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 "internal.h" 26#include "put_bits.h" 27 28/** 29 * @file 30 * SEGA CRI adx codecs. 31 * 32 * Reference documents: 33 * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html 34 * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/ 35 */ 36 37static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav, 38 ADXChannelState *prev, int channels) 39{ 40 PutBitContext pb; 41 int scale; 42 int i, j; 43 int s0, s1, s2, d; 44 int max = 0; 45 int min = 0; 46 int data[BLOCK_SAMPLES]; 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 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; 53 data[j] = d; 54 if (max < d) 55 max = d; 56 if (min > d) 57 min = d; 58 s2 = s1; 59 s1 = s0; 60 } 61 prev->s1 = s1; 62 prev->s2 = s2; 63 64 if (max == 0 && min == 0) { 65 memset(adx, 0, BLOCK_SIZE); 66 return; 67 } 68 69 if (max / 7 > -min / 8) 70 scale = max / 7; 71 else 72 scale = -min / 8; 73 74 if (scale == 0) 75 scale = 1; 76 77 AV_WB16(adx, scale); 78 79 init_put_bits(&pb, adx + 2, 16); 80 for (i = 0; i < BLOCK_SAMPLES; i++) 81 put_sbits(&pb, 4, av_clip(data[i] / scale, -8, 7)); 82 flush_put_bits(&pb); 83} 84 85#define HEADER_SIZE 36 86 87static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize) 88{ 89 ADXContext *c = avctx->priv_data; 90 91 bytestream_put_be16(&buf, 0x8000); /* header signature */ 92 bytestream_put_be16(&buf, HEADER_SIZE - 4); /* copyright offset */ 93 bytestream_put_byte(&buf, 3); /* encoding */ 94 bytestream_put_byte(&buf, BLOCK_SIZE); /* block size */ 95 bytestream_put_byte(&buf, 4); /* sample size */ 96 bytestream_put_byte(&buf, avctx->channels); /* channels */ 97 bytestream_put_be32(&buf, avctx->sample_rate); /* sample rate */ 98 bytestream_put_be32(&buf, 0); /* total sample count */ 99 bytestream_put_be16(&buf, c->cutoff); /* cutoff frequency */ 100 bytestream_put_byte(&buf, 3); /* version */ 101 bytestream_put_byte(&buf, 0); /* flags */ 102 bytestream_put_be32(&buf, 0); /* unknown */ 103 bytestream_put_be32(&buf, 0); /* loop enabled */ 104 bytestream_put_be16(&buf, 0); /* padding */ 105 bytestream_put_buffer(&buf, "(c)CRI", 6); /* copyright signature */ 106 107 return HEADER_SIZE; 108} 109 110static av_cold int adx_encode_init(AVCodecContext *avctx) 111{ 112 ADXContext *c = avctx->priv_data; 113 114 if (avctx->channels > 2) { 115 av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n"); 116 return AVERROR(EINVAL); 117 } 118 avctx->frame_size = BLOCK_SAMPLES; 119 120 /* the cutoff can be adjusted, but this seems to work pretty well */ 121 c->cutoff = 500; 122 ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff); 123 124 return 0; 125} 126 127static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, 128 const AVFrame *frame, int *got_packet_ptr) 129{ 130 ADXContext *c = avctx->priv_data; 131 const int16_t *samples = (const int16_t *)frame->data[0]; 132 uint8_t *dst; 133 int ch, out_size, ret; 134 135 out_size = BLOCK_SIZE * avctx->channels + !c->header_parsed * HEADER_SIZE; 136 if ((ret = ff_alloc_packet2(avctx, avpkt, out_size)) < 0) 137 return ret; 138 dst = avpkt->data; 139 140 if (!c->header_parsed) { 141 int hdrsize; 142 if ((hdrsize = adx_encode_header(avctx, dst, avpkt->size)) < 0) { 143 av_log(avctx, AV_LOG_ERROR, "output buffer is too small\n"); 144 return AVERROR(EINVAL); 145 } 146 dst += hdrsize; 147 c->header_parsed = 1; 148 } 149 150 for (ch = 0; ch < avctx->channels; ch++) { 151 adx_encode(c, dst, samples + ch, &c->prev[ch], avctx->channels); 152 dst += BLOCK_SIZE; 153 } 154 155 *got_packet_ptr = 1; 156 return 0; 157} 158 159AVCodec ff_adpcm_adx_encoder = { 160 .name = "adpcm_adx", 161 .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"), 162 .type = AVMEDIA_TYPE_AUDIO, 163 .id = AV_CODEC_ID_ADPCM_ADX, 164 .priv_data_size = sizeof(ADXContext), 165 .init = adx_encode_init, 166 .encode2 = adx_encode_frame, 167 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, 168 AV_SAMPLE_FMT_NONE }, 169}; 170