1/*
2 * Sony PlayStation MDEC (Motion DECoder)
3 * Copyright (c) 2003 Michael Niedermayer
4 *
5 * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
6 *
7 * This file is part of FFmpeg.
8 *
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.
13 *
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.
18 *
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
22 */
23
24/**
25 * @file
26 * Sony PlayStation MDEC (Motion DECoder)
27 * This is very similar to intra-only MPEG-1.
28 */
29
30#include "avcodec.h"
31#include "dsputil.h"
32#include "mpegvideo.h"
33#include "mpeg12.h"
34
35typedef struct MDECContext{
36    AVCodecContext *avctx;
37    DSPContext dsp;
38    AVFrame picture;
39    GetBitContext gb;
40    ScanTable scantable;
41    int version;
42    int qscale;
43    int last_dc[3];
44    int mb_width;
45    int mb_height;
46    int mb_x, mb_y;
47    DECLARE_ALIGNED(16, DCTELEM, block)[6][64];
48    uint8_t *bitstream_buffer;
49    unsigned int bitstream_buffer_size;
50    int block_last_index[6];
51} MDECContext;
52
53//very similar to MPEG-1
54static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n)
55{
56    int level, diff, i, j, run;
57    int component;
58    RLTable *rl = &ff_rl_mpeg1;
59    uint8_t * const scantable= a->scantable.permutated;
60    const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix;
61    const int qscale= a->qscale;
62
63    /* DC coefficient */
64    if(a->version==2){
65        block[0]= 2*get_sbits(&a->gb, 10) + 1024;
66    }else{
67        component = (n <= 3 ? 0 : n - 4 + 1);
68        diff = decode_dc(&a->gb, component);
69        if (diff >= 0xffff)
70            return -1;
71        a->last_dc[component]+= diff;
72        block[0] = a->last_dc[component]<<3;
73    }
74
75    i = 0;
76    {
77        OPEN_READER(re, &a->gb);
78        /* now quantify & encode AC coefficients */
79        for(;;) {
80            UPDATE_CACHE(re, &a->gb);
81            GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
82
83            if(level == 127){
84                break;
85            } else if(level != 0) {
86                i += run;
87                j = scantable[i];
88                level= (level*qscale*quant_matrix[j])>>3;
89                level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
90                LAST_SKIP_BITS(re, &a->gb, 1);
91            } else {
92                /* escape */
93                run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
94                UPDATE_CACHE(re, &a->gb);
95                level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
96                i += run;
97                j = scantable[i];
98                if(level<0){
99                    level= -level;
100                    level= (level*qscale*quant_matrix[j])>>3;
101                    level= (level-1)|1;
102                    level= -level;
103                }else{
104                    level= (level*qscale*quant_matrix[j])>>3;
105                    level= (level-1)|1;
106                }
107            }
108            if (i > 63){
109                av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
110                return -1;
111            }
112
113            block[j] = level;
114        }
115        CLOSE_READER(re, &a->gb);
116    }
117    a->block_last_index[n] = i;
118    return 0;
119}
120
121static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){
122    int i;
123    const int block_index[6]= {5,4,0,1,2,3};
124
125    a->dsp.clear_blocks(block[0]);
126
127    for(i=0; i<6; i++){
128        if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0)
129            return -1;
130    }
131    return 0;
132}
133
134static inline void idct_put(MDECContext *a, int mb_x, int mb_y){
135    DCTELEM (*block)[64]= a->block;
136    int linesize= a->picture.linesize[0];
137
138    uint8_t *dest_y  = a->picture.data[0] + (mb_y * 16* linesize              ) + mb_x * 16;
139    uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8;
140    uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8;
141
142    a->dsp.idct_put(dest_y                 , linesize, block[0]);
143    a->dsp.idct_put(dest_y              + 8, linesize, block[1]);
144    a->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
145    a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
146
147    if(!(a->avctx->flags&CODEC_FLAG_GRAY)){
148        a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]);
149        a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]);
150    }
151}
152
153static int decode_frame(AVCodecContext *avctx,
154                        void *data, int *data_size,
155                        AVPacket *avpkt)
156{
157    const uint8_t *buf = avpkt->data;
158    int buf_size = avpkt->size;
159    MDECContext * const a = avctx->priv_data;
160    AVFrame *picture = data;
161    AVFrame * const p= &a->picture;
162    int i;
163
164    if(p->data[0])
165        avctx->release_buffer(avctx, p);
166
167    p->reference= 0;
168    if(avctx->get_buffer(avctx, p) < 0){
169        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
170        return -1;
171    }
172    p->pict_type= FF_I_TYPE;
173    p->key_frame= 1;
174
175    av_fast_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
176    if (!a->bitstream_buffer)
177        return AVERROR(ENOMEM);
178    for(i=0; i<buf_size; i+=2){
179        a->bitstream_buffer[i]  = buf[i+1];
180        a->bitstream_buffer[i+1]= buf[i  ];
181    }
182    init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8);
183
184    /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
185    skip_bits(&a->gb, 32);
186
187    a->qscale=  get_bits(&a->gb, 16);
188    a->version= get_bits(&a->gb, 16);
189
190    a->last_dc[0]=
191    a->last_dc[1]=
192    a->last_dc[2]= 128;
193
194    for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){
195        for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){
196            if( decode_mb(a, a->block) <0)
197                return -1;
198
199            idct_put(a, a->mb_x, a->mb_y);
200        }
201    }
202
203    p->quality= a->qscale * FF_QP2LAMBDA;
204    memset(p->qscale_table, a->qscale, a->mb_width);
205
206    *picture   = a->picture;
207    *data_size = sizeof(AVPicture);
208
209    return (get_bits_count(&a->gb)+31)/32*4;
210}
211
212static av_cold void mdec_common_init(AVCodecContext *avctx){
213    MDECContext * const a = avctx->priv_data;
214
215    dsputil_init(&a->dsp, avctx);
216
217    a->mb_width   = (avctx->coded_width  + 15) / 16;
218    a->mb_height  = (avctx->coded_height + 15) / 16;
219
220    avctx->coded_frame= &a->picture;
221    a->avctx= avctx;
222}
223
224static av_cold int decode_init(AVCodecContext *avctx){
225    MDECContext * const a = avctx->priv_data;
226    AVFrame *p= &a->picture;
227
228    mdec_common_init(avctx);
229    ff_mpeg12_init_vlcs();
230    ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct);
231
232    p->qstride= 0;
233    p->qscale_table= av_mallocz(a->mb_width);
234    avctx->pix_fmt= PIX_FMT_YUV420P;
235
236    return 0;
237}
238
239static av_cold int decode_end(AVCodecContext *avctx){
240    MDECContext * const a = avctx->priv_data;
241
242    if(a->picture.data[0])
243        avctx->release_buffer(avctx, &a->picture);
244    av_freep(&a->bitstream_buffer);
245    av_freep(&a->picture.qscale_table);
246    a->bitstream_buffer_size=0;
247
248    return 0;
249}
250
251AVCodec mdec_decoder = {
252    "mdec",
253    AVMEDIA_TYPE_VIDEO,
254    CODEC_ID_MDEC,
255    sizeof(MDECContext),
256    decode_init,
257    NULL,
258    decode_end,
259    decode_frame,
260    CODEC_CAP_DR1,
261    .long_name= NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
262};
263
264