1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
/*
* Real Audio 1.0 (14.4K)
*
* Copyright (c) 2008 Vitor Sessak
* Copyright (c) 2003 Nick Kurshev
* Based on public domain decoder at http://www.honeypot.net/audio
*
* 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
*/
#include "libavutil/channel_layout.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "get_bits.h"
#include "internal.h"
#include "ra144.h"
static av_cold int ra144_decode_init(AVCodecContext * avctx)
{
RA144Context *ractx = avctx->priv_data;
ractx->avctx = avctx;
ff_audiodsp_init(&ractx->adsp);
ractx->lpc_coef[0] = ractx->lpc_tables[0];
ractx->lpc_coef[1] = ractx->lpc_tables[1];
av_channel_layout_uninit(&avctx->ch_layout);
avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
return 0;
}
static void do_output_subblock(RA144Context *ractx, const int16_t *lpc_coefs,
int gval, GetBitContext *gb)
{
int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none
int gain = get_bits(gb, 8);
int cb1_idx = get_bits(gb, 7);
int cb2_idx = get_bits(gb, 7);
ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval,
gain);
}
/** Uncompress one block (20 bytes -> 160*2 bytes). */
static int ra144_decode_frame(AVCodecContext * avctx, AVFrame *frame,
int *got_frame_ptr, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
static const uint8_t sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
unsigned int refl_rms[NBLOCKS]; // RMS of the reflection coefficients
int16_t block_coefs[NBLOCKS][LPC_ORDER]; // LPC coefficients of each sub-block
unsigned int lpc_refl[LPC_ORDER]; // LPC reflection coefficients of the frame
int i, j;
int ret;
int16_t *samples;
unsigned int energy;
RA144Context *ractx = avctx->priv_data;
GetBitContext gb;
if (buf_size < FRAME_SIZE) {
av_log(avctx, AV_LOG_ERROR,
"Frame too small (%d bytes). Truncated file?\n", buf_size);
*got_frame_ptr = 0;
return AVERROR_INVALIDDATA;
}
/* get output buffer */
frame->nb_samples = NBLOCKS * BLOCKSIZE;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
samples = (int16_t *)frame->data[0];
init_get_bits8(&gb, buf, FRAME_SIZE);
for (i = 0; i < LPC_ORDER; i++)
lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])];
ff_eval_coefs(ractx->lpc_coef[0], lpc_refl);
ractx->lpc_refl_rms[0] = ff_rms(lpc_refl);
energy = ff_energy_tab[get_bits(&gb, 5)];
refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
refl_rms[1] = ff_interp(ractx, block_coefs[1], 2,
energy <= ractx->old_energy,
ff_t_sqrt(energy*ractx->old_energy) >> 12);
refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy);
refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy);
ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]);
for (i=0; i < NBLOCKS; i++) {
do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);
for (j=0; j < BLOCKSIZE; j++)
*samples++ = av_clip_int16(ractx->curr_sblock[j + 10] * (1 << 2));
}
ractx->old_energy = energy;
ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];
FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);
*got_frame_ptr = 1;
return FRAME_SIZE;
}
const FFCodec ff_ra_144_decoder = {
.p.name = "real_144",
.p.long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_RA_144,
.priv_data_size = sizeof(RA144Context),
.init = ra144_decode_init,
FF_CODEC_DECODE_CB(ra144_decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
};
|
