/*
  * Electronic Arts TGQ Video Decoder
  * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
  *
  * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 /**

  * @file

  * Electronic Arts TGQ Video Decoder
  * @author Peter Ross <pross@xvid.org>
  *
  * Technical details here:
  * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGQ
  */
 
 #include "avcodec.h"

 #define BITSTREAM_READER_LE

 #include "get_bits.h"

 #include "bytestream.h"

 #include "idctdsp.h"

 #include "aandcttab.h"

 #include "eaidct.h"

 #include "internal.h"

 
 typedef struct TgqContext {
     AVCodecContext *avctx;

     int width, height;

     ScanTable scantable;
     int qtable[64];

     DECLARE_ALIGNED(16, int16_t, block)[6][64];

     GetByteContext gb;

 } TgqContext;
 

 static av_cold int tgq_decode_init(AVCodecContext *avctx)
 {

     TgqContext *s = avctx->priv_data;

     uint8_t idct_permutation[64];

     s->avctx = avctx;

     ff_init_scantable_permutation(idct_permutation, FF_NO_IDCT_PERM);
     ff_init_scantable(idct_permutation, &s->scantable, ff_zigzag_direct);

     avctx->time_base = (AVRational){1, 15};

     avctx->pix_fmt   = AV_PIX_FMT_YUV420P;

     return 0;
 }
 

 static void tgq_decode_block(TgqContext *s, int16_t block[64], GetBitContext *gb)
 {

     uint8_t *perm = s->scantable.permutated;

     int i, j, value;
     block[0] = get_sbits(gb, 8) * s->qtable[0];
     for (i = 1; i < 64;) {
         switch (show_bits(gb, 3)) {

         case 4:
             block[perm[i++]] = 0;
         case 0:
             block[perm[i++]] = 0;

             skip_bits(gb, 3);

             break;
         case 5:
         case 1:

             skip_bits(gb, 2);
             value = get_bits(gb, 6);
             for (j = 0; j < value; j++)

                 block[perm[i++]] = 0;
             break;
         case 6:

             skip_bits(gb, 3);

             block[perm[i]] = -s->qtable[perm[i]];
             i++;
             break;
         case 2:

             skip_bits(gb, 3);

             block[perm[i]] = s->qtable[perm[i]];
             i++;
             break;
         case 7: // 111b
         case 3: // 011b

             skip_bits(gb, 2);
             if (show_bits(gb, 6) == 0x3F) {

                 skip_bits(gb, 6);

                 block[perm[i]] = get_sbits(gb, 8) * s->qtable[perm[i]];
             } else {
                 block[perm[i]] = get_sbits(gb, 6) * s->qtable[perm[i]];

             }
             i++;
             break;
         }
     }

     block[0] += 128 << 4;

 }
 

 static void tgq_idct_put_mb(TgqContext *s, int16_t (*block)[64], AVFrame *frame,

                             int mb_x, int mb_y)
 {

     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;

     ff_ea_idct_put_c(dest_y                   , linesize, block[0]);
     ff_ea_idct_put_c(dest_y                + 8, linesize, block[1]);
     ff_ea_idct_put_c(dest_y + 8 * linesize    , linesize, block[2]);
     ff_ea_idct_put_c(dest_y + 8 * linesize + 8, linesize, block[3]);
     if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {

          ff_ea_idct_put_c(dest_cb, frame->linesize[1], block[4]);
          ff_ea_idct_put_c(dest_cr, frame->linesize[2], block[5]);

     }
 }
 

 static inline void tgq_dconly(TgqContext *s, unsigned char *dst,
                               int dst_stride, int dc)
 {
     int level = av_clip_uint8((dc*s->qtable[0] + 2056) >> 4);

     int j;

     for (j = 0; j < 8; j++)
         memset(dst + j * dst_stride, level, 8);

 }
 

 static void tgq_idct_put_mb_dconly(TgqContext *s, AVFrame *frame,
                                    int mb_x, int mb_y, const int8_t *dc)

 {

     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;

     tgq_dconly(s, dest_y,                    linesize, dc[0]);
     tgq_dconly(s, dest_y                + 8, linesize, dc[1]);
     tgq_dconly(s, dest_y + 8 * linesize,     linesize, dc[2]);
     tgq_dconly(s, dest_y + 8 * linesize + 8, linesize, dc[3]);
     if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {

         tgq_dconly(s, dest_cb, frame->linesize[1], dc[4]);
         tgq_dconly(s, dest_cr, frame->linesize[2], dc[5]);

     }
 }
 

 static int tgq_decode_mb(TgqContext *s, AVFrame *frame, int mb_y, int mb_x)

 {

     int mode;
     int i;
     int8_t dc[6];
 

     mode = bytestream2_get_byte(&s->gb);

     if (mode > 12) {

         GetBitContext gb;

         init_get_bits8(&gb, s->gb.buffer, FFMIN(bytestream2_get_bytes_left(&s->gb), mode));

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

             tgq_decode_block(s, s->block[i], &gb);

         tgq_idct_put_mb(s, s->block, frame, mb_x, mb_y);

         bytestream2_skip(&s->gb, mode);

     } else {
         if (mode == 3) {

             memset(dc, bytestream2_get_byte(&s->gb), 4);
             dc[4] = bytestream2_get_byte(&s->gb);
             dc[5] = bytestream2_get_byte(&s->gb);

         } else if (mode == 6) {

             bytestream2_get_buffer(&s->gb, dc, 6);

         } else if (mode == 12) {

             for (i = 0; i < 6; i++) {
                 dc[i] = bytestream2_get_byte(&s->gb);
                 bytestream2_skip(&s->gb, 1);
             }

         } else {

             av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);

             return -1;

         }

         tgq_idct_put_mb_dconly(s, frame, mb_x, mb_y, dc);

     }

     return 0;

 }
 

 static void tgq_calculate_qtable(TgqContext *s, int quant)
 {
     int i, j;
     const int a = (14 * (100 - quant)) / 100 + 1;
     const int b = (11 * (100 - quant)) / 100 + 4;
     for (j = 0; j < 8; j++)
         for (i = 0; i < 8; i++)
             s->qtable[j * 8 + i] = ((a * (j + i) / (7 + 7) + b) *
                                     ff_inv_aanscales[j * 8 + i]) >> (14 - 4);

 }
 
 static int tgq_decode_frame(AVCodecContext *avctx,

                             void *data, int *got_frame,

                             AVPacket *avpkt)
 {

     const uint8_t *buf = avpkt->data;

     int buf_size       = avpkt->size;
     TgqContext *s      = avctx->priv_data;

     AVFrame *frame     = data;

     int x, y, ret;

     int big_endian;

     if (buf_size < 16) {

         av_log(avctx, AV_LOG_WARNING, "truncated header\n");

         return AVERROR_INVALIDDATA;

     }

     big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;

     bytestream2_init(&s->gb, buf + 8, buf_size - 8);
     if (big_endian) {
         s->width  = bytestream2_get_be16u(&s->gb);
         s->height = bytestream2_get_be16u(&s->gb);
     } else {
         s->width  = bytestream2_get_le16u(&s->gb);
         s->height = bytestream2_get_le16u(&s->gb);
     }

     ret = ff_set_dimensions(s->avctx, s->width, s->height);
     if (ret < 0)
         return ret;
 

     tgq_calculate_qtable(s, bytestream2_get_byteu(&s->gb));
     bytestream2_skip(&s->gb, 3);

     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

         return ret;
     frame->key_frame = 1;
     frame->pict_type = AV_PICTURE_TYPE_I;

     for (y = 0; y < FFALIGN(avctx->height, 16) >> 4; y++)
         for (x = 0; x < FFALIGN(avctx->width, 16) >> 4; x++)

             if (tgq_decode_mb(s, frame, y, x) < 0)

                 return AVERROR_INVALIDDATA;

     *got_frame = 1;

     return avpkt->size;

 }
 

 AVCodec ff_eatgq_decoder = {

     .name           = "eatgq",

     .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_TGQ,

     .priv_data_size = sizeof(TgqContext),
     .init           = tgq_decode_init,
     .decode         = tgq_decode_frame,
     .capabilities   = CODEC_CAP_DR1,

 };