ffpresent.sh

#!/bin/bash
#################################################
# reads config file ($1)
#   and converts each file one by one to dnxhd according to provided config
#   then combine everythin into a file outputted video in the folder $2
#################################################
# mediainfo <video> # (useful command)
# get help with a filter (e.g. apad):
#  ffmpeg -h filter=apad
#
# TODO: https://ffmpeg.org/ffmpeg-filters.html#concat
#       https://stackoverflow.com/questions/47050033/ffmpeg-join-two-movies-with-different-timebase
#       https://github.com/leandromoreira/ffmpeg-libav-tutorial#learn-ffmpeg-libav-the-hard-way

#
# TODO: store these values somewhere at top of project.ffpres?
####################################################################################################
OUT_SCALE=("1920" "1080")  # output resoulution
FPS="25"                   # frames per second (25, 30000/1001, 50, ...)
AUDIO_FREQ="48000"         # output audio frequency in HZ (number of samples of audio carried per second)
IMG_DUR="3.5"              # default image duration (sec). overwritten by "dur" field in config if a number is provided there
B_COLOR="black"            # background color for padding videos to fit OUT_SCALE (set to "blur" to blur background instead)
FFMPEG_THREADS="1"         # number of threads for ffmpeg to use
DEBUG="0"                  # 0 for normal mode, 1 for debug mode (overlaid text details on video)
FONT="/usr/share/fonts/gnu-free/FreeSans.ttf"   # path to font file used for debug text
OUT_EXT="mp4"              # default output file extension ("mp4" or "webm" or "mov")
####################################################################################################

# mp4 specific ffmpeg flags
mp4_flags=(
    -c:a aac #libfdk_aac # https://trac.ffmpeg.org/wiki/Encode/AAC
    -c:v libx264
    -b:v 2M
    -strict -2
    # TODO: crf option isn't working (for lowering file size):
    #-crf 5 # Valid range is 0 (lower quality) to 63 (higher quality). Only used if set; by default only the bitrate target is used.
)
# mov specific ffmpeg flags
mov_flags=(
    # https://en.wikipedia.org/wiki/List_of_Avid_DNxHD_resolutions
    # TODO: try to make mov files smaller? https://superuser.com/questions/525279/reduce-mov-file-size https://ffmpeg.org/ffmpeg-codecs.html
    -c:a pcm_s16le
    -c:v dnxhd
    -b:v 36M          # output bitrate (36M, 45M, 75M, 115M, ...) (Mbps)
)

webm_flags=(
    # https://trac.ffmpeg.org/wiki/Encode/VP9
    -c:a libopus
    -c:v libvpx-vp9
    -b:v 2M
)

# flags used if media has no audio
#  (fixes issue with final combined video's audio when a video in the middle has no audio)
SILENT_FIX_FLAGS=(
    #   https://superuser.com/a/1096968
    #-f lavfi -i aevalsrc=0 -shortest
    #   https://stackoverflow.com/a/12375018
    -f lavfi -i anullsrc=cl=stereo:r=$AUDIO_FREQ
)


# primary ffmpeg flags for video conversion:
#   (best to store these in an array!) https://stackoverflow.com/a/29175560
CONV_FLAGS=(
    -threads "$FFMPEG_THREADS"
    -af "aresample=async=1024,apad"
    #-async 25
    #-af "asettb=expr=1/48000"
    -shortest
    #-avoid_negative_ts make_zero
    #-video_track_timescale 600
    -fflags +genpts
    -ar $AUDIO_FREQ # set the audio sampling frequency
    # important! videos must either be all stereo or all mono before concat:
    -ac 2 # force all videos to have exactly two audio channels
    -shortest # needed for SILENT_FIX_FLAGS
    # NOTE: last flag must be the value for -vf (because later we will reference [-1] to modify it)
    -vf "settb=expr=1/30000,fps=$FPS,format=yuv422p"
)

function usage() {
    echo "USAGE:"
    echo "    ./ffpresent.sh <config_file> <output_folder> [--mov | --mp4 | --webm]"
    echo "EXAMPLES:"
    echo "    ./ffpresent.sh project.ffpres .         # (uses default output format mp4)"
    echo "    ./ffpresent.sh project.ffpres . --mov   # output as mov file"
    echo "    ./ffpresent.sh project.ffpres . --mp4   # output as mp4 file"
    echo "    ./ffpresent.sh project.ffpres . --webm  # output as webm file"
}
function process_config() {
    if [ "$#" ==  3 ]; then
        if [ $3 == "--mov" ]; then
            OUT_EXT="mov"
        elif [ $3 == "--mp4" ]; then
            OUT_EXT="mp4"
        elif [ $3 == "--webm" ]; then
            OUT_EXT="webm"
        else
            echo "ERROR invalid flag provided '$3'" >&2; usage; exit 1
        fi
    elif [ "$#" -ne 2 ]; then
        echo "ERROR invalid usage" >&2; usage; exit 1
    fi

    if [ "$OUT_EXT" == "mp4" ]; then
        SPECIFIC_FLAGS=("${mp4_flags[@]}")
        echo "using mp4_flags"
    elif [ "$OUT_EXT" == "mov" ]; then
        SPECIFIC_FLAGS=("${mov_flags[@]}")
    elif [ "$OUT_EXT" == "webm" ]; then
        SPECIFIC_FLAGS=("${webm_flags[@]}")
    else
        echo "ERROR: output extension '$OUT_EXT' not supported" >&2
        exit 1
    fi
    echo -e "NOTE: using output extension '$OUT_EXT'"
    # specific codec flags to actually use

    CONFIG_FILE="$1"
    FOLDER="$2/combined_output"
    FOLDER_INTER="$FOLDER/intermediary" # folder to store converted mov files
    LOG_FILE="$FOLDER/log-ffmpeg.txt"
    OUT_LIST="$FOLDER/combine-list.txt"
    OUT_COMBINED="$FOLDER/out-combined.$OUT_EXT"
    CONT="0" # "1" if we are continuing a previous run that failed
    if [ "$B_COLOR" == "blur" ] && [ "$DEBUG" -eq "1" ]; then
        # in debug mode, don't waste time blurring the background
        B_COLOR="black"
    fi

    if [ -d "$FOLDER" ]; then
        echo "output folder \"$FOLDER\" already exists. Delete and try again."
        read -p "Or continue previous run using existing folder? (y/n): " -n 1 -r && echo ""
        if [[ ! $REPLY =~ ^[Yy] ]]; then exit 1; fi
        CONT="1"

        echo -e "\n\n===== Continuing previous run (`date`) =====" > "$LOG_FILE"
        rm -f "$OUT_LIST" # remove existing OUT_LIST (we will recreate it below)
    fi
    echo "All outputs will be saved in: \"${FOLDER}\"..."
    mkdir -p "$FOLDER" && mkdir -p "$FOLDER_INTER"
    echo "ffmpeg progress will be logged to: \"${LOG_FILE}\"..."

    echo -e "\ncurrent line (note lines starting with '#' are skipped):"
    local skipCount="0"
    local curLine="0"
    local totalLines="$(wc -l "$CONFIG_FILE")"
    local errCount="0"
    # iterate over lines in $config_file
    # TODO: convert videos in the list in parallel
    #   https://stackoverflow.com/a/43308733
    while IFS= read -r line
    do
        curLine="$((curLine+1))"
        # support commented lines here
        # TODO: get it working with leading spaces
        #if [[ "$(echo $("$line" | xargs echo -n ))" == \#* ]]; then
        if [[ "$(echo $(echo "$line"))" == \#* ]]; then
            skipCount="$((skipCount+1))"
            continue
        fi
        echo -e "(line $curLine/$totalLines) >>> $line"
        echo -e "\n(line $curLine/$totalLines) >>> $line" >> "${LOG_FILE}"
        # parse values from line:
        IFS=',' read -ra ARR <<< "$line"
        local count=$(awk -F"," '{print NF-1}' <<< "${line}")
        if [ "$count" -lt "5" ]; then # may be more than 5 if fname contains a comma
            echo "ERROR: found $count occurences of delimter (expected 5)."
            exit 1
        elif [ "$count" -gt "5" ]; then
            echo "WARNING: found $count occurences of delimter (expected 5)."
            echo "  line> $line"
            continue # TODO: for now
            # TODO: if count > 5 we should combine the last elements of the array (to handle filenames with a comma
        fi
        local fType="${ARR[0]}"; local width="${ARR[1]}"; local height="${ARR[2]}";
        local rot="${ARR[3]}";   local dur="${ARR[4]}";   local fname="${ARR[5]}"

        if ! [ -f "$fname" ]; then
            echo -e "\tERROR: file not found (skipping for now): '$fname'"
            errCount="$((errCount+1))"
            continue
        fi
        ###
        # generate filename (doesn't create file):
        #   TODO: create a new folder and put all the new files in with the same hierachy as before???
        #   https://www.cyberciti.biz/faq/bash-get-basename-of-filename-or-directory-name/
        #   https://stackoverflow.com/a/14892459
        #newFile="$(mktemp -u "$FOLDER_INTER/`basename "$fname"`.XXXXX".${OUT_EXT})" # handles duplicates
        local newFile="$(realpath "$FOLDER_INTER/`basename "$fname"`.${OUT_EXT}")" # TODO: this doesn't handle duplicates (files with same basename)
        if [ -f "$newFile" ]; then
            if [[ "$CONT" == "1" ]]; then
                # continue old run that may have failed half way:
                echo -e "\tNOTE: skipping existing file '$newFile'"
                if [[ "$OSTYPE" == "msys" ]] || [[ "$OSTYPE" == "win32" ]]; then
                    # fix for windows https://stackoverflow.com/a/8597411 (where absolute path doesn't work in this file)
                    newFile="$(basename $(dirname "$newFile"))/$(basename "$newFile")"
                fi

                # TODO: replace occurences of ' in $newFile with '\'' https://superuser.com/a/787651 (in case image has ' in its filename)
                printf "file \'$newFile\'\n" >> "$OUT_LIST" # store the path to this file in "$OUT_LIST"
                continue
            else
                echo -e "\tWARNING: overwriting existing file '$newFile'"
            fi
        fi
        ###

        local conv_flags=("${SPECIFIC_FLAGS[@]}" "${CONV_FLAGS[@]}")         # copy array of flags
        #printf 'flags: %s\n' "${conv_flags[@]}"
        local pre_flags=()                            # flags coming in command before "-i $fname"
        ########
        # flags to force videos with no audio stream to have a silent audio stream:
        # (needed for video concat to have the audios line up)
        if [[ -z "$(ffprobe -i "$fname" -show_streams -select_streams a -loglevel error)" ]]; then
            pre_flags=("${SILENT_FIX_FLAGS[@]}")
        fi
        ########
        local imgDur="$IMG_DUR"
        if [[ "$dur" =~ ^[0-9]+([.][0-9]+)?$ ]]; then # check if $dur is a number (int or float)
            imgDur="$dur"
        fi
        if [ "$fType" == "image" ]; then
            # adjust flags as needed to convert this image to a video:
            pre_flags+=("-loop" "1" "-f" "image2")
            conv_flags=("-t" "$imgDur" "${conv_flags[@]}")
            #echo "image's encoding is: $(exiftool "$fname" | grep -i "encoding")"
            # TODO: for images set a timeout timer for ffmpeg conversion
            #   because for example 20180625_162004.jpg never times out do to some issue with that image...

            # TODO: add ability to slowly zoom in or zoom out on images
            #   https://superuser.com/a/1127759
            #   https://ffmpeg.org/ffmpeg-filters.html#zoompan
          elif [ "$fType" == "video" ]; then
            if [ "$fname" == "*.webm" ]; then
              # only use this option when file ends in '.webm'?
              # TODO: be insensitive to case in filename check
              conv_flags=(-max_muxing_queue_size 30000 "${conv_flags[@]}") # fix for https://stackoverflow.com/q/49686244
            fi
            #conv_flags=("-t" "$imgDur" "${conv_flags[@]}") # limit video length too
        fi

        # compare current to desired aspect ratio to desired to determine how to scale (before padding)
        #   https://ffmpeg.org/ffmpeg-filters.html#pad-1
        if [ "$width" == "${OUT_SCALE[0]}" ] && [ "$height" == "${OUT_SCALE[1]}" ]; then
            : # no op
        elif [ "$(awk -v a="$width" -v b="$height" -v c="${OUT_SCALE[0]}" -v d="${OUT_SCALE[1]}" "BEGIN{print( a/b <= c/d )}")" -eq "1" ]; then
            # and example of this case would be a (skinny) vertical video (where we'd want to add black bars on either side)
            if [ "$B_COLOR" == "blur" ]; then
                # add a blurred background (instead of a solid color) to get right dimensions
                #   based loosely on https://stackoverflow.com/a/54618683
                # blurred: scale width to desired output (e.g. 1920), then crop off excess height and blur
                local blurred_args="scale=${OUT_SCALE[0]}:-1,crop=${OUT_SCALE[0]}:${OUT_SCALE[1]}:0:(ih-${OUT_SCALE[1]})/2, gblur=sigma=20"
                conv_flags[-1]="[IN]scale=-1:${OUT_SCALE[1]}[original]; [original]split [original][copy]; [copy]${blurred_args}[blurred]; [blurred][original]overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2[OUT]"
            else
                # pad background with a solid color
                conv_flags[-1]="scale=-1:${OUT_SCALE[1]},pad=${OUT_SCALE[0]}:${OUT_SCALE[1]}:x=(ow-iw)/2:color=${B_COLOR},${conv_flags[-1]}"
            fi
        else
            # an example of this case would be a very wide panorama image
            if [ "$B_COLOR" == "blur" ]; then
                local blurred_args="scale=-1:${OUT_SCALE[1]},crop=${OUT_SCALE[0]}:${OUT_SCALE[1]}:0:(ih-${OUT_SCALE[1]})/2, gblur=sigma=20"
                conv_flags[-1]="[IN]scale=${OUT_SCALE[0]}:-1[original]; [original]split [original][copy]; [copy]${blurred_args}[blurred]; [blurred][original]overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2[OUT]"
            else
                # pad background with a solid color
                conv_flags[-1]="scale=${OUT_SCALE[0]}:-1,pad=${OUT_SCALE[0]}:${OUT_SCALE[1]}:y=(oh-ih)/2:color=${B_COLOR},${conv_flags[-1]}"
            fi
        fi

        # debug mode (ovelay text details on videos):
        # TODO: debug text appears to only work on images?
        if [ "$DEBUG" -eq "1" ]; then
            local debugText="line #${curLine}, \"$(basename "$fname")\""
            # using printf to escape symbols like spaces, etc https://stackoverflow.com/a/12811033
            conv_flags[-1]="${conv_flags[-1]},drawtext=fontfile=${FONT}:text='$(printf %q "$debugText")':fontcolor=white:fontsize=24:box=1:boxcolor=black:x=(w-text_w)/2:y=h-th"
        fi
        # pop arg string for -vf option into a different variable
        #   allows us to put extra quotes around vf_args in the command below (needed when doing text overlay e.g. if there's a space in the text)
        local vf_args="${conv_flags[-1]}"
        conv_flags[-1]=""

        # print command to log then re-encode:
        echo -e "\nffmpeg -hide_banner -loglevel warning -y ${pre_flags[@]} -i \"$fname\" ${conv_flags[@]} \"$vf_args\" \"${newFile}\""  >>"${LOG_FILE}"

        #printf 'running with flags: %s\n' "${conf_flags[@]}"
        ffmpeg -hide_banner -loglevel warning -y ${pre_flags[@]} -i "$fname" ${conv_flags[@]} "$vf_args" "${newFile}"  </dev/null >>"${LOG_FILE}" 2>&1
        # trying to combine these args
        exitCode=$?
        # TODO: replace occurences of ' in $newFile with '\'' https://superuser.com/a/787651 (in case image has ' in its filename)
        if [[ "$OSTYPE" == "msys" ]] || [[ "$OSTYPE" == "win32" ]]; then
            # fix for windows https://stackoverflow.com/a/8597411 (where absolute path doesn't work in this file)
            newFile="$(basename $(dirname "$newFile"))/$(basename "$newFile")"
        fi
        if [ "$exitCode" -ne "0" ]; then
            rm -f "${newFile}"
            echo -e "ERROR: (exit code $exitCode) converting video: \"$fname\" (skipping for now)...\n"
            errCount="$((errCount+1))"
            continue
        fi
        printf "file \'$newFile\'\n" >> "$OUT_LIST" # store the path to this file in "$OUT_LIST"
        touch -r "$fname" "$newFile" # copy original timestamps
    done < "$CONFIG_FILE"

    echo -e "\n*****************:\nFinished re-encoding videos!"
    if [ "$skipCount" -gt "0" ]; then
        echo "Note: skipped $skipCount commented lines in \"$CONFIG_FILE\""
    fi
    if [ "$errCount" -gt "0" ]; then
        echo "WARNING: $errCount errors processing \"$CONFIG_FILE\""
    fi
    echo "List of videos used to concatenate outputted to: \"$OUT_LIST\""
    echo "*****************:"

    # concatenate videos into one:
    #  (keep in mind that for this step it is critical that all videos being combined
    #    are the exact same encoding, number of audio streams, SAR/DAR, etc)
    echo -e "\nCombining videos... in \"$OUT_LIST\"\n"
    echo -e "\n===================\nCommand for combining videos:" >>"${LOG_FILE}"
    echo -e "ffmpeg -hide_banner -loglevel warning -f concat -y -safe 0 -i \"$OUT_LIST\" -c copy -threads \"$FFMPEG_THREADS\" \"$OUT_COMBINED\""  >>"${LOG_FILE}"
    # TODO: consider putting this output to the terminal as well (it seems to exit with code 0 even if it can't open one image)
    ffmpeg -hide_banner -loglevel warning -f concat -y -safe 0 -i "$OUT_LIST" -c copy -threads "$FFMPEG_THREADS" "$OUT_COMBINED"  </dev/null >>"${LOG_FILE}" 2>&1
    exitCode=$?
    if [ "$exitCode" -ne "0" ]; then
        echo "  ERROR: (exit code $exitCode) combining videos"
        errCount="$((errCount+1))"
        exit $errCount
    fi
    echo "  combined video generated: \"$OUT_COMBINED\""
    exit $errCount
}

if [ -z `which ffmpeg` ] || [ -z `which ffprobe` ]; then
    echo "ERROR: ffmpeg not installed?" >&2
    exit 1
fi
process_config "$@"