ffmpeg: Fixed forced subtitles display in PGS stream

Associated ffmpeg commits:

https://github.com/FFmpeg/FFmpeg/commit/36436a4032b022f5439fa86a0986065d24cd51fd
Add option forced_subs_only for Bluray subtitles.
2012-01-30 04:25:59

https://github.com/FFmpeg/FFmpeg/commit/1885ffb03d0af28e6bac2bcc8725fa15b93f6ac9
PGS subtitles: Expose forced flag
2012-10-20 11:56:11

https://github.com/FFmpeg/FFmpeg/commit/1c5805521c3e406886341d752ebf38f8d41e1d13
PGS subtitles: Set AVSubtitle pts value
2012-11-02 11:30:39

https://github.com/FFmpeg/FFmpeg/commit/6549a9b75333027f66cdaac450a66b6a6186fc6e
pgssubdec: remove unused variable
2012-11-28 10:20:08

https://github.com/FFmpeg/FFmpeg/commit/1f46b50a9591f68b697e943f829c79a4f4829dd6
Added AVClass for AVSubtitleRect
2012-04-18 01:08:25

4 files changed, 81 insertions, 16 deletions

diff --git a/lib/ffmpeg/libavcodec/avcodec.h b/lib/ffmpeg/libavcodec/avcodec.h
index 6996c9266b..585414bf9c 100644
--- a/lib/ffmpeg/libavcodec/avcodec.h
+++ b/lib/ffmpeg/libavcodec/avcodec.h
@@ -3245,6 +3245,12 @@ typedef struct AVCodecContext {
     int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
     int64_t pts_correction_last_pts;       /// PTS of the last frame
     int64_t pts_correction_last_dts;       /// DTS of the last frame
+    /** 
+     * Requests that only forced subpictures be decoded. 
+     * - decoding: set by user 
+     * - encoding: unused 
+     */ 
+    int forced_subs_only;
 
 } AVCodecContext;
 
@@ -3488,6 +3494,8 @@ enum AVSubtitleType {
     SUBTITLE_ASS,
 };
 
+#define AV_SUBTITLE_FLAG_FORCED 0x00000001
+
 typedef struct AVSubtitleRect {
     int x;         ///< top left corner  of pict, undefined when pict is not set
     int y;         ///< top left corner  of pict, undefined when pict is not set
@@ -3510,6 +3518,8 @@ typedef struct AVSubtitleRect {
      * struct.
      */
     char *ass;
+
+    int flags;
 } AVSubtitleRect;
 
 typedef struct AVSubtitle {
@@ -4895,6 +4905,14 @@ const AVClass *avcodec_get_class(void);
 const AVClass *avcodec_get_frame_class(void);
 
 /**
+ * Get the AVClass for AVSubtitleRect. It can be used in combination with
+ * AV_OPT_SEARCH_FAKE_OBJ for examining options.
+ *
+ * @see av_opt_find().
+ */
+const AVClass *avcodec_get_subtitle_rect_class(void);
+
+/**
  * @return a positive value if s is open (i.e. avcodec_open2() was called on it
  * with no corresponding avcodec_close()), 0 otherwise.
  */
diff --git a/lib/ffmpeg/libavcodec/dvdsubdec.c b/lib/ffmpeg/libavcodec/dvdsubdec.c
index d0d13eecec..46a0b8d384 100644
--- a/lib/ffmpeg/libavcodec/dvdsubdec.c
+++ b/lib/ffmpeg/libavcodec/dvdsubdec.c
@@ -375,6 +375,7 @@ static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
                 sub_header->rects[0]->h = h;
                 sub_header->rects[0]->type = SUBTITLE_BITMAP;
                 sub_header->rects[0]->pict.linesize[0] = w;
+                sub_header->rects[0]->flags = is_menu ? AV_SUBTITLE_FLAG_FORCED : 0;
             }
         }
         if (next_cmd_pos < cmd_pos) {
diff --git a/lib/ffmpeg/libavcodec/options.c b/lib/ffmpeg/libavcodec/options.c
index 5f940a0af6..ae62e75867 100644
--- a/lib/ffmpeg/libavcodec/options.c
+++ b/lib/ffmpeg/libavcodec/options.c
@@ -730,3 +730,28 @@ const AVClass *avcodec_get_frame_class(void)
 {
     return &av_frame_class;
 }
+
+#define SROFFSET(x) offsetof(AVSubtitleRect,x)
+
+static const AVOption subtitle_rect_options[]={
+{"x", "", SROFFSET(x), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
+{"y", "", SROFFSET(y), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
+{"w", "", SROFFSET(w), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
+{"h", "", SROFFSET(h), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
+{"type", "", SROFFSET(type), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, 0},
+{"flags", "", SROFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, 1, 0, "flags"},
+{"forced", "", SROFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, 1, 0},
+{NULL},
+};
+
+static const AVClass av_subtitle_rect_class = {
+    .class_name             = "AVSubtitleRect",
+    .item_name              = NULL,
+    .option                 = subtitle_rect_options,
+    .version                = LIBAVUTIL_VERSION_INT,
+};
+
+const AVClass *avcodec_get_subtitle_rect_class(void)
+{
+    return &av_subtitle_rect_class;
+}
\ No newline at end of file
diff --git a/lib/ffmpeg/libavcodec/pgssubdec.c b/lib/ffmpeg/libavcodec/pgssubdec.c
index 02e650acbc..83d7f43e67 100644
--- a/lib/ffmpeg/libavcodec/pgssubdec.c
+++ b/lib/ffmpeg/libavcodec/pgssubdec.c
@@ -29,6 +29,7 @@
 #include "bytestream.h"
 #include "libavutil/colorspace.h"
 #include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
 
 #define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
 
@@ -44,12 +45,14 @@ typedef struct PGSSubPictureReference {
     int x;
     int y;
     int picture_id;
+    int composition;
 } PGSSubPictureReference;
 
 typedef struct PGSSubPresentation {
     int                    id_number;
     int                    object_count;
     PGSSubPictureReference *objects;
+    int64_t pts;
 } PGSSubPresentation;
 
 typedef struct PGSSubPicture {
@@ -61,10 +64,11 @@ typedef struct PGSSubPicture {
 } PGSSubPicture;
 
 typedef struct PGSSubContext {
+    AVClass *class;
     PGSSubPresentation presentation;
     uint32_t           clut[256];
     PGSSubPicture      pictures[UINT16_MAX];
-    int64_t            pts;
+    int forced_subs_only;
 } PGSSubContext;
 
 static av_cold int init_decoder(AVCodecContext *avctx)
@@ -284,10 +288,10 @@ static void parse_palette_segment(AVCodecContext *avctx,
  * @param buf pointer to the packet to process
  * @param buf_size size of packet to process
  * @todo TODO: Implement cropping
- * @todo TODO: Implement forcing of subtitles
  */
 static void parse_presentation_segment(AVCodecContext *avctx,
-                                       const uint8_t *buf, int buf_size)
+                                       const uint8_t *buf, int buf_size,
+                                       int64_t pts)
 {
     PGSSubContext *ctx = avctx->priv_data;
 
@@ -296,6 +300,8 @@ static void parse_presentation_segment(AVCodecContext *avctx,
 
     uint16_t object_index;
 
+    ctx->presentation.pts = pts;
+
     av_dlog(avctx, "Video Dimensions %dx%d\n",
             w, h);
     if (av_image_check_size(w, h, 0, avctx) >= 0)
@@ -336,12 +342,10 @@ static void parse_presentation_segment(AVCodecContext *avctx,
         PGSSubPictureReference *reference = &ctx->presentation.objects[object_index];
         reference->picture_id             = bytestream_get_be16(&buf);
 
-         /*
-         * Skip 2 bytes of unknown:
-         *     window_id_ref,
-         *     composition_flag (0x80 - object cropped, 0x40 - object forced)
-         */
-        buf += 2;
+        /* Skip window_id_ref */
+        buf++;
+        /* composition_flag (0x80 - object cropped, 0x40 - object forced) */
+        reference->composition = bytestream_get_byte(&buf);
 
         reference->x = bytestream_get_be16(&buf);
         reference->y = bytestream_get_be16(&buf);
@@ -388,10 +392,10 @@ static int display_end_segment(AVCodecContext *avctx, void *data,
      *      not been cleared by a subsequent empty display command.
      */
 
-    pts = ctx->pts != AV_NOPTS_VALUE ? ctx->pts : sub->pts;
+    pts = ctx->presentation.pts != AV_NOPTS_VALUE ? ctx->presentation.pts : sub->pts;
     memset(sub, 0, sizeof(*sub));
     sub->pts = pts;
-    ctx->pts = AV_NOPTS_VALUE;
+    ctx->presentation.pts = AV_NOPTS_VALUE;
 
     // Blank if last object_count was 0.
     if (!ctx->presentation.object_count)
@@ -427,6 +431,10 @@ static int display_end_segment(AVCodecContext *avctx, void *data,
         sub->rects[rect]->nb_colors    = 256;
         sub->rects[rect]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
 
+        /* Copy the forced flag */
+        sub->rects[rect]->flags = (ctx->presentation.objects[rect].composition & 0x40) != 0 ? AV_SUBTITLE_FLAG_FORCED : 0;
+
+        if (!ctx->forced_subs_only || ctx->presentation.objects[rect].composition & 0x40)
         memcpy(sub->rects[rect]->pict.data[1], ctx->clut, sub->rects[rect]->nb_colors * sizeof(uint32_t));
     }
 
@@ -436,7 +444,6 @@ static int display_end_segment(AVCodecContext *avctx, void *data,
 static int decode(AVCodecContext *avctx, void *data, int *data_size,
                   AVPacket *avpkt)
 {
-    PGSSubContext *ctx = avctx->priv_data;
     const uint8_t *buf = avpkt->data;
     int buf_size       = avpkt->size;
     AVSubtitle *sub    = data;
@@ -483,8 +490,7 @@ static int decode(AVCodecContext *avctx, void *data, int *data_size,
             parse_picture_segment(avctx, buf, segment_length);
             break;
         case PRESENTATION_SEGMENT:
-            parse_presentation_segment(avctx, buf, segment_length);
-            ctx->pts = sub->pts;
+            parse_presentation_segment(avctx, buf, segment_length, sub->pts);
             break;
         case WINDOW_SEGMENT:
             /*
@@ -511,6 +517,20 @@ static int decode(AVCodecContext *avctx, void *data, int *data_size,
     return buf_size;
 }
 
+#define OFFSET(x) offsetof(PGSSubContext, x)
+#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
+static const AVOption options[] = {
+    {"forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
+    { NULL },
+};
+
+static const AVClass pgsdec_class = {
+    .class_name = "PGS subtitle decoder",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
 AVCodec ff_pgssub_decoder = {
     .name           = "pgssub",
     .type           = AVMEDIA_TYPE_SUBTITLE,
@@ -519,5 +539,6 @@ AVCodec ff_pgssub_decoder = {
     .init           = init_decoder,
     .close          = close_decoder,
     .decode         = decode,
-    .long_name = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"),
-};
+    .long_name      = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"),
+    .priv_class     = &pgsdec_class,
+};
\ No newline at end of file