Use Animation Playback when frames have different names My addon renders frames whose names are not constant.  How can I use Python to get the playback to work?  

I'm working on a time remapping addon and wanted to give the user the option to include the true frame number in the filename, e.g.:

1.00_0001.png

1.25_0002.png

1.50_0003.png

But bpy.ops.render.play_rendered_anim() doesn't work on these, although importing these images into the Video Editor works fine.
The operator doesn't expose any options you could set, but this seems to be the command it uses:

'C:\\Program Files\\Blender Foundation\\Blender\\blender.exe -a -f 24 1.0 -s 1 -e 250 -j 1 C:\\tmp\\0001.png'


There's even a step / frame jump parameter:

http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Command_Line#Animation_Playback_Options:

But it doesn't really help in your case. You need to specify every single frame:

blender -a -f 24 1.0 00_0001.png 25_0002.png 50_0003.png 75_0004.png