If you are monkeying around with the capture cards on you system, you will soon discover that the numbering of the cards is not to your liking. When cards are added, the table that contains their information (capturecard) uses an autoincrement column to number each card.
Normally, this would be irrelevant except that the card number is shown in certain user displays (e.g. the upcoming recordings display shows which encoder will record each program). If you would like to know which encoder is doing each recording but have no clue which one is 11, or 4, or 7, you can reset the auto increment value in the capturecard table so that the encoders are numbered sequentially from 1.
Begin by deleting all of the capture cards, using the MythTV Backend Setup program and selecting the Capture Cards section. The Delete All Capture Cards choice will get rid of all the capture cards. Then, do the following from the command prompt:
mysql -umrwizard -psecretpassword mythconverg
alter table capturecard auto_increment=1;
quit
This will reset the auto increment value to 1. You can then re-add all of the capture cards in the order that you like (note that you must do this on each individual machine in the system), making sure to choose the correct options for each one. The cards will be numbered sequentially, from 1, in the order that they are added. Incidentally, if you are going to be using MythWeb, you can also give them more meaningful names (e.g. "HDTV 1" or "Analog 1") for it to use.
Incidentally, if you have any recording rules that are set to use a preferred input, they may not work after you move any of the capture cards around. You can check which recording specified a preferred input. From the database command prompt (see above), you can use this command:
select recordid, title, prefinput from record
where prefinput != 0 order by prefinput asc, title asc;
You should be able to figure out which recording rules need to be reset to a different preferred input.