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FFmpeg/libavcodec/dsicinaudio.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

134 lines
5.2 KiB
C

/*
* Delphine Software International CIN audio decoder
* Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
*
* 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
* Delphine Software International CIN audio decoder
*/
#include "libavutil/channel_layout.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include "mathops.h"
typedef struct CinAudioContext {
int initial_decode_frame;
int delta;
} CinAudioContext;
/* table defining a geometric sequence with multiplier = 32767 ^ (1 / 128) */
static const int16_t cinaudio_delta16_table[256] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, -30210, -27853, -25680, -23677, -21829,
-20126, -18556, -17108, -15774, -14543, -13408, -12362, -11398,
-10508, -9689, -8933, -8236, -7593, -7001, -6455, -5951,
-5487, -5059, -4664, -4300, -3964, -3655, -3370, -3107,
-2865, -2641, -2435, -2245, -2070, -1908, -1759, -1622,
-1495, -1379, -1271, -1172, -1080, -996, -918, -847,
-781, -720, -663, -612, -564, -520, -479, -442,
-407, -376, -346, -319, -294, -271, -250, -230,
-212, -196, -181, -166, -153, -141, -130, -120,
-111, -102, -94, -87, -80, -74, -68, -62,
-58, -53, -49, -45, -41, -38, -35, -32,
-30, -27, -25, -23, -21, -20, -18, -17,
-15, -14, -13, -12, -11, -10, -9, -8,
-7, -6, -5, -4, -3, -2, -1, 0,
0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
17, 18, 20, 21, 23, 25, 27, 30,
32, 35, 38, 41, 45, 49, 53, 58,
62, 68, 74, 80, 87, 94, 102, 111,
120, 130, 141, 153, 166, 181, 196, 212,
230, 250, 271, 294, 319, 346, 376, 407,
442, 479, 520, 564, 612, 663, 720, 781,
847, 918, 996, 1080, 1172, 1271, 1379, 1495,
1622, 1759, 1908, 2070, 2245, 2435, 2641, 2865,
3107, 3370, 3655, 3964, 4300, 4664, 5059, 5487,
5951, 6455, 7001, 7593, 8236, 8933, 9689, 10508,
11398, 12362, 13408, 14543, 15774, 17108, 18556, 20126,
21829, 23677, 25680, 27853, 30210, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
};
static av_cold int cinaudio_decode_init(AVCodecContext *avctx)
{
CinAudioContext *cin = avctx->priv_data;
cin->initial_decode_frame = 1;
cin->delta = 0;
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
avctx->channels = 1;
avctx->channel_layout = AV_CH_LAYOUT_MONO;
return 0;
}
static int cinaudio_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
AVFrame *frame = data;
const uint8_t *buf = avpkt->data;
CinAudioContext *cin = avctx->priv_data;
const uint8_t *buf_end = buf + avpkt->size;
int16_t *samples;
int delta, ret;
/* get output buffer */
frame->nb_samples = avpkt->size - cin->initial_decode_frame;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
samples = (int16_t *)frame->data[0];
delta = cin->delta;
if (cin->initial_decode_frame) {
cin->initial_decode_frame = 0;
delta = sign_extend(AV_RL16(buf), 16);
buf += 2;
*samples++ = delta;
}
while (buf < buf_end) {
delta += cinaudio_delta16_table[*buf++];
delta = av_clip_int16(delta);
*samples++ = delta;
}
cin->delta = delta;
*got_frame_ptr = 1;
return avpkt->size;
}
const AVCodec ff_dsicinaudio_decoder = {
.name = "dsicinaudio",
.long_name = NULL_IF_CONFIG_SMALL("Delphine Software International CIN audio"),
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_DSICINAUDIO,
.priv_data_size = sizeof(CinAudioContext),
.init = cinaudio_decode_init,
.decode = cinaudio_decode_frame,
.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
};