idct: Split off Xvid IDCT

The Xvid IDCT is only required to decode some Xvid-encoded MPEG-4 files,
so there is no point in having it as an unconditional part of idctdsp.

1 files changed, 63 insertions, 0 deletions

diff --git a/libavcodec/x86/xvididct_init.c b/libavcodec/x86/xvididct_init.c
new file mode 100644
index 0000000000..3112fb5e92
--- /dev/null
+++ b/libavcodec/x86/xvididct_init.c
@@ -0,0 +1,63 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "libavutil/attributes.h"
+#include "libavutil/cpu.h"
+#include "libavutil/x86/cpu.h"
+#include "libavcodec/idctdsp.h"
+#include "libavcodec/xvididct.h"
+#include "idct_xvid.h"
+#include "idctdsp.h"
+
+static const uint8_t idct_sse2_row_perm[8] = { 0, 4, 1, 5, 2, 6, 3, 7 };
+
+static av_cold void init_scantable_permutation_sse2(uint8_t *idct_permutation,
+                                                    enum idct_permutation_type perm_type)
+{
+    int i;
+
+    for (i = 0; i < 64; i++)
+        idct_permutation[i] = (i & 0x38) | idct_sse2_row_perm[i & 7];
+}
+
+av_cold void ff_xvididct_init_x86(IDCTDSPContext *c)
+{
+    int cpu_flags = av_get_cpu_flags();
+
+    if (INLINE_MMX(cpu_flags)) {
+        c->idct_put  = ff_idct_xvid_mmx_put;
+        c->idct_add  = ff_idct_xvid_mmx_add;
+        c->idct      = ff_idct_xvid_mmx;
+    }
+
+    if (INLINE_MMXEXT(cpu_flags)) {
+        c->idct_put  = ff_idct_xvid_mmxext_put;
+        c->idct_add  = ff_idct_xvid_mmxext_add;
+        c->idct      = ff_idct_xvid_mmxext;
+    }
+
+    if (INLINE_SSE2(cpu_flags)) {
+        c->idct_put  = ff_idct_xvid_sse2_put;
+        c->idct_add  = ff_idct_xvid_sse2_add;
+        c->idct      = ff_idct_xvid_sse2;
+        c->perm_type = FF_IDCT_PERM_SSE2;
+
+        init_scantable_permutation_sse2(c->idct_permutation, c->perm_type);
+    }
+}