Add script for converting AVI file to MKV, while fixing potential audio issues.HEADmaster

1 files changed, 55 insertions, 0 deletions

diff --git a/avi2mkv.sh b/avi2mkv.sh
new file mode 100755
index 0000000..3de6c62
--- /dev/null
+++ b/avi2mkv.sh
@@ -0,0 +1,55 @@
+#!/bin/bash
+
+# See https://video.stackexchange.com/a/32719
+
+set -o nounset
+set -o errexit
+set -o pipefail
+
+readonly ARGS=( "${@}" );
+
+main()
+{
+  local _avi_path;
+  _avi_path="${1}"; shift;
+
+  local _mkv_path;
+  _mkv_path="${1}"; shift;
+
+  local avi_path;
+  avi_path="$(readlink --canonicalize-existing "${_avi_path}")";
+
+  local mkv_path;
+  mkv_path="$(readlink --canonicalize-missing "${_mkv_path}")";
+
+  # Check whether the mp3 header is missing in the input file
+  local missing_count;
+  missing_count=0;
+  set +o errexit
+  missing_count="$(ffprobe -hide_banner -i "${avi_path}" 2>& 1 \
+                  | grep -i 'mp3float' \
+                  | grep -c -i 'Header missing')";
+  set -o errexit
+
+  if [ 0 -eq "${missing_count}" ];
+  then
+    # Trivial copy
+    ffmpeg -i "${avi_path}" -c:v copy -c:a copy "${mkv_path}"
+  else
+    # Extract the mp3 stream
+    local mp3_stream;
+    mp3_stream="$(mktemp --suffix='.mp3')";
+
+    ffmpeg -i "${avi_path}" -c:a copy "${mp3_stream}"
+
+    # Combine it back into the original AVI file
+    ffmpeg -i "${avi_path}" -i "${mp3_stream}" \
+           -c:v libx264 -c:a copy -map 0:v:0 -map 1:a:0 \
+           "${mkv_path}"
+
+    rm "${mp3_stream}"
+  fi
+}
+
+main "${ARGS[@]}"
+exit 0