Theora image latency
I have several cameras - different models and different ros drivers - that show significant latency (about one second) between theora and image_raw, while there is no latency between compressed and image_raw.
I am wondering what causes this. Does theora get processed on the computer or is this a driver/setup related issue?
I was unable to find a good answer online for this so I am hoping someone could clarify this.
Thank you
EDIT: Clarification
You question is not clear: your first paragraph says theora has low latency, and your 2nd implies it has high latency.
Sorry if I was unclear i will edit the post, There IS latency between theora and image_raw, there is no or little latency between compressed and image_raw
I'm not seeing a good reference right now but theora is compressing the images a lot more aggressively than the regular
compressedso takes more time to do it, and is very probably looking at multiple frames in a sequence for better compression so always is more behind. Regular compressed is doing jpeg or png compression on a single frame but won't take advantage of a series of images that are mostly the same.Take a look at https://github.com/daniilidis-group/f..., which is similar high compression and definitly looking at multiple frames so will have latency, but maybe less than theora (also depending on configuration)- possibly ffmpeg is better optimized than theora compression because it is so much more widely used.
Thank you, this certainly makes sense.