now with fast codec-copy and output filename selection. not cleaned up, but it works

dhcp2024/render-chunks.sh

@@ -1,6 +1,12 @@
 #!/usr/bin/env bash
 set -euxo pipefail
 
+# License MIT
+# Authors 2024
+#   thunfisch
+#   iiidefix
+#   l3d
+
 # This script is designed to help you automatically select the correct intro
 # and outro files (prerendered with built-in fades) and the correct chunks
 # of a chunked recording (e.g. OBS with automatic split every 5 minutes).
@@ -9,10 +15,7 @@ set -euxo pipefail
 # them into the script for now (no idea how to convince mpv to output it).
 # After that the script will render the introfile with the first chunk and the
 # last chunk with the outrofile, and then in the last step assemble everything
-# into the final recording with audio normalization. The final version should
-# try to use -c:v copy in the last step, so that no re-encoding of the chunks
-# in the middle will be done. This does not work yet, so please excuse the slow
-# rendering. Upcoming version hopefully fixes it.
+# into the final recording with audio normalization.
 
 # This script requires you to have ffmpeg and fzf installed.
 which ffmpeg >/dev/null || (echo "Please install ffmpeg" ; exit 1)
@@ -30,6 +33,10 @@ SELECTED_OUTRO="$(find  "$OUTROS_PATH" -type f | sort --reverse --human-numeric-
 SELECTED_CHUNKS="$(find "$CHUNKS_PATH" -type f | sort --reverse | fzf --delimiter / --with-nth -1 -m --prompt "Video Chunks (use tab to select multiple):" | sort )"
 readarray -t CHUNKS_ARRAY < <(echo "$SELECTED_CHUNKS")
 
+FOOBARWTF="$(basename "$SELECTED_INTRO")"
+DEFAULT_OUTPUT_NAME="${FOOBARWTF%.*}"
+read -p "Please enter a name for the outputfile (path and extension will be added automatically): " -i "$DEFAULT_OUTPUT_NAME" -e OUTPUT_NAME
+
 # find the start-offset for the first chunk
 read -p "Do you want to play the first chunk ${CHUNKS_ARRAY[0]} to find the start-offset? (y/n) [n]: " PLAY_FIRST_CHUNK
 PLAY_FIRST_CHUNK="${PLAY_FIRST_CHUNK:-n}"
@@ -80,14 +87,15 @@ then
     echo "Too few chunks, this script can't handle this yet. Please do that on your own."
     exit 1
 fi
-#ffmpeg -i "$SELECTED_INTRO" \
-#       -i "$SELECTED_OUTRO" \
-#    -ss "$START_OFFSET" -i "${CHUNKS_ARRAY[0]}" \
-echo    "${CHUNKS_ARRAY[@]:1:-2}"
-#    -t "$END_OFFSET" -i "${CHUNKS_ARRAY[-1]}" \
+
 # STEP 1
 # temp dir
 WORKDIR=$(mktemp -d)
+function finish {
+  rm -r "$WORKDIR"
+}
+trap finish EXIT
+
 # STEP 2
 # introfile with first chunk and crossfade encode
 ffmpeg -i "$SELECTED_INTRO" -ss "$START_OFFSET" -i "${CHUNKS_ARRAY[0]}" \
@@ -123,26 +131,26 @@ ffmpeg -i "$SELECTED_OUTRO" -t "$END_OFFSET" -i "${CHUNKS_ARRAY[-1]}" \
 # STEP 4
 # encoded intro+outro and all chunks in between with c:v copy and audio dynnorm + encode
 
-FFMPEG_CHUNKS=""
-FFMPEG_CONCAT=""
+CHUNKLIST="${WORKDIR}/chunklist.txt"
+
+echo "file '${WORKDIR}/introcombined.mkv'" > "$CHUNKLIST"
+
+FFMPEG_CONCAT_CHUNKS=""
 if [[ ${ARRAY_LENGTH} -gt 2 ]]
 then
     for index in $(seq 1 $(( ${ARRAY_LENGTH} - 2 )) )
     do
-        FFMPEG_CHUNKS="${FFMPEG_CHUNKS} -i ${CHUNKS_ARRAY[index]}"
-        FFMPEG_CONCAT="${FFMPEG_CONCAT} [$((index + 1)):v:0][$((index + 1)):a:0]"
+        FFMPEG_CONCAT_CHUNKS="${FFMPEG_CONCAT_CHUNKS}|${CHUNKS_ARRAY[index]}"
+        echo "file '${CHUNKS_ARRAY[index]}'" >> "$CHUNKLIST"
     done
 fi
 
-ffmpeg -i "${WORKDIR}/introcombined.mkv" -i "${WORKDIR}/outrocombined.mkv" \
-    $FFMPEG_CHUNKS -filter_complex \
-    "[0:v:0][0:a:0]
-    $FFMPEG_CONCAT
-    [1:v:0][1:a:0]
-    concat=n=${ARRAY_LENGTH}:v=1:a=1
-    [v][a];[a]dynaudnorm[ad]" \
-    -map '[v]' -map '[ad]' \
-    -c:v libx264 -threads 0 -pix_fmt yuv420p -crf 18 -profile:v high -level 4.1 -disposition default \
+echo "file '${WORKDIR}/outrocombined.mkv'" >> "$CHUNKLIST"
+
+ffmpeg \
+    -f concat -safe 0 -i "$CHUNKLIST" \
+    -af dynaudnorm \
+    -c:v copy \
     -c:a aac -b:a 192k \
     -metadata:s:a:0 language=native \
-    "${OUTPUT_PATH}/combinedrender.mkv"
+    "${OUTPUT_PATH}/${OUTPUT_NAME}.mkv"