command: add a mechanism to allow scripts to intercept file loads

A vague idea to get something similar what libquvi did.

Undocumented because it might change a lot, or even be removed. To give
an idea what it does, a Lua script could do the following:

--                      type       ID priority
mp.commandv("hook_add", "on_load", 0, 0)
mp.register_script_message("hook_run", function(param, param2)
    -- param is "0", the user-chosen ID from the hook_add command
    -- param2 is the magic value that has to be passed to finish
    -- the hook
    mp.resume_all()
    -- do something, maybe set options that are reset on end:
    mp.set_property("file-local-options/name", "value")
    -- or change the URL that's being opened:
    local url = mp.get_property("stream-open-filename")
    mp.set_property("stream-open-filename", url .. ".png")
    -- let the player (or the next script) continue
    mp.commandv("hook_ack", param2)
end)

1 files changed, 1 insertions, 0 deletions

diff --git a/input/input.h b/input/input.h
index 40c9369271..877f79a0e6 100644
--- a/input/input.h
+++ b/input/input.h
@@ -82,6 +82,7 @@ typedef struct mp_cmd {
     struct mp_cmd *queue_next;
     double scale;               // for scaling numeric arguments
     const struct mp_cmd_def *def;
+    char *sender; // name of the client API user which sent this
 } mp_cmd_t;
 
 struct mp_input_src {