| 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 */ |
| 46 | typedef 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 | |
| 57 | static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 }; |
| 58 | static 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 | */ |
| 69 | static 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 */ |
| 86 | static 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_INVALIDDATA; |
| 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_INVALIDDATA; |
| 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 | |
| 154 | static 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 | |
| 175 | static 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 |
| 188 | AVCodec 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 |
| 203 | AVCodec 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 |