librempeg/libavcodec/sp5xdec.c
Andreas Rheinhardt 05086a6c93 avcodec/mjpegdec: Only use receive_frame for SMVJPEG
Only one codec using mjpegdec.c actually creates multiple
frames from a single packet, namely SMVJPEG. The other can
use the ordinary decode callback just fine. This e.g. has
the advantage of confining the special SP5X/AMV code to sp5xdec.c.

This reverts most of commit e9a2a8777317d91af658f774c68442ac4aa726ec;
of course it is not a simple revert: Way too much has changed;
furthermore, outright reverting the sp5xdec.c changes would readd
a stack packet to sp5x_decode_frame() which is not desired.
In order to avoid this without modifying the given AVPacket,
a variant of ff_mjpeg_decode_frame() with explicit buf and size
parameters has been added.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-12-10 21:15:27 +01:00

126 lines
3.6 KiB
C

/*
* 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 "config_components.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "mjpeg.h"
#include "mjpegdec.h"
#include "sp5x.h"
static int sp5x_decode_frame(AVCodecContext *avctx,
AVFrame *frame, int *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
uint8_t *recoded;
int i = 0, j = 0;
int ret;
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_qscale_five_quant_table[0], 64);
memcpy(recoded + j + 70, &sp5x_qscale_five_quant_table[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;
ret = ff_mjpeg_decode_frame_from_buf(avctx, frame, got_frame,
avpkt, recoded, j);
av_free(recoded);
return ret < 0 ? ret : avpkt->size;
}
#if CONFIG_SP5X_DECODER
const FFCodec ff_sp5x_decoder = {
.p.name = "sp5x",
CODEC_LONG_NAME("Sunplus JPEG (SP5X)"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_SP5X,
.priv_data_size = sizeof(MJpegDecodeContext),
.init = ff_mjpeg_decode_init,
.close = ff_mjpeg_decode_end,
FF_CODEC_DECODE_CB(sp5x_decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
.p.max_lowres = 3,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};
#endif
#if CONFIG_AMV_DECODER
const FFCodec ff_amv_decoder = {
.p.name = "amv",
CODEC_LONG_NAME("AMV Video"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_AMV,
.priv_data_size = sizeof(MJpegDecodeContext),
.init = ff_mjpeg_decode_init,
.close = ff_mjpeg_decode_end,
FF_CODEC_DECODE_CB(sp5x_decode_frame),
.p.max_lowres = 3,
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};
#endif