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FFmpeg/libavcodec/sp5xdec.c

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/*
* Sunplus JPEG decoder (SP5X)
* Copyright (c) 2003 Alex Beregszaszi
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Sunplus JPEG decoder (SP5X).
*/
#include "avcodec.h"
#include "mjpeg.h"
#include "mjpegdec.h"
#include "sp5x.h"
static int sp5x_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
AVPacket avpkt_recoded;
const int qscale = 5;
uint8_t *recoded;
int i = 0, j = 0;
if (!avctx->width || !avctx->height)
return -1;
recoded = av_mallocz(buf_size + 1024);
if (!recoded)
return -1;
/* SOI */
recoded[j++] = 0xFF;
recoded[j++] = 0xD8;
memcpy(recoded+j, &sp5x_data_dqt[0], sizeof(sp5x_data_dqt));
memcpy(recoded+j+5, &sp5x_quant_table[qscale * 2], 64);
memcpy(recoded+j+70, &sp5x_quant_table[(qscale * 2) + 1], 64);
j += sizeof(sp5x_data_dqt);
memcpy(recoded+j, &sp5x_data_dht[0], sizeof(sp5x_data_dht));
j += sizeof(sp5x_data_dht);
memcpy(recoded+j, &sp5x_data_sof[0], sizeof(sp5x_data_sof));
AV_WB16(recoded+j+5, avctx->coded_height);
AV_WB16(recoded+j+7, avctx->coded_width);
j += sizeof(sp5x_data_sof);
memcpy(recoded+j, &sp5x_data_sos[0], sizeof(sp5x_data_sos));
j += sizeof(sp5x_data_sos);
if(avctx->codec_id==AV_CODEC_ID_AMV)
for (i = 2; i < buf_size-2 && j < buf_size+1024-2; i++)
recoded[j++] = buf[i];
else
for (i = 14; i < buf_size && j < buf_size+1024-3; i++)
{
recoded[j++] = buf[i];
if (buf[i] == 0xff)
recoded[j++] = 0;
}
/* EOI */
recoded[j++] = 0xFF;
recoded[j++] = 0xD9;
av_init_packet(&avpkt_recoded);
avpkt_recoded.data = recoded;
avpkt_recoded.size = j;
i = ff_mjpeg_decode_frame(avctx, data, data_size, &avpkt_recoded);
av_free(recoded);
return i < 0 ? i : avpkt->size;
}
#if CONFIG_SP5X_DECODER
AVCodec ff_sp5x_decoder = {
.name = "sp5x",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_SP5X,
.priv_data_size = sizeof(MJpegDecodeContext),
.init = ff_mjpeg_decode_init,
.close = ff_mjpeg_decode_end,
.decode = sp5x_decode_frame,
.capabilities = CODEC_CAP_DR1,
.max_lowres = 3,
.long_name = NULL_IF_CONFIG_SMALL("Sunplus JPEG (SP5X)"),
};
#endif
#if CONFIG_AMV_DECODER
AVCodec ff_amv_decoder = {
.name = "amv",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_AMV,
.priv_data_size = sizeof(MJpegDecodeContext),
.init = ff_mjpeg_decode_init,
.close = ff_mjpeg_decode_end,
.decode = sp5x_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("AMV Video"),
};
#endif