/*

  * Sony PlayStation MDEC (Motion DECoder)

  * Copyright (c) 2003 Michael Niedermayer
  *

  * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
  *

  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

  * version 2.1 of the License, or (at your option) any later version.

  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */

 /**

  * @file

  * Sony PlayStation MDEC (Motion DECoder)
  * This is very similar to intra-only MPEG-1.

  */

 #include "avcodec.h"

 #include "blockdsp.h"

 #include "bswapdsp.h"

 #include "idctdsp.h"

 #include "mpeg12.h"

 #include "thread.h"

 typedef struct MDECContext {

     AVCodecContext *avctx;

     BlockDSPContext bdsp;

     BswapDSPContext bbdsp;

     IDCTDSPContext idsp;

     ThreadFrame frame;

     GetBitContext gb;
     ScanTable scantable;
     int version;
     int qscale;
     int last_dc[3];
     int mb_width;
     int mb_height;
     int mb_x, mb_y;

     DECLARE_ALIGNED(32, int16_t, block)[6][64];

     DECLARE_ALIGNED(16, uint16_t, quant_matrix)[64];

     uint8_t *bitstream_buffer;

     unsigned int bitstream_buffer_size;

     int block_last_index[6];
 } MDECContext;
 

 //very similar to MPEG-1

 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)

 {
     int level, diff, i, j, run;
     int component;

     RLTable *rl = &ff_rl_mpeg1;

     uint8_t * const scantable = a->scantable.permutated;

     const uint16_t *quant_matrix = a->quant_matrix;

     const int qscale = a->qscale;

     /* DC coefficient */

     if (a->version == 2) {
         block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
     } else {

         component = (n <= 3 ? 0 : n - 4 + 1);
         diff = decode_dc(&a->gb, component);
         if (diff >= 0xffff)

             return AVERROR_INVALIDDATA;

         a->last_dc[component] += diff;

         block[0] = a->last_dc[component] * (1 << 3);

     }

     i = 0;
     {

         OPEN_READER(re, &a->gb);

         /* now quantify & encode AC coefficients */

         for (;;) {

             UPDATE_CACHE(re, &a->gb);

             GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);

             if (level == 127) {

                 break;

             } else if (level != 0) {

                 i += run;
                 if (i > 63) {
                     av_log(a->avctx, AV_LOG_ERROR,
                            "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
                     return AVERROR_INVALIDDATA;
                 }

                 j     = scantable[i];
                 level = (level * qscale * quant_matrix[j]) >> 3;

                 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
                 LAST_SKIP_BITS(re, &a->gb, 1);
             } else {
                 /* escape */
                 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
                 UPDATE_CACHE(re, &a->gb);

                 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);

                 i += run;
                 if (i > 63) {
                     av_log(a->avctx, AV_LOG_ERROR,
                            "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
                     return AVERROR_INVALIDDATA;
                 }
                 j = scantable[i];

                 if (level < 0) {
                     level = -level;

                     level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;

                     level = (level - 1) | 1;
                     level = -level;
                 } else {

                     level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;

                     level = (level - 1) | 1;

                 }

             }
 
             block[j] = level;
         }
         CLOSE_READER(re, &a->gb);
     }
     a->block_last_index[n] = i;
     return 0;
 }
 

 static inline int decode_mb(MDECContext *a, int16_t block[6][64])
 {

     int i, ret;

     static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };

     a->bdsp.clear_blocks(block[0]);

     for (i = 0; i < 6; i++) {

         if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
                                            block_index[i])) < 0)
             return ret;
         if (get_bits_left(&a->gb) < 0)
             return AVERROR_INVALIDDATA;

     }
     return 0;
 }
 

 static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)

 {
     int16_t (*block)[64] = a->block;

     int linesize = frame->linesize[0];

     uint8_t *dest_y  = frame->data[0] + (mb_y * 16* linesize              ) + mb_x * 16;
     uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
     uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;

     a->idsp.idct_put(dest_y,                    linesize, block[0]);
     a->idsp.idct_put(dest_y + 8,                linesize, block[1]);
     a->idsp.idct_put(dest_y + 8 * linesize,     linesize, block[2]);
     a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);

     if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {

         a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
         a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);

     }
 }
 

 static int decode_frame(AVCodecContext *avctx,

                         void *data, int *got_frame,

                         AVPacket *avpkt)

 {
     MDECContext * const a = avctx->priv_data;

     const uint8_t *buf    = avpkt->data;
     int buf_size          = avpkt->size;

     ThreadFrame frame     = { .f = data };

     int ret;

     if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)

         return ret;

     frame.f->pict_type = AV_PICTURE_TYPE_I;
     frame.f->key_frame = 1;

     av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);

     if (!a->bitstream_buffer)
         return AVERROR(ENOMEM);

     a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);

     if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
         return ret;

     /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
     skip_bits(&a->gb, 32);
 

     a->qscale  = get_bits(&a->gb, 16);
     a->version = get_bits(&a->gb, 16);

     a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;

     for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
         for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {

             if ((ret = decode_mb(a, a->block)) < 0)
                 return ret;

             idct_put(a, frame.f, a->mb_x, a->mb_y);

         }
     }
 

     *got_frame = 1;

     return (get_bits_count(&a->gb) + 31) / 32 * 4;

 }
 

 static av_cold int decode_init(AVCodecContext *avctx)
 {

     MDECContext * const a = avctx->priv_data;

     int i;

     a->mb_width  = (avctx->coded_width  + 15) / 16;
     a->mb_height = (avctx->coded_height + 15) / 16;

     a->avctx           = avctx;

     ff_blockdsp_init(&a->bdsp, avctx);

     ff_bswapdsp_init(&a->bbdsp);

     ff_idctdsp_init(&a->idsp, avctx);

     ff_mpeg12_init_vlcs();

     ff_init_scantable(a->idsp.idct_permutation, &a->scantable,
                       ff_zigzag_direct);

     avctx->pix_fmt  = AV_PIX_FMT_YUVJ420P;

     avctx->color_range = AVCOL_RANGE_JPEG;

     /* init q matrix */
     for (i = 0; i < 64; i++) {
         int j = a->idsp.idct_permutation[i];
 
         a->quant_matrix[j] = ff_mpeg1_default_intra_matrix[i];
     }
 

     return 0;
 }
 

 #if HAVE_THREADS

 static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
 {

     MDECContext * const a = avctx->priv_data;
 

     a->avctx           = avctx;

 
     return 0;
 }

 #endif

 static av_cold int decode_end(AVCodecContext *avctx)
 {

     MDECContext * const a = avctx->priv_data;
 
     av_freep(&a->bitstream_buffer);

     a->bitstream_buffer_size = 0;

     return 0;
 }
 

 AVCodec ff_mdec_decoder = {

     .name             = "mdec",

     .long_name        = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),

     .type             = AVMEDIA_TYPE_VIDEO,

     .id               = AV_CODEC_ID_MDEC,

     .priv_data_size   = sizeof(MDECContext),
     .init             = decode_init,
     .close            = decode_end,
     .decode           = decode_frame,

     .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,

     .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy)

 };