3 * Copyright (c) 2003 Michael Niedermayer
5 * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
7 * This file is part of FFmpeg.
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 * This is very similar to intra only MPEG1.
32 #include "mpegvideo.h"
34 typedef struct MDECContext{
35 AVCodecContext *avctx;
46 DECLARE_ALIGNED_16(DCTELEM, block[6][64]);
47 DECLARE_ALIGNED_8(uint16_t, intra_matrix[64]);
48 DECLARE_ALIGNED_8(int, q_intra_matrix[64]);
49 uint8_t *bitstream_buffer;
50 unsigned int bitstream_buffer_size;
51 int block_last_index[6];
54 //very similar to mpeg1
55 static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n)
57 int level, diff, i, j, run;
59 RLTable *rl = &ff_rl_mpeg1;
60 uint8_t * const scantable= a->scantable.permutated;
61 const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix;
62 const int qscale= a->qscale;
66 block[0]= 2*get_sbits(&a->gb, 10) + 1024;
68 component = (n <= 3 ? 0 : n - 4 + 1);
69 diff = decode_dc(&a->gb, component);
72 a->last_dc[component]+= diff;
73 block[0] = a->last_dc[component]<<3;
78 OPEN_READER(re, &a->gb);
79 /* now quantify & encode AC coefs */
81 UPDATE_CACHE(re, &a->gb);
82 GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
86 } else if(level != 0) {
89 level= (level*qscale*quant_matrix[j])>>3;
90 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
91 LAST_SKIP_BITS(re, &a->gb, 1);
94 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
95 UPDATE_CACHE(re, &a->gb);
96 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
101 level= (level*qscale*quant_matrix[j])>>3;
105 level= (level*qscale*quant_matrix[j])>>3;
110 av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
116 CLOSE_READER(re, &a->gb);
118 a->block_last_index[n] = i;
122 static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){
124 const int block_index[6]= {5,4,0,1,2,3};
126 a->dsp.clear_blocks(block[0]);
129 if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0)
135 static inline void idct_put(MDECContext *a, int mb_x, int mb_y){
136 DCTELEM (*block)[64]= a->block;
137 int linesize= a->picture.linesize[0];
139 uint8_t *dest_y = a->picture.data[0] + (mb_y * 16* linesize ) + mb_x * 16;
140 uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8;
141 uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8;
143 a->dsp.idct_put(dest_y , linesize, block[0]);
144 a->dsp.idct_put(dest_y + 8, linesize, block[1]);
145 a->dsp.idct_put(dest_y + 8*linesize , linesize, block[2]);
146 a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
148 if(!(a->avctx->flags&CODEC_FLAG_GRAY)){
149 a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]);
150 a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]);
154 static int decode_frame(AVCodecContext *avctx,
155 void *data, int *data_size,
156 const uint8_t *buf, int buf_size)
158 MDECContext * const a = avctx->priv_data;
159 AVFrame *picture = data;
160 AVFrame * const p= &a->picture;
164 avctx->release_buffer(avctx, p);
167 if(avctx->get_buffer(avctx, p) < 0){
168 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
171 p->pict_type= FF_I_TYPE;
174 a->bitstream_buffer= av_fast_realloc(a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
175 for(i=0; i<buf_size; i+=2){
176 a->bitstream_buffer[i] = buf[i+1];
177 a->bitstream_buffer[i+1]= buf[i ];
179 init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8);
181 /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
182 skip_bits(&a->gb, 32);
184 a->qscale= get_bits(&a->gb, 16);
185 a->version= get_bits(&a->gb, 16);
191 for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){
192 for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){
193 if( decode_mb(a, a->block) <0)
196 idct_put(a, a->mb_x, a->mb_y);
200 p->quality= a->qscale * FF_QP2LAMBDA;
201 memset(p->qscale_table, a->qscale, p->qstride*a->mb_height);
203 *picture = a->picture;
204 *data_size = sizeof(AVPicture);
206 return (get_bits_count(&a->gb)+31)/32*4;
209 static av_cold void mdec_common_init(AVCodecContext *avctx){
210 MDECContext * const a = avctx->priv_data;
212 dsputil_init(&a->dsp, avctx);
214 a->mb_width = (avctx->coded_width + 15) / 16;
215 a->mb_height = (avctx->coded_height + 15) / 16;
217 avctx->coded_frame= &a->picture;
221 static av_cold int decode_init(AVCodecContext *avctx){
222 MDECContext * const a = avctx->priv_data;
223 AVFrame *p= &a->picture;
225 mdec_common_init(avctx);
227 ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct);
229 p->qstride= a->mb_width;
230 p->qscale_table= av_mallocz( p->qstride * a->mb_height);
231 avctx->pix_fmt= PIX_FMT_YUV420P;
236 static av_cold int decode_end(AVCodecContext *avctx){
237 MDECContext * const a = avctx->priv_data;
239 av_freep(&a->bitstream_buffer);
240 av_freep(&a->picture.qscale_table);
241 a->bitstream_buffer_size=0;
246 AVCodec mdec_decoder = {
256 .long_name= NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),