subtitles: style support for common SubRip tags and MicroDVD

SubRip subtitles have no "official" spec for any styling support, but
various tags are in common use; previous code filtered out text
between <> to remove HTML-style tags. Add support for those tags and
for MicroDVD subtitle styling. The style display is implemented by
converting the subtitles to the ASS subtitle format and displaying
them with libass, so libass needs to be enabled.

Original patch by Clément Bœsch <ubitux@gmail.com>.

1 files changed, 134 insertions, 18 deletions

diff --git a/subreader.c b/subreader.c
index c9b3261c0e..10794b2ff5 100644
--- a/subreader.c
+++ b/subreader.c
@@ -33,6 +33,8 @@
 #include "mp_msg.h"
 #include "subreader.h"
 #include "mpcommon.h"
+#include "sub/subassconvert.h"
+#include "options.h"
 #include "stream/stream.h"
 #include "libavutil/common.h"
 #include "libavutil/avstring.h"
@@ -54,6 +56,12 @@ int flip_hebrew = 1;            ///flip subtitles using fribidi
 int fribidi_flip_commas = 0;    ///flip comma when fribidi is used
 #endif
 
+// Parameter struct for the format-specific readline functions
+struct readline_args {
+    int utf16;
+    struct MPOpts *opts;
+};
+
 /* Maximal length of line of a subtitle */
 #define LINE_LEN 1000
 static float mpsub_position=0;
@@ -119,7 +127,10 @@ static void sami_add_line(subtitle *current, char *buffer, char **pos) {
     *pos = buffer;
 }
 
-static subtitle *sub_read_line_sami(stream_t* st, subtitle *current, int utf16) {
+static subtitle *sub_read_line_sami(stream_t* st, subtitle *current,
+                                    struct readline_args *args)
+{
+    int utf16 = args->utf16;
     static char line[LINE_LEN+1];
     static char *s = NULL, *slacktime_s;
     char text[LINE_LEN+1], *p=NULL, *q;
@@ -278,7 +289,10 @@ static char *sub_readtext(char *source, char **dest) {
     else return NULL;  // last text field
 }
 
-static subtitle *sub_read_line_microdvd(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_microdvd(stream_t *st,subtitle *current,
+                                        struct readline_args *args)
+{
+    int utf16 = args->utf16;
     char line[LINE_LEN+1];
     char line2[LINE_LEN+1];
     char *p, *next;
@@ -293,7 +307,11 @@ static subtitle *sub_read_line_microdvd(stream_t *st,subtitle *current, int utf1
 		      "{%ld}{%ld}%[^\r\n]",
 		      &(current->start), &(current->end), line2) < 3));
 
-    p=line2;
+    if (args->opts->ass_enabled) {
+        subassconvert_microdvd(line2, line, LINE_LEN + 1);
+        p = line;
+    } else
+        p = line2;
 
     next=p, i=0;
     while ((next =sub_readtext (next, &(current->text[i])))) {
@@ -306,7 +324,10 @@ static subtitle *sub_read_line_microdvd(stream_t *st,subtitle *current, int utf1
     return current;
 }
 
-static subtitle *sub_read_line_mpl2(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_mpl2(stream_t *st,subtitle *current,
+                                    struct readline_args *args)
+{
+    int utf16 = args->utf16;
     char line[LINE_LEN+1];
     char line2[LINE_LEN+1];
     char *p, *next;
@@ -332,7 +353,10 @@ static subtitle *sub_read_line_mpl2(stream_t *st,subtitle *current, int utf16) {
     return current;
 }
 
-static subtitle *sub_read_line_subrip(stream_t* st, subtitle *current, int utf16) {
+static subtitle *sub_read_line_subrip(stream_t* st, subtitle *current,
+                                    struct readline_args *args)
+{
+    int utf16 = args->utf16;
     char line[LINE_LEN+1];
     int a1,a2,a3,a4,b1,b2,b3,b4;
     char *p=NULL, *q=NULL;
@@ -362,12 +386,75 @@ static subtitle *sub_read_line_subrip(stream_t* st, subtitle *current, int utf16
     return current;
 }
 
-static subtitle *sub_read_line_subviewer(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_ass_read_line_subviewer(stream_t *st, subtitle *current,
+                                             struct readline_args *args)
+{
+    int utf16 = args->utf16;
+    int a1, a2, a3, a4, b1, b2, b3, b4, j = 0;
+
+    while (!current->text[0]) {
+        char line[LINE_LEN + 1], full_line[LINE_LEN + 1], sep;
+        int i;
+
+        /* Parse SubRip header */
+        if (!stream_read_line(st, line, LINE_LEN, utf16))
+            return NULL;
+        if (sscanf(line, "%d:%d:%d%[,.:]%d --> %d:%d:%d%[,.:]%d",
+                     &a1, &a2, &a3, &sep, &a4, &b1, &b2, &b3, &sep, &b4) < 10)
+            continue;
+
+        current->start = a1 * 360000 + a2 * 6000 + a3 * 100 + a4 / 10;
+        current->end   = b1 * 360000 + b2 * 6000 + b3 * 100 + b4 / 10;
+
+        /* Concat lines */
+        full_line[0] = 0;
+        for (i = 0; i < SUB_MAX_TEXT; i++) {
+            int blank = 1, len = 0;
+            char *p;
+
+            if (!stream_read_line(st, line, LINE_LEN, utf16))
+                break;
+
+            for (p = line; *p != '\n' && *p != '\r' && *p; p++, len++)
+                if (*p != ' ' && *p != '\t')
+                    blank = 0;
+
+            if (blank)
+                break;
+
+            *p = 0;
+
+            if (!(j + 1 + len < sizeof(full_line) - 1))
+                break;
+
+            if (j != 0)
+                full_line[j++] = '\n';
+            strcpy(&full_line[j], line);
+            j += len;
+        }
+
+        /* Use the ASS/SSA converter to transform the whole lines */
+        if (full_line[0]) {
+            char converted_line[LINE_LEN + 1];
+            subassconvert_subrip(full_line, converted_line, LINE_LEN + 1);
+            current->text[0] = strdup(converted_line);
+            current->lines = 1;
+        }
+    }
+    return current;
+}
+
+static subtitle *sub_read_line_subviewer(stream_t *st,subtitle *current,
+                                         struct readline_args *args)
+{
+    int utf16 = args->utf16;
     char line[LINE_LEN+1];
     int a1,a2,a3,a4,b1,b2,b3,b4;
     char *p=NULL;
     int i,len;
 
+    if (args->opts->ass_enabled)
+        return sub_ass_read_line_subviewer(st, current, args);
     while (!current->text[0]) {
 	if (!stream_read_line (st, line, LINE_LEN, utf16)) return NULL;
 	if ((len=sscanf (line, "%d:%d:%d%[,.:]%d --> %d:%d:%d%[,.:]%d",&a1,&a2,&a3,(char *)&i,&a4,&b1,&b2,&b3,(char *)&i,&b4)) < 10)
@@ -414,7 +501,10 @@ static subtitle *sub_read_line_subviewer(stream_t *st,subtitle *current, int utf
     return current;
 }
 
-static subtitle *sub_read_line_subviewer2(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_subviewer2(stream_t *st,subtitle *current,
+                                          struct readline_args *args)
+{
+    int utf16 = args->utf16;
     char line[LINE_LEN+1];
     int a1,a2,a3,a4;
     char *p=NULL;
@@ -447,7 +537,10 @@ static subtitle *sub_read_line_subviewer2(stream_t *st,subtitle *current, int ut
 }
 
 
-static subtitle *sub_read_line_vplayer(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_vplayer(stream_t *st,subtitle *current,
+                                       struct readline_args *args)
+{
+        int utf16 = args->utf16;
 	char line[LINE_LEN+1];
 	int a1,a2,a3;
 	char *p=NULL, *next,separator;
@@ -493,7 +586,11 @@ static subtitle *sub_read_line_vplayer(stream_t *st,subtitle *current, int utf16
 	return current;
 }
 
-static subtitle *sub_read_line_rt(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_rt(stream_t *st,subtitle *current,
+                                    struct readline_args *args)
+{
+    int utf16 = args->utf16;
+
 	//TODO: This format uses quite rich (sub/super)set of xhtml
 	// I couldn't check it since DTD is not included.
 	// WARNING: full XML parses can be required for proper parsing
@@ -543,7 +640,9 @@ static subtitle *sub_read_line_rt(stream_t *st,subtitle *current, int utf16) {
     return current;
 }
 
-static subtitle *sub_read_line_ssa(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_ssa(stream_t *st,subtitle *current,
+                                    struct readline_args *args)
+{
 /*
  * Sub Station Alpha v4 (and v2?) scripts have 9 commas before subtitle
  * other Sub Station Alpha scripts have only 8 commas before subtitle
@@ -553,6 +652,7 @@ static subtitle *sub_read_line_ssa(stream_t *st,subtitle *current, int utf16) {
  * http://www.scriptclub.org is a good place to find more examples
  * http://www.eswat.demon.co.uk is where the SSA specs can be found
  */
+        int utf16 = args->utf16;
         int comma;
         static int max_comma = 32; /* let's use 32 for the case that the */
                     /*  amount of commas increase with newer SSA versions */
@@ -645,7 +745,10 @@ static void sub_pp_ssa(subtitle *sub) {
  *
  * by set, based on code by szabi (dunnowhat sub format ;-)
  */
-static subtitle *sub_read_line_pjs(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_pjs(stream_t *st,subtitle *current,
+                                   struct readline_args *args)
+{
+    int utf16 = args->utf16;
     char line[LINE_LEN+1];
     char text[LINE_LEN+1], *s, *d;
 
@@ -683,7 +786,10 @@ static subtitle *sub_read_line_pjs(stream_t *st,subtitle *current, int utf16) {
     return current;
 }
 
-static subtitle *sub_read_line_mpsub(stream_t *st, subtitle *current, int utf16) {
+static subtitle *sub_read_line_mpsub(stream_t *st, subtitle *current,
+                                     struct readline_args *args)
+{
+        int utf16 = args->utf16;
 	char line[LINE_LEN+1];
 	float a,b;
 	int num=0;
@@ -728,7 +834,10 @@ static subtitle *sub_read_line_mpsub(stream_t *st, subtitle *current, int utf16)
 subtitle *previous_aqt_sub = NULL;
 #endif
 
-static subtitle *sub_read_line_aqt(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_aqt(stream_t *st,subtitle *current,
+                                   struct readline_args *args)
+{
+    int utf16 = args->utf16;
     char line[LINE_LEN+1];
     char *next;
     int i;
@@ -785,7 +894,10 @@ static subtitle *sub_read_line_aqt(stream_t *st,subtitle *current, int utf16) {
 subtitle *previous_subrip09_sub = NULL;
 #endif
 
-static subtitle *sub_read_line_subrip09(stream_t *st,subtitle *current, int utf16) {
+static subtitle *sub_read_line_subrip09(stream_t *st,subtitle *current,
+                                    struct readline_args *args)
+{
+    int utf16 = args->utf16;
     char line[LINE_LEN+1];
     int a1,a2,a3;
     char * next=NULL;
@@ -837,8 +949,10 @@ static subtitle *sub_read_line_subrip09(stream_t *st,subtitle *current, int utf1
     return current;
 }
 
-static subtitle *sub_read_line_jacosub(stream_t* st, subtitle * current, int utf16)
+static subtitle *sub_read_line_jacosub(stream_t* st, subtitle * current,
+                                       struct readline_args *args)
 {
+    int utf16 = args->utf16;
     char line1[LINE_LEN], line2[LINE_LEN], directive[LINE_LEN], *p, *q;
     unsigned a1, a2, a3, a4, b1, b2, b3, b4, comment = 0;
     static unsigned jacoTimeres = 30;
@@ -1285,7 +1399,8 @@ static void adjust_subs_time(subtitle* sub, float subtime, float fps, int block,
 }
 
 struct subreader {
-    subtitle * (*read)(stream_t *st,subtitle *dest,int utf16);
+    subtitle * (*read)(stream_t *st, subtitle *dest,
+                       struct readline_args *args);
     void       (*post)(subtitle *dest);
     const char *name;
 };
@@ -1351,7 +1466,8 @@ const char* guess_cp(stream_t *st, const char *preferred_language, const char *f
 #undef MAX_GUESS_BUFFER_SIZE
 #endif
 
-sub_data* sub_read_file (char *filename, float fps) {
+sub_data* sub_read_file(char *filename, float fps, struct MPOpts *opts)
+{
     int utf16;
     stream_t* fd;
     int n_max, n_first, i, j, sub_first, sub_orig;
@@ -1436,7 +1552,7 @@ sub_data* sub_read_file (char *filename, float fps) {
 	sub = &first[sub_num];
 #endif
 	memset(sub, '\0', sizeof(subtitle));
-        sub=srp->read(fd,sub,utf16);
+        sub=srp->read(fd, sub, &(struct readline_args){utf16, opts});
         if(!sub) break;   // EOF
 #ifdef CONFIG_ICONV
 	if ((sub!=ERR) && sub_utf8 == 2) sub=subcp_recode(sub);