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FFmpeg/libavcodec/tmv.c

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/*
* 8088flex TMV video decoder
* Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
*
* 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
* 8088flex TMV video decoder
* @author Daniel Verkamp
* @see http://www.oldskool.org/pc/8088_Corruption
*/
#include <string.h>
#include "avcodec.h"
#include "libavutil/internal.h"
#include "cga_data.h"
typedef struct TMVContext {
AVFrame pic;
} TMVContext;
static int tmv_decode_frame(AVCodecContext *avctx, void *data,
int *data_size, AVPacket *avpkt)
{
TMVContext *tmv = avctx->priv_data;
const uint8_t *src = avpkt->data;
uint8_t *dst;
unsigned char_cols = avctx->width >> 3;
unsigned char_rows = avctx->height >> 3;
unsigned x, y, fg, bg, c;
if (tmv->pic.data[0])
avctx->release_buffer(avctx, &tmv->pic);
if (avctx->get_buffer(avctx, &tmv->pic) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
if (avpkt->size < 2*char_rows*char_cols) {
av_log(avctx, AV_LOG_ERROR,
"Input buffer too small, truncated sample?\n");
*data_size = 0;
return -1;
}
tmv->pic.pict_type = AV_PICTURE_TYPE_I;
tmv->pic.key_frame = 1;
dst = tmv->pic.data[0];
tmv->pic.palette_has_changed = 1;
memcpy(tmv->pic.data[1], ff_cga_palette, 16 * 4);
for (y = 0; y < char_rows; y++) {
for (x = 0; x < char_cols; x++) {
c = *src++;
bg = *src >> 4;
fg = *src++ & 0xF;
ff_draw_pc_font(dst + x * 8, tmv->pic.linesize[0],
ff_cga_font, 8, c, fg, bg);
}
dst += tmv->pic.linesize[0] * 8;
}
*data_size = sizeof(AVFrame);
*(AVFrame *)data = tmv->pic;
return avpkt->size;
}
static av_cold int tmv_decode_init(AVCodecContext *avctx)
{
TMVContext *tmv = avctx->priv_data;
avctx->pix_fmt = PIX_FMT_PAL8;
avcodec_get_frame_defaults(&tmv->pic);
return 0;
}
static av_cold int tmv_decode_close(AVCodecContext *avctx)
{
TMVContext *tmv = avctx->priv_data;
if (tmv->pic.data[0])
avctx->release_buffer(avctx, &tmv->pic);
return 0;
}
AVCodec ff_tmv_decoder = {
.name = "tmv",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_TMV,
.priv_data_size = sizeof(TMVContext),
.init = tmv_decode_init,
.close = tmv_decode_close,
.decode = tmv_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
};