Forum: Subtitling
Topic: Ask me anything about subtitling
Poster: Carlos Castillo
Post title: Difference in SCC timecodes between raw file and editor
[quote]Max Deryagin wrote:
Hi Carlos,
The timecodes you see in the SCC file aren't for when your captions are supposed to pop on; they are for when your captions are supposed to start loading on the CC decoding device. At 29.97 FPS DF, each four-byte group will take one frame to load, and all of them need to load before your caption can be displayed. What happens when you open your file in an editor is the editor adds these frames back for export compatibility purposes, so you get different timecodes.
So, what you need to do with your converter is take into account the load times of your captions. (Or better still, use a pro captioning tool.) [/quote]
Thank you very much for your reply, Max. I thought I enabled email notifications for replies here, that's why I took long to reply.
Now I understand. The thing is that these captions are for a client that sends sporadic work, not steady enough to pay for a tool myself. Another client pays for an editing platform that handles this professionally. So, no problem there.
I can see now why different captions have different "delays." Do you know why these loading times do not affect the captions in VLC media player? When I play a video with a .scc file that accounts for those times, they always lead the audio. Is this only for TV broadcasting? What about DVDs?
A few other questions:
- What about other framerates?
- Does this count for text bytes and commands too?
- What about the doubled-up commands? Are they considered in the calculation or only one of them?
Thank you very much again.
[Edited at 2019-11-27 13:14 GMT]
Topic: Ask me anything about subtitling
Poster: Carlos Castillo
Post title: Difference in SCC timecodes between raw file and editor
[quote]Max Deryagin wrote:
Hi Carlos,
The timecodes you see in the SCC file aren't for when your captions are supposed to pop on; they are for when your captions are supposed to start loading on the CC decoding device. At 29.97 FPS DF, each four-byte group will take one frame to load, and all of them need to load before your caption can be displayed. What happens when you open your file in an editor is the editor adds these frames back for export compatibility purposes, so you get different timecodes.
So, what you need to do with your converter is take into account the load times of your captions. (Or better still, use a pro captioning tool.) [/quote]
Thank you very much for your reply, Max. I thought I enabled email notifications for replies here, that's why I took long to reply.
Now I understand. The thing is that these captions are for a client that sends sporadic work, not steady enough to pay for a tool myself. Another client pays for an editing platform that handles this professionally. So, no problem there.
I can see now why different captions have different "delays." Do you know why these loading times do not affect the captions in VLC media player? When I play a video with a .scc file that accounts for those times, they always lead the audio. Is this only for TV broadcasting? What about DVDs?
A few other questions:
- What about other framerates?
- Does this count for text bytes and commands too?
- What about the doubled-up commands? Are they considered in the calculation or only one of them?
Thank you very much again.
[Edited at 2019-11-27 13:14 GMT]