6fd96d1a |
/*
* 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 |
aa872af5 |
#include "internal.h" |
9a9e2f1c |
#include "audiodsp.h" |
e0cc66df |
#include "ac3enc.h"
#include "eac3enc.h" |
a45fbda9 |
#include "kbdwin.h" |
6fd96d1a |
|
e0cc66df |
#define AC3ENC_TYPE AC3ENC_TYPE_AC3
#include "ac3enc_opts_template.c" |
e9d5c052 |
static const AVClass ac3enc_class = {
.class_name = "AC-3 Encoder",
.item_name = av_default_item_name,
.option = ac3_options,
.version = LIBAVUTIL_VERSION_INT,
}; |
e0cc66df |
|
f0d3e43b |
/*
* 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));
}
/*
* Clip MDCT coefficients to allowable range.
*/
static void clip_coefficients(AudioDSPContext *adsp, float *coef,
unsigned int len)
{
adsp->vector_clipf(coef, coef, len, COEF_MIN, COEF_MAX);
}
/*
* 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);
}
|
e7ec8c18 |
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);
}
|
f0d3e43b |
|
e0cc66df |
#include "ac3enc_template.c"
|
6fd96d1a |
/**
* Finalize MDCT and free allocated memory. |
c2d9a65b |
*
* @param s AC-3 encoder private context |
6fd96d1a |
*/ |
b5849f77 |
av_cold void ff_ac3_float_mdct_end(AC3EncodeContext *s) |
6fd96d1a |
{ |
b5849f77 |
ff_mdct_end(&s->mdct);
av_freep(&s->mdct_window); |
6fd96d1a |
}
/**
* Initialize MDCT tables. |
c2d9a65b |
*
* @param s AC-3 encoder private context
* @return 0 on success, negative error code on failure |
6fd96d1a |
*/ |
b5849f77 |
av_cold int ff_ac3_float_mdct_init(AC3EncodeContext *s) |
6fd96d1a |
{
float *window; |
3b924294 |
int i, n, n2; |
6fd96d1a |
|
b5849f77 |
n = 1 << 9; |
6fd96d1a |
n2 = n >> 1;
|
c8a1f10c |
window = av_malloc_array(n, sizeof(*window)); |
6fd96d1a |
if (!window) { |
b5849f77 |
av_log(s->avctx, AV_LOG_ERROR, "Cannot allocate memory.\n"); |
6fd96d1a |
return AVERROR(ENOMEM);
}
ff_kbd_window_init(window, 5.0, n2); |
3b924294 |
for (i = 0; i < n2; i++)
window[n-1-i] = window[i]; |
b5849f77 |
s->mdct_window = window; |
6fd96d1a |
|
b5849f77 |
return ff_mdct_init(&s->mdct, 9, 0, -2.0 / n); |
6fd96d1a |
}
|
27631796 |
av_cold int ff_ac3_float_encode_init(AVCodecContext *avctx)
{
AC3EncodeContext *s = avctx->priv_data; |
94d68a41 |
s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT); |
cae851c7 |
if (!s->fdsp)
return AVERROR(ENOMEM); |
27631796 |
return ff_ac3_encode_init(avctx);
} |
ae264bb2 |
|
9f4d37f4 |
AVCodec ff_ac3_encoder = { |
00c3b67b |
.name = "ac3", |
b2bed932 |
.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"), |
00c3b67b |
.type = AVMEDIA_TYPE_AUDIO, |
36ef5369 |
.id = AV_CODEC_ID_AC3, |
00c3b67b |
.priv_data_size = sizeof(AC3EncodeContext), |
27631796 |
.init = ff_ac3_float_encode_init, |
00c3b67b |
.encode2 = ff_ac3_float_encode_frame,
.close = ff_ac3_encode_close, |
b1540fc8 |
.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, |
00c3b67b |
AV_SAMPLE_FMT_NONE },
.priv_class = &ac3enc_class, |
1aeb88b7 |
.channel_layouts = ff_ac3_channel_layouts, |
4e99501f |
.defaults = ac3_defaults, |
6fd96d1a |
}; |