* 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.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * 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.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * 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 FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/** Complex multiply */
-#define CMUL(pre, pim, are, aim, bre, bim) \
+#define CMUL(pre, pim, are, aim, bre, bim, rshift) \
{ \
- pre = (MUL16(are, bre) - MUL16(aim, bim)) >> 15; \
- pim = (MUL16(are, bim) + MUL16(bre, aim)) >> 15; \
+ pre = (MUL16(are, bre) - MUL16(aim, bim)) >> rshift; \
+ pim = (MUL16(are, bim) + MUL16(bre, aim)) >> rshift; \
}
p++;
q++;
for(l = nblocks; l < np2; l += nblocks) {
- CMUL(tmp_re, tmp_im, mdct->costab[l], -mdct->sintab[l], q->re, q->im);
+ CMUL(tmp_re, tmp_im, mdct->costab[l], -mdct->sintab[l], q->re, q->im, 15);
BF(p->re, p->im, q->re, q->im,
p->re, p->im, tmp_re, tmp_im);
p++;
for (i = 0; i < n4; i++) {
re = ((int)rot[ 2*i] - (int)rot[ n-1-2*i]) >> 1;
im = -((int)rot[n2+2*i] - (int)rot[n2-1-2*i]) >> 1;
- CMUL(x[i].re, x[i].im, re, im, -mdct->xcos1[i], mdct->xsin1[i]);
+ CMUL(x[i].re, x[i].im, re, im, -mdct->xcos1[i], mdct->xsin1[i], 15);
}
fft(mdct, x, mdct->nbits - 2);
for (i = 0; i < n4; i++) {
re = x[i].re;
im = x[i].im;
- CMUL(out[n2-1-2*i], out[2*i], re, im, mdct->xsin1[i], mdct->xcos1[i]);
+ CMUL(out[n2-1-2*i], out[2*i], re, im, mdct->xsin1[i], mdct->xcos1[i], 0);
}
}
/**
* Apply KBD window to input samples prior to MDCT.
*/
-static void apply_window(int16_t *output, const int16_t *input,
- const int16_t *window, int n)
+static void apply_window(DSPContext *dsp, int16_t *output, const int16_t *input,
+ const int16_t *window, unsigned int len)
{
- int i;
- int n2 = n >> 1;
-
- for (i = 0; i < n2; i++) {
- output[i] = MUL16(input[i], window[i]) >> 15;
- output[n-i-1] = MUL16(input[n-i-1], window[i]) >> 15;
- }
+ dsp->apply_window_int16(output, input, window, len);
}
* @param n number of values in the array
* @return log2(max(abs(tab[])))
*/
-static int log2_tab(int16_t *tab, int n)
+static int log2_tab(AC3EncodeContext *s, int16_t *src, int len)
{
- int i, v;
-
- v = 0;
- for (i = 0; i < n; i++)
- v |= abs(tab[i]);
-
+ int v = s->ac3dsp.ac3_max_msb_abs_int16(src, len);
return av_log2(v);
}
/**
- * Left-shift each value in an array by a specified amount.
- * @param tab input array
- * @param n number of values in the array
- * @param lshift left shift amount. a negative value means right shift.
- */
-static void lshift_tab(int16_t *tab, int n, int lshift)
-{
- int i;
-
- if (lshift > 0) {
- for (i = 0; i < n; i++)
- tab[i] <<= lshift;
- } else if (lshift < 0) {
- lshift = -lshift;
- for (i = 0; i < n; i++)
- tab[i] >>= lshift;
- }
-}
-
-
-/**
* Normalize the input samples to use the maximum available precision.
- * This assumes signed 16-bit input samples. Exponents are reduced by 9 to
- * match the 24-bit internal precision for MDCT coefficients.
+ * This assumes signed 16-bit input samples.
*
* @return exponent shift
*/
static int normalize_samples(AC3EncodeContext *s)
{
- int v = 14 - log2_tab(s->windowed_samples, AC3_WINDOW_SIZE);
- v = FFMAX(0, v);
- lshift_tab(s->windowed_samples, AC3_WINDOW_SIZE, v);
- return v - 9;
+ int v = 14 - log2_tab(s, s->windowed_samples, AC3_WINDOW_SIZE);
+ 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 from float to fixed-point.
+ * Scale MDCT coefficients to 25-bit signed fixed-point.
*/
static void scale_coefficients(AC3EncodeContext *s)
{
- /* scaling/conversion is obviously not needed for the fixed-point encoder
- since the coefficients are already fixed-point. */
- return;
+ int blk, ch;
+
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ for (ch = 0; ch < s->channels; ch++) {
+ s->ac3dsp.ac3_rshift_int32(block->mdct_coef[ch], AC3_MAX_COEFS,
+ block->coeff_shift[ch]);
+ }
+ }
}
#endif /* TEST */
-AVCodec ac3_fixed_encoder = {
+AVCodec ff_ac3_fixed_encoder = {
"ac3_fixed",
AVMEDIA_TYPE_AUDIO,
CODEC_ID_AC3,
NULL,
.sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
+ .priv_class = &ac3enc_class,
.channel_layouts = ac3_channel_layouts,
};
projects / ffmpeg.git / blobdiff