avcodec/ass: make default playback resolution available to decoders

libavcodec/ass.c

@@ -36,8 +36,8 @@ int ff_ass_subtitle_header(AVCodecContext *avctx,
              "[Script Info]\r\n"
              "; Script generated by FFmpeg/Lavc%s\r\n"
              "ScriptType: v4.00+\r\n"
-             "PlayResX: 384\r\n"
-             "PlayResY: 288\r\n"
+             "PlayResX: %d\r\n"
+             "PlayResY: %d\r\n"
              "\r\n"
              "[V4+ Styles]\r\n"
 
@@ -67,6 +67,7 @@ int ff_ass_subtitle_header(AVCodecContext *avctx,
              "[Events]\r\n"
              "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",
              !(avctx->flags & CODEC_FLAG_BITEXACT) ? AV_STRINGIFY(LIBAVCODEC_VERSION) : "",
+             ASS_DEFAULT_PLAYRESX, ASS_DEFAULT_PLAYRESY,
              font, font_size, color, color, back_color, back_color,
              -bold, -italic, -underline, alignment);
 

libavcodec/ass.h

@@ -25,6 +25,9 @@
 #include "avcodec.h"
 #include "libavutil/bprint.h"
 
+#define ASS_DEFAULT_PLAYRESX 384
+#define ASS_DEFAULT_PLAYRESY 288
+
 /**
  * @name Default values for ASS style
  * @{