hevc: ppc: Add HEVC 4x4 IDCT for PowerPC

Signed-off-by: Diego Biurrun <diego@biurrun.de>

libavcodec/hevcdsp.c

@@ -245,6 +245,8 @@ void ff_hevc_dsp_init(HEVCDSPContext *hevcdsp, int bit_depth)
         break;
     }
 
+    if (ARCH_PPC)
+        ff_hevc_dsp_init_ppc(hevcdsp, bit_depth);
     if (ARCH_X86)
         ff_hevc_dsp_init_x86(hevcdsp, bit_depth);
 }

libavcodec/hevcdsp.h

@@ -115,6 +115,7 @@ typedef struct HEVCDSPContext {
 
 void ff_hevc_dsp_init(HEVCDSPContext *hpc, int bit_depth);
 
+void ff_hevc_dsp_init_ppc(HEVCDSPContext *c, const int bit_depth);
 void ff_hevc_dsp_init_x86(HEVCDSPContext *c, const int bit_depth);
 
 extern const int16_t ff_hevc_epel_coeffs[7][16];

libavcodec/ppc/Makefile

@@ -25,6 +25,7 @@ OBJS-$(CONFIG_VP8DSP)                  += ppc/vp8dsp_altivec.o
 
 # decoders/encoders
 OBJS-$(CONFIG_APE_DECODER)             += ppc/apedsp_altivec.o
+OBJS-$(CONFIG_HEVC_DECODER)            += ppc/hevcdsp.o
 OBJS-$(CONFIG_SVQ1_ENCODER)            += ppc/svq1enc_altivec.o
 OBJS-$(CONFIG_VORBIS_DECODER)          += ppc/vorbisdsp_altivec.o
 OBJS-$(CONFIG_VP7_DECODER)             += ppc/vp8dsp_altivec.o

libavcodec/ppc/hevcdsp.c

@@ -0,0 +1,108 @@
+/* SIMD-optimized IDCT functions for HEVC decoding
+ * Copyright (c) Alexandra Hajkova
+ *
+ * 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"
+#if HAVE_ALTIVEC_H
+#include <altivec.h>
+#endif
+
+#include "libavutil/cpu.h"
+#include "libavutil/ppc/cpu.h"
+#include "libavutil/ppc/types_altivec.h"
+#include "libavutil/ppc/util_altivec.h"
+
+#include "libavcodec/hevcdsp.h"
+
+#if HAVE_ALTIVEC
+static const vector int16_t trans4[4] = {
+    { 64,  64, 64,  64, 64,  64, 64,  64 },
+    { 83,  36, 83,  36, 83,  36, 83,  36 },
+    { 64, -64, 64, -64, 64, -64, 64, -64 },
+    { 36, -83, 36, -83, 36, -83, 36, -83 },
+};
+
+static const vec_u8 mask[2] = {
+    { 0x00, 0x01, 0x08, 0x09, 0x10, 0x11, 0x18, 0x19, 0x02, 0x03, 0x0A, 0x0B, 0x12, 0x13, 0x1A, 0x1B },
+    { 0x04, 0x05, 0x0C, 0x0D, 0x14, 0x15, 0x1C, 0x1D, 0x06, 0x07, 0x0E, 0x0F, 0x16, 0x17, 0x1E, 0x1F },
+};
+
+static void transform4x4(vector int16_t src_01, vector int16_t src_23,
+                         vector int32_t res[4], const int shift, int16_t *coeffs)
+{
+    vector int16_t src_02, src_13;
+    vector int32_t zero = vec_splat_s32(0);
+    vector int32_t e0, o0, e1, o1;
+    vector int32_t add;
+
+    src_13 = vec_mergel(src_01, src_23);
+    src_02 = vec_mergeh(src_01, src_23);
+
+    e0 = vec_msums(src_02, trans4[0], zero);
+    o0 = vec_msums(src_13, trans4[1], zero);
+    e1 = vec_msums(src_02, trans4[2], zero);
+    o1 = vec_msums(src_13, trans4[3], zero);
+
+    add = vec_sl(vec_splat_s32(1), vec_splat_u32(shift - 1));
+    e0 = vec_add(e0, add);
+    e1 = vec_add(e1, add);
+
+    res[0] = vec_add(e0, o0);
+    res[1] = vec_add(e1, o1);
+    res[2] = vec_sub(e1, o1);
+    res[3] = vec_sub(e0, o0);
+}
+
+static void scale(vector int32_t res[4], vector int16_t res_packed[2], int shift)
+{
+    int i;
+    vector unsigned int v_shift = vec_splat_u32(shift);
+
+    for (i = 0; i < 4; i++)
+        res[i] = vec_sra(res[i], v_shift);
+
+    // clip16
+    res_packed[0] = vec_packs(res[0], res[1]);
+    res_packed[1] = vec_packs(res[2], res[3]);
+}
+
+#define FUNCDECL(a, depth) a ## _ ## depth ## _altivec
+#define FUNC(a, b) FUNCDECL(a, b)
+
+#define BIT_DEPTH 8
+#include "hevcdsp_template.c"
+#undef BIT_DEPTH
+
+#define BIT_DEPTH 10
+#include "hevcdsp_template.c"
+#undef BIT_DEPTH
+#endif /* HAVE_ALTIVEC */
+
+av_cold void ff_hevc_dsp_init_ppc(HEVCDSPContext *c, const int bit_depth)
+{
+#if HAVE_ALTIVEC
+    if (!PPC_ALTIVEC(av_get_cpu_flags()))
+        return;
+
+    if (bit_depth == 8)
+        c->idct[0] = ff_hevc_idct_4x4_8_altivec;
+    if (bit_depth == 10)
+        c->idct[0] = ff_hevc_idct_4x4_10_altivec;
+#endif /* HAVE_ALTIVEC */
+}

libavcodec/ppc/hevcdsp_template.c

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) Alexandra Hajkova
+ *
+ * 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
+ */
+
+static void FUNC(ff_hevc_idct_4x4, BIT_DEPTH)(int16_t *coeffs, int col_limit)
+{
+    const int shift = 7;
+    const int shift2 = 20 - BIT_DEPTH;
+    vector int16_t src_01, src_23;
+    vector int32_t res[4];
+    vector int16_t res_packed[2];
+
+    src_01 = vec_ld(0, coeffs);
+    src_23 = vec_ld(16, coeffs);
+
+    transform4x4(src_01, src_23, res, shift, coeffs);
+    src_01 = vec_packs(res[0], res[1]);
+    src_23 = vec_packs(res[2], res[3]);
+    scale(res, res_packed, shift);
+    // transpose
+    src_01 = vec_perm(res_packed[0], res_packed[1], mask[0]);
+    src_23 = vec_perm(res_packed[0], res_packed[1], mask[1]);
+
+    transform4x4(src_01, src_23, res, shift2, coeffs);
+    scale(res, res_packed, shift2);
+    // transpose
+    src_01 = vec_perm(res_packed[0], res_packed[1], mask[0]);
+    src_23 = vec_perm(res_packed[0], res_packed[1], mask[1]);
+
+    vec_st(src_01, 0, coeffs);
+    vec_st(src_23, 16, coeffs);
+}