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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 "libavutil/mem_internal.h"
31 
32 #include "avcodec.h"
33 #include "blockdsp.h"
34 #include "bswapdsp.h"
35 #include "codec_internal.h"
36 #include "idctdsp.h"
37 #include "mpeg12data.h"
38 #include "mpeg12dec.h"
39 #include "thread.h"
40 
41 typedef struct MDECContext {
42     AVCodecContext *avctx;
43     BlockDSPContext bdsp;
44     BswapDSPContext bbdsp;
45     IDCTDSPContext idsp;
46     GetBitContext gb;
47     ScanTable scantable;
48     int version;
49     int qscale;
50     int last_dc[3];
51     int mb_width;
52     int mb_height;
53     int mb_x, mb_y;
54     DECLARE_ALIGNED(32, int16_t, block)[6][64];
55     DECLARE_ALIGNED(16, uint16_t, quant_matrix)[64];
56     uint8_t *bitstream_buffer;
57     unsigned int bitstream_buffer_size;
58     int block_last_index[6];
59 } MDECContext;
60 
61 //very similar to MPEG-1
mdec_decode_block_intra(MDECContext * a,int16_t * block,int n)62 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
63 {
64     int level, diff, i, j, run;
65     int component;
66     RLTable *rl = &ff_rl_mpeg1;
67     uint8_t * const scantable = a->scantable.permutated;
68     const uint16_t *quant_matrix = a->quant_matrix;
69     const int qscale = a->qscale;
70 
71     /* DC coefficient */
72     if (a->version == 2) {
73         block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
74     } else {
75         component = (n <= 3 ? 0 : n - 4 + 1);
76         diff = decode_dc(&a->gb, component);
77         a->last_dc[component] += diff;
78         block[0] = a->last_dc[component] * (1 << 3);
79     }
80 
81     i = 0;
82     {
83         OPEN_READER(re, &a->gb);
84         /* now quantify & encode AC coefficients */
85         for (;;) {
86             UPDATE_CACHE(re, &a->gb);
87             GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
88 
89             if (level == 127) {
90                 break;
91             } else if (level != 0) {
92                 i += run;
93                 if (i > 63) {
94                     av_log(a->avctx, AV_LOG_ERROR,
95                            "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
96                     return AVERROR_INVALIDDATA;
97                 }
98                 j     = scantable[i];
99                 level = (level * qscale * quant_matrix[j]) >> 3;
100                 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
101                 LAST_SKIP_BITS(re, &a->gb, 1);
102             } else {
103                 /* escape */
104                 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
105                 UPDATE_CACHE(re, &a->gb);
106                 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
107                 i += run;
108                 if (i > 63) {
109                     av_log(a->avctx, AV_LOG_ERROR,
110                            "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
111                     return AVERROR_INVALIDDATA;
112                 }
113                 j = scantable[i];
114                 if (level < 0) {
115                     level = -level;
116                     level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;
117                     level = (level - 1) | 1;
118                     level = -level;
119                 } else {
120                     level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;
121                     level = (level - 1) | 1;
122                 }
123             }
124 
125             block[j] = level;
126         }
127         CLOSE_READER(re, &a->gb);
128     }
129     a->block_last_index[n] = i;
130     return 0;
131 }
132 
decode_mb(MDECContext * a,int16_t block[6][64])133 static inline int decode_mb(MDECContext *a, int16_t block[6][64])
134 {
135     int i, ret;
136     static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };
137 
138     a->bdsp.clear_blocks(block[0]);
139 
140     for (i = 0; i < 6; i++) {
141         if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
142                                            block_index[i])) < 0)
143             return ret;
144         if (get_bits_left(&a->gb) < 0)
145             return AVERROR_INVALIDDATA;
146     }
147     return 0;
148 }
149 
idct_put(MDECContext * a,AVFrame * frame,int mb_x,int mb_y)150 static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
151 {
152     int16_t (*block)[64] = a->block;
153     int linesize = frame->linesize[0];
154 
155     uint8_t *dest_y  = frame->data[0] + (mb_y * 16* linesize              ) + mb_x * 16;
156     uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
157     uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
158 
159     a->idsp.idct_put(dest_y,                    linesize, block[0]);
160     a->idsp.idct_put(dest_y + 8,                linesize, block[1]);
161     a->idsp.idct_put(dest_y + 8 * linesize,     linesize, block[2]);
162     a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);
163 
164     if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {
165         a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
166         a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);
167     }
168 }
169 
decode_frame(AVCodecContext * avctx,AVFrame * frame,int * got_frame,AVPacket * avpkt)170 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
171                         int *got_frame, AVPacket *avpkt)
172 {
173     MDECContext * const a = avctx->priv_data;
174     const uint8_t *buf    = avpkt->data;
175     int buf_size          = avpkt->size;
176     int ret;
177 
178     if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0)
179         return ret;
180     frame->pict_type = AV_PICTURE_TYPE_I;
181     frame->key_frame = 1;
182 
183     av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);
184     if (!a->bitstream_buffer)
185         return AVERROR(ENOMEM);
186     a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);
187     if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
188         return ret;
189 
190     /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
191     skip_bits(&a->gb, 32);
192 
193     a->qscale  = get_bits(&a->gb, 16);
194     a->version = get_bits(&a->gb, 16);
195 
196     a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
197 
198     for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
199         for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
200             if ((ret = decode_mb(a, a->block)) < 0)
201                 return ret;
202 
203             idct_put(a, frame, a->mb_x, a->mb_y);
204         }
205     }
206 
207     *got_frame = 1;
208 
209     return (get_bits_count(&a->gb) + 31) / 32 * 4;
210 }
211 
decode_init(AVCodecContext * avctx)212 static av_cold int decode_init(AVCodecContext *avctx)
213 {
214     MDECContext * const a = avctx->priv_data;
215     int i;
216 
217     a->mb_width  = (avctx->coded_width  + 15) / 16;
218     a->mb_height = (avctx->coded_height + 15) / 16;
219 
220     a->avctx           = avctx;
221 
222     ff_blockdsp_init(&a->bdsp, avctx);
223     ff_bswapdsp_init(&a->bbdsp);
224     ff_idctdsp_init(&a->idsp, avctx);
225     ff_mpeg12_init_vlcs();
226     ff_init_scantable(a->idsp.idct_permutation, &a->scantable,
227                       ff_zigzag_direct);
228 
229     avctx->pix_fmt  = AV_PIX_FMT_YUVJ420P;
230     avctx->color_range = AVCOL_RANGE_JPEG;
231 
232     /* init q matrix */
233     for (i = 0; i < 64; i++) {
234         int j = a->idsp.idct_permutation[i];
235 
236         a->quant_matrix[j] = ff_mpeg1_default_intra_matrix[i];
237     }
238 
239     return 0;
240 }
241 
decode_end(AVCodecContext * avctx)242 static av_cold int decode_end(AVCodecContext *avctx)
243 {
244     MDECContext * const a = avctx->priv_data;
245 
246     av_freep(&a->bitstream_buffer);
247     a->bitstream_buffer_size = 0;
248 
249     return 0;
250 }
251 
252 const FFCodec ff_mdec_decoder = {
253     .p.name           = "mdec",
254     .p.long_name      = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
255     .p.type           = AVMEDIA_TYPE_VIDEO,
256     .p.id             = AV_CODEC_ID_MDEC,
257     .priv_data_size   = sizeof(MDECContext),
258     .init             = decode_init,
259     .close            = decode_end,
260     FF_CODEC_DECODE_CB(decode_frame),
261     .p.capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
262     .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE,
263 };
264