1/* 2 * 8088flex TMV video decoder 3 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu> 4 * 5 * This file is part of Libav. 6 * 7 * Libav 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 * Libav 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 Libav; 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 "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; 43 unsigned char_cols = avctx->width >> 3; 44 unsigned char_rows = avctx->height >> 3; 45 unsigned x, 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 = AV_PICTURE_TYPE_I; 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++; 72 bg = *src >> 4; 73 fg = *src++ & 0xF; 74 ff_draw_pc_font(dst + x * 8, tmv->pic.linesize[0], 75 ff_cga_font, 8, c, fg, bg); 76 } 77 dst += tmv->pic.linesize[0] * 8; 78 } 79 80 *data_size = sizeof(AVFrame); 81 *(AVFrame *)data = tmv->pic; 82 return avpkt->size; 83} 84 85static av_cold int tmv_decode_init(AVCodecContext *avctx) 86{ 87 avctx->pix_fmt = PIX_FMT_PAL8; 88 return 0; 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 ff_tmv_decoder = { 102 .name = "tmv", 103 .type = AVMEDIA_TYPE_VIDEO, 104 .id = CODEC_ID_TMV, 105 .priv_data_size = sizeof(TMVContext), 106 .init = tmv_decode_init, 107 .close = tmv_decode_close, 108 .decode = tmv_decode_frame, 109 .capabilities = CODEC_CAP_DR1, 110 .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"), 111}; 112