tmv.c
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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 
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 {
39 } TMVContext;
40 
41 static int tmv_decode_frame(AVCodecContext *avctx, void *data,
42  int *got_frame, 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  *got_frame = 0;
63  return -1;
64  }
65 
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  *got_frame = 1;
85  *(AVFrame *)data = tmv->pic;
86  return avpkt->size;
87 }
88 
90 {
91  avctx->pix_fmt = AV_PIX_FMT_PAL8;
92  return 0;
93 }
94 
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 
106  .name = "tmv",
107  .type = AVMEDIA_TYPE_VIDEO,
108  .id = AV_CODEC_ID_TMV,
109  .priv_data_size = sizeof(TMVContext),
113  .capabilities = CODEC_CAP_DR1,
114  .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
115 };