Improve usage doc for -ac

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main.cpp b/src/main.cpp
index f4f058f..6b75d5c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -569,7 +569,7 @@ static void usage() {
         " and the video will only be saved when the gpu-screen-recorder is closed. This feature is similar to Nvidia's instant replay feature."
         " This option has be between 5 and 1200. Note that the replay buffer size will not always be precise, because of keyframes. Optional, disabled by default.\n");
     fprintf(stderr, "  -k    Video codec to use. Should be either 'auto', 'h264' or 'h265'. Defaults to 'auto' which defaults to 'h265' unless recording at a higher resolution than 3840x2160. Forcefully set to 'h264' if -c is 'flv'.\n");
-    fprintf(stderr, "  -ac   Audio codec to use. Should be either 'aac', 'opus' or 'flac'. Defaults to 'opus' for .mp4/.mkv files, otherwise defaults to 'aac'\n");
+    fprintf(stderr, "  -ac   Audio codec to use. Should be either 'aac', 'opus' or 'flac'. Defaults to 'opus' for .mp4/.mkv files, otherwise defaults to 'aac'. 'opus' is only supported by .mp4/.mkv files and 'flac' is only supported by .mkv files.\n");
     fprintf(stderr, "  -o    The output file path. If omitted then the encoded data is sent to stdout. Required in replay mode (when using -r). In replay mode this has to be an existing directory instead of a file.\n");
     fprintf(stderr, "NOTES:\n");
     fprintf(stderr, "  Send signal SIGINT (Ctrl+C) to gpu-screen-recorder to stop and save the recording (when not using replay mode).\n");