[FFmpeg-devel,2/8] avcodec/texturedsp: add TextureDSPThreadContext for common decode/encode function

diff --git a/libavcodec/texturedsp.c b/libavcodec/texturedsp.c
index b7dd8baa12..b8938213ef 100644
--- a/libavcodec/texturedsp.c
+++ b/libavcodec/texturedsp.c
@@ -652,3 +652,7 @@  av_cold void ff_texturedsp_init(TextureDSPContext *c)
     c->rgtc2u_block       = rgtc2u_block;
     c->dxn3dc_block       = dxn3dc_block;
 }
+
+#define TEXTUREDSP_FUNC_NAME ff_texturedsp_decompress_thread
+#define TEXTUREDSP_TEX_FUNC(a, b, c) tex_funct(a, b, c)
+#include "texturedsp_template.c"
diff --git a/libavcodec/texturedsp.h b/libavcodec/texturedsp.h
index 90ceb2b6aa..e15d3c2b02 100644
--- a/libavcodec/texturedsp.h
+++ b/libavcodec/texturedsp.h
@@ -39,6 +39,8 @@ 
 #include <stddef.h>
 #include <stdint.h>
 
+#include "avcodec.h"
+
 #define TEXTURE_BLOCK_W 4
 #define TEXTURE_BLOCK_H 4
 
@@ -60,7 +62,28 @@  typedef struct TextureDSPContext {
     int (*dxn3dc_block)      (uint8_t *dst, ptrdiff_t stride, const uint8_t *block);
 } TextureDSPContext;
 
+typedef struct TextureDSPThreadContext {
+    union {
+        const uint8_t *in;       // Input frame data
+        uint8_t *out;            // Output frame data
+    } frame_data;
+    ptrdiff_t stride;            // Frame linesize
+    union {
+        const uint8_t *in;       // Compressed texture for decompression
+        uint8_t *out;            // Compressed texture of compression
+    } tex_data;
+    int tex_ratio;               // Number of compressed bytes in a texture block
+    int raw_ratio;               // Number bytes in a line of a raw block
+    int slice_count;             // Number of slices for threaded operations
+
+    /* Pointer to the selected compress or decompress function. */
+    int (*tex_funct)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block);
+} TextureDSPThreadContext;
+
 void ff_texturedsp_init(TextureDSPContext *c);
 void ff_texturedspenc_init(TextureDSPContext *c);
 
+int ff_texturedsp_decompress_thread(AVCodecContext *avctx, void *arg, int slice, int thread_nb);
+int ff_texturedsp_compress_thread(AVCodecContext *avctx, void *arg, int slice, int thread_nb);
+
 #endif /* AVCODEC_TEXTUREDSP_H */
diff --git a/libavcodec/texturedsp_template.c b/libavcodec/texturedsp_template.c
new file mode 100644
index 0000000000..bd193aa97c
--- /dev/null
+++ b/libavcodec/texturedsp_template.c
@@ -0,0 +1,57 @@ 
+/*
+ * Texture block compression and decompression
+ * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@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
+ *
+ */
+
+int TEXTUREDSP_FUNC_NAME(AVCodecContext *avctx, void *arg,
+                         int slice, int thread_nb)
+{
+    TextureDSPThreadContext *ctx = arg;
+    uint8_t *d = ctx->tex_data.out;
+    int w_block = avctx->coded_width / TEXTURE_BLOCK_W;
+    int h_block = avctx->coded_height / TEXTURE_BLOCK_H;
+    int x, y;
+    int start_slice, end_slice;
+    int base_blocks_per_slice = h_block / ctx->slice_count;
+    int remainder_blocks = h_block % ctx->slice_count;
+
+    /* When the frame height (in blocks) doesn't divide evenly between the
+     * number of slices, spread the remaining blocks evenly between the first
+     * operations */
+    start_slice = slice * base_blocks_per_slice;
+    /* Add any extra blocks (one per slice) that have been added before this slice */
+    start_slice += FFMIN(slice, remainder_blocks);
+
+    end_slice = start_slice + base_blocks_per_slice;
+    /* Add an extra block if there are still remainder blocks to be accounted for */
+    if (slice < remainder_blocks)
+        end_slice++;
+
+    for (y = start_slice; y < end_slice; y++) {
+        uint8_t *p = ctx->frame_data.out + y * ctx->stride * TEXTURE_BLOCK_H;
+        int off = y * w_block;
+        for (x = 0; x < w_block; x++) {
+            ctx->TEXTUREDSP_TEX_FUNC(p + x * ctx->raw_ratio, ctx->stride,
+                                     d + (off + x) * ctx->tex_ratio);
+        }
+    }
+
+    return 0;
+}
diff --git a/libavcodec/texturedspenc.c b/libavcodec/texturedspenc.c
index 3d68e0cf39..381be16f75 100644
--- a/libavcodec/texturedspenc.c
+++ b/libavcodec/texturedspenc.c
@@ -670,3 +670,7 @@  av_cold void ff_texturedspenc_init(TextureDSPContext *c)
     c->dxt5ys_block       = dxt5ys_block;
     c->rgtc1u_alpha_block = rgtc1u_alpha_block;
 }
+
+#define TEXTUREDSP_FUNC_NAME ff_texturedsp_compress_thread
+#define TEXTUREDSP_TEX_FUNC(a, b, c) tex_funct(c, b, a)
+#include "texturedsp_template.c"