jpeg2000: Use separate fields for int and float codepaths

Split stepsize and data into int and float variants.
Eliminates a number of casts and simplifies spotting errors.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/jpeg2000.c

@@ -217,9 +217,17 @@ 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);
@@ -290,8 +298,8 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
                 /*TODO: Compute formula to implement. */
                 numbps = cbps +
                          lut_gain[codsty->transform == FF_DWT53][bandno + (reslevelno > 0)];
-                band->stepsize = (float)SHL(2048 + qntsty->mant[gbandno],
-                                            2 + numbps - qntsty->expn[gbandno]);
+                band->f_stepsize = SHL(2048 + qntsty->mant[gbandno],
+                                       2 + numbps - qntsty->expn[gbandno]);
                 break;
             case JPEG2000_QSTY_SE:
                 /* Exponent quantization step.
@@ -303,20 +311,20 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
                  * but it works (compared to OpenJPEG). Why?
                  * Further investigation needed. */
                 gain            = cbps;
-                band->stepsize  = pow(2.0, gain - qntsty->expn[gbandno]);
-                band->stepsize *= (float)qntsty->mant[gbandno] / 2048.0 + 1.0;
+                band->f_stepsize  = pow(2.0, gain - qntsty->expn[gbandno]);
+                band->f_stepsize *= qntsty->mant[gbandno] / 2048.0 + 1.0;
                 break;
             default:
-                band->stepsize = 0;
+                band->f_stepsize = 0;
                 av_log(avctx, AV_LOG_ERROR, "Unknown quantization format\n");
                 break;
             }
             /* FIXME: In openjepg code stespize = stepsize * 0.5. Why?
              * If not set output of entropic decoder is not correct. */
-            band->stepsize *= 0.5;
-            /* BITEXACT computing case --> convert to int */
-            if (avctx->flags & CODEC_FLAG_BITEXACT)
-                band->stepsize = (int32_t)(band->stepsize * (1 << 16));
+            if (!av_codec_is_encoder(avctx->codec))
+                band->f_stepsize *= 0.5;
+
+            band->i_stepsize = band->f_stepsize * (1 << 16);
 
             /* computation of tbx_0, tbx_1, tby_0, tby_1
              * see ISO/IEC 15444-1:2002 B.5 eq. B-15 and tbl B.1
@@ -491,5 +499,6 @@ 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);
 }

libavcodec/jpeg2000.h

@@ -178,12 +178,11 @@ typedef struct Jpeg2000Prec {
     uint16_t coord[2][2]; // border coordinates {{x0, x1}, {y0, y1}}
 } Jpeg2000Prec; // precinct
 
-/* TODO: stepsize can be float or integer depending on
- * reversible or irreversible transformation. */
 typedef struct Jpeg2000Band {
     uint16_t coord[2][2]; // border coordinates {{x0, x1}, {y0, y1}}
     uint16_t log2_cblk_width, log2_cblk_height;
-    float stepsize; // quantization stepsize
+    int i_stepsize; // quantization stepsize
+    float f_stepsize; // quantization stepsize
     Jpeg2000Prec *prec;
 } Jpeg2000Band; // subband
 
@@ -195,13 +194,11 @@ 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;

libavcodec/jpeg2000dec.c

@@ -990,11 +990,11 @@ 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;
-            datap[idx] = (float)(t1->data[j][i]) * ((float)band->stepsize);
+            datap[idx] = (float)(t1->data[j][i]) * band->f_stepsize;
         }
 }
 
@@ -1004,13 +1004,12 @@ 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;
             datap[idx] =
-                ((int32_t)(t1->data[j][i]) * ((int32_t)band->stepsize) + (1 << 15)) >> 16;
+                ((int32_t)(t1->data[j][i]) * band->i_stepsize + (1 << 15)) >> 16;
         }
 }
 
@@ -1037,9 +1036,9 @@ 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];
@@ -1129,21 +1128,23 @@ 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]) {
@@ -1171,8 +1172,8 @@ 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;