crusher11 842 Posted August 22, 2019 Share Posted August 22, 2019 I'm watching Breaking Bad, and some of the conversation is super quiet so I turned on subtitles. This obviously requires the video to be transcoded to burn them in, but it also changed the audio from the original DTS to AC3. Why can't it simply transcode the video and mux it with the original audio? Link to comment Share on other sites More sharing options...
Happy2Play 8138 Posted August 22, 2019 Share Posted August 22, 2019 Please post the corresponding server and ffmpeg logs. Link to comment Share on other sites More sharing options...
Luke 36879 Posted August 22, 2019 Share Posted August 22, 2019 Because the transcoding format can't carry DTS so the audio has to convert as well. Link to comment Share on other sites More sharing options...
crusher11 842 Posted August 22, 2019 Author Share Posted August 22, 2019 Why can't it transcode into something that can carry DTS? Link to comment Share on other sites More sharing options...
Luke 36879 Posted August 22, 2019 Share Posted August 22, 2019 There isn't really a suitable option for that. Link to comment Share on other sites More sharing options...
crusher11 842 Posted August 22, 2019 Author Share Posted August 22, 2019 Why not? The format it's originally in can handle DTS, why can't it transcode into that format? Link to comment Share on other sites More sharing options...
Luke 36879 Posted August 22, 2019 Share Posted August 22, 2019 The HLS streaming protocol does not support DTS. Link to comment Share on other sites More sharing options...
crusher11 842 Posted August 22, 2019 Author Share Posted August 22, 2019 What's the "HLS streaming protocol"? Link to comment Share on other sites More sharing options...
Luke 36879 Posted August 22, 2019 Share Posted August 22, 2019 https://www.dacast.com/blog/hls-streaming-protocol/ Link to comment Share on other sites More sharing options...
crusher11 842 Posted August 22, 2019 Author Share Posted August 22, 2019 But how does that tie in to this specific context? Link to comment Share on other sites More sharing options...
Happy2Play 8138 Posted August 22, 2019 Share Posted August 22, 2019 But how does that tie in to this specific context? The delivery method changed when you add I assume unsupported subtitles and that method required the audio track to be changes also. Link to comment Share on other sites More sharing options...
crusher11 842 Posted August 22, 2019 Author Share Posted August 22, 2019 But I'm still not seeing why the remux can't use the original delivery method. Link to comment Share on other sites More sharing options...
Luke 36879 Posted August 22, 2019 Share Posted August 22, 2019 Because the original delivery method is a completed static file. When you have to convert on the fly that's no longer the case. I assume you don't want to wait for the entire file to be converted, so we use a streaming protocol that allows us to send small chunks at a time. 1 Link to comment Share on other sites More sharing options...
Happy2Play 8138 Posted August 22, 2019 Share Posted August 22, 2019 (edited) But I'm still not seeing why the remux can't use the original delivery method. You have not provided the ffmpeg log so we don't know exactly what is going on. But the file is not being remuxed anymore it is being converted/transcoded. Edited August 22, 2019 by Happy2Play Link to comment Share on other sites More sharing options...
rbjtech 4170 Posted August 22, 2019 Share Posted August 22, 2019 If you want to maintain the original video and DTS audio - then use an external subtitle text file (.srt) - then it would most likely not need to transcode in the first place... 1 Link to comment Share on other sites More sharing options...
Happy2Play 8138 Posted August 22, 2019 Share Posted August 22, 2019 That is where I was headed but did not know the specifics of this transcode session. Link to comment Share on other sites More sharing options...
crusher11 842 Posted August 22, 2019 Author Share Posted August 22, 2019 (edited) It's PGS from the BDs. I'm aware that requires the video to be transcoded, I just didn't understand why it would affect the audio. Because the original delivery method is a completed static file. When you have to convert on the fly that's no longer the case. I assume you don't want to wait for the entire file to be converted, so we use a streaming protocol that allows us to send small chunks at a time. This is the sort of explanation I was looking for, thanks. Edited August 22, 2019 by crusher11 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now