/*

  * 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 "mpegvideo.h"

 #include "mpeg12.h"

 #include "thread.h"

 typedef struct MDECContext {

     AVCodecContext *avctx;
     DSPContext dsp;
     AVFrame picture;
     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(16, int16_t, block)[6][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 = ff_mpeg1_default_intra_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] << 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;
                 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;
                 j     = scantable[i];
                 if (level < 0) {
                     level = -level;
                     level = (level * qscale * quant_matrix[j]) >> 3;
                     level = (level - 1) | 1;
                     level = -level;
                 } else {
                     level = (level * qscale * quant_matrix[j]) >> 3;
                     level = (level - 1) | 1;

                 }

             }

             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;

             }
 
             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;

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

 
     a->dsp.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, int mb_x, int mb_y)
 {
     int16_t (*block)[64] = a->block;
     int linesize = a->picture.linesize[0];

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

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

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

         a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]);
         a->dsp.idct_put(dest_cr, a->picture.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;
     AVFrame *picture      = data;
     AVFrame * const p     = &a->picture;

     int i, ret;

     if (p->data[0])

         ff_thread_release_buffer(avctx, p);

     p->reference = 0;

     if ((ret = ff_thread_get_buffer(avctx, p)) < 0) {

         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

         return ret;

     }

     p->pict_type = AV_PICTURE_TYPE_I;
     p->key_frame = 1;

     av_fast_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
     if (!a->bitstream_buffer)
         return AVERROR(ENOMEM);

     for (i = 0; i < buf_size; i += 2) {
         a->bitstream_buffer[i]     = buf[i + 1];
         a->bitstream_buffer[i + 1] = buf[i];

     }

     init_get_bits(&a->gb, a->bitstream_buffer, buf_size * 8);

     /* 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, a->mb_x, a->mb_y);
         }
     }
 

     p->quality = a->qscale * FF_QP2LAMBDA;

     memset(p->qscale_table, a->qscale, a->mb_width);

     *picture   = a->picture;

     *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;

     AVFrame *p            = &a->picture;

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

     avcodec_get_frame_defaults(&a->picture);

     avctx->coded_frame = &a->picture;
     a->avctx           = avctx;

     ff_dsputil_init(&a->dsp, avctx);

     ff_mpeg12_init_vlcs();

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

     if (avctx->idct_algo == FF_IDCT_AUTO)

         avctx->idct_algo = FF_IDCT_SIMPLE;

     p->qstride      = 0;
     p->qscale_table = av_mallocz(a->mb_width);
     avctx->pix_fmt  = AV_PIX_FMT_YUVJ420P;

 
     return 0;
 }
 

 static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
 {

     MDECContext * const a = avctx->priv_data;

     AVFrame *p            = &a->picture;

     avctx->coded_frame = p;

     a->avctx           = avctx;

     p->qscale_table= av_mallocz(a->mb_width);

 
     return 0;
 }
 

 static av_cold int decode_end(AVCodecContext *avctx)
 {

     MDECContext * const a = avctx->priv_data;
 

     if (a->picture.data[0])

         avctx->release_buffer(avctx, &a->picture);

     av_freep(&a->bitstream_buffer);
     av_freep(&a->picture.qscale_table);

     a->bitstream_buffer_size = 0;

     return 0;
 }
 

 AVCodec ff_mdec_decoder = {

     .name             = "mdec",
     .type             = AVMEDIA_TYPE_VIDEO,

     .id               = AV_CODEC_ID_MDEC,

     .priv_data_size   = sizeof(MDECContext),
     .init             = decode_init,
     .close            = decode_end,
     .decode           = decode_frame,
     .capabilities     = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
     .long_name        = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
     .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy)

 };