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path: root/libavcodec/mdec.c (plain)
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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 "avcodec.h"
31#include "blockdsp.h"
32#include "bswapdsp.h"
33#include "idctdsp.h"
34#include "mpeg12.h"
35#include "thread.h"
36
37typedef struct MDECContext {
38 AVCodecContext *avctx;
39 BlockDSPContext bdsp;
40 BswapDSPContext bbdsp;
41 IDCTDSPContext idsp;
42 ThreadFrame frame;
43 GetBitContext gb;
44 ScanTable scantable;
45 int version;
46 int qscale;
47 int last_dc[3];
48 int mb_width;
49 int mb_height;
50 int mb_x, mb_y;
51 DECLARE_ALIGNED(16, int16_t, block)[6][64];
52 uint8_t *bitstream_buffer;
53 unsigned int bitstream_buffer_size;
54 int block_last_index[6];
55} MDECContext;
56
57//very similar to MPEG-1
58static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
59{
60 int level, diff, i, j, run;
61 int component;
62 RLTable *rl = &ff_rl_mpeg1;
63 uint8_t * const scantable = a->scantable.permutated;
64 const uint16_t *quant_matrix = ff_mpeg1_default_intra_matrix;
65 const int qscale = a->qscale;
66
67 /* DC coefficient */
68 if (a->version == 2) {
69 block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
70 } else {
71 component = (n <= 3 ? 0 : n - 4 + 1);
72 diff = decode_dc(&a->gb, component);
73 if (diff >= 0xffff)
74 return AVERROR_INVALIDDATA;
75 a->last_dc[component] += diff;
76 block[0] = a->last_dc[component] << 3;
77 }
78
79 i = 0;
80 {
81 OPEN_READER(re, &a->gb);
82 /* now quantify & encode AC coefficients */
83 for (;;) {
84 UPDATE_CACHE(re, &a->gb);
85 GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
86
87 if (level == 127) {
88 break;
89 } else if (level != 0) {
90 i += run;
91 if (i > 63) {
92 av_log(a->avctx, AV_LOG_ERROR,
93 "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
94 return AVERROR_INVALIDDATA;
95 }
96 j = scantable[i];
97 level = (level * qscale * quant_matrix[j]) >> 3;
98 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
99 LAST_SKIP_BITS(re, &a->gb, 1);
100 } else {
101 /* escape */
102 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
103 UPDATE_CACHE(re, &a->gb);
104 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
105 i += run;
106 if (i > 63) {
107 av_log(a->avctx, AV_LOG_ERROR,
108 "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
109 return AVERROR_INVALIDDATA;
110 }
111 j = scantable[i];
112 if (level < 0) {
113 level = -level;
114 level = (level * qscale * quant_matrix[j]) >> 3;
115 level = (level - 1) | 1;
116 level = -level;
117 } else {
118 level = (level * qscale * quant_matrix[j]) >> 3;
119 level = (level - 1) | 1;
120 }
121 }
122
123 block[j] = level;
124 }
125 CLOSE_READER(re, &a->gb);
126 }
127 a->block_last_index[n] = i;
128 return 0;
129}
130
131static inline int decode_mb(MDECContext *a, int16_t block[6][64])
132{
133 int i, ret;
134 static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };
135
136 a->bdsp.clear_blocks(block[0]);
137
138 for (i = 0; i < 6; i++) {
139 if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
140 block_index[i])) < 0)
141 return ret;
142 if (get_bits_left(&a->gb) < 0)
143 return AVERROR_INVALIDDATA;
144 }
145 return 0;
146}
147
148static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
149{
150 int16_t (*block)[64] = a->block;
151 int linesize = frame->linesize[0];
152
153 uint8_t *dest_y = frame->data[0] + (mb_y * 16* linesize ) + mb_x * 16;
154 uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
155 uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
156
157 a->idsp.idct_put(dest_y, linesize, block[0]);
158 a->idsp.idct_put(dest_y + 8, linesize, block[1]);
159 a->idsp.idct_put(dest_y + 8 * linesize, linesize, block[2]);
160 a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);
161
162 if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {
163 a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
164 a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);
165 }
166}
167
168static int decode_frame(AVCodecContext *avctx,
169 void *data, int *got_frame,
170 AVPacket *avpkt)
171{
172 MDECContext * const a = avctx->priv_data;
173 const uint8_t *buf = avpkt->data;
174 int buf_size = avpkt->size;
175 ThreadFrame frame = { .f = data };
176 int ret;
177
178 if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
179 return ret;
180 frame.f->pict_type = AV_PICTURE_TYPE_I;
181 frame.f->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.f, 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
216 a->mb_width = (avctx->coded_width + 15) / 16;
217 a->mb_height = (avctx->coded_height + 15) / 16;
218
219 a->avctx = avctx;
220
221 ff_blockdsp_init(&a->bdsp, avctx);
222 ff_bswapdsp_init(&a->bbdsp);
223 ff_idctdsp_init(&a->idsp, avctx);
224 ff_mpeg12_init_vlcs();
225 ff_init_scantable(a->idsp.idct_permutation, &a->scantable,
226 ff_zigzag_direct);
227
228 if (avctx->idct_algo == FF_IDCT_AUTO)
229 avctx->idct_algo = FF_IDCT_SIMPLE;
230 avctx->pix_fmt = AV_PIX_FMT_YUVJ420P;
231 avctx->color_range = AVCOL_RANGE_JPEG;
232
233 return 0;
234}
235
236#if HAVE_THREADS
237static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
238{
239 MDECContext * const a = avctx->priv_data;
240
241 a->avctx = avctx;
242
243 return 0;
244}
245#endif
246
247static av_cold int decode_end(AVCodecContext *avctx)
248{
249 MDECContext * const a = avctx->priv_data;
250
251 av_freep(&a->bitstream_buffer);
252 a->bitstream_buffer_size = 0;
253
254 return 0;
255}
256
257AVCodec ff_mdec_decoder = {
258 .name = "mdec",
259 .long_name = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
260 .type = AVMEDIA_TYPE_VIDEO,
261 .id = AV_CODEC_ID_MDEC,
262 .priv_data_size = sizeof(MDECContext),
263 .init = decode_init,
264 .close = decode_end,
265 .decode = decode_frame,
266 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
267 .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy)
268};
269
generated by cgit at 2024-05-17 05:05:54 (GMT)