sof-testbench4
-TOPOLOGY_S16=$SOF_WORKSPACE/sof/tools/build_tools/topology/topology2/development/sof-hda-benchmark-mfcc16.tplg
-TOPOLOGY_S24=$SOF_WORKSPACE/sof/tools/build_tools/topology/topology2/development/sof-hda-benchmark-mfcc24.tplg
-TOPOLOGY_S32=$SOF_WORKSPACE/sof/tools/build_tools/topology/topology2/development/sof-hda-benchmark-mfcc32.tplg
-OPT_S16="-r 16000 -c 2 -b S16_LE -p 3,4 -t $TOPOLOGY_S16"
-OPT_S24="-r 16000 -c 2 -b S24_LE -p 3,4 -t $TOPOLOGY_S24"
-OPT_S32="-r 16000 -c 2 -b S32_LE -p 3,4 -t $TOPOLOGY_S32"
-
-# Convert input audio file raw 16 kHz 2 channel 16 bit
-sox -R --encoding signed-integer "$1" -L -r 16000 -c 2 -b 16 "$RAW_INPUT_S16"
-sox -R --no-dither --encoding signed-integer -L -r 16000 -c 2 -b 16 "$RAW_INPUT_S16" -b 32 "$RAW_INPUT_S32"
-sox -R --no-dither --encoding signed-integer -L -r 16000 -c 2 -b 16 "$RAW_INPUT_S16" -b 32 "$RAW_INPUT_S24" vol 0.003906250000
-
-# Run testbench
-$VALGRIND $TESTBENCH $OPT_S16 -i "$RAW_INPUT_S16" -o "$RAW_OUTPUT_S16"
-$VALGRIND $TESTBENCH $OPT_S24 -i "$RAW_INPUT_S24" -o "$RAW_OUTPUT_S24"
-$VALGRIND $TESTBENCH $OPT_S32 -i "$RAW_INPUT_S32" -o "$RAW_OUTPUT_S32"
-
-echo ----------------------------------------------------------------------------------
-echo The MFCC data was output to file $RAW_OUTPUT_S16, $RAW_OUTPUT_S24, $RAW_OUTPUT_S32
-echo ----------------------------------------------------------------------------------
-
-RAW_OUTPUT_S16=mel_s16.raw
-RAW_OUTPUT_S24=mel_s24.raw
-RAW_OUTPUT_S32=mel_s32.raw
-
-TESTBENCH=$SOF_WORKSPACE/sof/tools/testbench/build_testbench/install/bin/sof-testbench4
-TOPOLOGY_S16=$SOF_WORKSPACE/sof/tools/build_tools/topology/topology2/development/sof-hda-benchmark-mfccmel16.tplg
-TOPOLOGY_S24=$SOF_WORKSPACE/sof/tools/build_tools/topology/topology2/development/sof-hda-benchmark-mfccmel24.tplg
-TOPOLOGY_S32=$SOF_WORKSPACE/sof/tools/build_tools/topology/topology2/development/sof-hda-benchmark-mfccmel32.tplg
-OPT_S16="-r 16000 -c 2 -b S16_LE -p 3,4 -t $TOPOLOGY_S16"
-OPT_S24="-r 16000 -c 2 -b S24_LE -p 3,4 -t $TOPOLOGY_S24"
-OPT_S32="-r 16000 -c 2 -b S32_LE -p 3,4 -t $TOPOLOGY_S32"
-
-# Run testbench
-$VALGRIND $TESTBENCH $OPT_S16 -i "$RAW_INPUT_S16" -o "$RAW_OUTPUT_S16"
-$VALGRIND $TESTBENCH $OPT_S24 -i "$RAW_INPUT_S24" -o "$RAW_OUTPUT_S24"
-$VALGRIND $TESTBENCH $OPT_S32 -i "$RAW_INPUT_S32" -o "$RAW_OUTPUT_S32"
-
-echo ----------------------------------------------------------------------------------
-echo The MFCC Mel data was output to file $RAW_OUTPUT_S16, $RAW_OUTPUT_S24, $RAW_OUTPUT_S32
-echo ----------------------------------------------------------------------------------
+TESTBENCH_RUN="$VALGRIND $TESTBENCH"
+
+convert_input() {
+	sox -R --encoding signed-integer "$1" -L -r 16000 -c 2 -b 16 "$RAW_INPUT_S16"
+	sox -R --no-dither --encoding signed-integer -L -r 16000 -c 2 -b 16 \
+		"$RAW_INPUT_S16" -b 32 "$RAW_INPUT_S32"
+	sox -R --no-dither --encoding signed-integer -L -r 16000 -c 2 -b 16 \
+		"$RAW_INPUT_S16" -b 32 "$RAW_INPUT_S24" vol 0.003906250000
+}
+
+run_testbench() {
+	local tplg_base="$1"
+	local out_s16="$2"
+	local out_s24="$3"
+	local out_s32="$4"
+	local label="$5"
+	local tplg_s16="${SOF_WORKSPACE}/sof/tools/build_tools/topology/topology2/development/${tplg_base}16.tplg"
+	local tplg_s24="${SOF_WORKSPACE}/sof/tools/build_tools/topology/topology2/development/${tplg_base}24.tplg"
+	local tplg_s32="${SOF_WORKSPACE}/sof/tools/build_tools/topology/topology2/development/${tplg_base}32.tplg"
+
+	$TESTBENCH_RUN -r 16000 -c 2 -b S16_LE -p 3,4 -t "$tplg_s16" -i "$RAW_INPUT_S16" -o "$out_s16"
+	$TESTBENCH_RUN -r 16000 -c 2 -b S24_LE -p 3,4 -t "$tplg_s24" -i "$RAW_INPUT_S24" -o "$out_s24"
+	$TESTBENCH_RUN -r 16000 -c 2 -b S32_LE -p 3,4 -t "$tplg_s32" -i "$RAW_INPUT_S32" -o "$out_s32"
+
+	echo ----------------------------------------------------------------------------------
+	echo "The ${label} data was output to file ${out_s16}, ${out_s24}, ${out_s32}"
+	echo ----------------------------------------------------------------------------------
+}
+
+main() {
+	convert_input "$1"
+	run_testbench "sof-hda-benchmark-mfcc" mfcc_s16.raw mfcc_s24.raw mfcc_s32.raw "MFCC"
+	run_testbench "sof-hda-benchmark-mfccmel" mel_s16.raw mel_s24.raw mel_s32.raw "MFCC Mel"
+
+	if [ -n "$XTENSA_PATH" ]; then
+		TESTBENCH_RUN="$XTENSA_PATH/xt-run $SOF_WORKSPACE/sof/tools/testbench/build_xt_testbench/sof-testbench4"
+		run_testbench "sof-hda-benchmark-mfcc" xt_mfcc_s16.raw xt_mfcc_s24.raw xt_mfcc_s32.raw "Xtensa MFCC"
+		run_testbench "sof-hda-benchmark-mfccmel" xt_mel_s16.raw xt_mel_s24.raw xt_mel_s32.raw "Xtensa MFCC Mel"
+	fi
+}
+
+main "$@"