yatzeee
i dont like to re-encode stuff, so here is just remuxing from one format to another

  • first create a folder named newfiles
  • create a convert.bat file and put the command you pick below

webm (audio only) to ogg
for %%a in ("*.webm") do ffmpeg -i "%%a" -acodec copy "newfiles\%%~na.ogg"

mp4 crap to mkv awesomeness
for %%a in ("*.mp4") do ffmpeg -i "%%a" -acodec copy -vcodec copy "newfiles\%%~na.mkv"

m4a crap to mkv awesomeness
for %%a in ("*.mp4") do ffmpeg -i "%%a" -acodec copy -vcodec copy "newfiles\%%~na.mkv"

webm awesomeness to mkv awesomeness
for %%a in ("*.webm") do ffmpeg -i "%%a" -acodec copy -vcodec copy "newfiles\%%~na.mkv"

mkv awesomeness to mp4 crap (only h264/aac etc)
for %%a in ("*.mkv") do ffmpeg -i "%%a" -acodec copy -vcodec copy "newfiles\%%~na.mp4"