File size: 2,795 Bytes
d6ea02e | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 | #!/usr/bin/env bash
# SPDX-License-Identifier: MIT
# Copyright (C) Intel Corporation
#
# Prepare the sample video for the scene-change-detection use case.
# This use case uses classical computer vision (frame histogram
# comparison) with OpenCV; no model export or quantization is required.
#
# A single continuous shot never triggers a scene change, so this script
# builds a short montage (test_video.mp4) from several distinct sample
# clips joined with hard cuts. Each clip is normalized to the same size and
# frame rate and trimmed to 2 seconds, producing a scene change every 2
# seconds that the histogram detector flags.
# Usage: ./export_and_quantize.sh
set -euo pipefail
SAMPLE_BASE_URL="https://github.com/intel-iot-devkit/sample-videos/raw/master"
# Distinct scenes joined into the montage, in order.
SAMPLE_CLIPS=(
"one-by-one-person-detection.mp4"
"bottle-detection.mp4"
"person-bicycle-car-detection.mp4"
"head-pose-face-detection-female.mp4"
)
CLIP_SECONDS=2 # length of each scene in the montage
CLIP_WIDTH=640
CLIP_HEIGHT=360
CLIP_FPS=30
# Ask for approval before downloading models and sample files
echo ""
echo "This script will download:"
echo " - Model weights and/or sample files"
echo ""
read -p "Continue with downloads? (yes/no): " APPROVAL
if [[ "${APPROVAL}" != "yes" ]]; then
echo "Download cancelled by user."
exit 0
fi
command -v ffmpeg >/dev/null 2>&1 || {
echo "ERROR: ffmpeg is required to build the montage sample video." >&2
exit 1
}
echo ""
if [[ -f test_video.mp4 ]]; then
echo "Already present: test_video.mp4"
else
echo "--- Downloading sample clips and building montage ---"
WORK_DIR="$(mktemp -d)"
trap 'rm -rf "${WORK_DIR}"' EXIT
CONCAT_LIST="${WORK_DIR}/concat.txt"
: > "${CONCAT_LIST}"
idx=0
for clip in "${SAMPLE_CLIPS[@]}"; do
src="${WORK_DIR}/src_${idx}.mp4"
norm="${WORK_DIR}/clip_${idx}.mp4"
echo "Downloading: ${clip}"
wget -q -O "${src}" "${SAMPLE_BASE_URL}/${clip}"
# Trim to CLIP_SECONDS and normalize size/fps so the clips concatenate
# cleanly and every join is a clean scene cut.
ffmpeg -nostdin -y -loglevel error -t "${CLIP_SECONDS}" -i "${src}" \
-vf "scale=${CLIP_WIDTH}:${CLIP_HEIGHT},fps=${CLIP_FPS},setsar=1" \
-an -pix_fmt yuv420p "${norm}"
echo "file 'clip_${idx}.mp4'" >> "${CONCAT_LIST}"
idx=$((idx + 1))
done
ffmpeg -nostdin -y -loglevel error -f concat -safe 0 -i "${CONCAT_LIST}" \
-c copy test_video.mp4
echo "Built: test_video.mp4 (${#SAMPLE_CLIPS[@]} scenes, ${CLIP_SECONDS}s each)"
fi
echo "--- Done ---"
echo "Sample : $(pwd)/test_video.mp4"
echo "Note : This use case requires no model; run the README samples directly."
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