FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
roqvideodec.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2003 The FFmpeg Project
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * id RoQ Video Decoder by Dr. Tim Ferguson
24  * For more information about the id RoQ format, visit:
25  * http://www.csse.monash.edu.au/~timf/
26  */
27 
28 #include "libavutil/avassert.h"
29 #include "avcodec.h"
30 #include "bytestream.h"
31 #include "internal.h"
32 #include "roqvideo.h"
33 
34 static void roqvideo_decode_frame(RoqContext *ri)
35 {
36  unsigned int chunk_id = 0, chunk_arg = 0;
37  unsigned long chunk_size = 0;
38  int i, j, k, nv1, nv2, vqflg = 0, vqflg_pos = -1;
39  int vqid, xpos, ypos, xp, yp, x, y, mx, my;
40  int frame_stats[2][4] = {{0},{0}};
41  roq_qcell *qcell;
42  int64_t chunk_start;
43 
44  while (bytestream2_get_bytes_left(&ri->gb) >= 8) {
45  chunk_id = bytestream2_get_le16(&ri->gb);
46  chunk_size = bytestream2_get_le32(&ri->gb);
47  chunk_arg = bytestream2_get_le16(&ri->gb);
48 
49  if(chunk_id == RoQ_QUAD_VQ)
50  break;
51  if(chunk_id == RoQ_QUAD_CODEBOOK) {
52  if((nv1 = chunk_arg >> 8) == 0)
53  nv1 = 256;
54  if((nv2 = chunk_arg & 0xff) == 0 && nv1 * 6 < chunk_size)
55  nv2 = 256;
56  for(i = 0; i < nv1; i++) {
57  ri->cb2x2[i].y[0] = bytestream2_get_byte(&ri->gb);
58  ri->cb2x2[i].y[1] = bytestream2_get_byte(&ri->gb);
59  ri->cb2x2[i].y[2] = bytestream2_get_byte(&ri->gb);
60  ri->cb2x2[i].y[3] = bytestream2_get_byte(&ri->gb);
61  ri->cb2x2[i].u = bytestream2_get_byte(&ri->gb);
62  ri->cb2x2[i].v = bytestream2_get_byte(&ri->gb);
63  }
64  for(i = 0; i < nv2; i++)
65  for(j = 0; j < 4; j++)
66  ri->cb4x4[i].idx[j] = bytestream2_get_byte(&ri->gb);
67  }
68  }
69 
70  chunk_start = bytestream2_tell(&ri->gb);
71  xpos = ypos = 0;
72 
73  if (chunk_size > bytestream2_get_bytes_left(&ri->gb)) {
74  av_log(ri->avctx, AV_LOG_ERROR, "Chunk does not fit in input buffer\n");
75  chunk_size = bytestream2_get_bytes_left(&ri->gb);
76  }
77 
78  while (bytestream2_tell(&ri->gb) < chunk_start + chunk_size) {
79  for (yp = ypos; yp < ypos + 16; yp += 8)
80  for (xp = xpos; xp < xpos + 16; xp += 8) {
81  if (bytestream2_tell(&ri->gb) >= chunk_start + chunk_size) {
82  av_log(ri->avctx, AV_LOG_VERBOSE, "Chunk is too short\n");
83  return;
84  }
85  if (vqflg_pos < 0) {
86  vqflg = bytestream2_get_le16(&ri->gb);
87  vqflg_pos = 7;
88  }
89  vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
90  frame_stats[0][vqid]++;
91  vqflg_pos--;
92 
93  switch(vqid) {
94  case RoQ_ID_MOT:
95  break;
96  case RoQ_ID_FCC: {
97  int byte = bytestream2_get_byte(&ri->gb);
98  mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));
99  my = 8 - (byte & 0xf) - ((signed char) chunk_arg);
100  ff_apply_motion_8x8(ri, xp, yp, mx, my);
101  break;
102  }
103  case RoQ_ID_SLD:
104  qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);
105  ff_apply_vector_4x4(ri, xp, yp, ri->cb2x2 + qcell->idx[0]);
106  ff_apply_vector_4x4(ri, xp + 4, yp, ri->cb2x2 + qcell->idx[1]);
107  ff_apply_vector_4x4(ri, xp, yp + 4, ri->cb2x2 + qcell->idx[2]);
108  ff_apply_vector_4x4(ri, xp + 4, yp + 4, ri->cb2x2 + qcell->idx[3]);
109  break;
110  case RoQ_ID_CCC:
111  for (k = 0; k < 4; k++) {
112  x = xp; y = yp;
113  if(k & 0x01) x += 4;
114  if(k & 0x02) y += 4;
115 
116  if (bytestream2_tell(&ri->gb) >= chunk_start + chunk_size) {
117  av_log(ri->avctx, AV_LOG_VERBOSE, "Chunk is too short\n");
118  return;
119  }
120  if (vqflg_pos < 0) {
121  vqflg = bytestream2_get_le16(&ri->gb);
122  vqflg_pos = 7;
123  }
124  vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
125  frame_stats[1][vqid]++;
126  vqflg_pos--;
127  switch(vqid) {
128  case RoQ_ID_MOT:
129  break;
130  case RoQ_ID_FCC: {
131  int byte = bytestream2_get_byte(&ri->gb);
132  mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));
133  my = 8 - (byte & 0xf) - ((signed char) chunk_arg);
134  ff_apply_motion_4x4(ri, x, y, mx, my);
135  break;
136  }
137  case RoQ_ID_SLD:
138  qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);
139  ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + qcell->idx[0]);
140  ff_apply_vector_2x2(ri, x + 2, y, ri->cb2x2 + qcell->idx[1]);
141  ff_apply_vector_2x2(ri, x, y + 2, ri->cb2x2 + qcell->idx[2]);
142  ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + qcell->idx[3]);
143  break;
144  case RoQ_ID_CCC:
145  ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
146  ff_apply_vector_2x2(ri, x + 2, y, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
147  ff_apply_vector_2x2(ri, x, y + 2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
148  ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
149  break;
150  }
151  }
152  break;
153  default:
154  av_assert2(0);
155  }
156  }
157 
158  xpos += 16;
159  if (xpos >= ri->width) {
160  xpos -= ri->width;
161  ypos += 16;
162  }
163  if(ypos >= ri->height)
164  break;
165  }
166 }
167 
168 
169 static av_cold int roq_decode_init(AVCodecContext *avctx)
170 {
171  RoqContext *s = avctx->priv_data;
172 
173  s->avctx = avctx;
174 
175  if (avctx->width % 16 || avctx->height % 16) {
176  av_log(avctx, AV_LOG_ERROR,
177  "Dimensions must be a multiple of 16\n");
178  return AVERROR_PATCHWELCOME;
179  }
180 
181  s->width = avctx->width;
182  s->height = avctx->height;
183 
184  s->last_frame = av_frame_alloc();
185  s->current_frame = av_frame_alloc();
186  if (!s->current_frame || !s->last_frame) {
187  av_frame_free(&s->current_frame);
188  av_frame_free(&s->last_frame);
189  return AVERROR(ENOMEM);
190  }
191 
192  avctx->pix_fmt = AV_PIX_FMT_YUVJ444P;
193  avctx->color_range = AVCOL_RANGE_JPEG;
194 
195  return 0;
196 }
197 
198 static int roq_decode_frame(AVCodecContext *avctx,
199  void *data, int *got_frame,
200  AVPacket *avpkt)
201 {
202  const uint8_t *buf = avpkt->data;
203  int buf_size = avpkt->size;
204  RoqContext *s = avctx->priv_data;
205  int copy= !s->current_frame->data[0];
206  int ret;
207 
208  if ((ret = ff_reget_buffer(avctx, s->current_frame)) < 0)
209  return ret;
210 
211  if(copy)
212  av_picture_copy((AVPicture*)s->current_frame, (AVPicture*)s->last_frame,
213  avctx->pix_fmt, avctx->width, avctx->height);
214 
215  bytestream2_init(&s->gb, buf, buf_size);
216  roqvideo_decode_frame(s);
217 
218  if ((ret = av_frame_ref(data, s->current_frame)) < 0)
219  return ret;
220  *got_frame = 1;
221 
222  /* shuffle frames */
223  FFSWAP(AVFrame *, s->current_frame, s->last_frame);
224 
225  return buf_size;
226 }
227 
228 static av_cold int roq_decode_end(AVCodecContext *avctx)
229 {
230  RoqContext *s = avctx->priv_data;
231 
232  av_frame_free(&s->current_frame);
233  av_frame_free(&s->last_frame);
234 
235  return 0;
236 }
237 
238 AVCodec ff_roq_decoder = {
239  .name = "roqvideo",
240  .long_name = NULL_IF_CONFIG_SMALL("id RoQ video"),
241  .type = AVMEDIA_TYPE_VIDEO,
242  .id = AV_CODEC_ID_ROQ,
243  .priv_data_size = sizeof(RoqContext),
244  .init = roq_decode_init,
245  .close = roq_decode_end,
246  .decode = roq_decode_frame,
247  .capabilities = CODEC_CAP_DR1,
248 };
Generated on Fri Dec 5 2014 04:42:01 for FFmpeg by   doxygen 1.8.2