FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
mvcdec.c
Go to the documentation of this file.
1 /*
2  * Silicon Graphics Motion Video Compressor 1 & 2 decoder
3  * Copyright (c) 2012 Peter Ross
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  * Silicon Graphics Motion Video Compressor 1 & 2 decoder
25  */
26 
27 #include "libavutil/intreadwrite.h"
28 #include "avcodec.h"
29 #include "bytestream.h"
30 #include "internal.h"
31 
32 typedef struct MvcContext {
33  AVFrame *frame;
34  int vflip;
35 } MvcContext;
36 
37 static av_cold int mvc_decode_init(AVCodecContext *avctx)
38 {
39  MvcContext *s = avctx->priv_data;
40  int width = avctx->width;
41  int height = avctx->height;
42 
43  if (avctx->codec_id == AV_CODEC_ID_MVC1) {
44  width += 3;
45  height += 3;
46  }
47  width &= ~3;
48  height &= ~3;
49  if (width != avctx->width || height != avctx->height)
50  avcodec_set_dimensions(avctx, width, height);
51 
52  avctx->pix_fmt = (avctx->codec_id == AV_CODEC_ID_MVC1) ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_BGRA;
53  s->frame = av_frame_alloc();
54  if (!s->frame)
55  return AVERROR(ENOMEM);
56 
57  s->vflip = avctx->extradata_size >= 9 && !memcmp(avctx->extradata + avctx->extradata_size - 9, "BottomUp", 9);
58  return 0;
59 }
60 
61 static int decode_mvc1(AVCodecContext *avctx, GetByteContext *gb, uint8_t *dst_start, int width, int height, int linesize)
62 {
63  uint8_t *dst;
64  uint16_t v[8];
65  int mask, x, y, i;
66 
67  x = y= 0;
68  while (bytestream2_get_bytes_left(gb) >= 6) {
69  mask = bytestream2_get_be16u(gb);
70  v[0] = bytestream2_get_be16u(gb);
71  v[1] = bytestream2_get_be16u(gb);
72  if ((v[0] & 0x8000)) {
73  if (bytestream2_get_bytes_left(gb) < 12) {
74  av_log(avctx, AV_LOG_WARNING, "buffer overflow\n");
75  return AVERROR_INVALIDDATA;
76  }
77  for (i = 2; i < 8; i++)
78  v[i] = bytestream2_get_be16u(gb);
79  } else {
80  v[2] = v[4] = v[6] = v[0];
81  v[3] = v[5] = v[7] = v[1];
82  }
83 
84 #define PIX16(target, true, false) \
85  i = (mask & target) ? true : false; \
86  AV_WN16A(dst, (v[i] & 0x7C00) | (v[i] & 0x3E0) | (v[i] & 0x1F)); \
87  dst += 2;
88 
89 #define ROW16(row, a1, a0, b1, b0) \
90  dst = dst_start + (y + row) * linesize + x * 2; \
91  PIX16(1 << (row * 4), a1, a0) \
92  PIX16(1 << (row * 4 + 1), a1, a0) \
93  PIX16(1 << (row * 4 + 2), b1, b0) \
94  PIX16(1 << (row * 4 + 3), b1, b0)
95 
96  ROW16(0, 0, 1, 2, 3);
97  ROW16(1, 0, 1, 2, 3);
98  ROW16(2, 4, 5, 6, 7);
99  ROW16(3, 4, 5, 6, 7);
100 
101  x += 4;
102  if (x >= width) {
103  y += 4;
104  if (y >= height) {
105  break;
106  }
107  x = 0;
108  }
109  }
110  return 0;
111 }
112 
113 static void set_4x4_block(uint8_t *dst, int linesize, uint32_t pixel)
114 {
115  int i, j;
116  for (j = 0; j < 4; j++)
117  for (i = 0; i < 4; i++)
118  AV_WN32A(dst + j * linesize + i * 4, pixel);
119 }
120 
121 #define PIX32(target, true, false) \
122  AV_WN32A(dst, (mask & target) ? v[true] : v[false]); \
123  dst += 4;
124 
125 #define ROW32(row, a1, a0, b1, b0) \
126  dst = dst_start + (y + row) * linesize + x * 4; \
127  PIX32(1 << (row * 4), a1, a0) \
128  PIX32(1 << (row * 4 + 1), a1, a0) \
129  PIX32(1 << (row * 4 + 2), b1, b0) \
130  PIX32(1 << (row * 4 + 3), b1, b0)
131 
132 #define MVC2_BLOCK \
133  ROW32(0, 1, 0, 3, 2); \
134  ROW32(1, 1, 0, 3, 2); \
135  ROW32(2, 5, 4, 7, 6); \
136  ROW32(3, 5, 4, 7, 6);
137 
138 static int decode_mvc2(AVCodecContext *avctx, GetByteContext *gb, uint8_t *dst_start, int width, int height, int linesize, int vflip)
139 {
140  uint8_t *dst;
141  uint32_t color[128], v[8];
142  int w, h, nb_colors, i, x, y, p0, p1, mask;
143 
144  if (bytestream2_get_bytes_left(gb) < 6)
145  return AVERROR_INVALIDDATA;
146 
147  w = bytestream2_get_be16u(gb);
148  h = bytestream2_get_be16u(gb);
149  if ((w & ~3) != width || (h & ~3) != height)
150  av_log(avctx, AV_LOG_WARNING, "dimension mismatch\n");
151 
152  if (bytestream2_get_byteu(gb)) {
153  avpriv_request_sample(avctx, "bitmap feature");
154  return AVERROR_PATCHWELCOME;
155  }
156 
157  nb_colors = bytestream2_get_byteu(gb);
158  if (bytestream2_get_bytes_left(gb) < nb_colors * 3)
159  return AVERROR_INVALIDDATA;
160  for (i = 0; i < FFMIN(nb_colors, 128); i++)
161  color[i] = 0xFF000000 | bytestream2_get_be24u(gb);
162  if (nb_colors > 128)
163  bytestream2_skip(gb, (nb_colors - 128) * 3);
164 
165  if (vflip) {
166  dst_start += (height - 1) * linesize;
167  linesize = -linesize;
168  }
169  x = y = 0;
170  while (bytestream2_get_bytes_left(gb) >= 1) {
171  p0 = bytestream2_get_byteu(gb);
172  if ((p0 & 0x80)) {
173  if ((p0 & 0x40)) {
174  p0 &= 0x3F;
175  p0 = (p0 << 2) | (p0 >> 4);
176  set_4x4_block(dst_start + y * linesize + x * 4, linesize, 0xFF000000 | (p0 << 16) | (p0 << 8) | p0);
177  } else {
178  int g, r;
179  p0 &= 0x3F;
180  p0 = (p0 << 2) | (p0 >> 4);
181  if (bytestream2_get_bytes_left(gb) < 2)
182  return AVERROR_INVALIDDATA;
183  g = bytestream2_get_byteu(gb);
184  r = bytestream2_get_byteu(gb);
185  set_4x4_block(dst_start + y * linesize + x * 4, linesize, 0xFF000000 | (r << 16) | (g << 8) | p0);
186  }
187  } else {
188  if (bytestream2_get_bytes_left(gb) < 1)
189  return AVERROR_INVALIDDATA;
190  p1 = bytestream2_get_byteu(gb);
191  if ((p1 & 0x80)) {
192  if ((p0 & 0x7F) == (p1 & 0x7F)) {
193  set_4x4_block(dst_start + y * linesize + x * 4, linesize, color[p0 & 0x7F]);
194  } else {
195  if (bytestream2_get_bytes_left(gb) < 2)
196  return AVERROR_INVALIDDATA;
197  v[0] = v[2] = v[4] = v[6] = color[p0 & 0x7F];
198  v[1] = v[3] = v[5] = v[7] = color[p1 & 0x7F];
199  mask = bytestream2_get_le16u(gb);
200  MVC2_BLOCK
201  }
202  } else {
203  if (bytestream2_get_bytes_left(gb) < 8)
204  return AVERROR_INVALIDDATA;
205  v[0] = color[p0 & 0x7F];
206  v[1] = color[p1 & 0x7F];
207  for (i = 2; i < 8; i++)
208  v[i] = color[bytestream2_get_byteu(gb) & 0x7F];
209  mask = bytestream2_get_le16u(gb);
210  MVC2_BLOCK
211  }
212  }
213 
214  x += 4;
215  if (x >= width) {
216  y += 4;
217  if (y >= height)
218  break;
219  x = 0;
220  }
221  }
222  return 0;
223 }
224 
225 static int mvc_decode_frame(AVCodecContext *avctx,
226  void *data, int *got_frame,
227  AVPacket *avpkt)
228 {
229  MvcContext *s = avctx->priv_data;
230  GetByteContext gb;
231  int ret;
232 
233  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
234  return ret;
235 
236  bytestream2_init(&gb, avpkt->data, avpkt->size);
237  if (avctx->codec_id == AV_CODEC_ID_MVC1)
238  ret = decode_mvc1(avctx, &gb, s->frame->data[0], avctx->width, avctx->height, s->frame->linesize[0]);
239  else
240  ret = decode_mvc2(avctx, &gb, s->frame->data[0], avctx->width, avctx->height, s->frame->linesize[0], s->vflip);
241  if (ret < 0)
242  return ret;
243 
244  *got_frame = 1;
245  if ((ret = av_frame_ref(data, s->frame)) < 0)
246  return ret;
247 
248  return avpkt->size;
249 }
250 
251 static av_cold int mvc_decode_end(AVCodecContext *avctx)
252 {
253  MvcContext *s = avctx->priv_data;
254 
255  av_frame_free(&s->frame);
256 
257  return 0;
258 }
259 
260 #if CONFIG_MVC1_DECODER
261 AVCodec ff_mvc1_decoder = {
262  .name = "mvc1",
263  .type = AVMEDIA_TYPE_VIDEO,
264  .id = AV_CODEC_ID_MVC1,
265  .priv_data_size = sizeof(MvcContext),
266  .init = mvc_decode_init,
267  .close = mvc_decode_end,
268  .decode = mvc_decode_frame,
269  .capabilities = CODEC_CAP_DR1,
270  .long_name = NULL_IF_CONFIG_SMALL("Silicon Graphics Motion Video Compressor 1"),
271 };
272 #endif
273 
274 #if CONFIG_MVC2_DECODER
275 AVCodec ff_mvc2_decoder = {
276  .name = "mvc2",
277  .type = AVMEDIA_TYPE_VIDEO,
278  .id = AV_CODEC_ID_MVC2,
279  .priv_data_size = sizeof(MvcContext),
280  .init = mvc_decode_init,
281  .close = mvc_decode_end,
282  .decode = mvc_decode_frame,
283  .capabilities = CODEC_CAP_DR1,
284  .long_name = NULL_IF_CONFIG_SMALL("Silicon Graphics Motion Video Compressor 2"),
285 };
286 #endif
Generated on Wed Jul 10 2013 23:48:02 for FFmpeg by   doxygen 1.8.2