1/* 2 * 8088flex TMV video decoder 3 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * 8088flex TMV video decoder 25 * @author Daniel Verkamp 26 * @see http://www.oldskool.org/pc/8088_Corruption 27 */ 28 29#include <string.h> 30 31#include "avcodec.h" 32#include "internal.h" 33#include "libavutil/internal.h" 34#include "libavutil/xga_font_data.h" 35 36#include "cga_data.h" 37 38static int tmv_decode_frame(AVCodecContext *avctx, void *data, 39 int *got_frame, AVPacket *avpkt) 40{ 41 AVFrame *frame = data; 42 const uint8_t *src = avpkt->data; 43 uint8_t *dst; 44 unsigned char_cols = avctx->width >> 3; 45 unsigned char_rows = avctx->height >> 3; 46 unsigned x, y, fg, bg, c; 47 int ret; 48 49 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 50 return ret; 51 52 if (avpkt->size < 2*char_rows*char_cols) { 53 av_log(avctx, AV_LOG_ERROR, 54 "Input buffer too small, truncated sample?\n"); 55 *got_frame = 0; 56 return AVERROR_INVALIDDATA; 57 } 58 59 frame->pict_type = AV_PICTURE_TYPE_I; 60 frame->key_frame = 1; 61 dst = frame->data[0]; 62 63 frame->palette_has_changed = 1; 64 memcpy(frame->data[1], ff_cga_palette, 16 * 4); 65 memset(frame->data[1] + 16 * 4, 0, AVPALETTE_SIZE - 16 * 4); 66 67 for (y = 0; y < char_rows; y++) { 68 for (x = 0; x < char_cols; x++) { 69 c = *src++; 70 bg = *src >> 4; 71 fg = *src++ & 0xF; 72 ff_draw_pc_font(dst + x * 8, frame->linesize[0], 73 avpriv_cga_font, 8, c, fg, bg); 74 } 75 dst += frame->linesize[0] * 8; 76 } 77 78 *got_frame = 1; 79 80 return avpkt->size; 81} 82 83static av_cold int tmv_decode_init(AVCodecContext *avctx) 84{ 85 avctx->pix_fmt = AV_PIX_FMT_PAL8; 86 return 0; 87} 88 89AVCodec ff_tmv_decoder = { 90 .name = "tmv", 91 .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"), 92 .type = AVMEDIA_TYPE_VIDEO, 93 .id = AV_CODEC_ID_TMV, 94 .init = tmv_decode_init, 95 .decode = tmv_decode_frame, 96 .capabilities = CODEC_CAP_DR1, 97}; 98