eatgq.c
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1 /*
2  * Electronic Arts TGQ Video Decoder
3  * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
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 St, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
31 #include "avcodec.h"
32 #define BITSTREAM_READER_LE
33 #include "get_bits.h"
34 #include "bytestream.h"
35 #include "dsputil.h"
36 #include "aandcttab.h"
37 
38 typedef struct TgqContext {
44  int qtable[64];
47 } TgqContext;
48 
50  TgqContext *s = avctx->priv_data;
51  s->avctx = avctx;
52  if(avctx->idct_algo==FF_IDCT_AUTO)
53  avctx->idct_algo=FF_IDCT_EA;
54  dsputil_init(&s->dsp, avctx);
56  avctx->time_base = (AVRational){1, 15};
57  avctx->pix_fmt = PIX_FMT_YUV420P;
58  return 0;
59 }
60 
62  uint8_t *perm = s->scantable.permutated;
63  int i,j,value;
64  block[0] = get_sbits(gb,8) * s->qtable[0];
65  for(i=1; i<64; ) {
66  switch(show_bits(gb,3)) {
67  case 4:
68  block[perm[i++]] = 0;
69  case 0:
70  block[perm[i++]] = 0;
71  skip_bits(gb,3);
72  break;
73  case 5:
74  case 1:
75  skip_bits(gb,2);
76  value = get_bits(gb,6);
77  for(j=0; j<value; j++)
78  block[perm[i++]] = 0;
79  break;
80  case 6:
81  skip_bits(gb,3);
82  block[perm[i]] = -s->qtable[perm[i]];
83  i++;
84  break;
85  case 2:
86  skip_bits(gb,3);
87  block[perm[i]] = s->qtable[perm[i]];
88  i++;
89  break;
90  case 7: // 111b
91  case 3: // 011b
92  skip_bits(gb,2);
93  if (show_bits(gb,6)==0x3F) {
94  skip_bits(gb, 6);
95  block[perm[i]] = get_sbits(gb,8)*s->qtable[perm[i]];
96  }else{
97  block[perm[i]] = get_sbits(gb,6)*s->qtable[perm[i]];
98  }
99  i++;
100  break;
101  }
102  }
103  block[0] += 128<<4;
104 }
105 
106 static void tgq_idct_put_mb(TgqContext *s, DCTELEM (*block)[64], int mb_x, int mb_y){
107  int linesize= s->frame.linesize[0];
108  uint8_t *dest_y = s->frame.data[0] + (mb_y * 16* linesize ) + mb_x * 16;
109  uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
110  uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
111 
112  s->dsp.idct_put(dest_y , linesize, block[0]);
113  s->dsp.idct_put(dest_y + 8, linesize, block[1]);
114  s->dsp.idct_put(dest_y + 8*linesize , linesize, block[2]);
115  s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
116  if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
117  s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
118  s->dsp.idct_put(dest_cr, s->frame.linesize[2], block[5]);
119  }
120 }
121 
122 static inline void tgq_dconly(TgqContext *s, unsigned char *dst, int dst_stride, int dc){
123  int level = av_clip_uint8((dc*s->qtable[0] + 2056)>>4);
124  int j;
125  for(j=0;j<8;j++)
126  memset(dst+j*dst_stride, level, 8);
127 }
128 
129 static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
130 {
131  int linesize= s->frame.linesize[0];
132  uint8_t *dest_y = s->frame.data[0] + (mb_y * 16* linesize ) + mb_x * 16;
133  uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
134  uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
135  tgq_dconly(s,dest_y , linesize, dc[0]);
136  tgq_dconly(s,dest_y + 8, linesize, dc[1]);
137  tgq_dconly(s,dest_y + 8*linesize , linesize, dc[2]);
138  tgq_dconly(s,dest_y + 8*linesize + 8, linesize, dc[3]);
139  if(!(s->avctx->flags&CODEC_FLAG_GRAY)) {
140  tgq_dconly(s,dest_cb, s->frame.linesize[1], dc[4]);
141  tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
142  }
143 }
144 
145 static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x){
146  int mode;
147  int i;
148  int8_t dc[6];
149 
150  mode = bytestream2_get_byte(&s->gb);
151  if (mode>12) {
152  GetBitContext gb;
153  init_get_bits(&gb, s->gb.buffer, FFMIN(s->gb.buffer_end - s->gb.buffer, mode) * 8);
154  for(i=0; i<6; i++)
155  tgq_decode_block(s, s->block[i], &gb);
156  tgq_idct_put_mb(s, s->block, mb_x, mb_y);
157  bytestream2_skip(&s->gb, mode);
158  }else{
159  if (mode==3) {
160  memset(dc, bytestream2_get_byte(&s->gb), 4);
161  dc[4] = bytestream2_get_byte(&s->gb);
162  dc[5] = bytestream2_get_byte(&s->gb);
163  }else if (mode==6) {
164  bytestream2_get_buffer(&s->gb, dc, 6);
165  }else if (mode==12) {
166  for (i = 0; i < 6; i++) {
167  dc[i] = bytestream2_get_byte(&s->gb);
168  bytestream2_skip(&s->gb, 1);
169  }
170  }else{
171  av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
172  }
173  tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
174  }
175 }
176 
177 static void tgq_calculate_qtable(TgqContext *s, int quant){
178  int i,j;
179  const int a = (14*(100-quant))/100 + 1;
180  const int b = (11*(100-quant))/100 + 4;
181  for(j=0;j<8;j++)
182  for(i=0;i<8;i++)
183  if (s->avctx->idct_algo==FF_IDCT_EA)
184  s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
185  else
186  s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
187 }
188 
190  void *data, int *data_size,
191  AVPacket *avpkt){
192  const uint8_t *buf = avpkt->data;
193  int buf_size = avpkt->size;
194  TgqContext *s = avctx->priv_data;
195  int x,y;
196  int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
197 
198  if (buf_size < 16) {
199  av_log(avctx, AV_LOG_WARNING, "truncated header\n");
200  return -1;
201  }
202  bytestream2_init(&s->gb, buf + 8, buf_size - 8);
203  if (big_endian) {
204  s->width = bytestream2_get_be16u(&s->gb);
205  s->height = bytestream2_get_be16u(&s->gb);
206  } else {
207  s->width = bytestream2_get_le16u(&s->gb);
208  s->height = bytestream2_get_le16u(&s->gb);
209  }
210 
211  if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
213  if (s->frame.data[0])
214  avctx->release_buffer(avctx, &s->frame);
215  }
216  tgq_calculate_qtable(s, bytestream2_get_byteu(&s->gb));
217  bytestream2_skip(&s->gb, 3);
218 
219  if (!s->frame.data[0]) {
220  s->frame.key_frame = 1;
223  if (avctx->get_buffer(avctx, &s->frame)) {
224  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
225  return -1;
226  }
227  }
228 
229  for (y = 0; y < FFALIGN(avctx->height, 16) >> 4; y++)
230  for (x = 0; x < FFALIGN(avctx->width, 16) >> 4; x++)
231  tgq_decode_mb(s, y, x);
232 
233  *data_size = sizeof(AVFrame);
234  *(AVFrame*)data = s->frame;
235 
236  return avpkt->size;
237 }
238 
240  TgqContext *s = avctx->priv_data;
241  if (s->frame.data[0])
242  s->avctx->release_buffer(avctx, &s->frame);
243  return 0;
244 }
245 
247  .name = "eatgq",
248  .type = AVMEDIA_TYPE_VIDEO,
249  .id = CODEC_ID_TGQ,
250  .priv_data_size = sizeof(TgqContext),
254  .capabilities = CODEC_CAP_DR1,
255  .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
256 };