avcodec/pgssubdec: Use dedicated pointer for accesses

Improves readability and decreases codesize.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/pgssubdec.c

@@ -443,6 +443,7 @@ static int parse_presentation_segment(AVCodecContext *avctx,
 
     for (i = 0; i < ctx->presentation.object_count; i++)
     {
+        PGSSubObjectRef *const object = &ctx->presentation.objects[i];
 
         if (buf_end - buf < 8) {
             av_log(avctx, AV_LOG_ERROR, "Insufficent space for object\n");
@@ -450,32 +451,29 @@ static int parse_presentation_segment(AVCodecContext *avctx,
             return AVERROR_INVALIDDATA;
         }
 
-        ctx->presentation.objects[i].id = bytestream_get_be16(&buf);
-        ctx->presentation.objects[i].window_id = bytestream_get_byte(&buf);
-        ctx->presentation.objects[i].composition_flag = bytestream_get_byte(&buf);
+        object->id               = bytestream_get_be16(&buf);
+        object->window_id        = bytestream_get_byte(&buf);
+        object->composition_flag = bytestream_get_byte(&buf);
 
-        ctx->presentation.objects[i].x = bytestream_get_be16(&buf);
-        ctx->presentation.objects[i].y = bytestream_get_be16(&buf);
+        object->x = bytestream_get_be16(&buf);
+        object->y = bytestream_get_be16(&buf);
 
         // If cropping
-        if (ctx->presentation.objects[i].composition_flag & 0x80) {
-            ctx->presentation.objects[i].crop_x = bytestream_get_be16(&buf);
-            ctx->presentation.objects[i].crop_y = bytestream_get_be16(&buf);
-            ctx->presentation.objects[i].crop_w = bytestream_get_be16(&buf);
-            ctx->presentation.objects[i].crop_h = bytestream_get_be16(&buf);
+        if (object->composition_flag & 0x80) {
+            object->crop_x = bytestream_get_be16(&buf);
+            object->crop_y = bytestream_get_be16(&buf);
+            object->crop_w = bytestream_get_be16(&buf);
+            object->crop_h = bytestream_get_be16(&buf);
         }
 
         ff_dlog(avctx, "Subtitle Placement x=%d, y=%d\n",
-                ctx->presentation.objects[i].x, ctx->presentation.objects[i].y);
+                object->x, object->y);
 
-        if (ctx->presentation.objects[i].x > avctx->width ||
-            ctx->presentation.objects[i].y > avctx->height) {
+        if (object->x > avctx->width || object->y > avctx->height) {
             av_log(avctx, AV_LOG_ERROR, "Subtitle out of video bounds. x = %d, y = %d, video width = %d, video height = %d.\n",
-                   ctx->presentation.objects[i].x,
-                   ctx->presentation.objects[i].y,
+                   object->x, object->y,
                     avctx->width, avctx->height);
-            ctx->presentation.objects[i].x = 0;
-            ctx->presentation.objects[i].y = 0;
+            object->y = object->x = 0;
             if (avctx->err_recognition & AV_EF_EXPLODE) {
                 return AVERROR_INVALIDDATA;
             }
@@ -531,13 +529,13 @@ static int display_end_segment(AVCodecContext *avctx, void *data,
         return AVERROR_INVALIDDATA;
     }
     for (i = 0; i < ctx->presentation.object_count; i++) {
+        AVSubtitleRect *const rect = av_mallocz(sizeof(*rect));
         PGSSubObject *object;
 
-        sub->rects[i]  = av_mallocz(sizeof(*sub->rects[0]));
-        if (!sub->rects[i])
+        if (!rect)
             return AVERROR(ENOMEM);
-        sub->num_rects++;
-        sub->rects[i]->type = SUBTITLE_BITMAP;
+        sub->rects[sub->num_rects++] = rect;
+        rect->type = SUBTITLE_BITMAP;
 
         /* Process bitmap */
         object = find_object(ctx->presentation.objects[i].id, &ctx->objects);
@@ -551,16 +549,16 @@ static int display_end_segment(AVCodecContext *avctx, void *data,
             continue;
         }
         if (ctx->presentation.objects[i].composition_flag & 0x40)
-            sub->rects[i]->flags |= AV_SUBTITLE_FLAG_FORCED;
+            rect->flags |= AV_SUBTITLE_FLAG_FORCED;
 
-        sub->rects[i]->x    = ctx->presentation.objects[i].x;
-        sub->rects[i]->y    = ctx->presentation.objects[i].y;
+        rect->x    = ctx->presentation.objects[i].x;
+        rect->y    = ctx->presentation.objects[i].y;
 
         if (object->rle) {
-            sub->rects[i]->w    = object->w;
-            sub->rects[i]->h    = object->h;
+            rect->w    = object->w;
+            rect->h    = object->h;
 
-            sub->rects[i]->linesize[0] = object->w;
+            rect->linesize[0] = object->w;
 
             if (object->rle_remaining_len) {
                 av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n",
@@ -568,25 +566,25 @@ static int display_end_segment(AVCodecContext *avctx, void *data,
                 if (avctx->err_recognition & AV_EF_EXPLODE)
                     return AVERROR_INVALIDDATA;
             }
-            ret = decode_rle(avctx, sub->rects[i], object->rle, object->rle_data_len);
+            ret = decode_rle(avctx, rect, object->rle, object->rle_data_len);
             if (ret < 0) {
                 if ((avctx->err_recognition & AV_EF_EXPLODE) ||
                     ret == AVERROR(ENOMEM)) {
                     return ret;
                 }
-                sub->rects[i]->w = 0;
-                sub->rects[i]->h = 0;
+                rect->w = 0;
+                rect->h = 0;
                 continue;
             }
         }
         /* Allocate memory for colors */
-        sub->rects[i]->nb_colors    = 256;
-        sub->rects[i]->data[1] = av_mallocz(AVPALETTE_SIZE);
-        if (!sub->rects[i]->data[1])
+        rect->nb_colors = 256;
+        rect->data[1]   = av_mallocz(AVPALETTE_SIZE);
+        if (!rect->data[1])
             return AVERROR(ENOMEM);
 
         if (!ctx->forced_subs_only || ctx->presentation.objects[i].composition_flag & 0x40)
-        memcpy(sub->rects[i]->data[1], palette->clut, sub->rects[i]->nb_colors * sizeof(uint32_t));
+            memcpy(rect->data[1], palette->clut, rect->nb_colors * sizeof(uint32_t));
     }
     return 1;
 }