yading@10: /*
yading@10:  * Copyright (C) 2008 Jaikrishnan Menon
yading@10:  * Copyright (C) 2011 Stefano Sabatini
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * 8svx audio decoder
yading@10:  * @author Jaikrishnan Menon
yading@10:  *
yading@10:  * supports: fibonacci delta encoding
yading@10:  *         : exponential encoding
yading@10:  *
yading@10:  * For more information about the 8SVX format:
yading@10:  * http://netghost.narod.ru/gff/vendspec/iff/iff.txt
yading@10:  * http://sox.sourceforge.net/AudioFormats-11.html
yading@10:  * http://aminet.net/package/mus/misc/wavepak
yading@10:  * http://amigan.1emu.net/reg/8SVX.txt
yading@10:  *
yading@10:  * Samples can be found here:
yading@10:  * http://aminet.net/mods/smpl/
yading@10:  */
yading@10: 
yading@10: #include "libavutil/avassert.h"
yading@10: #include "avcodec.h"
yading@10: #include "internal.h"
yading@10: #include "libavutil/common.h"
yading@10: 
yading@10: /** decoder context */
yading@10: typedef struct EightSvxContext {
yading@10:     uint8_t fib_acc[2];
yading@10:     const int8_t *table;
yading@10: 
yading@10:     /* buffer used to store the whole first packet.
yading@10:        data is only sent as one large packet */
yading@10:     uint8_t *data[2];
yading@10:     int data_size;
yading@10:     int data_idx;
yading@10: } EightSvxContext;
yading@10: 
yading@10: static const int8_t fibonacci[16]   = { -34,  -21, -13,  -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8,  13, 21 };
yading@10: static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 };
yading@10: 
yading@10: #define MAX_FRAME_SIZE 2048
yading@10: 
yading@10: /**
yading@10:  * Delta decode the compressed values in src, and put the resulting
yading@10:  * decoded samples in dst.
yading@10:  *
yading@10:  * @param[in,out] state starting value. it is saved for use in the next call.
yading@10:  * @param table delta sequence table
yading@10:  */
yading@10: static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
yading@10:                          uint8_t *state, const int8_t *table)
yading@10: {
yading@10:     uint8_t val = *state;
yading@10: 
yading@10:     while (src_size--) {
yading@10:         uint8_t d = *src++;
yading@10:         val = av_clip_uint8(val + table[d & 0xF]);
yading@10:         *dst++ = val;
yading@10:         val = av_clip_uint8(val + table[d >> 4]);
yading@10:         *dst++ = val;
yading@10:     }
yading@10: 
yading@10:     *state = val;
yading@10: }
yading@10: 
yading@10: /** decode a frame */
yading@10: static int eightsvx_decode_frame(AVCodecContext *avctx, void *data,
yading@10:                                  int *got_frame_ptr, AVPacket *avpkt)
yading@10: {
yading@10:     EightSvxContext *esc = avctx->priv_data;
yading@10:     AVFrame *frame       = data;
yading@10:     int buf_size;
yading@10:     int ch, ret;
yading@10:     int hdr_size = 2;
yading@10: 
yading@10:     /* decode and interleave the first packet */
yading@10:     if (!esc->data[0] && avpkt) {
yading@10:         int chan_size = avpkt->size / avctx->channels - hdr_size;
yading@10: 
yading@10:         if (avpkt->size % avctx->channels) {
yading@10:             av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n");
yading@10:         }
yading@10:         if (avpkt->size < (hdr_size + 1) * avctx->channels) {
yading@10:             av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
yading@10:             return AVERROR(EINVAL);
yading@10:         }
yading@10: 
yading@10:         esc->fib_acc[0] = avpkt->data[1] + 128;
yading@10:         if (avctx->channels == 2)
yading@10:             esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128;
yading@10: 
yading@10:         esc->data_idx  = 0;
yading@10:         esc->data_size = chan_size;
yading@10:         if (!(esc->data[0] = av_malloc(chan_size)))
yading@10:             return AVERROR(ENOMEM);
yading@10:         if (avctx->channels == 2) {
yading@10:             if (!(esc->data[1] = av_malloc(chan_size))) {
yading@10:                 av_freep(&esc->data[0]);
yading@10:                 return AVERROR(ENOMEM);
yading@10:             }
yading@10:         }
yading@10:         memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size);
yading@10:         if (avctx->channels == 2)
yading@10:             memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size);
yading@10:     }
yading@10:     if (!esc->data[0]) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n");
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     /* decode next piece of data from the buffer */
yading@10:     buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx);
yading@10:     if (buf_size <= 0) {
yading@10:         *got_frame_ptr = 0;
yading@10:         return avpkt->size;
yading@10:     }
yading@10: 
yading@10:     /* get output buffer */
yading@10:     frame->nb_samples = buf_size * 2;
yading@10:     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     for (ch = 0; ch < avctx->channels; ch++) {
yading@10:         delta_decode(frame->data[ch], &esc->data[ch][esc->data_idx],
yading@10:                      buf_size, &esc->fib_acc[ch], esc->table);
yading@10:     }
yading@10: 
yading@10:     esc->data_idx += buf_size;
yading@10: 
yading@10:     *got_frame_ptr = 1;
yading@10: 
yading@10:     return ((avctx->frame_number == 0)*hdr_size + buf_size)*avctx->channels;
yading@10: }
yading@10: 
yading@10: static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     EightSvxContext *esc = avctx->priv_data;
yading@10: 
yading@10:     if (avctx->channels < 1 || avctx->channels > 2) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     switch (avctx->codec->id) {
yading@10:     case AV_CODEC_ID_8SVX_FIB: esc->table = fibonacci;    break;
yading@10:     case AV_CODEC_ID_8SVX_EXP: esc->table = exponential;  break;
yading@10:     default:
yading@10:         av_log(avctx, AV_LOG_ERROR, "Invalid codec id %d.\n", avctx->codec->id);
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10:     avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
yading@10: {
yading@10:     EightSvxContext *esc = avctx->priv_data;
yading@10: 
yading@10:     av_freep(&esc->data[0]);
yading@10:     av_freep(&esc->data[1]);
yading@10:     esc->data_size = 0;
yading@10:     esc->data_idx = 0;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: #if CONFIG_EIGHTSVX_FIB_DECODER
yading@10: AVCodec ff_eightsvx_fib_decoder = {
yading@10:   .name           = "8svx_fib",
yading@10:   .type           = AVMEDIA_TYPE_AUDIO,
yading@10:   .id             = AV_CODEC_ID_8SVX_FIB,
yading@10:   .priv_data_size = sizeof (EightSvxContext),
yading@10:   .init           = eightsvx_decode_init,
yading@10:   .decode         = eightsvx_decode_frame,
yading@10:   .close          = eightsvx_decode_close,
yading@10:   .capabilities   = CODEC_CAP_DR1,
yading@10:   .long_name      = NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
yading@10:   .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
yading@10:                                                     AV_SAMPLE_FMT_NONE },
yading@10: };
yading@10: #endif
yading@10: #if CONFIG_EIGHTSVX_EXP_DECODER
yading@10: AVCodec ff_eightsvx_exp_decoder = {
yading@10:   .name           = "8svx_exp",
yading@10:   .type           = AVMEDIA_TYPE_AUDIO,
yading@10:   .id             = AV_CODEC_ID_8SVX_EXP,
yading@10:   .priv_data_size = sizeof (EightSvxContext),
yading@10:   .init           = eightsvx_decode_init,
yading@10:   .decode         = eightsvx_decode_frame,
yading@10:   .close          = eightsvx_decode_close,
yading@10:   .capabilities   = CODEC_CAP_DR1,
yading@10:   .long_name      = NULL_IF_CONFIG_SMALL("8SVX exponential"),
yading@10:   .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
yading@10:                                                     AV_SAMPLE_FMT_NONE },
yading@10: };
yading@10: #endif