[FFmpeg-devel] [PATCH]Implement Bluray subtitle forcing

[Carl Eugen Hoyos]

On Sunday 29 January 2012 05:46:13 pm Reimar Döffinger wrote:
> On Sun, Jan 29, 2012 at 04:42:04PM +0000, Carl Eugen Hoyos wrote:
> > Reimar Döffinger <Reimar.Doeffinger <at> gmx.de> writes:
> > > > +        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));
> > >
> > > Well, I'd be in favour of having some flags in sub->rects, but
> > > I think that would mean an API/ABI change...
> >
> > So may I commit?
> 
> I don't know if the patch is correct otherwise, I don't use
> the option code usually.
> I don't really see why you need the AVCodecContext in the struct
> for example.

I thought it is needed, but it seems I was wrong.

New patch attached.

Please comment, Carl Eugen
-------------- next part --------------
diff --git a/libavcodec/pgssubdec.c b/libavcodec/pgssubdec.c
index 2785d25..e9c1b0e 100644
--- a/libavcodec/pgssubdec.c
+++ b/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))
 
@@ -44,6 +45,7 @@ typedef struct PGSSubPictureReference {
     int x;
     int y;
     int picture_id;
+    int composition;
 } PGSSubPictureReference;
 
 typedef struct PGSSubPresentation {
@@ -61,9 +63,11 @@ typedef struct PGSSubPicture {
 } PGSSubPicture;
 
 typedef struct PGSSubContext {
+    AVClass *class;
     PGSSubPresentation presentation;
     uint32_t           clut[256];
     PGSSubPicture      pictures[UINT16_MAX];
+    int forced_subs_only;
 } PGSSubContext;
 
 static av_cold int init_decoder(AVCodecContext *avctx)
@@ -283,7 +287,6 @@ 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)
@@ -335,12 +338,10 @@ 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);
@@ -422,6 +423,7 @@ 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);
 
+        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));
     }
 
@@ -503,6 +505,20 @@ 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, {.dbl = 0}, 0, 1, SD},
+    { NULL },
+};
+
+static const AVClass pgsdec_class = {
+    .class_name = "PGS subtitle decdoder",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
 AVCodec ff_pgssub_decoder = {
     .name           = "pgssub",
     .type           = AVMEDIA_TYPE_SUBTITLE,
@@ -512,4 +528,5 @@ AVCodec ff_pgssub_decoder = {
     .close          = close_decoder,
     .decode         = decode,
     .long_name = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"),
+    .priv_class     = &pgsdec_class,
 };