1/* 2 * ADX ADPCM codecs 3 * Copyright (c) 2001,2003 BERO 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg 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. 11 * 12 * FFmpeg 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. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "libavutil/intreadwrite.h" 23#include "avcodec.h" 24#include "adx.h" 25#include "codec_internal.h" 26#include "get_bits.h" 27#include "internal.h" 28 29/** 30 * @file 31 * SEGA CRI adx codecs. 32 * 33 * Reference documents: 34 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html 35 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/ 36 */ 37 38static av_cold int adx_decode_init(AVCodecContext *avctx) 39{ 40 ADXContext *c = avctx->priv_data; 41 int ret, header_size; 42 43 if (avctx->extradata_size >= 24) { 44 if ((ret = ff_adx_decode_header(avctx, avctx->extradata, 45 avctx->extradata_size, &header_size, 46 c->coeff)) < 0) { 47 av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n"); 48 return AVERROR_INVALIDDATA; 49 } 50 c->channels = avctx->ch_layout.nb_channels; 51 c->header_parsed = 1; 52 } 53 54 avctx->sample_fmt = AV_SAMPLE_FMT_S16P; 55 56 return 0; 57} 58 59/** 60 * Decode 32 samples from 18 bytes. 61 * 62 * A 16-bit scalar value is applied to 32 residuals, which then have a 63 * 2nd-order LPC filter applied to it to form the output signal for a single 64 * channel. 65 */ 66static int adx_decode(ADXContext *c, int16_t *out, int offset, 67 const uint8_t *in, int ch) 68{ 69 ADXChannelState *prev = &c->prev[ch]; 70 GetBitContext gb; 71 int scale = AV_RB16(in); 72 int i; 73 int s0, s1, s2, d; 74 75 /* check if this is an EOF packet */ 76 if (scale & 0x8000) 77 return -1; 78 79 init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8); 80 out += offset; 81 s1 = prev->s1; 82 s2 = prev->s2; 83 for (i = 0; i < BLOCK_SAMPLES; i++) { 84 d = get_sbits(&gb, 4); 85 s0 = d * scale + ((c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS); 86 s2 = s1; 87 s1 = av_clip_int16(s0); 88 *out++ = s1; 89 } 90 prev->s1 = s1; 91 prev->s2 = s2; 92 93 return 0; 94} 95 96static int adx_decode_frame(AVCodecContext *avctx, AVFrame *frame, 97 int *got_frame_ptr, AVPacket *avpkt) 98{ 99 int buf_size = avpkt->size; 100 ADXContext *c = avctx->priv_data; 101 int16_t **samples; 102 int samples_offset; 103 const uint8_t *buf = avpkt->data; 104 const uint8_t *buf_end = buf + avpkt->size; 105 int num_blocks, ch, ret; 106 size_t new_extradata_size; 107 uint8_t *new_extradata; 108 109 new_extradata = av_packet_get_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA, 110 &new_extradata_size); 111 if (new_extradata && new_extradata_size > 0) { 112 int header_size; 113 if ((ret = ff_adx_decode_header(avctx, new_extradata, 114 new_extradata_size, &header_size, 115 c->coeff)) < 0) { 116 av_log(avctx, AV_LOG_ERROR, "error parsing new ADX extradata\n"); 117 return AVERROR_INVALIDDATA; 118 } 119 120 c->eof = 0; 121 } 122 123 if (c->eof) { 124 *got_frame_ptr = 0; 125 return buf_size; 126 } 127 128 if (!c->header_parsed && buf_size >= 2 && AV_RB16(buf) == 0x8000) { 129 int header_size; 130 if ((ret = ff_adx_decode_header(avctx, buf, buf_size, &header_size, 131 c->coeff)) < 0) { 132 av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n"); 133 return AVERROR_INVALIDDATA; 134 } 135 c->channels = avctx->ch_layout.nb_channels; 136 c->header_parsed = 1; 137 if (buf_size < header_size) 138 return AVERROR_INVALIDDATA; 139 buf += header_size; 140 buf_size -= header_size; 141 } 142 if (!c->header_parsed) 143 return AVERROR_INVALIDDATA; 144 145 /* calculate number of blocks in the packet */ 146 num_blocks = buf_size / (BLOCK_SIZE * c->channels); 147 148 /* if the packet is not an even multiple of BLOCK_SIZE, check for an EOF 149 packet */ 150 if (!num_blocks || buf_size % (BLOCK_SIZE * c->channels)) { 151 if (buf_size >= 4 && (AV_RB16(buf) & 0x8000)) { 152 c->eof = 1; 153 *got_frame_ptr = 0; 154 return avpkt->size; 155 } 156 return AVERROR_INVALIDDATA; 157 } 158 159 /* get output buffer */ 160 frame->nb_samples = num_blocks * BLOCK_SAMPLES; 161 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 162 return ret; 163 samples = (int16_t **)frame->extended_data; 164 samples_offset = 0; 165 166 while (num_blocks--) { 167 for (ch = 0; ch < c->channels; ch++) { 168 if (buf_end - buf < BLOCK_SIZE || adx_decode(c, samples[ch], samples_offset, buf, ch)) { 169 c->eof = 1; 170 buf = avpkt->data + avpkt->size; 171 break; 172 } 173 buf_size -= BLOCK_SIZE; 174 buf += BLOCK_SIZE; 175 } 176 if (!c->eof) 177 samples_offset += BLOCK_SAMPLES; 178 } 179 180 frame->nb_samples = samples_offset; 181 *got_frame_ptr = 1; 182 183 return buf - avpkt->data; 184} 185 186static void adx_decode_flush(AVCodecContext *avctx) 187{ 188 ADXContext *c = avctx->priv_data; 189 memset(c->prev, 0, sizeof(c->prev)); 190 c->eof = 0; 191} 192 193const FFCodec ff_adpcm_adx_decoder = { 194 .p.name = "adpcm_adx", 195 .p.long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"), 196 .p.type = AVMEDIA_TYPE_AUDIO, 197 .p.id = AV_CODEC_ID_ADPCM_ADX, 198 .priv_data_size = sizeof(ADXContext), 199 .init = adx_decode_init, 200 FF_CODEC_DECODE_CB(adx_decode_frame), 201 .flush = adx_decode_flush, 202 .p.capabilities = AV_CODEC_CAP_CHANNEL_CONF | 203 AV_CODEC_CAP_DR1, 204 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P, 205 AV_SAMPLE_FMT_NONE }, 206 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 207}; 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