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 "blockdsp.h"
32#include "bswapdsp.h"
33#include "idctdsp.h"
34#include "mpegvideo.h"
35#include "mpeg12.h"
36#include "thread.h"
37
38typedef struct MDECContext {
39    AVCodecContext *avctx;
40    BlockDSPContext bdsp;
41    BswapDSPContext bbdsp;
42    IDCTDSPContext idsp;
43    ThreadFrame frame;
44    GetBitContext gb;
45    ScanTable scantable;
46    int version;
47    int qscale;
48    int last_dc[3];
49    int mb_width;
50    int mb_height;
51    int mb_x, mb_y;
52    DECLARE_ALIGNED(16, int16_t, block)[6][64];
53    uint8_t *bitstream_buffer;
54    unsigned int bitstream_buffer_size;
55    int block_last_index[6];
56} MDECContext;
57
58//very similar to MPEG-1
59static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
60{
61    int level, diff, i, j, run;
62    int component;
63    RLTable *rl = &ff_rl_mpeg1;
64    uint8_t * const scantable = a->scantable.permutated;
65    const uint16_t *quant_matrix = ff_mpeg1_default_intra_matrix;
66    const int qscale = a->qscale;
67
68    /* DC coefficient */
69    if (a->version == 2) {
70        block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
71    } else {
72        component = (n <= 3 ? 0 : n - 4 + 1);
73        diff = decode_dc(&a->gb, component);
74        if (diff >= 0xffff)
75            return AVERROR_INVALIDDATA;
76        a->last_dc[component] += diff;
77        block[0] = a->last_dc[component] << 3;
78    }
79
80    i = 0;
81    {
82        OPEN_READER(re, &a->gb);
83        /* now quantify & encode AC coefficients */
84        for (;;) {
85            UPDATE_CACHE(re, &a->gb);
86            GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
87
88            if (level == 127) {
89                break;
90            } else if (level != 0) {
91                i    += run;
92                j     = scantable[i];
93                level = (level * qscale * quant_matrix[j]) >> 3;
94                level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
95                LAST_SKIP_BITS(re, &a->gb, 1);
96            } else {
97                /* escape */
98                run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
99                UPDATE_CACHE(re, &a->gb);
100                level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
101                i    += run;
102                j     = scantable[i];
103                if (level < 0) {
104                    level = -level;
105                    level = (level * qscale * quant_matrix[j]) >> 3;
106                    level = (level - 1) | 1;
107                    level = -level;
108                } else {
109                    level = (level * qscale * quant_matrix[j]) >> 3;
110                    level = (level - 1) | 1;
111                }
112            }
113            if (i > 63) {
114                av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
115                return AVERROR_INVALIDDATA;
116            }
117
118            block[j] = level;
119        }
120        CLOSE_READER(re, &a->gb);
121    }
122    a->block_last_index[n] = i;
123    return 0;
124}
125
126static inline int decode_mb(MDECContext *a, int16_t block[6][64])
127{
128    int i, ret;
129    static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };
130
131    a->bdsp.clear_blocks(block[0]);
132
133    for (i = 0; i < 6; i++) {
134        if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
135                                           block_index[i])) < 0)
136            return ret;
137        if (get_bits_left(&a->gb) < 0)
138            return AVERROR_INVALIDDATA;
139    }
140    return 0;
141}
142
143static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
144{
145    int16_t (*block)[64] = a->block;
146    int linesize = frame->linesize[0];
147
148    uint8_t *dest_y  = frame->data[0] + (mb_y * 16* linesize              ) + mb_x * 16;
149    uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
150    uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
151
152    a->idsp.idct_put(dest_y,                    linesize, block[0]);
153    a->idsp.idct_put(dest_y + 8,                linesize, block[1]);
154    a->idsp.idct_put(dest_y + 8 * linesize,     linesize, block[2]);
155    a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);
156
157    if (!(a->avctx->flags & CODEC_FLAG_GRAY)) {
158        a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
159        a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);
160    }
161}
162
163static int decode_frame(AVCodecContext *avctx,
164                        void *data, int *got_frame,
165                        AVPacket *avpkt)
166{
167    MDECContext * const a = avctx->priv_data;
168    const uint8_t *buf    = avpkt->data;
169    int buf_size          = avpkt->size;
170    ThreadFrame frame     = { .f = data };
171    int ret;
172
173    if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
174        return ret;
175    frame.f->pict_type = AV_PICTURE_TYPE_I;
176    frame.f->key_frame = 1;
177
178    av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);
179    if (!a->bitstream_buffer)
180        return AVERROR(ENOMEM);
181    a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);
182    if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
183        return ret;
184
185    /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
186    skip_bits(&a->gb, 32);
187
188    a->qscale  = get_bits(&a->gb, 16);
189    a->version = get_bits(&a->gb, 16);
190
191    a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
192
193    for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
194        for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
195            if ((ret = decode_mb(a, a->block)) < 0)
196                return ret;
197
198            idct_put(a, frame.f, a->mb_x, a->mb_y);
199        }
200    }
201
202    *got_frame = 1;
203
204    return (get_bits_count(&a->gb) + 31) / 32 * 4;
205}
206
207static av_cold int decode_init(AVCodecContext *avctx)
208{
209    MDECContext * const a = avctx->priv_data;
210
211    a->mb_width  = (avctx->coded_width  + 15) / 16;
212    a->mb_height = (avctx->coded_height + 15) / 16;
213
214    a->avctx           = avctx;
215
216    ff_blockdsp_init(&a->bdsp, avctx);
217    ff_bswapdsp_init(&a->bbdsp);
218    ff_idctdsp_init(&a->idsp, avctx);
219    ff_mpeg12_init_vlcs();
220    ff_init_scantable(a->idsp.idct_permutation, &a->scantable,
221                      ff_zigzag_direct);
222
223    if (avctx->idct_algo == FF_IDCT_AUTO)
224        avctx->idct_algo = FF_IDCT_SIMPLE;
225    avctx->pix_fmt  = AV_PIX_FMT_YUVJ420P;
226    avctx->color_range = AVCOL_RANGE_JPEG;
227
228    return 0;
229}
230
231static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
232{
233    MDECContext * const a = avctx->priv_data;
234
235    a->avctx           = avctx;
236
237    return 0;
238}
239
240static av_cold int decode_end(AVCodecContext *avctx)
241{
242    MDECContext * const a = avctx->priv_data;
243
244    av_freep(&a->bitstream_buffer);
245    a->bitstream_buffer_size = 0;
246
247    return 0;
248}
249
250AVCodec ff_mdec_decoder = {
251    .name             = "mdec",
252    .long_name        = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
253    .type             = AVMEDIA_TYPE_VIDEO,
254    .id               = AV_CODEC_ID_MDEC,
255    .priv_data_size   = sizeof(MDECContext),
256    .init             = decode_init,
257    .close            = decode_end,
258    .decode           = decode_frame,
259    .capabilities     = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
260    .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy)
261};
262