j2k/jpeg2000: split data pointer in int & float.

This fixes a TODO item and unifies both decoders structures
It also fixes undefined behavior due to aliasing violations

I choose 2 fields instead of a union because mistakely using the
wrong type with a union will lead to hard to debug "wrong output"
while with 2 fields mistakely using the wrong type will crash
with a null pointer derefernce which is much easier to debug

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 13 insertions, 4 deletions

diff --git a/libavcodec/jpeg2000.c b/libavcodec/jpeg2000.c
index bcbb25c806..62b6874a96 100644
--- a/libavcodec/jpeg2000.c
+++ b/libavcodec/jpeg2000.c
@@ -200,9 +200,17 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
     csize = (comp->coord[0][1] - comp->coord[0][0]) *
             (comp->coord[1][1] - comp->coord[1][0]);
 
-    comp->data = av_malloc_array(csize, sizeof(*comp->data));
-    if (!comp->data)
-        return AVERROR(ENOMEM);
+    if (codsty->transform == FF_DWT97) {
+        comp->i_data = NULL;
+        comp->f_data = av_malloc_array(csize, sizeof(*comp->f_data));
+        if (!comp->f_data)
+            return AVERROR(ENOMEM);
+    } else {
+        comp->f_data = NULL;
+        comp->i_data = av_malloc_array(csize, sizeof(*comp->i_data));
+        if (!comp->i_data)
+            return AVERROR(ENOMEM);
+    }
     comp->reslevel = av_malloc_array(codsty->nreslevels, sizeof(*comp->reslevel));
     if (!comp->reslevel)
         return AVERROR(ENOMEM);
@@ -470,5 +478,6 @@ void ff_jpeg2000_cleanup(Jpeg2000Component *comp, Jpeg2000CodingStyle *codsty)
 
     ff_dwt_destroy(&comp->dwt);
     av_freep(&comp->reslevel);
-    av_freep(&comp->data);
+    av_freep(&comp->i_data);
+    av_freep(&comp->f_data);
 }