mmvideo.c
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1 /*
2  * American Laser Games MM Video Decoder
3  * Copyright (c) 2006,2008 Peter Ross
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 
34 #include "libavutil/intreadwrite.h"
35 #include "avcodec.h"
36 #include "bytestream.h"
37 
38 #define MM_PREAMBLE_SIZE 6
39 
40 #define MM_TYPE_INTER 0x5
41 #define MM_TYPE_INTRA 0x8
42 #define MM_TYPE_INTRA_HH 0xc
43 #define MM_TYPE_INTER_HH 0xd
44 #define MM_TYPE_INTRA_HHV 0xe
45 #define MM_TYPE_INTER_HHV 0xf
46 #define MM_TYPE_PALETTE 0x31
47 
48 typedef struct MmContext {
53 } MmContext;
54 
56 {
57  MmContext *s = avctx->priv_data;
58 
59  s->avctx = avctx;
60 
61  avctx->pix_fmt = PIX_FMT_PAL8;
62 
63  if (!avctx->width || !avctx->height ||
64  (avctx->width & 1) || (avctx->height & 1)) {
65  av_log(avctx, AV_LOG_ERROR, "Invalid video dimensions: %dx%d\n",
66  avctx->width, avctx->height);
67  return AVERROR(EINVAL);
68  }
69 
70  s->frame.reference = 1;
71 
72  return 0;
73 }
74 
75 static int mm_decode_pal(MmContext *s)
76 {
77  int i;
78 
79  bytestream2_skip(&s->gb, 4);
80  for (i = 0; i < 128; i++) {
81  s->palette[i] = bytestream2_get_be24(&s->gb);
82  s->palette[i+128] = s->palette[i]<<2;
83  }
84 
85  return 0;
86 }
87 
92 static int mm_decode_intra(MmContext * s, int half_horiz, int half_vert)
93 {
94  int i, x, y;
95  i=0; x=0; y=0;
96 
97  while (bytestream2_get_bytes_left(&s->gb) > 0) {
98  int run_length, color;
99 
100  if (y >= s->avctx->height)
101  return 0;
102 
103  color = bytestream2_get_byte(&s->gb);
104  if (color & 0x80) {
105  run_length = 1;
106  }else{
107  run_length = (color & 0x7f) + 2;
108  color = bytestream2_get_byte(&s->gb);
109  }
110 
111  if (half_horiz)
112  run_length *=2;
113 
114  if (color) {
115  memset(s->frame.data[0] + y*s->frame.linesize[0] + x, color, run_length);
116  if (half_vert)
117  memset(s->frame.data[0] + (y+1)*s->frame.linesize[0] + x, color, run_length);
118  }
119  x+= run_length;
120 
121  if (x >= s->avctx->width) {
122  x=0;
123  y += 1 + half_vert;
124  }
125  }
126 
127  return 0;
128 }
129 
130 /*
131  * @param half_horiz Half horizontal resolution (0 or 1)
132  * @param half_vert Half vertical resolution (0 or 1)
133  */
134 static int mm_decode_inter(MmContext * s, int half_horiz, int half_vert)
135 {
136  int data_off = bytestream2_get_le16(&s->gb), y;
137  GetByteContext data_ptr;
138 
139  if (bytestream2_get_bytes_left(&s->gb) < data_off)
140  return AVERROR_INVALIDDATA;
141 
142  bytestream2_init(&data_ptr, s->gb.buffer + data_off, bytestream2_get_bytes_left(&s->gb) - data_off);
143  while (s->gb.buffer < data_ptr.buffer_start) {
144  int i, j;
145  int length = bytestream2_get_byte(&s->gb);
146  int x = bytestream2_get_byte(&s->gb) + ((length & 0x80) << 1);
147  length &= 0x7F;
148 
149  if (length==0) {
150  y += x;
151  continue;
152  }
153 
154  if (y + half_vert >= s->avctx->height)
155  return 0;
156 
157  for(i=0; i<length; i++) {
158  int replace_array = bytestream2_get_byte(&s->gb);
159  for(j=0; j<8; j++) {
160  int replace = (replace_array >> (7-j)) & 1;
161  if (x + half_horiz >= s->avctx->width)
162  return AVERROR_INVALIDDATA;
163  if (replace) {
164  int color = bytestream2_get_byte(&data_ptr);
165  s->frame.data[0][y*s->frame.linesize[0] + x] = color;
166  if (half_horiz)
167  s->frame.data[0][y*s->frame.linesize[0] + x + 1] = color;
168  if (half_vert) {
169  s->frame.data[0][(y+1)*s->frame.linesize[0] + x] = color;
170  if (half_horiz)
171  s->frame.data[0][(y+1)*s->frame.linesize[0] + x + 1] = color;
172  }
173  }
174  x += 1 + half_horiz;
175  }
176  }
177 
178  y += 1 + half_vert;
179  }
180 
181  return 0;
182 }
183 
184 static int mm_decode_frame(AVCodecContext *avctx,
185  void *data, int *data_size,
186  AVPacket *avpkt)
187 {
188  const uint8_t *buf = avpkt->data;
189  int buf_size = avpkt->size;
190  MmContext *s = avctx->priv_data;
191  int type, res;
192 
193  if (buf_size < MM_PREAMBLE_SIZE)
194  return AVERROR_INVALIDDATA;
195  type = AV_RL16(&buf[0]);
196  buf += MM_PREAMBLE_SIZE;
197  buf_size -= MM_PREAMBLE_SIZE;
198  bytestream2_init(&s->gb, buf, buf_size);
199 
200  if (avctx->reget_buffer(avctx, &s->frame) < 0) {
201  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
202  return -1;
203  }
204 
205  switch(type) {
206  case MM_TYPE_PALETTE : res = mm_decode_pal(s); return buf_size;
207  case MM_TYPE_INTRA : res = mm_decode_intra(s, 0, 0); break;
208  case MM_TYPE_INTRA_HH : res = mm_decode_intra(s, 1, 0); break;
209  case MM_TYPE_INTRA_HHV : res = mm_decode_intra(s, 1, 1); break;
210  case MM_TYPE_INTER : res = mm_decode_inter(s, 0, 0); break;
211  case MM_TYPE_INTER_HH : res = mm_decode_inter(s, 1, 0); break;
212  case MM_TYPE_INTER_HHV : res = mm_decode_inter(s, 1, 1); break;
213  default:
214  res = AVERROR_INVALIDDATA;
215  break;
216  }
217  if (res < 0)
218  return res;
219 
220  memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
221 
222  *data_size = sizeof(AVFrame);
223  *(AVFrame*)data = s->frame;
224 
225  return buf_size;
226 }
227 
229 {
230  MmContext *s = avctx->priv_data;
231 
232  if(s->frame.data[0])
233  avctx->release_buffer(avctx, &s->frame);
234 
235  return 0;
236 }
237 
239  .name = "mmvideo",
240  .type = AVMEDIA_TYPE_VIDEO,
241  .id = CODEC_ID_MMVIDEO,
242  .priv_data_size = sizeof(MmContext),
243  .init = mm_decode_init,
244  .close = mm_decode_end,
246  .capabilities = CODEC_CAP_DR1,
247  .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM Video"),
248 };