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 "avcodec.h"
30 
31 #include "cga_data.h"
32 
33 typedef struct TMVContext {
35 } TMVContext;
36 
37 static int tmv_decode_frame(AVCodecContext *avctx, void *data,
38  int *data_size, AVPacket *avpkt)
39 {
40  TMVContext *tmv = avctx->priv_data;
41  const uint8_t *src = avpkt->data;
42  uint8_t *dst;
43  unsigned char_cols = avctx->width >> 3;
44  unsigned char_rows = avctx->height >> 3;
45  unsigned x, y, fg, bg, c;
46 
47  if (tmv->pic.data[0])
48  avctx->release_buffer(avctx, &tmv->pic);
49 
50  if (avctx->get_buffer(avctx, &tmv->pic) < 0) {
51  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
52  return -1;
53  }
54 
55  if (avpkt->size < 2*char_rows*char_cols) {
56  av_log(avctx, AV_LOG_ERROR,
57  "Input buffer too small, truncated sample?\n");
58  *data_size = 0;
59  return -1;
60  }
61 
63  tmv->pic.key_frame = 1;
64  dst = tmv->pic.data[0];
65 
66  tmv->pic.palette_has_changed = 1;
67  memcpy(tmv->pic.data[1], ff_cga_palette, 16 * 4);
68 
69  for (y = 0; y < char_rows; y++) {
70  for (x = 0; x < char_cols; x++) {
71  c = *src++;
72  bg = *src >> 4;
73  fg = *src++ & 0xF;
74  ff_draw_pc_font(dst + x * 8, tmv->pic.linesize[0],
75  ff_cga_font, 8, c, fg, bg);
76  }
77  dst += tmv->pic.linesize[0] * 8;
78  }
79 
80  *data_size = sizeof(AVFrame);
81  *(AVFrame *)data = tmv->pic;
82  return avpkt->size;
83 }
84 
86 {
87  avctx->pix_fmt = PIX_FMT_PAL8;
88  return 0;
89 }
90 
92 {
93  TMVContext *tmv = avctx->priv_data;
94 
95  if (tmv->pic.data[0])
96  avctx->release_buffer(avctx, &tmv->pic);
97 
98  return 0;
99 }
100 
102  .name = "tmv",
103  .type = AVMEDIA_TYPE_VIDEO,
104  .id = CODEC_ID_TMV,
105  .priv_data_size = sizeof(TMVContext),
109  .capabilities = CODEC_CAP_DR1,
110  .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
111 };