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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 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 St, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Electronic Arts TGQ Video Decoder
25  * @author Peter Ross <pross@xvid.org>
26  *
27  * Technical details here:
28  * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGQ
29  */
30 
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 #include "eaidct.h"
38 #include "internal.h"
39 
40 typedef struct TgqContext {
41  AVCodecContext *avctx;
42  AVFrame frame;
43  int width, height;
44  ScanTable scantable;
45  int qtable[64];
46  DECLARE_ALIGNED(16, int16_t, block)[6][64];
47  GetByteContext gb;
48 } TgqContext;
49 
50 static av_cold int tgq_decode_init(AVCodecContext *avctx)
51 {
52  TgqContext *s = avctx->priv_data;
53  uint8_t idct_permutation[64];
54  s->avctx = avctx;
55  ff_init_scantable_permutation(idct_permutation, FF_NO_IDCT_PERM);
56  ff_init_scantable(idct_permutation, &s->scantable, ff_zigzag_direct);
57  avctx->time_base = (AVRational){1, 15};
58  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
59  return 0;
60 }
61 
62 static void tgq_decode_block(TgqContext *s, int16_t block[64], GetBitContext *gb)
63 {
64  uint8_t *perm = s->scantable.permutated;
65  int i, j, value;
66  block[0] = get_sbits(gb, 8) * s->qtable[0];
67  for (i = 1; i < 64;) {
68  switch (show_bits(gb, 3)) {
69  case 4:
70  block[perm[i++]] = 0;
71  case 0:
72  block[perm[i++]] = 0;
73  skip_bits(gb, 3);
74  break;
75  case 5:
76  case 1:
77  skip_bits(gb, 2);
78  value = get_bits(gb, 6);
79  for (j = 0; j < value; j++)
80  block[perm[i++]] = 0;
81  break;
82  case 6:
83  skip_bits(gb, 3);
84  block[perm[i]] = -s->qtable[perm[i]];
85  i++;
86  break;
87  case 2:
88  skip_bits(gb, 3);
89  block[perm[i]] = s->qtable[perm[i]];
90  i++;
91  break;
92  case 7: // 111b
93  case 3: // 011b
94  skip_bits(gb, 2);
95  if (show_bits(gb, 6) == 0x3F) {
96  skip_bits(gb, 6);
97  block[perm[i]] = get_sbits(gb, 8) * s->qtable[perm[i]];
98  } else {
99  block[perm[i]] = get_sbits(gb, 6) * s->qtable[perm[i]];
100  }
101  i++;
102  break;
103  }
104  }
105  block[0] += 128 << 4;
106 }
107 
108 static void tgq_idct_put_mb(TgqContext *s, int16_t (*block)[64],
109  int mb_x, int mb_y)
110 {
111  int linesize = s->frame.linesize[0];
112  uint8_t *dest_y = s->frame.data[0] + (mb_y * 16 * linesize) + mb_x * 16;
113  uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
114  uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
115 
116  ff_ea_idct_put_c(dest_y , linesize, block[0]);
117  ff_ea_idct_put_c(dest_y + 8, linesize, block[1]);
118  ff_ea_idct_put_c(dest_y + 8 * linesize , linesize, block[2]);
119  ff_ea_idct_put_c(dest_y + 8 * linesize + 8, linesize, block[3]);
120  if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {
121  ff_ea_idct_put_c(dest_cb, s->frame.linesize[1], block[4]);
122  ff_ea_idct_put_c(dest_cr, s->frame.linesize[2], block[5]);
123  }
124 }
125 
126 static inline void tgq_dconly(TgqContext *s, unsigned char *dst,
127  int dst_stride, int dc)
128 {
129  int level = av_clip_uint8((dc*s->qtable[0] + 2056) >> 4);
130  int j;
131  for (j = 0; j < 8; j++)
132  memset(dst + j * dst_stride, level, 8);
133 }
134 
135 static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
136 {
137  int linesize = s->frame.linesize[0];
138  uint8_t *dest_y = s->frame.data[0] + (mb_y * 16 * linesize) + mb_x * 16;
139  uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
140  uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
141  tgq_dconly(s, dest_y, linesize, dc[0]);
142  tgq_dconly(s, dest_y + 8, linesize, dc[1]);
143  tgq_dconly(s, dest_y + 8 * linesize, linesize, dc[2]);
144  tgq_dconly(s, dest_y + 8 * linesize + 8, linesize, dc[3]);
145  if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {
146  tgq_dconly(s, dest_cb, s->frame.linesize[1], dc[4]);
147  tgq_dconly(s, dest_cr, s->frame.linesize[2], dc[5]);
148  }
149 }
150 
151 static int tgq_decode_mb(TgqContext *s, int mb_y, int mb_x)
152 {
153  int mode;
154  int i;
155  int8_t dc[6];
156 
157  mode = bytestream2_get_byte(&s->gb);
158  if (mode > 12) {
159  GetBitContext gb;
160  init_get_bits(&gb, s->gb.buffer, FFMIN(bytestream2_get_bytes_left(&s->gb), mode) * 8);
161  for (i = 0; i < 6; i++)
162  tgq_decode_block(s, s->block[i], &gb);
163  tgq_idct_put_mb(s, s->block, mb_x, mb_y);
164  bytestream2_skip(&s->gb, mode);
165  } else {
166  if (mode == 3) {
167  memset(dc, bytestream2_get_byte(&s->gb), 4);
168  dc[4] = bytestream2_get_byte(&s->gb);
169  dc[5] = bytestream2_get_byte(&s->gb);
170  } else if (mode == 6) {
171  bytestream2_get_buffer(&s->gb, dc, 6);
172  } else if (mode == 12) {
173  for (i = 0; i < 6; i++) {
174  dc[i] = bytestream2_get_byte(&s->gb);
175  bytestream2_skip(&s->gb, 1);
176  }
177  } else {
178  av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
179  return -1;
180  }
181  tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
182  }
183  return 0;
184 }
185 
186 static void tgq_calculate_qtable(TgqContext *s, int quant)
187 {
188  int i, j;
189  const int a = (14 * (100 - quant)) / 100 + 1;
190  const int b = (11 * (100 - quant)) / 100 + 4;
191  for (j = 0; j < 8; j++)
192  for (i = 0; i < 8; i++)
193  s->qtable[j * 8 + i] = ((a * (j + i) / (7 + 7) + b) *
194  ff_inv_aanscales[j * 8 + i]) >> (14 - 4);
195 }
196 
197 static int tgq_decode_frame(AVCodecContext *avctx,
198  void *data, int *got_frame,
199  AVPacket *avpkt)
200 {
201  const uint8_t *buf = avpkt->data;
202  int buf_size = avpkt->size;
203  TgqContext *s = avctx->priv_data;
204  int x, y, ret;
205  int big_endian;
206 
207  if (buf_size < 16) {
208  av_log(avctx, AV_LOG_WARNING, "truncated header\n");
209  return AVERROR_INVALIDDATA;
210  }
211  big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
212  bytestream2_init(&s->gb, buf + 8, buf_size - 8);
213  if (big_endian) {
214  s->width = bytestream2_get_be16u(&s->gb);
215  s->height = bytestream2_get_be16u(&s->gb);
216  } else {
217  s->width = bytestream2_get_le16u(&s->gb);
218  s->height = bytestream2_get_le16u(&s->gb);
219  }
220 
221  if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
222  avcodec_set_dimensions(s->avctx, s->width, s->height);
223  if (s->frame.data[0])
224  avctx->release_buffer(avctx, &s->frame);
225  }
226  tgq_calculate_qtable(s, bytestream2_get_byteu(&s->gb));
227  bytestream2_skip(&s->gb, 3);
228 
229  if (!s->frame.data[0]) {
230  s->frame.key_frame = 1;
231  s->frame.pict_type = AV_PICTURE_TYPE_I;
232  s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
233  if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
234  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
235  return ret;
236  }
237  }
238 
239  for (y = 0; y < FFALIGN(avctx->height, 16) >> 4; y++)
240  for (x = 0; x < FFALIGN(avctx->width, 16) >> 4; x++)
241  if (tgq_decode_mb(s, y, x) < 0)
242  return AVERROR_INVALIDDATA;
243 
244  *got_frame = 1;
245  *(AVFrame*)data = s->frame;
246 
247  return avpkt->size;
248 }
249 
250 static av_cold int tgq_decode_end(AVCodecContext *avctx)
251 {
252  TgqContext *s = avctx->priv_data;
253  if (s->frame.data[0])
254  s->avctx->release_buffer(avctx, &s->frame);
255  return 0;
256 }
257 
258 AVCodec ff_eatgq_decoder = {
259  .name = "eatgq",
260  .type = AVMEDIA_TYPE_VIDEO,
261  .id = AV_CODEC_ID_TGQ,
262  .priv_data_size = sizeof(TgqContext),
263  .init = tgq_decode_init,
264  .close = tgq_decode_end,
265  .decode = tgq_decode_frame,
266  .capabilities = CODEC_CAP_DR1,
267  .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
268 };
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