fix(color): propagate color mode to ffmpeg

Export ffmpeg/libav color environment variables alongside transcode.sh
color detection so subprocess logs follow the same color mode as the
wrapper.

Set AV_LOG_FORCE_COLOR when colors are forced or stdout is interactive,
and set AV_LOG_FORCE_NOCOLOR when NO_COLOR is present or output is
non-interactive.

Also propagate explicit --color and --no-color choices so later CLI
overrides stay consistent with ffmpeg output.

1 files changed, 12 insertions, 0 deletions

diff --git a/transcode.sh b/transcode.sh
index 20d4684..7f40e3b 100755
--- a/transcode.sh
+++ b/transcode.sh
@@ -1366,18 +1366,26 @@ encode_one() {
 # NOTE: This block calls debug() and reads $DEBUG. Both must be defined before
 # this point. Do not move this block above the GLOBAL VARIABLES or FUNCTION
 # DEFINITIONS sections without adjusting those dependencies.
+#
+# Keep ffmpeg/libav log coloring in sync with transcode.sh's color mode.
+# FFmpeg honors AV_LOG_FORCE_COLOR and AV_LOG_FORCE_NOCOLOR for its own output,
+# so exporting these prevents subprocess logs from using a different color style.
 if [[ -n "${NO_COLOR:-}" ]]; then
   debug "Colors are disabled via NO_COLOR"
   ENABLE_COLOR=0
+  export AV_LOG_FORCE_NOCOLOR=1
 elif [[ -n "${FORCE_COLOR:-}" ]]; then
   debug "Colors are forced via FORCE_COLOR"
   ENABLE_COLOR=1
+  export AV_LOG_FORCE_COLOR=1
 elif [[ -t 1 ]]; then
   debug "Colors are enabled via interactive terminal"
   ENABLE_COLOR=1
+  export AV_LOG_FORCE_COLOR=1
 else
   debug "Colors are disabled"
   ENABLE_COLOR=0
+  export AV_LOG_FORCE_NOCOLOR=1
 fi
 setup_colors
 
@@ -1418,11 +1426,15 @@ while [[ $# -gt 0 ]]; do
     ;;
   --color)
     ENABLE_COLOR=1
+    # Propagate the explicit color choice to ffmpeg/libav subprocesses.
+    export AV_LOG_FORCE_COLOR=1
     setup_colors
     shift
     ;;
   --no-color)
     ENABLE_COLOR=0
+    # Propagate the explicit color choice to ffmpeg/libav subprocesses.
+    export AV_LOG_FORCE_NOCOLOR=1
     setup_colors
     shift
     ;;