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def97856de
Express bitfields more simply. Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
136 lines
5.3 KiB
C
136 lines
5.3 KiB
C
/*
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* Delphine Software International CIN audio decoder
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* Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Delphine Software International CIN audio decoder
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*/
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#include "libavutil/channel_layout.h"
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#include "avcodec.h"
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#include "bytestream.h"
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#include "internal.h"
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#include "mathops.h"
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typedef struct CinAudioContext {
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int initial_decode_frame;
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int delta;
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} CinAudioContext;
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/* table defining a geometric sequence with multiplier = 32767 ^ (1 / 128) */
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static const int16_t cinaudio_delta16_table[256] = {
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, -30210, -27853, -25680, -23677, -21829,
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-20126, -18556, -17108, -15774, -14543, -13408, -12362, -11398,
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-10508, -9689, -8933, -8236, -7593, -7001, -6455, -5951,
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-5487, -5059, -4664, -4300, -3964, -3655, -3370, -3107,
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-2865, -2641, -2435, -2245, -2070, -1908, -1759, -1622,
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-1495, -1379, -1271, -1172, -1080, -996, -918, -847,
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-781, -720, -663, -612, -564, -520, -479, -442,
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-407, -376, -346, -319, -294, -271, -250, -230,
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-212, -196, -181, -166, -153, -141, -130, -120,
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-111, -102, -94, -87, -80, -74, -68, -62,
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-58, -53, -49, -45, -41, -38, -35, -32,
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-30, -27, -25, -23, -21, -20, -18, -17,
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-15, -14, -13, -12, -11, -10, -9, -8,
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-7, -6, -5, -4, -3, -2, -1, 0,
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0, 1, 2, 3, 4, 5, 6, 7,
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8, 9, 10, 11, 12, 13, 14, 15,
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17, 18, 20, 21, 23, 25, 27, 30,
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32, 35, 38, 41, 45, 49, 53, 58,
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62, 68, 74, 80, 87, 94, 102, 111,
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120, 130, 141, 153, 166, 181, 196, 212,
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230, 250, 271, 294, 319, 346, 376, 407,
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442, 479, 520, 564, 612, 663, 720, 781,
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847, 918, 996, 1080, 1172, 1271, 1379, 1495,
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1622, 1759, 1908, 2070, 2245, 2435, 2641, 2865,
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3107, 3370, 3655, 3964, 4300, 4664, 5059, 5487,
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5951, 6455, 7001, 7593, 8236, 8933, 9689, 10508,
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11398, 12362, 13408, 14543, 15774, 17108, 18556, 20126,
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21829, 23677, 25680, 27853, 30210, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0
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};
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static av_cold int cinaudio_decode_init(AVCodecContext *avctx)
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{
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CinAudioContext *cin = avctx->priv_data;
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cin->initial_decode_frame = 1;
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cin->delta = 0;
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avctx->sample_fmt = AV_SAMPLE_FMT_S16;
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avctx->channels = 1;
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avctx->channel_layout = AV_CH_LAYOUT_MONO;
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return 0;
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}
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static int cinaudio_decode_frame(AVCodecContext *avctx, void *data,
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int *got_frame_ptr, AVPacket *avpkt)
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{
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AVFrame *frame = data;
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const uint8_t *buf = avpkt->data;
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CinAudioContext *cin = avctx->priv_data;
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const uint8_t *buf_end = buf + avpkt->size;
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int16_t *samples;
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int delta, ret;
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/* get output buffer */
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frame->nb_samples = avpkt->size - cin->initial_decode_frame;
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if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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return ret;
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}
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samples = (int16_t *)frame->data[0];
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delta = cin->delta;
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if (cin->initial_decode_frame) {
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cin->initial_decode_frame = 0;
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delta = sign_extend(AV_RL16(buf), 16);
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buf += 2;
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*samples++ = delta;
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}
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while (buf < buf_end) {
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delta += cinaudio_delta16_table[*buf++];
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delta = av_clip_int16(delta);
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*samples++ = delta;
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}
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cin->delta = delta;
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*got_frame_ptr = 1;
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return avpkt->size;
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}
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AVCodec ff_dsicinaudio_decoder = {
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.name = "dsicinaudio",
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.long_name = NULL_IF_CONFIG_SMALL("Delphine Software International CIN audio"),
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.type = AVMEDIA_TYPE_AUDIO,
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.id = AV_CODEC_ID_DSICINAUDIO,
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.priv_data_size = sizeof(CinAudioContext),
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.init = cinaudio_decode_init,
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.decode = cinaudio_decode_frame,
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.capabilities = AV_CODEC_CAP_DR1,
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};
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