c56635e72248e19f8d64fddf4b8393081119038d
[libav.git] / libavcodec / tmv.c
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 <string.h>
30
31 #include "avcodec.h"
32 #include "internal.h"
33 #include "libavutil/internal.h"
34
35 #include "cga_data.h"
36
37 typedef struct TMVContext {
38 AVFrame pic;
39 } TMVContext;
40
41 static int tmv_decode_frame(AVCodecContext *avctx, void *data,
42 int *data_size, AVPacket *avpkt)
43 {
44 TMVContext *tmv = avctx->priv_data;
45 const uint8_t *src = avpkt->data;
46 uint8_t *dst;
47 unsigned char_cols = avctx->width >> 3;
48 unsigned char_rows = avctx->height >> 3;
49 unsigned x, y, fg, bg, c;
50
51 if (tmv->pic.data[0])
52 avctx->release_buffer(avctx, &tmv->pic);
53
54 if (ff_get_buffer(avctx, &tmv->pic) < 0) {
55 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
56 return -1;
57 }
58
59 if (avpkt->size < 2*char_rows*char_cols) {
60 av_log(avctx, AV_LOG_ERROR,
61 "Input buffer too small, truncated sample?\n");
62 *data_size = 0;
63 return -1;
64 }
65
66 tmv->pic.pict_type = AV_PICTURE_TYPE_I;
67 tmv->pic.key_frame = 1;
68 dst = tmv->pic.data[0];
69
70 tmv->pic.palette_has_changed = 1;
71 memcpy(tmv->pic.data[1], ff_cga_palette, 16 * 4);
72
73 for (y = 0; y < char_rows; y++) {
74 for (x = 0; x < char_cols; x++) {
75 c = *src++;
76 bg = *src >> 4;
77 fg = *src++ & 0xF;
78 ff_draw_pc_font(dst + x * 8, tmv->pic.linesize[0],
79 ff_cga_font, 8, c, fg, bg);
80 }
81 dst += tmv->pic.linesize[0] * 8;
82 }
83
84 *data_size = sizeof(AVFrame);
85 *(AVFrame *)data = tmv->pic;
86 return avpkt->size;
87 }
88
89 static av_cold int tmv_decode_init(AVCodecContext *avctx)
90 {
91 avctx->pix_fmt = AV_PIX_FMT_PAL8;
92 return 0;
93 }
94
95 static av_cold int tmv_decode_close(AVCodecContext *avctx)
96 {
97 TMVContext *tmv = avctx->priv_data;
98
99 if (tmv->pic.data[0])
100 avctx->release_buffer(avctx, &tmv->pic);
101
102 return 0;
103 }
104
105 AVCodec ff_tmv_decoder = {
106 .name = "tmv",
107 .type = AVMEDIA_TYPE_VIDEO,
108 .id = AV_CODEC_ID_TMV,
109 .priv_data_size = sizeof(TMVContext),
110 .init = tmv_decode_init,
111 .close = tmv_decode_close,
112 .decode = tmv_decode_frame,
113 .capabilities = CODEC_CAP_DR1,
114 .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
115 };