command, demux: add AB-loop keyframe cache align command

Helper for the ab-loop-dump-cache command, see manpage additions.

This is kind of shit. Not only is this a very "special" feature, but it
also vomits more messy code into the big and already bloated demux.c,
and the implementation is sort of duplicated with the dump-cache code.
(Except it's different.) In addition, the results sort of depend what a
video player would do with the dump-cache output, or what the user wants
(for example, a user might be more interested in the range of output
audio, instead of the video).

But hey, I don't actually need to justify it. I'm only justifying it for
fun.

1 files changed, 22 insertions, 0 deletions

diff --git a/player/command.c b/player/command.c
index b4c2ad1201..8c4f8de5ea 100644
--- a/player/command.c
+++ b/player/command.c
@@ -5336,6 +5336,26 @@ static void cmd_ab_loop(void *p)
     }
 }
 
+static void cmd_align_cache_ab(void *p)
+{
+    struct mp_cmd_ctx *cmd = p;
+    struct MPContext *mpctx = cmd->mpctx;
+
+    if (!mpctx->demuxer)
+        return;
+
+    double a = demux_probe_cache_dump_target(mpctx->demuxer,
+                                             mpctx->opts->ab_loop[0], false);
+    double b = demux_probe_cache_dump_target(mpctx->demuxer,
+                                             mpctx->opts->ab_loop[1], true);
+
+    mp_property_do("ab-loop-a", M_PROPERTY_SET, &a, mpctx);
+    mp_property_do("ab-loop-b", M_PROPERTY_SET, &b, mpctx);
+
+    // Happens to cover both properties.
+    show_property_osd(mpctx, "ab-loop-b", cmd->on_osd);
+}
+
 static void cmd_drop_buffers(void *p)
 {
     struct mp_cmd_ctx *cmd = p;
@@ -5986,6 +6006,8 @@ const struct mp_cmd_def mp_cmds[] = {
         .can_abort = true,
     },
 
+    { "ab-loop-align-cache", cmd_align_cache_ab },
+
     {0}
 };