Displaying "stop"... and other (unnecessary?) images

[hhannah]

On a thread regarding an ipod 320x240 theme (http://forums.rockbox.org/index.php?topic=16228.msg121928#msg121928), came the idea of suggesting to avoid loading the (very frequently used in themes) "stop" image, since it's apparently only displayed for a very brief moment, between the moment when a playlist ends and the menu screen is shown. Before adding this information to the CustomWPS wiki (http://www.rockbox.org/twiki/bin/view/Main/CustomWPS) in a more general way ("Optimizing the Use of Images”?), I'd appreciate feedback and ideas (see below), and of course, if the "stop thing" applies to the other targets, not only ipods.

Proposal:

A. Under the "Playback Mode" part (http://www.rockbox.org/twiki/bin/view/Main/CustomWPS#Playback_Mode) the following note would be placed:

Note: Playing status 0 (stop), is only entered for a brief period of time when the last file in a playlist ends, just before “menu” screen is automatically displayed.

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B. In the “Images” chapter,  I’d include a sub-chapter that could be called something like “Optimizing the Use of Images”, that would be like:

In order to save loading time and minimize the memory used by WPS loaded images, in general terms the number of images loaded should be minimized, as well as the images size:

1. Try to make the conditional images as small as possible, by placing just the portion of the image that actually changes, avoiding that it contains redundant static portions already in the main background.

2. Try to place in the background image one of the conditional images. That saves loading one image per case. Example: To display the “hold” status, instead of loading an “open lock” image to be displayed when hold is off, and a closed lock image when hold is on, you can put the opened lock image static in the main background image, “covering” it when hold is on. The hold switch tag instruction would look something like  %?mh<%xdH|>. Typical examples of cases where this applies are battery, volume, repeat, shuffle, play mode, etc.

3. Use bitmap strips (subimages) where possible, since only one image is loaded per case, versus loading single images one by one. [link to “bitmap strips”]

4. Avoid loading images that are finally not used (this is common sense but it happens all the time). A special example of this case is the “stop” image, since it is only displayed briefly when a playlist is over, just before jumping to the menu screen.

[Chronon]

I'm all for it.  I see you've covered the "stop" image issue and incorporated some other useful hints on image use in the WPS.  

[dreamlayers]

Omitting images or making them smaller won't save any memory because the size of the buffer is set at compile time.

It would decrease the time spent loading the theme, but not by much.  

IMHO you could decrease load time far more if the images were stored in a single file.  Edit:  Right after I posted this I saw another message about recent "bitmap strips" commits which do this very thing.

[Chronon]

Good point.  Though it's like a drippy faucet: Why waste the buffer if you don't need to?  And why make graphics that will rarely, if ever, get seen?

Still, this points to a revision for the text above.

[hhannah]

IMHO you could decrease load time far more if the images were stored in a single file.  Edit:  Right after I posted this I saw another message about recent "bitmap strips" commits which do this very thing.

See

3. Use bitmap strips (subimages) where possible, since only one image is loaded per case, versus loading single images one by one. [link to “bitmap strips”]

So I guess this is covered.

Omitting images or making them smaller won't save any memory because the size of the buffer is set at compile time.

I don't know much about the technical part of all this, so this imput is important... but is the buffer you mention only used for the images loaded?
...

Omitting images or making them smaller ... would decrease the time spent loading the theme, but not by much

You may be right, but I've seen different opinions, for example from Llorean in the default theme thread:

4) It should load quickly. Try to use as FEW individual images as possible to get your point across. Each extra file adds to load time. We want this to put forth the best foot possible. Increasing the boot time doesn't do this.

[Chronon]

Omitting images will shorten the time spent making a theme, though.  

Though, in fairness it's only the stop image that we've discussed omitting.

[linuxstb]

I would hope that in the future the status bar could be themeable in some way, so I would hope that theme designers keep producing STOP icons for their themes - they may not be useful today, but they probably will be in the future.

And if you're using bitmap strips (which are perfect for things like the playback status icons), then it doesn't add to the filecount.

[hhannah]

I would hope that in the future the status bar could be themeable in some way, so I would hope that theme designers keep producing STOP icons for their themes - they may not be useful today, but they probably will be in the future.

And if you're using bitmap strips (which are perfect for things like the playback status icons), then it doesn't add to the filecount.

OK, so I guess this makes it completely clear. In other words, as long as you put your images using bitmap strips, it doesn't really matter how many subimages you have, or their size. That makes 1),2) & 4) irrelevant. Bitmap strips should be a complete chapter, which would cover 3)

As for the "stop" note, it could be:

Note: Currently, playing status 0 (stop), is only entered for a brief period of time when the last file in a playlist ends, just before “menu” screen is automatically displayed.

In that way, people writing themes could decide wether to use it or not, until what linuxstb mentions about the progress bar (or something else), changes.

[Chronon]

I would hope that in the future the status bar could be themeable in some way, so I would hope that theme designers keep producing STOP icons for their themes - they may not be useful today, but they probably will be in the future.

It almost seems like producing the status bar theme would be better done once those details are nailed down though.  I would guess that a lot of theme authors would want to use different graphics for the themed status bar than they do to signify playback state on the WPS.

But I take your point about discouraging people from doing something that may be useful in the future.  Maybe we could advise people in what context the STOP icon is expected to be used (i.e. the status bar).

[LinusN]

I also anticipate that the WPS may some day be able to show even when the music is stopped.

[karashata]

I thought sometime back that it used to show when it was stopped, but people had decided that it didn't really make sense to have it show when music isn't being played, so they had it return to the file browser or database upon stopping playback...

[LinusN]

That is correct. That was however a looooooooong time ago.

[karashata]

I'm not against having the WPS remain displayed upon stopping playback (I've made images to indicate stopped playback for my themes, so it would be nice for them to have a purpose), however, I'm not exactly certain what the benefit to it would be.  I'm sure someone will be able to justify having the WPS remain displayed for some purpose or another after playback is stopped, and I may end up agreeing with that reason, but for now, I can't think of one.

[Llorean]

The  trick isn't that it's necessarily "the WPS will still display" so much as "with one of the ideas being played with, themes will have an option for displaying PART of the WPS as a status-bar for the menus"

[karashata]

Ohhh...  well, *that* makes a little more sense, and should be rather nice.  I feel I must ask, though.  Is the intention that the status bar will still be displayed at the top of the screen, or will it be able to be displayed at the bottom as well, or even possibly split over both the top and bottom at once?  I've seen a lot of nice themes that have the "status bar" part of the WPS at the bottom of the screen with maybe only the battery, hold, and virtual LED on a small bar at the top, as well as some that have everything at the bottom, in addition to the somewhat limited number that actually put all of the status info at the top.