libavcodec/mdec.c

   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.h"
  31 #include "libavutil/mem_internal.h"
  32
  33 #include "avcodec.h"
  34 #include "blockdsp.h"
  35 #include "bswapdsp.h"
  36 #include "codec_internal.h"
  37 #include "idctdsp.h"
  38 #include "mpeg12data.h"
  39 #include "mpeg12dec.h"
  40 #include "thread.h"
  41
  42 typedef struct MDECContext {
  43     AVCodecContext *avctx;
  44     BlockDSPContext bdsp;
  45     BswapDSPContext bbdsp;
  46     IDCTDSPContext idsp;
  47     GetBitContext gb;
  48     uint8_t permutated_scantable[64];
  49     int version;
  50     int qscale;
  51     int last_dc[3];
  52     int mb_width;
  53     int mb_height;
  54     int mb_x, mb_y;
  55     DECLARE_ALIGNED(32, int16_t, block)[6][64];
  56     DECLARE_ALIGNED(16, uint16_t, quant_matrix)[64];
  57     uint8_t *bitstream_buffer;
  58     unsigned int bitstream_buffer_size;
  59     int block_last_index[6];
  60 } MDECContext;
  61
  62 //very similar to MPEG-1
  63 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
  64 {
  65     int level, diff, i, j, run;
  66     int component;
  67     const uint8_t *const scantable = a->permutated_scantable;
  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, ff_mpeg1_rl_vlc, 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
 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
 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
 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
 181     av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);
 182     if (!a->bitstream_buffer)
 183         return AVERROR(ENOMEM);
 184     a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);
 185     if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
 186         return ret;
 187
 188     /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
 189     skip_bits(&a->gb, 32);
 190
 191     a->qscale  = get_bits(&a->gb, 16);
 192     a->version = get_bits(&a->gb, 16);
 193
 194     a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
 195
 196     for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
 197         for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
 198             if ((ret = decode_mb(a, a->block)) < 0)
 199                 return ret;
 200
 201             idct_put(a, frame, a->mb_x, a->mb_y);
 202         }
 203     }
 204
 205     *got_frame = 1;
 206
 207     return (get_bits_count(&a->gb) + 31) / 32 * 4;
 208 }
 209
 210 static av_cold int decode_init(AVCodecContext *avctx)
 211 {
 212     MDECContext * const a = avctx->priv_data;
 213     int i;
 214
 215     a->mb_width  = (avctx->coded_width  + 15) / 16;
 216     a->mb_height = (avctx->coded_height + 15) / 16;
 217
 218     a->avctx           = avctx;
 219
 220     ff_blockdsp_init(&a->bdsp);
 221     ff_bswapdsp_init(&a->bbdsp);
 222     ff_idctdsp_init(&a->idsp, avctx);
 223     ff_mpeg12_init_vlcs();
 224     ff_permute_scantable(a->permutated_scantable, ff_zigzag_direct,
 225                          a->idsp.idct_permutation);
 226
 227     avctx->pix_fmt  = AV_PIX_FMT_YUVJ420P;
 228     avctx->color_range = AVCOL_RANGE_JPEG;
 229
 230     /* init q matrix */
 231     for (i = 0; i < 64; i++) {
 232         int j = a->idsp.idct_permutation[i];
 233
 234         a->quant_matrix[j] = ff_mpeg1_default_intra_matrix[i];
 235     }
 236
 237     return 0;
 238 }
 239
 240 static 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
 250 const FFCodec ff_mdec_decoder = {
 251     .p.name           = "mdec",
 252     CODEC_LONG_NAME("Sony PlayStation MDEC (Motion DECoder)"),
 253     .p.type           = AVMEDIA_TYPE_VIDEO,
 254     .p.id             = AV_CODEC_ID_MDEC,
 255     .priv_data_size   = sizeof(MDECContext),
 256     .init             = decode_init,
 257     .close            = decode_end,
 258     FF_CODEC_DECODE_CB(decode_frame),
 259     .p.capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
 260 };