xref: /third_party/ffmpeg/libavcodec/mdec.c (revision cabdff1a)
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
41typedef 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
62static 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
133static 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
150static 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
170static 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
212static 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
242static 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
252const 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