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 "config_components.h" 41 42#include "libavutil/avassert.h" 43#include "avcodec.h" 44#include "codec_internal.h" 45#include "internal.h" 46#include "libavutil/common.h" 47 48/** decoder context */ 49typedef struct EightSvxContext { 50 uint8_t fib_acc[2]; 51 const int8_t *table; 52 53 /* buffer used to store the whole first packet. 54 data is only sent as one large packet */ 55 uint8_t *data[2]; 56 int data_size; 57 int data_idx; 58} EightSvxContext; 59 60static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 }; 61static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 }; 62 63#define MAX_FRAME_SIZE 2048 64 65/** 66 * Delta decode the compressed values in src, and put the resulting 67 * decoded samples in dst. 68 * 69 * @param[in,out] state starting value. it is saved for use in the next call. 70 * @param table delta sequence table 71 */ 72static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size, 73 uint8_t *state, const int8_t *table) 74{ 75 uint8_t val = *state; 76 77 while (src_size--) { 78 uint8_t d = *src++; 79 val = av_clip_uint8(val + table[d & 0xF]); 80 *dst++ = val; 81 val = av_clip_uint8(val + table[d >> 4]); 82 *dst++ = val; 83 } 84 85 *state = val; 86} 87 88/** decode a frame */ 89static int eightsvx_decode_frame(AVCodecContext *avctx, AVFrame *frame, 90 int *got_frame_ptr, AVPacket *avpkt) 91{ 92 EightSvxContext *esc = avctx->priv_data; 93 int channels = avctx->ch_layout.nb_channels; 94 int buf_size; 95 int ch, ret; 96 int hdr_size = 2; 97 98 /* decode and interleave the first packet */ 99 if (!esc->data[0] && avpkt) { 100 int chan_size = avpkt->size / channels - hdr_size; 101 102 if (avpkt->size % channels) { 103 av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n"); 104 } 105 if (avpkt->size < (hdr_size + 1) * channels) { 106 av_log(avctx, AV_LOG_ERROR, "packet size is too small\n"); 107 return AVERROR_INVALIDDATA; 108 } 109 110 esc->fib_acc[0] = avpkt->data[1] + 128; 111 if (channels == 2) 112 esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128; 113 114 esc->data_idx = 0; 115 esc->data_size = chan_size; 116 if (!(esc->data[0] = av_malloc(chan_size))) 117 return AVERROR(ENOMEM); 118 if (channels == 2) { 119 if (!(esc->data[1] = av_malloc(chan_size))) { 120 av_freep(&esc->data[0]); 121 return AVERROR(ENOMEM); 122 } 123 } 124 memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size); 125 if (channels == 2) 126 memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size); 127 } 128 if (!esc->data[0]) { 129 av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n"); 130 return AVERROR_INVALIDDATA; 131 } 132 133 /* decode next piece of data from the buffer */ 134 buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx); 135 if (buf_size <= 0) { 136 *got_frame_ptr = 0; 137 return avpkt->size; 138 } 139 140 /* get output buffer */ 141 frame->nb_samples = buf_size * 2; 142 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 143 return ret; 144 145 for (ch = 0; ch < channels; ch++) { 146 delta_decode(frame->data[ch], &esc->data[ch][esc->data_idx], 147 buf_size, &esc->fib_acc[ch], esc->table); 148 } 149 150 esc->data_idx += buf_size; 151 152 *got_frame_ptr = 1; 153 154 return ((avctx->frame_number == 0) * hdr_size + buf_size) * channels; 155} 156 157static av_cold int eightsvx_decode_init(AVCodecContext *avctx) 158{ 159 EightSvxContext *esc = avctx->priv_data; 160 161 if (avctx->ch_layout.nb_channels < 1 || avctx->ch_layout.nb_channels > 2) { 162 av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n"); 163 return AVERROR_INVALIDDATA; 164 } 165 166 switch (avctx->codec->id) { 167 case AV_CODEC_ID_8SVX_FIB: esc->table = fibonacci; break; 168 case AV_CODEC_ID_8SVX_EXP: esc->table = exponential; break; 169 default: 170 av_assert1(0); 171 } 172 avctx->sample_fmt = AV_SAMPLE_FMT_U8P; 173 174 return 0; 175} 176 177static av_cold int eightsvx_decode_close(AVCodecContext *avctx) 178{ 179 EightSvxContext *esc = avctx->priv_data; 180 181 av_freep(&esc->data[0]); 182 av_freep(&esc->data[1]); 183 esc->data_size = 0; 184 esc->data_idx = 0; 185 186 return 0; 187} 188 189#if CONFIG_EIGHTSVX_FIB_DECODER 190const FFCodec ff_eightsvx_fib_decoder = { 191 .p.name = "8svx_fib", 192 .p.long_name = NULL_IF_CONFIG_SMALL("8SVX fibonacci"), 193 .p.type = AVMEDIA_TYPE_AUDIO, 194 .p.id = AV_CODEC_ID_8SVX_FIB, 195 .priv_data_size = sizeof (EightSvxContext), 196 .init = eightsvx_decode_init, 197 FF_CODEC_DECODE_CB(eightsvx_decode_frame), 198 .close = eightsvx_decode_close, 199 .p.capabilities = AV_CODEC_CAP_DR1, 200 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P, 201 AV_SAMPLE_FMT_NONE }, 202 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 203}; 204#endif 205#if CONFIG_EIGHTSVX_EXP_DECODER 206const FFCodec ff_eightsvx_exp_decoder = { 207 .p.name = "8svx_exp", 208 .p.long_name = NULL_IF_CONFIG_SMALL("8SVX exponential"), 209 .p.type = AVMEDIA_TYPE_AUDIO, 210 .p.id = AV_CODEC_ID_8SVX_EXP, 211 .priv_data_size = sizeof (EightSvxContext), 212 .init = eightsvx_decode_init, 213 FF_CODEC_DECODE_CB(eightsvx_decode_frame), 214 .close = eightsvx_decode_close, 215 .p.capabilities = AV_CODEC_CAP_DR1, 216 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P, 217 AV_SAMPLE_FMT_NONE }, 218 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 219}; 220#endif 221