adding ffmpeg specific version

1 files changed, 168 insertions, 0 deletions

diff --git a/ffmpeg1/libavcodec/ac3enc_float.c b/ffmpeg1/libavcodec/ac3enc_float.c
new file mode 100644
index 0000000..7864f41
--- /dev/null
+++ b/ffmpeg1/libavcodec/ac3enc_float.c
@@ -0,0 +1,168 @@
+/*
+ * 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
+ * floating-point AC-3 encoder.
+ */
+
+#define CONFIG_AC3ENC_FLOAT 1
+#include "internal.h"
+#include "ac3enc.h"
+#include "eac3enc.h"
+#include "kbdwin.h"
+
+
+#if CONFIG_AC3_ENCODER
+#define AC3ENC_TYPE AC3ENC_TYPE_AC3
+#include "ac3enc_opts_template.c"
+static const AVClass ac3enc_class = {
+    .class_name = "AC-3 Encoder",
+    .item_name  = av_default_item_name,
+    .option     = ac3_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+#endif
+
+#include "ac3enc_template.c"
+
+
+/**
+ * Finalize MDCT and free allocated memory.
+ *
+ * @param s  AC-3 encoder private context
+ */
+av_cold void ff_ac3_float_mdct_end(AC3EncodeContext *s)
+{
+    ff_mdct_end(&s->mdct);
+    av_freep(&s->mdct_window);
+}
+
+
+/**
+ * Initialize MDCT tables.
+ *
+ * @param s  AC-3 encoder private context
+ * @return   0 on success, negative error code on failure
+ */
+av_cold int ff_ac3_float_mdct_init(AC3EncodeContext *s)
+{
+    float *window;
+    int i, n, n2;
+
+    n  = 1 << 9;
+    n2 = n >> 1;
+
+    window = av_malloc(n * sizeof(*window));
+    if (!window) {
+        av_log(s->avctx, AV_LOG_ERROR, "Cannot allocate memory.\n");
+        return AVERROR(ENOMEM);
+    }
+    ff_kbd_window_init(window, 5.0, n2);
+    for (i = 0; i < n2; i++)
+        window[n-1-i] = window[i];
+    s->mdct_window = window;
+
+    return ff_mdct_init(&s->mdct, 9, 0, -2.0 / n);
+}
+
+
+/*
+ * Apply KBD window to input samples prior to MDCT.
+ */
+static void apply_window(void *dsp, float *output,
+                         const float *input, const float *window,
+                         unsigned int len)
+{
+    AVFloatDSPContext *fdsp = dsp;
+    fdsp->vector_fmul(output, input, window, len);
+}
+
+
+/*
+ * Normalize the input samples.
+ * Not needed for the floating-point encoder.
+ */
+static int normalize_samples(AC3EncodeContext *s)
+{
+    return 0;
+}
+
+
+/*
+ * Scale MDCT coefficients from float to 24-bit fixed-point.
+ */
+static void scale_coefficients(AC3EncodeContext *s)
+{
+    int chan_size = AC3_MAX_COEFS * s->num_blocks;
+    int cpl       = s->cpl_on;
+    s->ac3dsp.float_to_fixed24(s->fixed_coef_buffer + (chan_size * !cpl),
+                               s->mdct_coef_buffer  + (chan_size * !cpl),
+                               chan_size * (s->channels + cpl));
+}
+
+static void sum_square_butterfly(AC3EncodeContext *s, float sum[4],
+                                 const float *coef0, const float *coef1,
+                                 int len)
+{
+    s->ac3dsp.sum_square_butterfly_float(sum, coef0, coef1, len);
+}
+
+/*
+ * Clip MDCT coefficients to allowable range.
+ */
+static void clip_coefficients(DSPContext *dsp, float *coef, unsigned int len)
+{
+    dsp->vector_clipf(coef, coef, COEF_MIN, COEF_MAX, len);
+}
+
+
+/*
+ * Calculate a single coupling coordinate.
+ */
+static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl)
+{
+    float coord = 0.125;
+    if (energy_cpl > 0)
+        coord *= sqrtf(energy_ch / energy_cpl);
+    return FFMIN(coord, COEF_MAX);
+}
+
+
+#if CONFIG_AC3_ENCODER
+AVCodec ff_ac3_encoder = {
+    .name            = "ac3",
+    .type            = AVMEDIA_TYPE_AUDIO,
+    .id              = AV_CODEC_ID_AC3,
+    .priv_data_size  = sizeof(AC3EncodeContext),
+    .init            = ff_ac3_encode_init,
+    .encode2         = ff_ac3_float_encode_frame,
+    .close           = ff_ac3_encode_close,
+    .sample_fmts     = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP,
+                                                      AV_SAMPLE_FMT_NONE },
+    .long_name       = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
+    .priv_class      = &ac3enc_class,
+    .channel_layouts = ff_ac3_channel_layouts,
+    .defaults        = ac3_defaults,
+};
+#endif