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1 | initial version |
@PapaG is not wrong, but I feel that answer misses an important point: the fact that bag_to_pcd
uses a fundamentally different way of processing the .bag
file.
Pub-sub is typically implemented such that it makes no guarantees about whether you receive a message (there are implementations that do, but ROS 1's is not one of those).
bag_to_pcd
does not use pub-sub, it iterates over the messages in the .bag
file directly (using the rosbag
API, examples here). That is a blocking operation, and that is why no messages are "lost".
2 | No.2 Revision |
@PapaG is not wrong, but I feel that answer misses an important point: the fact that bag_to_pcd
uses a fundamentally different way of processing the .bag
file.
Pub-sub is typically implemented such that it makes no guarantees about whether you receive a message (there are implementations that do, but ROS 1's is not one of those).
bag_to_pcd
does not use pub-sub, it iterates over the messages in the .bag
file directly (using the rosbag
API, examples here). That is implemented as a blocking operation, and that is why no messages are "lost". "lost": there is simply no way to advance to the next message before the current one has been processed.