1/* 2 * Copyright (C) 2008 Jaikrishnan Menon 3 * Copyright (C) 2011 Stefano Sabatini 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/** 23 * @file 24 * 8svx audio decoder 25 * @author Jaikrishnan Menon 26 * 27 * supports: fibonacci delta encoding 28 * : exponential encoding 29 * 30 * For more information about the 8SVX format: 31 * http://netghost.narod.ru/gff/vendspec/iff/iff.txt 32 * http://sox.sourceforge.net/AudioFormats-11.html 33 * http://aminet.net/package/mus/misc/wavepak 34 * http://amigan.1emu.net/reg/8SVX.txt 35 * 36 * Samples can be found here: 37 * http://aminet.net/mods/smpl/ 38 */ 39 40#include "libavutil/avassert.h" 41#include "avcodec.h" 42#include "internal.h" 43#include "libavutil/common.h" 44 45/** decoder context */ 46typedef struct EightSvxContext { 47 uint8_t fib_acc[2]; 48 const int8_t *table; 49 50 /* buffer used to store the whole first packet. 51 data is only sent as one large packet */ 52 uint8_t *data[2]; 53 int data_size; 54 int data_idx; 55} EightSvxContext; 56 57static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 }; 58static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 }; 59 60#define MAX_FRAME_SIZE 2048 61 62/** 63 * Delta decode the compressed values in src, and put the resulting 64 * decoded samples in dst. 65 * 66 * @param[in,out] state starting value. it is saved for use in the next call. 67 * @param table delta sequence table 68 */ 69static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size, 70 uint8_t *state, const int8_t *table) 71{ 72 uint8_t val = *state; 73 74 while (src_size--) { 75 uint8_t d = *src++; 76 val = av_clip_uint8(val + table[d & 0xF]); 77 *dst++ = val; 78 val = av_clip_uint8(val + table[d >> 4]); 79 *dst++ = val; 80 } 81 82 *state = val; 83} 84 85/** decode a frame */ 86static int eightsvx_decode_frame(AVCodecContext *avctx, void *data, 87 int *got_frame_ptr, AVPacket *avpkt) 88{ 89 EightSvxContext *esc = avctx->priv_data; 90 AVFrame *frame = data; 91 int buf_size; 92 int ch, ret; 93 int hdr_size = 2; 94 95 /* decode and interleave the first packet */ 96 if (!esc->data[0] && avpkt) { 97 int chan_size = avpkt->size / avctx->channels - hdr_size; 98 99 if (avpkt->size % avctx->channels) { 100 av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n"); 101 } 102 if (avpkt->size < (hdr_size + 1) * avctx->channels) { 103 av_log(avctx, AV_LOG_ERROR, "packet size is too small\n"); 104 return AVERROR(EINVAL); 105 } 106 107 esc->fib_acc[0] = avpkt->data[1] + 128; 108 if (avctx->channels == 2) 109 esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128; 110 111 esc->data_idx = 0; 112 esc->data_size = chan_size; 113 if (!(esc->data[0] = av_malloc(chan_size))) 114 return AVERROR(ENOMEM); 115 if (avctx->channels == 2) { 116 if (!(esc->data[1] = av_malloc(chan_size))) { 117 av_freep(&esc->data[0]); 118 return AVERROR(ENOMEM); 119 } 120 } 121 memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size); 122 if (avctx->channels == 2) 123 memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size); 124 } 125 if (!esc->data[0]) { 126 av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n"); 127 return AVERROR(EINVAL); 128 } 129 130 /* decode next piece of data from the buffer */ 131 buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx); 132 if (buf_size <= 0) { 133 *got_frame_ptr = 0; 134 return avpkt->size; 135 } 136 137 /* get output buffer */ 138 frame->nb_samples = buf_size * 2; 139 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 140 return ret; 141 142 for (ch = 0; ch < avctx->channels; ch++) { 143 delta_decode(frame->data[ch], &esc->data[ch][esc->data_idx], 144 buf_size, &esc->fib_acc[ch], esc->table); 145 } 146 147 esc->data_idx += buf_size; 148 149 *got_frame_ptr = 1; 150 151 return ((avctx->frame_number == 0)*hdr_size + buf_size)*avctx->channels; 152} 153 154static av_cold int eightsvx_decode_init(AVCodecContext *avctx) 155{ 156 EightSvxContext *esc = avctx->priv_data; 157 158 if (avctx->channels < 1 || avctx->channels > 2) { 159 av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n"); 160 return AVERROR_INVALIDDATA; 161 } 162 163 switch (avctx->codec->id) { 164 case AV_CODEC_ID_8SVX_FIB: esc->table = fibonacci; break; 165 case AV_CODEC_ID_8SVX_EXP: esc->table = exponential; break; 166 default: 167 av_log(avctx, AV_LOG_ERROR, "Invalid codec id %d.\n", avctx->codec->id); 168 return AVERROR_INVALIDDATA; 169 } 170 avctx->sample_fmt = AV_SAMPLE_FMT_U8P; 171 172 return 0; 173} 174 175static av_cold int eightsvx_decode_close(AVCodecContext *avctx) 176{ 177 EightSvxContext *esc = avctx->priv_data; 178 179 av_freep(&esc->data[0]); 180 av_freep(&esc->data[1]); 181 esc->data_size = 0; 182 esc->data_idx = 0; 183 184 return 0; 185} 186 187#if CONFIG_EIGHTSVX_FIB_DECODER 188AVCodec ff_eightsvx_fib_decoder = { 189 .name = "8svx_fib", 190 .long_name = NULL_IF_CONFIG_SMALL("8SVX fibonacci"), 191 .type = AVMEDIA_TYPE_AUDIO, 192 .id = AV_CODEC_ID_8SVX_FIB, 193 .priv_data_size = sizeof (EightSvxContext), 194 .init = eightsvx_decode_init, 195 .decode = eightsvx_decode_frame, 196 .close = eightsvx_decode_close, 197 .capabilities = CODEC_CAP_DR1, 198 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P, 199 AV_SAMPLE_FMT_NONE }, 200}; 201#endif 202#if CONFIG_EIGHTSVX_EXP_DECODER 203AVCodec ff_eightsvx_exp_decoder = { 204 .name = "8svx_exp", 205 .long_name = NULL_IF_CONFIG_SMALL("8SVX exponential"), 206 .type = AVMEDIA_TYPE_AUDIO, 207 .id = AV_CODEC_ID_8SVX_EXP, 208 .priv_data_size = sizeof (EightSvxContext), 209 .init = eightsvx_decode_init, 210 .decode = eightsvx_decode_frame, 211 .close = eightsvx_decode_close, 212 .capabilities = CODEC_CAP_DR1, 213 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P, 214 AV_SAMPLE_FMT_NONE }, 215}; 216#endif 217