@@ -7725,6 +7725,9 @@ changed.

 @item charenc

 Set subtitles input character encoding. @code{subtitles} filter only. Only

 useful if not UTF-8.

+

+@item stream_index, si

+Set subtitles stream index. @code{subtitles} filter only.

 @end table

 If the first key is not specified, it is assumed that the first value

@@ -7741,6 +7744,16 @@ which is equivalent to:

 subtitles=filename=sub.srt

 @end example

+To render the default subtitles stream from file @file{video.mkv}, use:

+@example

+subtitles=video.mkv

+@end example

+

+To render the second subtitles stream from that file, use:

+@example

+subtitles=video.mkv:si=1

+@end example

+

 @section super2xsai

 Scale the input by 2x and smooth using the Super2xSaI (Scale and

@@ -51,6 +51,7 @@ typedef struct {

     ASS_Track    *track;

     char *filename;

     char *charenc;

+    int stream_index;

     uint8_t rgba_map[4];

     int     pix_step[4];       ///< steps per pixel for each plane of the main output

     int original_w, original_h;

@@ -247,7 +248,9 @@ AVFilter ff_vf_ass = {

 static const AVOption subtitles_options[] = {

     COMMON_OPTIONS

-    {"charenc", "set input character encoding", OFFSET(charenc), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS},

+    {"charenc",      "set input character encoding", OFFSET(charenc),      AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS},

+    {"stream_index", "set stream index",             OFFSET(stream_index), AV_OPT_TYPE_INT,    { .i64 = -1 }, -1,       INT_MAX,  FLAGS},

+    {"si",           "set stream index",             OFFSET(stream_index), AV_OPT_TYPE_INT,    { .i64 = -1 }, -1,       INT_MAX,  FLAGS},

     {NULL},

 };

@@ -279,6 +282,7 @@ AVFILTER_DEFINE_CLASS(subtitles);

 static av_cold int init_subtitles(AVFilterContext *ctx)

 {

     int j, ret, sid;

+    int k = 0;

     AVDictionary *codec_opts = NULL;

     AVFormatContext *fmt = NULL;

     AVCodecContext *dec_ctx = NULL;

@@ -309,7 +313,23 @@ static av_cold int init_subtitles(AVFilterContext *ctx)

         goto end;

     /* Locate subtitles stream */

-    ret = av_find_best_stream(fmt, AVMEDIA_TYPE_SUBTITLE, -1, -1, NULL, 0);

+    if (ass->stream_index < 0)

+        ret = av_find_best_stream(fmt, AVMEDIA_TYPE_SUBTITLE, -1, -1, NULL, 0);

+    else {

+        ret = -1;

+        if (ass->stream_index < fmt->nb_streams) {

+            for (j = 0; j < fmt->nb_streams; j++) {

+                if (fmt->streams[j]->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {

+                    if (ass->stream_index == k) {

+                        ret = j;

+                        break;

+                    }

+                    k++;

+                }

+            }

+        }

+    }

+

     if (ret < 0) {

         av_log(ctx, AV_LOG_ERROR, "Unable to locate subtitle stream in %s\n",

                ass->filename);