

-b:a 384k 384k bitrate (I don't know what's good for aac stereo but this is really high since it's for 5.1 aac)Ī video with two audio streams.Important! You must change the output channel to a higher number if there are multiple audio streams to prevent overwriting them. -c:a:1 aac Output the audio to a 2nd audio channel (0 = first channel) in aac format.-map 0:a:0 Tell ffmpeg to read the first audio stream for the following arguments.-map 0 Tell ffmpeg read all Video, Audio, and Subtitle streams for the following arguments.ffmpeg -i INPUT.mkv The application and input file.

It will be in AAC 384k.įfmpeg -i INPUT.mkv -strict -2 -map 0 -c copy -map 0:a:0 -c:a:1 aac -b:a 384k -ac 2 OUTPUT.mkv Explanation of the command This command will take a video with 1 audio stream, and downmix to stereo and convert the audio stream and add it as a 2nd audio stream. Maybe someone have more knowledge about it? It is not a great encoder, but it is not too bad at higher bitrates.Īccording to wikipedia, there is no difference between AC3 and ATSC A/52: the 1st one is the name of the codec, the 2nd is the name of the standard specifying the AC3 codec.

strict -2 is required as a way that you acknowledge that the encoder is designated as experimental.

-strict -2 -c:a aac – Use the native FFmpeg AAC audio encoder.-map 0:a – Designate the audio stream(s) from the first input as a source for the output file.-map 0:v – Designate the video stream(s) from the first input as a source for the output file.-y – A global option to overwrite the output file if it already exists.This works for me: ffmpeg -y -i Source.mkv -map 0:v -c:v copy -map 0:a -c:a copy -map 0:a -strict -2 -c:a aac out.mkv
