| 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 | |
| 38 | static 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 | |
| 83 | static av_cold int tmv_decode_init(AVCodecContext *avctx) |
| 84 | { |
| 85 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| 86 | return 0; |
| 87 | } |
| 88 | |
| 89 | AVCodec 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 | }; |