Parse and animate all colors and alpha values like VSFilter

* Allow exactly one of these prefixes in header values:
  0x, 0X, &h, &H. Note that "0x0xFFFFFF" is a correct value,
  as the first 0x is consumed by the parser and the second by
  the string-to-number conversion following strtol semantics.

* Allow arbitrary numbers of leading & and H
 (and not h) in any order in override tag values.

* Reduce header values modulo 2**32 instead
  of saturating them to LLONG_MIN/MAX.

* Saturate override tag values to INT32_MIN/MAX
  rather than to LLONG_MIN/MAX.

* Don't fiddle with bytes in alpha override tag values.
 (They can be outside of the 0..255 range.)

Also change the byte swapping code to be more sensible.

Fixes #80.
Fixes #145.
Fixes #178.

Also fixes our behavior in the case described in
https://code.google.com/p/xy-vsfilter/issues/detail?id=80.

1 files changed, 1 insertions, 1 deletions

diff --git a/libass/ass_parse.h b/libass/ass_parse.h
index e8512b2..2b4cee0 100644
--- a/libass/ass_parse.h
+++ b/libass/ass_parse.h
@@ -36,7 +36,7 @@ void process_karaoke_effects(ASS_Renderer *render_priv);
 unsigned get_next_char(ASS_Renderer *render_priv, char **str);
 char *parse_tag(ASS_Renderer *render_priv, char *p, char *end, double pwr);
 int event_has_hard_overrides(char *str);
-extern void change_alpha(uint32_t *var, uint32_t new, double pwr);
+extern void change_alpha(uint32_t *var, int32_t new, double pwr);
 extern uint32_t mult_alpha(uint32_t a, uint32_t b);