3 * Copyright (c) 2001,2003 BERO
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/intreadwrite.h"
29 * SEGA CRI adx codecs.
31 * Reference documents:
32 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
33 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
36 static av_cold int adx_decode_init(AVCodecContext *avctx)
38 ADXContext *c = avctx->priv_data;
41 if (avctx->extradata_size >= 24) {
42 if ((ret = avpriv_adx_decode_header(avctx, avctx->extradata,
43 avctx->extradata_size, &header_size,
45 av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
46 return AVERROR_INVALIDDATA;
48 c->channels = avctx->channels;
52 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
54 avcodec_get_frame_defaults(&c->frame);
55 avctx->coded_frame = &c->frame;
61 * Decode 32 samples from 18 bytes.
63 * A 16-bit scalar value is applied to 32 residuals, which then have a
64 * 2nd-order LPC filter applied to it to form the output signal for a single
67 static int adx_decode(ADXContext *c, int16_t *out, const uint8_t *in, int ch)
69 ADXChannelState *prev = &c->prev[ch];
71 int scale = AV_RB16(in);
75 /* check if this is an EOF packet */
79 init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8);
82 for (i = 0; i < BLOCK_SAMPLES; i++) {
83 d = get_sbits(&gb, 4);
84 s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS;
86 s1 = av_clip_int16(s0);
96 static int adx_decode_frame(AVCodecContext *avctx, void *data,
97 int *got_frame_ptr, AVPacket *avpkt)
99 int buf_size = avpkt->size;
100 ADXContext *c = avctx->priv_data;
102 const uint8_t *buf = avpkt->data;
103 int num_blocks, ch, ret;
110 if (!c->header_parsed && buf_size >= 2 && AV_RB16(buf) == 0x8000) {
112 if ((ret = avpriv_adx_decode_header(avctx, buf, buf_size, &header_size,
114 av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
115 return AVERROR_INVALIDDATA;
117 c->channels = avctx->channels;
118 c->header_parsed = 1;
119 if (buf_size < header_size)
120 return AVERROR_INVALIDDATA;
122 buf_size -= header_size;
124 if (!c->header_parsed)
125 return AVERROR_INVALIDDATA;
127 /* calculate number of blocks in the packet */
128 num_blocks = buf_size / (BLOCK_SIZE * c->channels);
130 /* if the packet is not an even multiple of BLOCK_SIZE, check for an EOF
132 if (!num_blocks || buf_size % (BLOCK_SIZE * avctx->channels)) {
133 if (buf_size >= 4 && (AV_RB16(buf) & 0x8000)) {
138 return AVERROR_INVALIDDATA;
141 /* get output buffer */
142 c->frame.nb_samples = num_blocks * BLOCK_SAMPLES;
143 if ((ret = avctx->get_buffer(avctx, &c->frame)) < 0) {
144 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
147 samples = (int16_t *)c->frame.data[0];
149 while (num_blocks--) {
150 for (ch = 0; ch < c->channels; ch++) {
151 if (adx_decode(c, samples + ch, buf, ch)) {
153 buf = avpkt->data + avpkt->size;
156 buf_size -= BLOCK_SIZE;
159 samples += BLOCK_SAMPLES * c->channels;
163 *(AVFrame *)data = c->frame;
165 return buf - avpkt->data;
168 static void adx_decode_flush(AVCodecContext *avctx)
170 ADXContext *c = avctx->priv_data;
171 memset(c->prev, 0, sizeof(c->prev));
175 AVCodec ff_adpcm_adx_decoder = {
177 .type = AVMEDIA_TYPE_AUDIO,
178 .id = AV_CODEC_ID_ADPCM_ADX,
179 .priv_data_size = sizeof(ADXContext),
180 .init = adx_decode_init,
181 .decode = adx_decode_frame,
182 .flush = adx_decode_flush,
183 .capabilities = CODEC_CAP_DR1,
184 .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),