/*
- * The simplest AC3 encoder
+ * The simplest AC-3 encoder
* Copyright (c) 2000 Fabrice Bellard.
*
* This file is part of FFmpeg.
/**
* @file ac3enc.c
- * The simplest AC3 encoder.
+ * The simplest AC-3 encoder.
*/
//#define DEBUG
//#define DEBUG_BITALLOC
+#include "libavutil/crc.h"
#include "avcodec.h"
#include "bitstream.h"
-#include "crc.h"
#include "ac3.h"
typedef struct AC3EncodeContext {
static int16_t costab[64];
static int16_t sintab[64];
-static int16_t fft_rev[512];
static int16_t xcos1[128];
static int16_t xsin1[128];
/* new exponents are sent if their Norm 1 exceed this number */
#define EXP_DIFF_THRESHOLD 1000
-static void fft_init(int ln);
-
static inline int16_t fix15(float a)
{
int v;
static void fft_init(int ln)
{
- int i, j, m, n;
+ int i, n;
float alpha;
n = 1 << ln;
costab[i] = fix15(cos(alpha));
sintab[i] = fix15(sin(alpha));
}
-
- for(i=0;i<n;i++) {
- m=0;
- for(j=0;j<ln;j++) {
- m |= ((i >> j) & 1) << (ln-j-1);
- }
- fft_rev[i]=m;
- }
}
/* butter fly op */
/* reverse */
for(j=0;j<np;j++) {
- int k;
- k = fft_rev[j];
+ int k = ff_reverse[j] >> (8 - ln);
if (k < j)
FFSWAP(IComplex, z[k], z[j]);
}
for(ch=0;ch<s->nb_all_channels;ch++) {
ff_ac3_bit_alloc_calc_bap(mask[i][ch], psd[i][ch], 0,
s->nb_coefs[ch], snr_offset,
- s->bit_alloc.floor, bap[i][ch]);
+ s->bit_alloc.floor, ff_ac3_bap_tab,
+ bap[i][ch]);
frame_bits += compute_mantissa_size(s, bap[i][ch],
s->nb_coefs[ch]);
}
uint8_t bap1[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50];
- static int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
+ static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
/* init default parameters */
s->slow_decay_code = 2;
return 0;
}
-static int AC3_encode_init(AVCodecContext *avctx)
+static av_cold int AC3_encode_init(AVCodecContext *avctx)
{
int freq = avctx->sample_rate;
int bitrate = avctx->bit_rate;
} else {
/* use default bandwidth setting */
/* XXX: should compute the bandwidth according to the frame
- size, so that we avoid anoying high freq artefacts */
+ size, so that we avoid annoying high frequency artifacts */
bw_code = 50;
}
for(ch=0;ch<s->nb_channels;ch++) {
return 0;
}
-/* output the AC3 frame header */
+/* output the AC-3 frame header */
static void output_frame_header(AC3EncodeContext *s, unsigned char *frame)
{
init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
return v & ((1 << qbits)-1);
}
-/* Output one audio block. There are NB_BLOCKS audio blocks in one AC3
+/* Output one audio block. There are NB_BLOCKS audio blocks in one AC-3
frame */
static void output_audio_block(AC3EncodeContext *s,
uint8_t exp_strategy[AC3_MAX_CHANNELS],
return output_frame_end(s);
}
-static int AC3_encode_close(AVCodecContext *avctx)
+static av_cold int AC3_encode_close(AVCodecContext *avctx)
{
av_freep(&avctx->coded_frame);
return 0;
AC3_encode_frame,
AC3_encode_close,
NULL,
+ .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
+ .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
};