#!/bin/bash


INFILES=( "$@" )
WORK_DIR=`pwd`/slideshow-$(date +%s)
TV_STANDARD="ntsc"
SLIDE_FRAMES=60
BINMAX=640
AR=1.333
FRAME_RATE=29.970
VIDSIZE=720x480

FFMOPTS="-b 8000k -maxrate 9000k -bufsize 224KiB -aspect 4:3"
IMGENC_CMD=(ffmpeg -f yuv4mpegpipe -r $FRAME_RATE \
-i -  -s $VIDSIZE $FFMOPTS -r $FRAME_RATE -y "$WORK_DIR/slideshow.m2v")


# make a fifo to send raw yuv to, to be encoded by ffmpeg
mkfifo "$WORK_DIR/enc.fifo"

# ffmpeg command reads from the fifo
"${IMGENC_CMD[@]}" < "$WORK_DIR/enc.fifo" &
# send fd 3 to enc.fifo
exec 3> "$WORK_DIR/enc.fifo"

for f in ${!INFILES[@]}; do
    # encode still frames
    ffmpeg -f image2 -loop_input -vframes $SLIDE_FRAMES -i "${INFILES[f]}" -pix_fmt yuv420p -f yuv4mpegpipe -
    if $SLIDE_FADE; then
        if [[ $f -lt ${#INFILES[@]} ]]; then
            base_ppm="$WORK_DIR/${f}.ppm"
            if ((f == (${#INFILES[@]} - 1) )); then
                overlay_ppm="$WORK_DIR/0.ppm"
            else
                overlay_ppm="$WORK_DIR/$((f+1)).ppm"
            fi

            [[ $TV_STANDARD = "ntsc" ]] && fade_frames=30 || fade_frames=25
            fade_incr=$(bc -l <<< "scale=2; 100 / $fade_frames")
            fade_slide=0
            echo
            for ((i=0; i<fade_frames; i++)); do
                BLEND_AMT=$(bc -l <<< "scale=2; $fade_slide * $fade_incr")
                composite_cmd=(composite -blend $BLEND_AMT -depth 8 "$overlay_ppm" \
                "$base_ppm" "$WORK_DIR/animenu/$(printf %06d%s $i .ppm)")
                "${composite_cmd[@]}"
                spin "Compositing ${overlay_ppm##*/} over ${base_ppm##*/} with -blend $BLEND_AMT"
                let fade_slide=fade_slide+1
            done
            let first_slide=first_slide+fade_frames+1
        else
            echo "Running ffmpeg to encode ppms"
            ffmpeg -f image2 -i "WORK_DIR/animenu/%06d.ppm" -pix_fmt yuv420p -f yuv4mpegpipe -
            FFPID=?!
            wait $FFPID
            rm -f "WORK_DIR/animenu/*.ppm"
        fi
    fi
done >&3