Rename ffmpeg-4.2-fit to ffmpeg-4-fit

trunk/3rdparty/ffmpeg-4-fit/libavcodec/ac3enc_fixed.c

@@ -0,0 +1,160 @@
+/*
+ * The simplest AC-3 encoder
+ * Copyright (c) 2000 Fabrice Bellard
+ * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
+ * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * fixed-point AC-3 encoder.
+ */
+
+#define FFT_FLOAT 0
+#undef CONFIG_AC3ENC_FLOAT
+#include "internal.h"
+#include "audiodsp.h"
+#include "ac3enc.h"
+#include "eac3enc.h"
+
+#define AC3ENC_TYPE AC3ENC_TYPE_AC3_FIXED
+#include "ac3enc_opts_template.c"
+
+static const AVClass ac3enc_class = {
+    .class_name = "Fixed-Point AC-3 Encoder",
+    .item_name  = av_default_item_name,
+    .option     = ac3_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+/*
+ * Normalize the input samples to use the maximum available precision.
+ * This assumes signed 16-bit input samples.
+ */
+static int normalize_samples(AC3EncodeContext *s)
+{
+    int v = s->ac3dsp.ac3_max_msb_abs_int16(s->windowed_samples, AC3_WINDOW_SIZE);
+    v = 14 - av_log2(v);
+    if (v > 0)
+        s->ac3dsp.ac3_lshift_int16(s->windowed_samples, AC3_WINDOW_SIZE, v);
+    /* +6 to right-shift from 31-bit to 25-bit */
+    return v + 6;
+}
+
+
+/*
+ * Scale MDCT coefficients to 25-bit signed fixed-point.
+ */
+static void scale_coefficients(AC3EncodeContext *s)
+{
+    int blk, ch;
+
+    for (blk = 0; blk < s->num_blocks; blk++) {
+        AC3Block *block = &s->blocks[blk];
+        for (ch = 1; ch <= s->channels; ch++) {
+            s->ac3dsp.ac3_rshift_int32(block->mdct_coef[ch], AC3_MAX_COEFS,
+                                       block->coeff_shift[ch]);
+        }
+    }
+}
+
+static void sum_square_butterfly(AC3EncodeContext *s, int64_t sum[4],
+                                 const int32_t *coef0, const int32_t *coef1,
+                                 int len)
+{
+    s->ac3dsp.sum_square_butterfly_int32(sum, coef0, coef1, len);
+}
+
+/*
+ * Clip MDCT coefficients to allowable range.
+ */
+static void clip_coefficients(AudioDSPContext *adsp, int32_t *coef,
+                              unsigned int len)
+{
+    adsp->vector_clip_int32(coef, coef, COEF_MIN, COEF_MAX, len);
+}
+
+
+/*
+ * Calculate a single coupling coordinate.
+ */
+static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl)
+{
+    if (energy_cpl <= COEF_MAX) {
+        return 1048576;
+    } else {
+        uint64_t coord   = energy_ch / (energy_cpl >> 24);
+        uint32_t coord32 = FFMIN(coord, 1073741824);
+        coord32          = ff_sqrt(coord32) << 9;
+        return FFMIN(coord32, COEF_MAX);
+    }
+}
+
+
+#include "ac3enc_template.c"
+
+
+/**
+ * Finalize MDCT and free allocated memory.
+ *
+ * @param s  AC-3 encoder private context
+ */
+av_cold void ff_ac3_fixed_mdct_end(AC3EncodeContext *s)
+{
+    ff_mdct_end(&s->mdct);
+}
+
+
+/**
+ * Initialize MDCT tables.
+ *
+ * @param s  AC-3 encoder private context
+ * @return   0 on success, negative error code on failure
+ */
+av_cold int ff_ac3_fixed_mdct_init(AC3EncodeContext *s)
+{
+    int ret = ff_mdct_init(&s->mdct, 9, 0, -1.0);
+    s->mdct_window = ff_ac3_window;
+    return ret;
+}
+
+
+static av_cold int ac3_fixed_encode_init(AVCodecContext *avctx)
+{
+    AC3EncodeContext *s = avctx->priv_data;
+    s->fixed_point = 1;
+    return ff_ac3_encode_init(avctx);
+}
+
+
+AVCodec ff_ac3_fixed_encoder = {
+    .name            = "ac3_fixed",
+    .long_name       = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
+    .type            = AVMEDIA_TYPE_AUDIO,
+    .id              = AV_CODEC_ID_AC3,
+    .priv_data_size  = sizeof(AC3EncodeContext),
+    .init            = ac3_fixed_encode_init,
+    .encode2         = ff_ac3_fixed_encode_frame,
+    .close           = ff_ac3_encode_close,
+    .sample_fmts     = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16P,
+                                                      AV_SAMPLE_FMT_NONE },
+    .priv_class      = &ac3enc_class,
+    .channel_layouts = ff_ac3_channel_layouts,
+    .defaults        = ac3_defaults,
+};