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 * 8088flex TMV video decoder 24 * @file 25 * @author Daniel Verkamp 26 * @sa http://www.oldskool.org/pc/8088_Corruption 27 */ 28 29#include "avcodec.h" 30 31#include "cga_data.h" 32 33typedef struct TMVContext { 34 AVFrame pic; 35} TMVContext; 36 37static int tmv_decode_frame(AVCodecContext *avctx, void *data, 38 int *data_size, AVPacket *avpkt) 39{ 40 TMVContext *tmv = avctx->priv_data; 41 const uint8_t *src = avpkt->data; 42 uint8_t *dst, *dst_char; 43 unsigned char_cols = avctx->width >> 3; 44 unsigned char_rows = avctx->height >> 3; 45 unsigned x, y, mask, char_y, fg, bg, c; 46 47 if (tmv->pic.data[0]) 48 avctx->release_buffer(avctx, &tmv->pic); 49 50 if (avctx->get_buffer(avctx, &tmv->pic) < 0) { 51 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 52 return -1; 53 } 54 55 if (avpkt->size < 2*char_rows*char_cols) { 56 av_log(avctx, AV_LOG_ERROR, 57 "Input buffer too small, truncated sample?\n"); 58 *data_size = 0; 59 return -1; 60 } 61 62 tmv->pic.pict_type = FF_I_TYPE; 63 tmv->pic.key_frame = 1; 64 dst = tmv->pic.data[0]; 65 66 tmv->pic.palette_has_changed = 1; 67 memcpy(tmv->pic.data[1], ff_cga_palette, 16 * 4); 68 69 for (y = 0; y < char_rows; y++) { 70 for (x = 0; x < char_cols; x++) { 71 c = *src++ * 8; 72 bg = *src >> 4; 73 fg = *src++ & 0xF; 74 75 dst_char = dst + x * 8; 76 for (char_y = 0; char_y < 8; char_y++) { 77 for (mask = 0x80; mask; mask >>= 1) { 78 *dst_char++ = ff_cga_font[c + char_y] & mask ? fg : bg; 79 } 80 dst_char += tmv->pic.linesize[0] - 8; 81 } 82 } 83 dst += tmv->pic.linesize[0] * 8; 84 } 85 86 *data_size = sizeof(AVFrame); 87 *(AVFrame *)data = tmv->pic; 88 return avpkt->size; 89} 90 91static av_cold int tmv_decode_close(AVCodecContext *avctx) 92{ 93 TMVContext *tmv = avctx->priv_data; 94 95 if (tmv->pic.data[0]) 96 avctx->release_buffer(avctx, &tmv->pic); 97 98 return 0; 99} 100 101AVCodec tmv_decoder = { 102 .name = "tmv", 103 .type = AVMEDIA_TYPE_VIDEO, 104 .id = CODEC_ID_TMV, 105 .priv_data_size = sizeof(TMVContext), 106 .close = tmv_decode_close, 107 .decode = tmv_decode_frame, 108 .capabilities = CODEC_CAP_DR1, 109 .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"), 110}; 111