Add a float DSP framework to libavutil

Move vector_fmul() from DSPContext to AVFloatDSPContext.

libavutil/float_dsp.h

@@ -0,0 +1,53 @@
+/*
+ * 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
+ */
+
+#ifndef AVUTIL_FLOAT_DSP_H
+#define AVUTIL_FLOAT_DSP_H
+
+typedef struct AVFloatDSPContext {
+    /**
+     * Calculate the product of two vectors of floats and store the result in
+     * a vector of floats.
+     *
+     * @param dst  output vector
+     *             constraints: 32-byte aligned
+     * @param src0 first input vector
+     *             constraints: 32-byte aligned
+     * @param src1 second input vector
+     *             constraints: 32-byte aligned
+     * @param len  number of elements in the input
+     *             constraints: multiple of 16
+     */
+    void (*vector_fmul)(float *dst, const float *src0, const float *src1,
+                        int len);
+} AVFloatDSPContext;
+
+/**
+ * Initialize a float DSP context.
+ *
+ * @param fdsp    float DSP context
+ * @param strict  setting to non-zero avoids using functions which may not be IEEE-754 compliant
+ */
+void avpriv_float_dsp_init(AVFloatDSPContext *fdsp, int strict);
+
+
+void ff_float_dsp_init_arm(AVFloatDSPContext *fdsp);
+void ff_float_dsp_init_ppc(AVFloatDSPContext *fdsp, int strict);
+void ff_float_dsp_init_x86(AVFloatDSPContext *fdsp);
+
+#endif /* AVUTIL_FLOAT_DSP_H */