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 "codec_internal.h"
33 #include "internal.h"
34 #include "libavutil/internal.h"
35 #include "libavutil/xga_font_data.h"
36
37 #include "cga_data.h"
38
tmv_decode_frame(AVCodecContext * avctx,AVFrame * frame,int * got_frame,AVPacket * avpkt)39 static int tmv_decode_frame(AVCodecContext *avctx, AVFrame *frame,
40 int *got_frame, AVPacket *avpkt)
41 {
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
tmv_decode_init(AVCodecContext * avctx)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 const FFCodec ff_tmv_decoder = {
90 .p.name = "tmv",
91 .p.long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
92 .p.type = AVMEDIA_TYPE_VIDEO,
93 .p.id = AV_CODEC_ID_TMV,
94 .init = tmv_decode_init,
95 FF_CODEC_DECODE_CB(tmv_decode_frame),
96 .p.capabilities = AV_CODEC_CAP_DR1,
97 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
98 };
99