Apr 04, 2024, 13:11 pm
(This post was last modified: Apr 07, 2024, 05:13 am by milahu. Edited 1 time in total.)
i know, audiotracks are rare...
currently there are only 3 audiotracks on TPB
why audiotracks?
i have limited disk space (2TB SSD)
so i dont want to waste disk space with N movies in N languages
instead, i want to have 1 movie in english + (N - 1) audiotracks
audio is 10% of the movie file size
muxing these files in my video player "just works"
when movie and audiotrack have the same frame rate:
mpv movie.mp4 --audio-file=audio.m4a
seeking the external audio file works well with m4a=aac, ac3 is worse
when the frame rates differ, i have to timestretch the audio track
ffmpeg -i movie-25000fpms.mp4 -map 0:a:0 -af atempo=23976/25000 -ar 48K -f caf - | fdkaac -S -b128 - -o audio-23976.m4a
when i mux video and audio to a new video file
then the mkv container gives better audio/video sync on slow hardware
ffmpeg -i video.mp4 -i audio.m4a -map 0:v:0 -map 1:a:0 -c copy new-video.mkv
... and/or im too lazy to downmix + normalize + mux the audiotrack
to create a dual-language movie release
but i still want to share the audiotrack sitting on my hard drive
so that others can create a movie release
in the mean time, my audiotrack torrents go to category "other / other"
(because audio and video categories block html files in torrents...)
currently there are only 3 audiotracks on TPB
why audiotracks?
i have limited disk space (2TB SSD)
so i dont want to waste disk space with N movies in N languages
instead, i want to have 1 movie in english + (N - 1) audiotracks
audio is 10% of the movie file size
muxing these files in my video player "just works"
when movie and audiotrack have the same frame rate:
mpv movie.mp4 --audio-file=audio.m4a
seeking the external audio file works well with m4a=aac, ac3 is worse
when the frame rates differ, i have to timestretch the audio track
ffmpeg -i movie-25000fpms.mp4 -map 0:a:0 -af atempo=23976/25000 -ar 48K -f caf - | fdkaac -S -b128 - -o audio-23976.m4a
when i mux video and audio to a new video file
then the mkv container gives better audio/video sync on slow hardware
ffmpeg -i video.mp4 -i audio.m4a -map 0:v:0 -map 1:a:0 -c copy new-video.mkv
... and/or im too lazy to downmix + normalize + mux the audiotrack
to create a dual-language movie release
but i still want to share the audiotrack sitting on my hard drive
so that others can create a movie release
in the mean time, my audiotrack torrents go to category "other / other"
(because audio and video categories block html files in torrents...)
