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 "avcodec.h" 23#include "adx.h" 24#include "bytestream.h" 25#include "codec_internal.h" 26#include "encode.h" 27#include "put_bits.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 void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav, 39 ADXChannelState *prev, int channels) 40{ 41 PutBitContext pb; 42 int scale; 43 int i, j; 44 int s0, s1, s2, d; 45 int max = 0; 46 int min = 0; 47 48 s1 = prev->s1; 49 s2 = prev->s2; 50 for (i = 0, j = 0; j < 32; i += channels, j++) { 51 s0 = wav[i]; 52 d = s0 + ((-c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS); 53 if (max < d) 54 max = d; 55 if (min > d) 56 min = d; 57 s2 = s1; 58 s1 = s0; 59 } 60 61 if (max == 0 && min == 0) { 62 prev->s1 = s1; 63 prev->s2 = s2; 64 memset(adx, 0, BLOCK_SIZE); 65 return; 66 } 67 68 if (max / 7 > -min / 8) 69 scale = max / 7; 70 else 71 scale = -min / 8; 72 73 if (scale == 0) 74 scale = 1; 75 76 AV_WB16(adx, scale); 77 78 init_put_bits(&pb, adx + 2, 16); 79 80 s1 = prev->s1; 81 s2 = prev->s2; 82 for (i = 0, j = 0; j < 32; i += channels, j++) { 83 d = wav[i] + ((-c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS); 84 85 d = av_clip_intp2(ROUNDED_DIV(d, scale), 3); 86 87 put_sbits(&pb, 4, d); 88 89 s0 = d * scale + ((c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS); 90 s2 = s1; 91 s1 = s0; 92 } 93 prev->s1 = s1; 94 prev->s2 = s2; 95 96 flush_put_bits(&pb); 97} 98 99#define HEADER_SIZE 36 100 101static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize) 102{ 103 ADXContext *c = avctx->priv_data; 104 105 bytestream_put_be16(&buf, 0x8000); /* header signature */ 106 bytestream_put_be16(&buf, HEADER_SIZE - 4); /* copyright offset */ 107 bytestream_put_byte(&buf, 3); /* encoding */ 108 bytestream_put_byte(&buf, BLOCK_SIZE); /* block size */ 109 bytestream_put_byte(&buf, 4); /* sample size */ 110 bytestream_put_byte(&buf, avctx->ch_layout.nb_channels); /* channels */ 111 bytestream_put_be32(&buf, avctx->sample_rate); /* sample rate */ 112 bytestream_put_be32(&buf, 0); /* total sample count */ 113 bytestream_put_be16(&buf, c->cutoff); /* cutoff frequency */ 114 bytestream_put_byte(&buf, 3); /* version */ 115 bytestream_put_byte(&buf, 0); /* flags */ 116 bytestream_put_be32(&buf, 0); /* unknown */ 117 bytestream_put_be32(&buf, 0); /* loop enabled */ 118 bytestream_put_be16(&buf, 0); /* padding */ 119 bytestream_put_buffer(&buf, "(c)CRI", 6); /* copyright signature */ 120 121 return HEADER_SIZE; 122} 123 124static av_cold int adx_encode_init(AVCodecContext *avctx) 125{ 126 ADXContext *c = avctx->priv_data; 127 128 if (avctx->ch_layout.nb_channels > 2) { 129 av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n"); 130 return AVERROR(EINVAL); 131 } 132 avctx->frame_size = BLOCK_SAMPLES; 133 134 /* the cutoff can be adjusted, but this seems to work pretty well */ 135 c->cutoff = 500; 136 ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff); 137 138 return 0; 139} 140 141static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, 142 const AVFrame *frame, int *got_packet_ptr) 143{ 144 ADXContext *c = avctx->priv_data; 145 const int16_t *samples = frame ? (const int16_t *)frame->data[0] : NULL; 146 uint8_t *dst; 147 int channels = avctx->ch_layout.nb_channels; 148 int ch, out_size, ret; 149 150 if (!samples) { 151 if (c->eof) 152 return 0; 153 if ((ret = ff_get_encode_buffer(avctx, avpkt, 18, 0)) < 0) 154 return ret; 155 c->eof = 1; 156 dst = avpkt->data; 157 bytestream_put_be16(&dst, 0x8001); 158 bytestream_put_be16(&dst, 0x000E); 159 bytestream_put_be64(&dst, 0x0); 160 bytestream_put_be32(&dst, 0x0); 161 bytestream_put_be16(&dst, 0x0); 162 *got_packet_ptr = 1; 163 return 0; 164 } 165 166 out_size = BLOCK_SIZE * channels + !c->header_parsed * HEADER_SIZE; 167 if ((ret = ff_get_encode_buffer(avctx, avpkt, out_size, 0)) < 0) 168 return ret; 169 dst = avpkt->data; 170 171 if (!c->header_parsed) { 172 int hdrsize; 173 if ((hdrsize = adx_encode_header(avctx, dst, avpkt->size)) < 0) { 174 av_log(avctx, AV_LOG_ERROR, "output buffer is too small\n"); 175 return AVERROR(EINVAL); 176 } 177 dst += hdrsize; 178 c->header_parsed = 1; 179 } 180 181 for (ch = 0; ch < channels; ch++) { 182 adx_encode(c, dst, samples + ch, &c->prev[ch], channels); 183 dst += BLOCK_SIZE; 184 } 185 186 avpkt->pts = frame->pts; 187 avpkt->duration = frame->nb_samples; 188 *got_packet_ptr = 1; 189 return 0; 190} 191 192const FFCodec ff_adpcm_adx_encoder = { 193 .p.name = "adpcm_adx", 194 .p.long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"), 195 .p.type = AVMEDIA_TYPE_AUDIO, 196 .p.id = AV_CODEC_ID_ADPCM_ADX, 197 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY, 198 .priv_data_size = sizeof(ADXContext), 199 .init = adx_encode_init, 200 FF_CODEC_ENCODE_CB(adx_encode_frame), 201 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, 202 AV_SAMPLE_FMT_NONE }, 203 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 204}; 205