lavc: APV decoder

libavcodec/apv_dsp.c

@@ -0,0 +1,136 @@
+/*
+ * 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 <stdint.h>
+
+#include "config.h"
+#include "libavutil/attributes.h"
+#include "libavutil/common.h"
+
+#include "apv.h"
+#include "apv_dsp.h"
+
+
+static const int8_t apv_trans_matrix[8][8] = {
+    {  64,  64,  64,  64,  64,  64,  64,  64 },
+    {  89,  75,  50,  18, -18, -50, -75, -89 },
+    {  84,  35, -35, -84, -84, -35,  35,  84 },
+    {  75, -18, -89, -50,  50,  89,  18, -75 },
+    {  64, -64, -64,  64,  64, -64, -64,  64 },
+    {  50, -89,  18,  75, -75, -18,  89, -50 },
+    {  35, -84,  84, -35, -35,  84, -84,  35 },
+    {  18, -50,  75, -89,  89, -75,  50, -18 },
+};
+
+static void apv_decode_transquant_c(void *output,
+                                    ptrdiff_t pitch,
+                                    const int16_t *input_flat,
+                                    const int16_t *qmatrix_flat,
+                                    int bit_depth,
+                                    int qp_shift)
+{
+    const int16_t (*input)[8]   = (const int16_t(*)[8])input_flat;
+    const int16_t (*qmatrix)[8] = (const int16_t(*)[8])qmatrix_flat;
+
+    int16_t scaled_coeff[8][8];
+    int32_t recon_sample[8][8];
+
+    // Dequant.
+    {
+        // Note that level_scale was already combined into qmatrix
+        // before we got here.
+        int bd_shift = bit_depth + 3 - 5;
+
+        for (int y = 0; y < 8; y++) {
+            for (int x = 0; x < 8; x++) {
+                int coeff = (((input[y][x] * qmatrix[y][x]) << qp_shift) +
+                             (1 << (bd_shift - 1))) >> bd_shift;
+
+                scaled_coeff[y][x] =
+                    av_clip(coeff, APV_MIN_TRANS_COEFF,
+                                   APV_MAX_TRANS_COEFF);
+            }
+        }
+    }
+
+    // Transform.
+    {
+        int32_t tmp[8][8];
+
+        // Vertical transform of columns.
+        for (int x = 0; x < 8; x++) {
+            for (int i = 0; i < 8; i++) {
+                int sum = 0;
+                for (int j = 0; j < 8; j++)
+                    sum += apv_trans_matrix[j][i] * scaled_coeff[j][x];
+                tmp[i][x] = sum;
+            }
+        }
+
+        // Renormalise.
+        for (int x = 0; x < 8; x++) {
+            for (int y = 0; y < 8; y++)
+                tmp[y][x] = (tmp[y][x] + 64) >> 7;
+        }
+
+        // Horizontal transform of rows.
+        for (int y = 0; y < 8; y++) {
+            for (int i = 0; i < 8; i++) {
+                int sum = 0;
+                for (int j = 0; j < 8; j++)
+                    sum += apv_trans_matrix[j][i] * tmp[y][j];
+                recon_sample[y][i] = sum;
+            }
+        }
+    }
+
+    // Output.
+    if (bit_depth == 8) {
+        uint8_t *ptr = output;
+        int bd_shift = 20 - bit_depth;
+
+        for (int y = 0; y < 8; y++) {
+            for (int x = 0; x < 8; x++) {
+                int sample = ((recon_sample[y][x] +
+                               (1 << (bd_shift - 1))) >> bd_shift) +
+                    (1 << (bit_depth - 1));
+                ptr[x] = av_clip_uintp2(sample, bit_depth);
+            }
+            ptr += pitch;
+        }
+    } else {
+        uint16_t *ptr = output;
+        int bd_shift = 20 - bit_depth;
+        pitch /= 2; // Pitch was in bytes, 2 bytes per sample.
+
+        for (int y = 0; y < 8; y++) {
+            for (int x = 0; x < 8; x++) {
+                int sample = ((recon_sample[y][x] +
+                               (1 << (bd_shift - 1))) >> bd_shift) +
+                    (1 << (bit_depth - 1));
+                ptr[x] = av_clip_uintp2(sample, bit_depth);
+            }
+            ptr += pitch;
+        }
+    }
+}
+
+av_cold void ff_apv_dsp_init(APVDSPContext *dsp)
+{
+    dsp->decode_transquant = apv_decode_transquant_c;
+}