From: Michael Niedermayer <[email protected]>

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 <[email protected]>

Conflicts:

        libavcodec/j2k.c
        libavcodec/j2k.h
        libavcodec/j2kdec.c
        libavcodec/j2kenc.c
---
 libavcodec/jpeg2000.c    |   17 +++++++++++++----
 libavcodec/jpeg2000.h    |    6 ++----
 libavcodec/jpeg2000dec.c |   25 +++++++++++++------------
 3 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/libavcodec/jpeg2000.c b/libavcodec/jpeg2000.c
index 57242d8..12acfe3 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);
 }
diff --git a/libavcodec/jpeg2000.h b/libavcodec/jpeg2000.h
index d78ed56..bf0a824 100644
--- a/libavcodec/jpeg2000.h
+++ b/libavcodec/jpeg2000.h
@@ -192,13 +192,11 @@ typedef struct Jpeg2000ResLevel {
     Jpeg2000Band *band;
 } Jpeg2000ResLevel; // resolution level
 
-/* TODO: data can be float of integer depending of reversible/irreversible
- * transformation.
- */
 typedef struct Jpeg2000Component {
     Jpeg2000ResLevel *reslevel;
     DWTContext dwt;
-    float *data;
+    float *f_data;
+    int *i_data;
     uint16_t coord[2][2];   // border coordinates {{x0, x1}, {y0, y1}} -- can 
be reduced with lowres option
     uint16_t coord_o[2][2]; // border coordinates {{x0, x1}, {y0, y1}} -- 
original values from jpeg2000 headers
 } Jpeg2000Component;
diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 9d40a4e..3e32b02 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -925,7 +925,7 @@ static void dequantization_float(int x, int y, Jpeg2000Cblk 
*cblk,
                                  Jpeg2000T1Context *t1, Jpeg2000Band *band)
 {
     int i, j, idx;
-    float *datap = &comp->data[(comp->coord[0][1] - comp->coord[0][0]) * y + 
x];
+    float *datap = &comp->f_data[(comp->coord[0][1] - comp->coord[0][0]) * y + 
x];
     for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j)
         for (i = 0; i < (cblk->coord[0][1] - cblk->coord[0][0]); ++i) {
             idx        = (comp->coord[0][1] - comp->coord[0][0]) * j + i;
@@ -939,8 +939,7 @@ static void dequantization_int(int x, int y, Jpeg2000Cblk 
*cblk,
                                Jpeg2000T1Context *t1, Jpeg2000Band *band)
 {
     int i, j, idx;
-    int32_t *datap =
-        (int32_t *) &comp->data[(comp->coord[0][1] - comp->coord[0][0]) * y + 
x];
+    int32_t *datap = &comp->i_data[(comp->coord[0][1] - comp->coord[0][0]) * y 
+ x];
     for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j)
         for (i = 0; i < (cblk->coord[0][1] - cblk->coord[0][0]); ++i) {
             idx        = (comp->coord[0][1] - comp->coord[0][0]) * j + i;
@@ -972,9 +971,9 @@ static void mct_decode(Jpeg2000DecoderContext *s, 
Jpeg2000Tile *tile)
 
     for (i = 0; i < 3; i++)
         if (tile->codsty[0].transform == FF_DWT97)
-            srcf[i] = tile->comp[i].data;
+            srcf[i] = tile->comp[i].f_data;
         else
-            src[i] = (int32_t *)tile->comp[i].data;
+            src [i] = tile->comp[i].i_data;
 
     for (i = 0; i < 2; i++)
         csize *= tile->comp[0].coord[i][1] - tile->comp[0].coord[i][0];
@@ -1065,21 +1064,23 @@ static int jpeg2000_decode_tile(Jpeg2000DecoderContext 
*s, Jpeg2000Tile *tile,
         } /* end reslevel */
 
         /* inverse DWT */
-        ff_dwt_decode(&comp->dwt, comp->data);
+        ff_dwt_decode(&comp->dwt, codsty->transform == FF_DWT97 ? 
(void*)comp->f_data : (void*)comp->i_data);
     } /*end comp */
 
     /* inverse MCT transformation */
     if (tile->codsty[0].mct)
         mct_decode(s, tile);
 
-    if (s->avctx->pix_fmt == AV_PIX_FMT_BGRA) // RGBA -> BGRA
-        FFSWAP(float *, tile->comp[0].data, tile->comp[2].data);
+    if (s->avctx->pix_fmt == AV_PIX_FMT_BGRA) { // RGBA -> BGRA
+        FFSWAP(float *, tile->comp[0].f_data, tile->comp[2].f_data);
+        FFSWAP(int *, tile->comp[0].i_data, tile->comp[2].i_data);
+    }
 
     if (s->precision <= 8) {
         for (compno = 0; compno < s->ncomponents; compno++) {
             Jpeg2000Component *comp = tile->comp + compno;
-            float *datap = comp->data;
-            int32_t *i_datap = (int32_t *) comp->data;
+            float *datap = comp->f_data;
+            int32_t *i_datap = comp->i_data;
             y    = tile->comp[compno].coord[1][0] - s->image_offset_y;
             line = picture->data[0] + y * picture->linesize[0];
             for (; y < tile->comp[compno].coord[1][1] - s->image_offset_y; y 
+= s->cdy[compno]) {
@@ -1107,8 +1108,8 @@ static int jpeg2000_decode_tile(Jpeg2000DecoderContext 
*s, Jpeg2000Tile *tile,
     } else {
         for (compno = 0; compno < s->ncomponents; compno++) {
             Jpeg2000Component *comp = tile->comp + compno;
-            float *datap = comp->data;
-            int32_t *i_datap = (int32_t *) comp->data;
+            float *datap = comp->f_data;
+            int32_t *i_datap = comp->i_data;
             uint16_t *linel;
 
             y     = tile->comp[compno].coord[1][0] - s->image_offset_y;
-- 
1.7.9.5

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