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