swscale: re-enable gamma

+added gamma conversion to refactored code

1 files changed, 72 insertions, 0 deletions

diff --git a/libswscale/gamma.c b/libswscale/gamma.c
new file mode 100644
index 0000000000..d7470cb1c9
--- /dev/null
+++ b/libswscale/gamma.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2015 Pedro Arthur <bygrandao@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "swscale_internal.h"
+
+typedef struct GammaContext
+{
+    uint16_t *table;
+} GammaContext;
+
+// gamma_convert expects 16 bit rgb format
+// it writes directly in src slice thus it must be modifiable (done through cascade context)
+static int gamma_convert(SwsContext *c, SwsFilterDescriptor *desc, int sliceY, int sliceH)
+{
+    GammaContext *instance = desc->instance;
+    uint16_t *table = instance->table;
+    int srcW = desc->src->width;
+
+    int i;
+    for (i = 0; i < sliceH; ++i) {
+        uint8_t ** src = desc->src->plane[0].line;
+        int src_pos = sliceY+i - desc->src->plane[0].sliceY;
+
+        uint16_t *src1 = (uint16_t*)*(src+src_pos);
+        int j;
+        for (j = 0; j < srcW; ++j) {
+            uint16_t r = AV_RL16(src1 + j*4 + 0);
+            uint16_t g = AV_RL16(src1 + j*4 + 1);
+            uint16_t b = AV_RL16(src1 + j*4 + 2);
+
+            AV_WL16(src1 + j*4 + 0, table[r]);
+            AV_WL16(src1 + j*4 + 1, table[g]);
+            AV_WL16(src1 + j*4 + 2, table[b]);
+        }
+
+    }
+    return sliceH;
+}
+
+
+int ff_init_gamma_convert(SwsFilterDescriptor *desc, SwsSlice * src, uint16_t *table)
+{
+    GammaContext *li = av_malloc(sizeof(GammaContext));
+    if (!li)
+        return AVERROR(ENOMEM);
+    li->table = table;
+
+    desc->instance = li;
+    desc->src = src;
+    desc->dst = NULL;
+    desc->process = &gamma_convert;
+
+    return 0;
+}
+