2 * Copyright (C) 2008 Jaikrishnan Menon
3 * Copyright (C) 2011 Stefano Sabatini
5 * This file is part of FFmpeg.
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.
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.
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
25 * @author Jaikrishnan Menon
27 * supports: fibonacci delta encoding
28 * : exponential encoding
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
36 * Samples can be found here:
37 * http://aminet.net/mods/smpl/
40 #include "libavutil/avassert.h"
42 #include "libavutil/common.h"
44 /** decoder context */
45 typedef struct EightSvxContext {
50 /* buffer used to store the whole first packet.
51 data is only sent as one large packet */
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 };
60 #define MAX_FRAME_SIZE 2048
63 * Delta decode the compressed values in src, and put the resulting
64 * decoded samples in dst.
66 * @param[in,out] state starting value. it is saved for use in the next call.
67 * @param table delta sequence table
69 static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
70 uint8_t *state, const int8_t *table)
76 val = av_clip_uint8(val + table[d & 0xF]);
78 val = av_clip_uint8(val + table[d >> 4]);
86 static int eightsvx_decode_frame(AVCodecContext *avctx, void *data,
87 int *got_frame_ptr, AVPacket *avpkt)
89 EightSvxContext *esc = avctx->priv_data;
94 /* decode and interleave the first packet */
95 if (!esc->data[0] && avpkt) {
96 int chan_size = avpkt->size / avctx->channels - hdr_size;
98 if (avpkt->size % avctx->channels) {
99 av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n");
101 if (avpkt->size < (hdr_size + 1) * avctx->channels) {
102 av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
103 return AVERROR(EINVAL);
106 esc->fib_acc[0] = avpkt->data[1] + 128;
107 if (avctx->channels == 2)
108 esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128;
111 esc->data_size = chan_size;
112 if (!(esc->data[0] = av_malloc(chan_size)))
113 return AVERROR(ENOMEM);
114 if (avctx->channels == 2) {
115 if (!(esc->data[1] = av_malloc(chan_size))) {
116 av_freep(&esc->data[0]);
117 return AVERROR(ENOMEM);
120 memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size);
121 if (avctx->channels == 2)
122 memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size);
125 av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n");
126 return AVERROR(EINVAL);
129 /* decode next piece of data from the buffer */
130 buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx);
136 /* get output buffer */
137 esc->frame.nb_samples = buf_size * 2;
138 if ((ret = avctx->get_buffer(avctx, &esc->frame)) < 0) {
139 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
143 for (ch = 0; ch < avctx->channels; ch++) {
144 delta_decode(esc->frame.data[ch], &esc->data[ch][esc->data_idx],
145 buf_size, &esc->fib_acc[ch], esc->table);
148 esc->data_idx += buf_size;
151 *(AVFrame *)data = esc->frame;
153 return ((avctx->frame_number == 0)*hdr_size + buf_size)*avctx->channels;
156 static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
158 EightSvxContext *esc = avctx->priv_data;
160 if (avctx->channels < 1 || avctx->channels > 2) {
161 av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
162 return AVERROR_INVALIDDATA;
165 switch (avctx->codec->id) {
166 case AV_CODEC_ID_8SVX_FIB: esc->table = fibonacci; break;
167 case AV_CODEC_ID_8SVX_EXP: esc->table = exponential; break;
169 av_log(avctx, AV_LOG_ERROR, "Invalid codec id %d.\n", avctx->codec->id);
170 return AVERROR_INVALIDDATA;
172 avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
174 avcodec_get_frame_defaults(&esc->frame);
175 avctx->coded_frame = &esc->frame;
180 static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
182 EightSvxContext *esc = avctx->priv_data;
184 av_freep(&esc->data[0]);
185 av_freep(&esc->data[1]);
192 #if CONFIG_EIGHTSVX_FIB_DECODER
193 AVCodec ff_eightsvx_fib_decoder = {
195 .type = AVMEDIA_TYPE_AUDIO,
196 .id = AV_CODEC_ID_8SVX_FIB,
197 .priv_data_size = sizeof (EightSvxContext),
198 .init = eightsvx_decode_init,
199 .decode = eightsvx_decode_frame,
200 .close = eightsvx_decode_close,
201 .capabilities = CODEC_CAP_DR1,
202 .long_name = NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
203 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
204 AV_SAMPLE_FMT_NONE },
207 #if CONFIG_EIGHTSVX_EXP_DECODER
208 AVCodec ff_eightsvx_exp_decoder = {
210 .type = AVMEDIA_TYPE_AUDIO,
211 .id = AV_CODEC_ID_8SVX_EXP,
212 .priv_data_size = sizeof (EightSvxContext),
213 .init = eightsvx_decode_init,
214 .decode = eightsvx_decode_frame,
215 .close = eightsvx_decode_close,
216 .capabilities = CODEC_CAP_DR1,
217 .long_name = NULL_IF_CONFIG_SMALL("8SVX exponential"),
218 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
219 AV_SAMPLE_FMT_NONE },