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* 8088flex TMV video decoder
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* Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
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* This file is part of FFmpeg.
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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* 8088flex TMV video decoder
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* @author Daniel Verkamp
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* @sa http://www.oldskool.org/pc/8088_Corruption
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typedef struct TMVContext {
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static int tmv_decode_frame(AVCodecContext *avctx, void *data,
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int *data_size, AVPacket *avpkt)
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TMVContext *tmv = avctx->priv_data;
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const uint8_t *src = avpkt->data;
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uint8_t *dst, *dst_char;
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unsigned char_cols = avctx->width >> 3;
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unsigned char_rows = avctx->height >> 3;
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unsigned x, y, mask, char_y, fg, bg, c;
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avctx->release_buffer(avctx, &tmv->pic);
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if (avctx->get_buffer(avctx, &tmv->pic) < 0) {
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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if (avpkt->size < 2*char_rows*char_cols) {
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av_log(avctx, AV_LOG_ERROR,
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"Input buffer too small, truncated sample?\n");
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tmv->pic.pict_type = FF_I_TYPE;
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tmv->pic.key_frame = 1;
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dst = tmv->pic.data[0];
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tmv->pic.palette_has_changed = 1;
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memcpy(tmv->pic.data[1], ff_cga_palette, 16 * 4);
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for (y = 0; y < char_rows; y++) {
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for (x = 0; x < char_cols; x++) {
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dst_char = dst + x * 8;
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for (char_y = 0; char_y < 8; char_y++) {
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for (mask = 0x80; mask; mask >>= 1) {
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*dst_char++ = ff_cga_font[c + char_y] & mask ? fg : bg;
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dst_char += tmv->pic.linesize[0] - 8;
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dst += tmv->pic.linesize[0] * 8;
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*data_size = sizeof(AVFrame);
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*(AVFrame *)data = tmv->pic;
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static av_cold int tmv_decode_close(AVCodecContext *avctx)
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TMVContext *tmv = avctx->priv_data;
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avctx->release_buffer(avctx, &tmv->pic);
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AVCodec tmv_decoder = {
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.type = AVMEDIA_TYPE_VIDEO,
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.priv_data_size = sizeof(TMVContext),
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.close = tmv_decode_close,
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.decode = tmv_decode_frame,
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.capabilities = CODEC_CAP_DR1,
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.long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),