[FFmpeg-devel] [PATCH 16/28] dvdsub hacks

[Mans Rullgard]

From: Cory Fields <theuni-nospam- at xbmc.org>

---
 libavcodec/dvdsubdec.c |   99 ++++++++++++++++++++++++++++++++++++++++++-----
 1 files changed, 88 insertions(+), 11 deletions(-)

diff --git a/libavcodec/dvdsubdec.c b/libavcodec/dvdsubdec.c
index 75b5256..a75aae0 100644
--- a/libavcodec/dvdsubdec.c
+++ b/libavcodec/dvdsubdec.c
@@ -25,6 +25,14 @@
 
 //#define DEBUG
 
+typedef struct DVDSubContext
+{
+  uint8_t  colormap[4];
+  uint8_t  alpha[4];
+  uint32_t palette[16];
+  int      has_palette;
+} DVDSubContext;
+
 static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *rgba, int num_values)
 {
     uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
@@ -42,6 +50,24 @@ static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *
     }
 }
 
+static void ayvu_to_argb(const uint8_t *ayvu, uint32_t *argb, int num_values)
+{
+    uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
+    uint8_t r, g, b;
+    int i, y, cb, cr, a;
+    int r_add, g_add, b_add;
+
+    for (i = num_values; i > 0; i--) {
+        a = *ayvu++;
+        y = *ayvu++;
+        cr = *ayvu++;
+        cb = *ayvu++;
+        YUV_TO_RGB1_CCIR(cb, cr);
+        YUV_TO_RGB2_CCIR(r, g, b, y);
+        *argb++ = (a << 24) | (r << 16) | (g << 8) | b;
+    }
+}
+
 static int decode_run_2bit(GetBitContext *gb, int *color)
 {
     unsigned int v, t;
@@ -115,13 +141,21 @@ static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,
     return 0;
 }
 
-static void guess_palette(uint32_t *rgba_palette,
-                          uint8_t *colormap,
-                          uint8_t *alpha,
-                          uint32_t subtitle_color)
+static void fill_palette(DVDSubContext* ctx,
+                         uint32_t *rgba_palette,
+                         uint32_t subtitle_color)
 {
     uint8_t color_used[16];
     int nb_opaque_colors, i, level, j, r, g, b;
+    uint8_t *colormap = ctx->colormap;
+    uint8_t *alpha = ctx->alpha;
+
+    if(ctx->has_palette) {
+        for(i = 0; i < 4; i++)
+            rgba_palette[i] = (ctx->palette[ctx->colormap[i]] & 0x00ffffff)
+                              | ((alpha[i] * 17) << 24);
+        return;
+    }
 
     for(i = 0; i < 4; i++)
         rgba_palette[i] = 0;
@@ -160,13 +194,14 @@ static void guess_palette(uint32_t *rgba_palette,
 
 #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
 
-static int decode_dvd_subtitles(AVSubtitle *sub_header,
+static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
                                 const uint8_t *buf, int buf_size)
 {
     int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
     int big_offsets, offset_size, is_8bit = 0;
     const uint8_t *yuv_palette = 0;
-    uint8_t colormap[4], alpha[256];
+    uint8_t *colormap = ctx->colormap;
+    uint8_t *alpha = ctx->alpha;
     int date;
     int i;
     int is_menu = 0;
@@ -326,8 +361,7 @@ static int decode_dvd_subtitles(AVSubtitle *sub_header,
                     yuv_a_to_rgba(yuv_palette, alpha, (uint32_t*)sub_header->rects[0]->pict.data[1], 256);
                 } else {
                     sub_header->rects[0]->nb_colors = 4;
-                    guess_palette((uint32_t*)sub_header->rects[0]->pict.data[1],
-                                  colormap, alpha, 0xffff00);
+                    fill_palette(ctx, sub_header->rects[0]->pict.data[1], 0xffff00);
                 }
                 sub_header->rects[0]->x = x1;
                 sub_header->rects[0]->y = y1;
@@ -458,12 +492,13 @@ static int dvdsub_decode(AVCodecContext *avctx,
                          void *data, int *data_size,
                          AVPacket *avpkt)
 {
+    DVDSubContext *ctx = (DVDSubContext*) avctx->priv_data;
     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;
     AVSubtitle *sub = (void *)data;
     int is_menu;
 
-    is_menu = decode_dvd_subtitles(sub, buf, buf_size);
+    is_menu = decode_dvd_subtitles(ctx, sub, buf, buf_size);
 
     if (is_menu < 0) {
     no_subtitle:
@@ -486,12 +521,54 @@ static int dvdsub_decode(AVCodecContext *avctx,
     return buf_size;
 }
 
+static int dvdsub_init(AVCodecContext *avctx)
+{
+    DVDSubContext *ctx = (DVDSubContext*) avctx->priv_data;
+    char *data = avctx->extradata;
+
+    if (!avctx->extradata || !avctx->extradata_size)
+        return 1;
+
+    data[avctx->extradata_size] = '\0';
+
+    for(;;) {
+        int pos = strcspn(data, "\n\r");
+        if (pos==0 && *data==0)
+            break;
+
+        if (strncmp("palette:", data, 8) == 0) {
+            int i;
+            char *p = data+8;
+            ctx->has_palette = 1;
+            for(i=0;i<16;i++) {
+                ctx->palette[i] = strtoul(p, &p, 16);
+                while(*p == ',' || isspace(*p))
+                    p++;
+            }
+#if defined(DEBUG)
+            av_log(avctx, AV_LOG_INFO, "palette:");
+            for(i=0;i<16;i++)
+                av_log(avctx, AV_LOG_WARNING, " 0x%06x", ctx->palette[i]);
+            av_log(avctx, AV_LOG_INFO, "\n");
+#endif
+        }
+
+        data += pos;
+        data += strspn(data, "\n\r");
+    }
+
+    if(!ctx->has_palette && avctx->extradata_size == 64)
+        ayvu_to_argb((uint8_t*)avctx->extradata, ctx->palette, 16);
+
+    return 1;
+}
+
 AVCodec dvdsub_decoder = {
     "dvdsub",
     AVMEDIA_TYPE_SUBTITLE,
     CODEC_ID_DVD_SUBTITLE,
-    0,
-    NULL,
+    sizeof(DVDSubContext),
+    dvdsub_init,
     NULL,
     NULL,
     dvdsub_decode,
-- 
1.7.1.1