3 * Copyright (c) 2003 Michael Niedermayer
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.
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.
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 02111-1307 USA
27 #include "mpegvideo.h"
32 #define BLOCK_TYPE_VLC_BITS 5
33 #define ACDC_VLC_BITS 9
35 #define CFRAME_BUFFER_COUNT 100
37 static const uint8_t block_type_tab[4][8][2]={
39 { 0,1}, { 2,2}, { 6,3}, {14,4}, {30,5}, {31,5}, { 0,0}
41 { 0,1}, { 0,0}, { 2,2}, { 6,3}, {14,4}, {15,4}, { 0,0}
43 { 0,1}, { 2,2}, { 0,0}, { 6,3}, {14,4}, {15,4}, { 0,0}
45 { 0,1}, { 0,0}, { 0,0}, { 2,2}, { 6,3}, {14,4}, {15,4}
49 static const uint8_t size2index[4][4]={
56 static const int8_t mv[256][2]={
57 { 0, 0},{ 0, -1},{ -1, 0},{ 1, 0},{ 0, 1},{ -1, -1},{ 1, -1},{ -1, 1},
58 { 1, 1},{ 0, -2},{ -2, 0},{ 2, 0},{ 0, 2},{ -1, -2},{ 1, -2},{ -2, -1},
59 { 2, -1},{ -2, 1},{ 2, 1},{ -1, 2},{ 1, 2},{ -2, -2},{ 2, -2},{ -2, 2},
60 { 2, 2},{ 0, -3},{ -3, 0},{ 3, 0},{ 0, 3},{ -1, -3},{ 1, -3},{ -3, -1},
61 { 3, -1},{ -3, 1},{ 3, 1},{ -1, 3},{ 1, 3},{ -2, -3},{ 2, -3},{ -3, -2},
62 { 3, -2},{ -3, 2},{ 3, 2},{ -2, 3},{ 2, 3},{ 0, -4},{ -4, 0},{ 4, 0},
63 { 0, 4},{ -1, -4},{ 1, -4},{ -4, -1},{ 4, -1},{ 4, 1},{ -1, 4},{ 1, 4},
64 { -3, -3},{ -3, 3},{ 3, 3},{ -2, -4},{ -4, -2},{ 4, -2},{ -4, 2},{ -2, 4},
65 { 2, 4},{ -3, -4},{ 3, -4},{ 4, -3},{ -5, 0},{ -4, 3},{ -3, 4},{ 3, 4},
66 { -1, -5},{ -5, -1},{ -5, 1},{ -1, 5},{ -2, -5},{ 2, -5},{ 5, -2},{ 5, 2},
67 { -4, -4},{ -4, 4},{ -3, -5},{ -5, -3},{ -5, 3},{ 3, 5},{ -6, 0},{ 0, 6},
68 { -6, -1},{ -6, 1},{ 1, 6},{ 2, -6},{ -6, 2},{ 2, 6},{ -5, -4},{ 5, 4},
69 { 4, 5},{ -6, -3},{ 6, 3},{ -7, 0},{ -1, -7},{ 5, -5},{ -7, 1},{ -1, 7},
70 { 4, -6},{ 6, 4},{ -2, -7},{ -7, 2},{ -3, -7},{ 7, -3},{ 3, 7},{ 6, -5},
71 { 0, -8},{ -1, -8},{ -7, -4},{ -8, 1},{ 4, 7},{ 2, -8},{ -2, 8},{ 6, 6},
72 { -8, 3},{ 5, -7},{ -5, 7},{ 8, -4},{ 0, -9},{ -9, -1},{ 1, 9},{ 7, -6},
73 { -7, 6},{ -5, -8},{ -5, 8},{ -9, 3},{ 9, -4},{ 7, -7},{ 8, -6},{ 6, 8},
74 { 10, 1},{-10, 2},{ 9, -5},{ 10, -3},{ -8, -7},{-10, -4},{ 6, -9},{-11, 0},
75 { 11, 1},{-11, -2},{ -2, 11},{ 7, -9},{ -7, 9},{ 10, 6},{ -4, 11},{ 8, -9},
76 { 8, 9},{ 5, 11},{ 7,-10},{ 12, -3},{ 11, 6},{ -9, -9},{ 8, 10},{ 5, 12},
77 {-11, 7},{ 13, 2},{ 6,-12},{ 10, 9},{-11, 8},{ -7, 12},{ 0, 14},{ 14, -2},
78 { -9, 11},{ -6, 13},{-14, -4},{ -5,-14},{ 5, 14},{-15, -1},{-14, -6},{ 3,-15},
79 { 11,-11},{ -7, 14},{ -5, 15},{ 8,-14},{ 15, 6},{ 3, 16},{ 7,-15},{-16, 5},
80 { 0, 17},{-16, -6},{-10, 14},{-16, 7},{ 12, 13},{-16, 8},{-17, 6},{-18, 3},
81 { -7, 17},{ 15, 11},{ 16, 10},{ 2,-19},{ 3,-19},{-11,-16},{-18, 8},{-19, -6},
82 { 2,-20},{-17,-11},{-10,-18},{ 8, 19},{-21, -1},{-20, 7},{ -4, 21},{ 21, 5},
83 { 15, 16},{ 2,-22},{-10,-20},{-22, 5},{ 20,-11},{ -7,-22},{-12, 20},{ 23, -5},
84 { 13,-20},{ 24, -2},{-15, 19},{-11, 22},{ 16, 19},{ 23,-10},{-18,-18},{ -9,-24},
85 { 24,-10},{ -3, 26},{-23, 13},{-18,-20},{ 17, 21},{ -4, 27},{ 27, 6},{ 1,-28},
86 {-11, 26},{-17,-23},{ 7, 28},{ 11,-27},{ 29, 5},{-23,-19},{-28,-11},{-21, 22},
87 {-30, 7},{-17, 26},{-27, 16},{ 13, 29},{ 19,-26},{ 10,-31},{-14,-30},{ 20,-27},
88 {-29, 18},{-16,-31},{-28,-22},{ 21,-30},{-25, 28},{ 26,-29},{ 25,-32},{-32,-32}
91 // this is simply the scaled down elementwise product of the standard jpeg quantizer table and the AAN premul table
92 static const uint8_t dequant_table[64]={
93 16, 15, 13, 19, 24, 31, 28, 17,
94 17, 23, 25, 31, 36, 63, 45, 21,
95 18, 24, 27, 37, 52, 59, 49, 20,
96 16, 28, 34, 40, 60, 80, 51, 20,
97 18, 31, 48, 66, 68, 86, 56, 21,
98 19, 38, 56, 59, 64, 64, 48, 20,
99 27, 48, 55, 55, 56, 51, 35, 15,
100 20, 35, 34, 32, 31, 22, 15, 8,
103 static VLC block_type_vlc[4];
106 typedef struct CFrameBuffer{
113 typedef struct FourXContext{
114 AVCodecContext *avctx;
116 AVFrame current_picture, last_picture;
117 GetBitContext pre_gb; ///< ac/dc prefix
120 uint16_t *wordstream;
124 DCTELEM __align8 block[6][64];
125 uint8_t *bitstream_buffer;
126 int bitstream_buffer_size;
127 CFrameBuffer cfrm[CFRAME_BUFFER_COUNT];
131 #define FIX_1_082392200 70936
132 #define FIX_1_414213562 92682
133 #define FIX_1_847759065 121095
134 #define FIX_2_613125930 171254
136 #define MULTIPLY(var,const) (((var)*(const)) >> 16)
138 static void idct(DCTELEM block[64]){
139 int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
140 int tmp10, tmp11, tmp12, tmp13;
141 int z5, z10, z11, z12, z13;
146 tmp10 = block[8*0 + i] + block[8*4 + i];
147 tmp11 = block[8*0 + i] - block[8*4 + i];
149 tmp13 = block[8*2 + i] + block[8*6 + i];
150 tmp12 = MULTIPLY(block[8*2 + i] - block[8*6 + i], FIX_1_414213562) - tmp13;
152 tmp0 = tmp10 + tmp13;
153 tmp3 = tmp10 - tmp13;
154 tmp1 = tmp11 + tmp12;
155 tmp2 = tmp11 - tmp12;
157 z13 = block[8*5 + i] + block[8*3 + i];
158 z10 = block[8*5 + i] - block[8*3 + i];
159 z11 = block[8*1 + i] + block[8*7 + i];
160 z12 = block[8*1 + i] - block[8*7 + i];
163 tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
165 z5 = MULTIPLY(z10 + z12, FIX_1_847759065);
166 tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5;
167 tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5;
173 temp[8*0 + i] = tmp0 + tmp7;
174 temp[8*7 + i] = tmp0 - tmp7;
175 temp[8*1 + i] = tmp1 + tmp6;
176 temp[8*6 + i] = tmp1 - tmp6;
177 temp[8*2 + i] = tmp2 + tmp5;
178 temp[8*5 + i] = tmp2 - tmp5;
179 temp[8*4 + i] = tmp3 + tmp4;
180 temp[8*3 + i] = tmp3 - tmp4;
183 for(i=0; i<8*8; i+=8){
184 tmp10 = temp[0 + i] + temp[4 + i];
185 tmp11 = temp[0 + i] - temp[4 + i];
187 tmp13 = temp[2 + i] + temp[6 + i];
188 tmp12 = MULTIPLY(temp[2 + i] - temp[6 + i], FIX_1_414213562) - tmp13;
190 tmp0 = tmp10 + tmp13;
191 tmp3 = tmp10 - tmp13;
192 tmp1 = tmp11 + tmp12;
193 tmp2 = tmp11 - tmp12;
195 z13 = temp[5 + i] + temp[3 + i];
196 z10 = temp[5 + i] - temp[3 + i];
197 z11 = temp[1 + i] + temp[7 + i];
198 z12 = temp[1 + i] - temp[7 + i];
201 tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
203 z5 = MULTIPLY(z10 + z12, FIX_1_847759065);
204 tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5;
205 tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5;
211 block[0 + i] = (tmp0 + tmp7)>>6;
212 block[7 + i] = (tmp0 - tmp7)>>6;
213 block[1 + i] = (tmp1 + tmp6)>>6;
214 block[6 + i] = (tmp1 - tmp6)>>6;
215 block[2 + i] = (tmp2 + tmp5)>>6;
216 block[5 + i] = (tmp2 - tmp5)>>6;
217 block[4 + i] = (tmp3 + tmp4)>>6;
218 block[3 + i] = (tmp3 - tmp4)>>6;
222 static void init_vlcs(FourXContext *f){
230 init_vlc(&block_type_vlc[i], BLOCK_TYPE_VLC_BITS, 7,
231 &block_type_tab[i][0][1], 2, 1,
232 &block_type_tab[i][0][0], 2, 1);
237 static void init_mv(FourXContext *f){
240 for(i=0; i<256; i++){
241 f->mv[i] = mv[i][0] + mv[i][1]*f->current_picture.linesize[0]/2;
245 static inline void mcdc(uint16_t *dst, uint16_t *src, int log2w, int h, int stride, int scale, int dc){
252 dst[0] = scale*src[0] + dc;
253 if(scale) src += stride;
259 ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
260 if(scale) src += stride;
266 ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
267 ((uint32_t*)dst)[1] = scale*((uint32_t*)src)[1] + dc;
268 if(scale) src += stride;
274 ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
275 ((uint32_t*)dst)[1] = scale*((uint32_t*)src)[1] + dc;
276 ((uint32_t*)dst)[2] = scale*((uint32_t*)src)[2] + dc;
277 ((uint32_t*)dst)[3] = scale*((uint32_t*)src)[3] + dc;
278 if(scale) src += stride;
286 static void decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src, int log2w, int log2h, int stride){
287 const int index= size2index[log2h][log2w];
288 const int h= 1<<log2h;
289 int code= get_vlc2(&f->gb, block_type_vlc[index].table, BLOCK_TYPE_VLC_BITS, 1);
291 assert(code>=0 && code<=6);
294 src += f->mv[ *f->bytestream++ ];
295 mcdc(dst, src, log2w, h, stride, 1, 0);
298 decode_p_block(f, dst , src , log2w, log2h, stride);
299 decode_p_block(f, dst + (stride<<log2h), src + (stride<<log2h), log2w, log2h, stride);
302 decode_p_block(f, dst , src , log2w, log2h, stride);
303 decode_p_block(f, dst + (1<<log2w), src + (1<<log2w), log2w, log2h, stride);
305 src += f->mv[ *f->bytestream++ ];
306 mcdc(dst, src, log2w, h, stride, 1, le2me_16(*f->wordstream++));
308 mcdc(dst, src, log2w, h, stride, 0, le2me_16(*f->wordstream++));
311 dst[0] = le2me_16(*f->wordstream++);
312 dst[1] = le2me_16(*f->wordstream++);
314 dst[0 ] = le2me_16(*f->wordstream++);
315 dst[stride] = le2me_16(*f->wordstream++);
320 static int get32(void *p){
321 return le2me_32(*(uint32_t*)p);
324 static int decode_p_frame(FourXContext *f, uint8_t *buf, int length){
326 const int width= f->avctx->width;
327 const int height= f->avctx->height;
328 uint16_t *src= (uint16_t*)f->last_picture.data[0];
329 uint16_t *dst= (uint16_t*)f->current_picture.data[0];
330 const int stride= f->current_picture.linesize[0]>>1;
331 const int bitstream_size= get32(buf+8);
332 const int bytestream_size= get32(buf+16);
333 const int wordstream_size= get32(buf+12);
335 if(bitstream_size+ bytestream_size+ wordstream_size + 20 != length)
336 printf("lengths %d %d %d %d\n", bitstream_size, bytestream_size, wordstream_size,
337 bitstream_size+ bytestream_size+ wordstream_size - length);
339 f->bitstream_buffer= av_fast_realloc(f->bitstream_buffer, &f->bitstream_buffer_size, bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);
340 f->dsp.bswap_buf((uint32_t*)f->bitstream_buffer, (uint32_t*)(buf + 20), bitstream_size/4);
341 init_get_bits(&f->gb, f->bitstream_buffer, 8*bitstream_size);
343 f->wordstream= (uint16_t*)(buf + 20 + bitstream_size);
344 f->bytestream= buf + 20 + bitstream_size + wordstream_size;
348 for(y=0; y<height; y+=8){
349 for(x=0; x<width; x+=8){
350 decode_p_block(f, dst + x, src + x, 3, 3, stride);
356 if(bitstream_size != (get_bits_count(&f->gb)+31)/32*4)
357 printf(" %d %d %d bytes left\n",
358 bitstream_size - (get_bits_count(&f->gb)+31)/32*4,
359 bytestream_size - (f->bytestream - (buf + 20 + bitstream_size + wordstream_size)),
360 wordstream_size - (((uint8_t*)f->wordstream) - (buf + 20 + bitstream_size))
367 * decode block and dequantize.
368 * Note this is allmost identical to mjpeg
370 static int decode_i_block(FourXContext *f, DCTELEM *block){
371 int code, i, j, level, val;
374 val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
376 printf("error dc run != 0\n");
380 val = get_xbits(&f->gb, val);
382 val = val * dequant_table[0] + f->last_dc;
388 code = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
396 level = get_xbits(&f->gb, code & 0xf);
399 printf("run %d oveflow\n", i);
403 j= ff_zigzag_direct[i];
404 block[j] = level * dequant_table[j];
414 static inline void idct_put(FourXContext *f, int x, int y){
415 DCTELEM (*block)[64]= f->block;
416 int stride= f->current_picture.linesize[0]>>1;
418 uint16_t *dst = ((uint16_t*)f->current_picture.data[0]) + y * stride + x;
421 block[i][0] += 0x80*8*8;
425 if(!(f->avctx->flags&CODEC_FLAG_GRAY)){
426 for(i=4; i<6; i++) idct(block[i]);
431 DCTELEM *temp= block[(x>>2) + 2*(y>>2)] + 2*(x&3) + 2*8*(y&3); //FIXME optimize
432 int cb= block[4][x + 8*y];
433 int cr= block[5][x + 8*y];
434 int cg= (cb + cr)>>1;
440 dst[0 ]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
442 dst[1 ]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
444 dst[ stride]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
446 dst[1+stride]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
449 dst += 2*stride - 2*8;
453 static int decode_i_mb(FourXContext *f){
456 f->dsp.clear_blocks(f->block[0]);
459 if(decode_i_block(f, f->block[i]) < 0)
466 static uint8_t *read_huffman_tables(FourXContext *f, uint8_t * const buf){
470 uint8_t len_tab[257];
476 memset(frequency, 0, sizeof(frequency));
477 memset(up, -1, sizeof(up));
484 for(i=start; i<=end; i++){
485 frequency[i]= *ptr++;
486 // printf("%d %d %d\n", start, end, frequency[i]);
495 while((ptr - buf)&3) ptr++; // 4byte align
497 // for(j=0; j<16; j++)
498 // printf("%2X", ptr[j]);
500 for(j=257; j<512; j++){
501 int min_freq[2]= {256*256, 256*256};
502 int smallest[2]= {0, 0};
505 if(frequency[i] == 0) continue;
506 if(frequency[i] < min_freq[1]){
507 if(frequency[i] < min_freq[0]){
508 min_freq[1]= min_freq[0]; smallest[1]= smallest[0];
509 min_freq[0]= frequency[i];smallest[0]= i;
511 min_freq[1]= frequency[i];smallest[1]= i;
515 if(min_freq[1] == 256*256) break;
517 frequency[j]= min_freq[0] + min_freq[1];
518 flag[ smallest[0] ]= 0;
519 flag[ smallest[1] ]= 1;
521 up[ smallest[1] ]= j;
522 frequency[ smallest[0] ]= frequency[ smallest[1] ]= 0;
525 for(j=0; j<257; j++){
530 for(node= j; up[node] != -1; node= up[node]){
531 bits += flag[node]<<len;
533 if(len > 31) printf("vlc length overflow\n"); //can this happen at all ?
540 init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257,
547 static int decode_i_frame(FourXContext *f, uint8_t *buf, int length){
549 const int width= f->avctx->width;
550 const int height= f->avctx->height;
551 uint16_t *dst= (uint16_t*)f->current_picture.data[0];
552 const int stride= f->current_picture.linesize[0]>>1;
553 const int bitstream_size= get32(buf);
554 const int token_count= get32(buf + bitstream_size + 8);
555 int prestream_size= 4*get32(buf + bitstream_size + 4);
556 uint8_t *prestream= buf + bitstream_size + 12;
558 if(prestream_size + bitstream_size + 12 != length)
559 fprintf(stderr, "size missmatch %d %d %d\n", prestream_size, bitstream_size, length);
561 prestream= read_huffman_tables(f, prestream);
563 init_get_bits(&f->gb, buf + 4, 8*bitstream_size);
565 prestream_size= length + buf - prestream;
567 f->bitstream_buffer= av_fast_realloc(f->bitstream_buffer, &f->bitstream_buffer_size, prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
568 f->dsp.bswap_buf((uint32_t*)f->bitstream_buffer, (uint32_t*)prestream, prestream_size/4);
569 init_get_bits(&f->pre_gb, f->bitstream_buffer, 8*prestream_size);
571 f->last_dc= 0*128*8*8;
573 for(y=0; y<height; y+=16){
574 for(x=0; x<width; x+=16){
575 if(decode_i_mb(f) < 0)
583 if(get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)
584 printf("end missmatch\n");
589 static int decode_frame(AVCodecContext *avctx,
590 void *data, int *data_size,
591 uint8_t *buf, int buf_size)
593 FourXContext * const f = avctx->priv_data;
594 AVFrame *picture = data;
596 int i, frame_4cc, frame_size;
600 /* special case for last picture */
605 frame_4cc= get32(buf);
606 if(buf_size != get32(buf+4)+8){
607 fprintf(stderr, "size missmatch %d %d\n", buf_size, get32(buf+4));
610 if(frame_4cc == ff_get_fourcc("cfrm")){
612 const int data_size= buf_size - 20;
613 const int id= get32(buf+12);
614 const int whole_size= get32(buf+16);
617 for(i=0; i<CFRAME_BUFFER_COUNT; i++){
618 if(f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)
619 printf("lost c frame %d\n", f->cfrm[i].id);
622 for(i=0; i<CFRAME_BUFFER_COUNT; i++){
623 if(f->cfrm[i].id == id) break;
624 if(f->cfrm[i].size == 0 ) free_index= i;
627 if(i>=CFRAME_BUFFER_COUNT){
633 cfrm->data= av_fast_realloc(cfrm->data, &cfrm->allocated_size, cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);
635 memcpy(cfrm->data + cfrm->size, buf+20, data_size);
636 cfrm->size += data_size;
638 if(cfrm->size >= whole_size){
640 frame_size= cfrm->size;
642 if(id != avctx->frame_number){
643 printf("cframe id missmatch %d %d\n", id, avctx->frame_number);
646 cfrm->size= cfrm->id= 0;
647 frame_4cc= ff_get_fourcc("pfrm");
652 frame_size= buf_size - 12;
655 temp= f->current_picture;
656 f->current_picture= f->last_picture;
657 f->last_picture= temp;
659 p= &f->current_picture;
660 avctx->coded_frame= p;
662 avctx->flags |= CODEC_FLAG_EMU_EDGE; // alternatively we would have to use our own buffer management
665 avctx->release_buffer(avctx, p);
668 if(avctx->get_buffer(avctx, p) < 0){
669 fprintf(stderr, "get_buffer() failed\n");
673 if(frame_4cc == ff_get_fourcc("ifrm")){
674 p->pict_type= I_TYPE;
675 if(decode_i_frame(f, buf, frame_size) < 0)
677 }else if(frame_4cc == ff_get_fourcc("pfrm")){
678 p->pict_type= P_TYPE;
679 if(decode_p_frame(f, buf, frame_size) < 0)
681 }else if(frame_4cc == ff_get_fourcc("snd_")){
682 printf("ignoring snd_ chunk length:%d\n", buf_size);
684 printf("ignoring unknown chunk length:%d\n", buf_size);
689 printf("%2X %c ", buf[i], clip(buf[i],16,126));
693 p->key_frame= p->pict_type == I_TYPE;
696 *data_size = sizeof(AVPicture);
704 static void common_init(AVCodecContext *avctx){
705 FourXContext * const f = avctx->priv_data;
707 dsputil_init(&f->dsp, avctx);
712 static int decode_init(AVCodecContext *avctx){
713 FourXContext * const f = avctx->priv_data;
718 avctx->pix_fmt= PIX_FMT_RGB565;
724 static int decode_end(AVCodecContext *avctx){
725 FourXContext * const f = avctx->priv_data;
728 av_freep(&f->bitstream_buffer);
729 f->bitstream_buffer_size=0;
730 for(i=0; i<CFRAME_BUFFER_COUNT; i++){
731 av_freep(&f->cfrm[i].data);
732 f->cfrm[i].allocated_size= 0;
734 free_vlc(&f->pre_vlc);
736 avcodec_default_free_buffers(avctx);
741 AVCodec fourxm_decoder = {
745 sizeof(FourXContext),