ffmpeg / libavcodec / mdec.c @ 20646267
History  View  Annotate  Download (7.93 KB)
1 
/*


2 
* PSX MDEC codec

3 
* Copyright (c) 2003 Michael Niedermayer

4 
*

5 
* This library is free software; you can redistribute it and/or

6 
* modify it under the terms of the GNU Lesser General Public

7 
* License as published by the Free Software Foundation; either

8 
* version 2 of the License, or (at your option) any later version.

9 
*

10 
* This library is distributed in the hope that it will be useful,

11 
* but WITHOUT ANY WARRANTY; without even the implied warranty of

12 
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

13 
* Lesser General Public License for more details.

14 
*

15 
* You should have received a copy of the GNU Lesser General Public

16 
* License along with this library; if not, write to the Free Software

17 
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 021111307 USA

18 
*

19 
* based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>

20 
*/

21 

22 
/**

23 
* @file mdec.c

24 
* PSX MDEC codec.

25 
* This is very similar to intra only MPEG1.

26 
*/

27 

28 
#include "avcodec.h" 
29 
#include "dsputil.h" 
30 
#include "mpegvideo.h" 
31  
32 
//#undef NDEBUG

33 
//#include <assert.h>

34  
35 
typedef struct MDECContext{ 
36 
AVCodecContext *avctx; 
37 
DSPContext dsp; 
38 
AVFrame picture; 
39 
PutBitContext pb; 
40 
GetBitContext gb; 
41 
ScanTable scantable; 
42 
int version;

43 
int qscale;

44 
int last_dc[3]; 
45 
int mb_width;

46 
int mb_height;

47 
int mb_x, mb_y;

48 
DCTELEM __align8 block[6][64]; 
49 
uint16_t __align8 intra_matrix[64];

50 
int __align8 q_intra_matrix[64]; 
51 
uint8_t *bitstream_buffer; 
52 
int bitstream_buffer_size;

53 
int block_last_index[6]; 
54 
} MDECContext; 
55  
56 
//very similar to mpeg1

57 
static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n) 
58 
{ 
59 
int level, diff, i, j, run;

60 
int component;

61 
RLTable *rl = &rl_mpeg1; 
62 
uint8_t * const scantable= a>scantable.permutated;

63 
const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix;

64 
const int qscale= a>qscale; 
65  
66 
/* DC coef */

67 
if(a>version==2){ 
68 
block[0]= 2*get_sbits(&a>gb, 10) + 1024; 
69 
}else{

70 
component = (n <= 3 ? 0 : n  4 + 1); 
71 
diff = decode_dc(&a>gb, component); 
72 
if (diff >= 0xffff) 
73 
return 1; 
74 
a>last_dc[component]+= diff; 
75 
block[0] = a>last_dc[component]<<3; 
76 
} 
77 

78 
i = 0;

79 
{ 
80 
OPEN_READER(re, &a>gb); 
81 
/* now quantify & encode AC coefs */

82 
for(;;) {

83 
UPDATE_CACHE(re, &a>gb); 
84 
GET_RL_VLC(level, run, re, &a>gb, rl>rl_vlc[0], TEX_VLC_BITS, 2); 
85 

86 
if(level == 127){ 
87 
break;

88 
} else if(level != 0) { 
89 
i += run; 
90 
j = scantable[i]; 
91 
level= (level*qscale*quant_matrix[j])>>3;

92 
// level= (level1)1;

93 
level = (level ^ SHOW_SBITS(re, &a>gb, 1))  SHOW_SBITS(re, &a>gb, 1); 
94 
LAST_SKIP_BITS(re, &a>gb, 1);

95 
} else {

96 
/* escape */

97 
run = SHOW_UBITS(re, &a>gb, 6)+1; LAST_SKIP_BITS(re, &a>gb, 6); 
98 
UPDATE_CACHE(re, &a>gb); 
99 
level = SHOW_SBITS(re, &a>gb, 10); SKIP_BITS(re, &a>gb, 10); 
100 
i += run; 
101 
j = scantable[i]; 
102 
if(level<0){ 
103 
level= level; 
104 
level= (level*qscale*quant_matrix[j])>>3;

105 
level= (level1)1; 
106 
level= level; 
107 
}else{

108 
level= (level*qscale*quant_matrix[j])>>3;

109 
level= (level1)1; 
110 
} 
111 
} 
112 
if (i > 63){ 
113 
av_log(a>avctx, AV_LOG_ERROR, "actex damaged at %d %d\n", a>mb_x, a>mb_y);

114 
return 1; 
115 
} 
116  
117 
block[j] = level; 
118 
} 
119 
CLOSE_READER(re, &a>gb); 
120 
} 
121 
a>block_last_index[n] = i; 
122 
return 0; 
123 
} 
124  
125 
static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){ 
126 
int i;

127 
const int block_index[6]= {5,4,0,1,2,3}; 
128  
129 
a>dsp.clear_blocks(block[0]);

130 

131 
for(i=0; i<6; i++){ 
132 
if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0) 
133 
return 1; 
134 
} 
135 
return 0; 
136 
} 
137  
138 
static inline void idct_put(MDECContext *a, int mb_x, int mb_y){ 
139 
DCTELEM (*block)[64]= a>block;

140 
int linesize= a>picture.linesize[0]; 
141 

142 
uint8_t *dest_y = a>picture.data[0] + (mb_y * 16* linesize ) + mb_x * 16; 
143 
uint8_t *dest_cb = a>picture.data[1] + (mb_y * 8 * a>picture.linesize[1]) + mb_x * 8; 
144 
uint8_t *dest_cr = a>picture.data[2] + (mb_y * 8 * a>picture.linesize[2]) + mb_x * 8; 
145  
146 
a>dsp.idct_put(dest_y , linesize, block[0]);

147 
a>dsp.idct_put(dest_y + 8, linesize, block[1]); 
148 
a>dsp.idct_put(dest_y + 8*linesize , linesize, block[2]); 
149 
a>dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]); 
150  
151 
if(!(a>avctx>flags&CODEC_FLAG_GRAY)){

152 
a>dsp.idct_put(dest_cb, a>picture.linesize[1], block[4]); 
153 
a>dsp.idct_put(dest_cr, a>picture.linesize[2], block[5]); 
154 
} 
155 
} 
156  
157 
static int decode_frame(AVCodecContext *avctx, 
158 
void *data, int *data_size, 
159 
uint8_t *buf, int buf_size)

160 
{ 
161 
MDECContext * const a = avctx>priv_data;

162 
AVFrame *picture = data; 
163 
AVFrame * const p= (AVFrame*)&a>picture;

164 
int i;

165  
166 
/* special case for last picture */

167 
if (buf_size == 0) { 
168 
return 0; 
169 
} 
170  
171 
if(p>data[0]) 
172 
avctx>release_buffer(avctx, p); 
173  
174 
p>reference= 0;

175 
if(avctx>get_buffer(avctx, p) < 0){ 
176 
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

177 
return 1; 
178 
} 
179 
p>pict_type= I_TYPE; 
180 
p>key_frame= 1;

181 
a>last_dc[0]=

182 
a>last_dc[1]=

183 
a>last_dc[2]= 0; 
184  
185 
a>bitstream_buffer= av_fast_realloc(a>bitstream_buffer, &a>bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); 
186 
for(i=0; i<buf_size; i+=2){ 
187 
a>bitstream_buffer[i] = buf[i+1];

188 
a>bitstream_buffer[i+1]= buf[i ];

189 
} 
190 
init_get_bits(&a>gb, a>bitstream_buffer, buf_size*8);

191 

192 
/* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */

193 
skip_bits(&a>gb, 32);

194  
195 
a>qscale= get_bits(&a>gb, 16);

196 
a>version= get_bits(&a>gb, 16);

197 

198 
// printf("qscale:%d (0x%X), version:%d (0x%X)\n", a>qscale, a>qscale, a>version, a>version);

199 

200 
for(a>mb_x=0; a>mb_x<a>mb_width; a>mb_x++){ 
201 
for(a>mb_y=0; a>mb_y<a>mb_height; a>mb_y++){ 
202 
if( decode_mb(a, a>block) <0) 
203 
return 1; 
204 

205 
idct_put(a, a>mb_x, a>mb_y); 
206 
} 
207 
} 
208  
209 
// p>quality= (32 + a>inv_qscale/2)/a>inv_qscale;

210 
// memset(p>qscale_table, p>quality, p>qstride*a>mb_height);

211 

212 
*picture= *(AVFrame*)&a>picture; 
213 
*data_size = sizeof(AVPicture);

214  
215 
emms_c(); 
216 

217 
return (get_bits_count(&a>gb)+31)/32*4; 
218 
} 
219  
220 
static void mdec_common_init(AVCodecContext *avctx){ 
221 
MDECContext * const a = avctx>priv_data;

222  
223 
dsputil_init(&a>dsp, avctx); 
224  
225 
a>mb_width = (avctx>width + 15) / 16; 
226 
a>mb_height = (avctx>height + 15) / 16; 
227  
228 
avctx>coded_frame= (AVFrame*)&a>picture; 
229 
a>avctx= avctx; 
230 
} 
231  
232 
static int decode_init(AVCodecContext *avctx){ 
233 
MDECContext * const a = avctx>priv_data;

234 
AVFrame *p= (AVFrame*)&a>picture; 
235 

236 
mdec_common_init(avctx); 
237 
init_vlcs(); 
238 
ff_init_scantable(a>dsp.idct_permutation, &a>scantable, ff_zigzag_direct); 
239 
/*

240 
for(i=0; i<64; i++){

241 
int index= ff_zigzag_direct[i];

242 
a>intra_matrix[i]= 64*ff_mpeg1_default_intra_matrix[index] / a>inv_qscale;

243 
}

244 
*/

245 
p>qstride= a>mb_width; 
246 
p>qscale_table= av_mallocz( p>qstride * a>mb_height); 
247  
248 
return 0; 
249 
} 
250  
251 
static int decode_end(AVCodecContext *avctx){ 
252 
MDECContext * const a = avctx>priv_data;

253  
254 
av_freep(&a>bitstream_buffer); 
255 
av_freep(&a>picture.qscale_table); 
256 
a>bitstream_buffer_size=0;

257 

258 
return 0; 
259 
} 
260  
261 
AVCodec mdec_decoder = { 
262 
"mdec",

263 
CODEC_TYPE_VIDEO, 
264 
CODEC_ID_MDEC, 
265 
sizeof(MDECContext),

266 
decode_init, 
267 
NULL,

268 
decode_end, 
269 
decode_frame, 
270 
CODEC_CAP_DR1, 
271 
}; 
272 