/*
  * 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 ALT_BITSTREAM_READER_LE

 #include "get_bits.h"

 #include "bytestream.h"
 #include "dsputil.h"

 #include "aandcttab.h"

 
 typedef struct TgqContext {
     AVCodecContext *avctx;
     DSPContext dsp;
     AVFrame frame;
     int width,height;
     ScanTable scantable;
     int qtable[64];

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

 } TgqContext;
 
 static av_cold int tgq_decode_init(AVCodecContext *avctx){
     TgqContext *s = avctx->priv_data;
     s->avctx = avctx;
     if(avctx->idct_algo==FF_IDCT_AUTO)
         avctx->idct_algo=FF_IDCT_EA;
     dsputil_init(&s->dsp, avctx);
     ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
     avctx->time_base = (AVRational){1, 15};
     avctx->pix_fmt = PIX_FMT_YUV420P;
     return 0;
 }
 
 static void tgq_decode_block(TgqContext *s, DCTELEM 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, DCTELEM (*block)[64], int mb_x, int mb_y){
     int linesize= s->frame.linesize[0];
     uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
     uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
     uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
 
     s->dsp.idct_put(dest_y                 , linesize, block[0]);
     s->dsp.idct_put(dest_y              + 8, linesize, block[1]);
     s->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
     s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
     if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
          s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
          s->dsp.idct_put(dest_cr, s->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, int mb_x, int mb_y, const int8_t *dc)
 {
     int linesize= s->frame.linesize[0];
     uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
     uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
     uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->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, s->frame.linesize[1], dc[4]);
         tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
     }
 }
 

 static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x, const uint8_t **bs, const uint8_t *buf_end){

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

     mode = bytestream_get_byte(bs);

     if (mode>buf_end-*bs) {
         av_log(s->avctx, AV_LOG_ERROR, "truncated macroblock\n");
         return;
     }
 
     if (mode>12) {
         GetBitContext gb;
         init_get_bits(&gb, *bs, mode*8);
         for(i=0; i<6; i++)

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

     }else{
         if (mode==3) {
             memset(dc, (*bs)[0], 4);
             dc[4] = (*bs)[1];
             dc[5] = (*bs)[2];
         }else if (mode==6) {
             memcpy(dc, *bs, 6);
         }else if (mode==12) {
             for(i=0; i<6; i++)
                 dc[i] = (*bs)[i*2];
         }else{
             av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
         }
         tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
     }
     *bs += mode;
 }
 
 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++)
         if (s->avctx->idct_algo==FF_IDCT_EA)
             s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
         else
             s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
 }
 
 static int tgq_decode_frame(AVCodecContext *avctx,
                             void *data, int *data_size,

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

     const uint8_t *buf_start = buf;
     const uint8_t *buf_end = buf + buf_size;
     TgqContext *s = avctx->priv_data;
     int x,y;
 
     int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
     buf += 8;
 
     if(8>buf_end-buf) {
         av_log(avctx, AV_LOG_WARNING, "truncated header\n");
         return -1;
     }
     s->width  = big_endian ? AV_RB16(&buf[0]) : AV_RL16(&buf[0]);
     s->height = big_endian ? AV_RB16(&buf[2]) : AV_RL16(&buf[2]);
 
     if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
         avcodec_set_dimensions(s->avctx, s->width, s->height);
         if (s->frame.data[0])
             avctx->release_buffer(avctx, &s->frame);
     }
     tgq_calculate_qtable(s, buf[4]);
     buf += 8;
 
     if (!s->frame.data[0]) {
         s->frame.key_frame = 1;

         s->frame.pict_type = AV_PICTURE_TYPE_I;

         s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
         if (avctx->get_buffer(avctx, &s->frame)) {
             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
             return -1;
         }
     }
 
     for (y=0; y<(avctx->height+15)/16; y++)
     for (x=0; x<(avctx->width+15)/16; x++)

         tgq_decode_mb(s, y, x, &buf, buf_end);

 
     *data_size = sizeof(AVFrame);
     *(AVFrame*)data = s->frame;
 
     return buf-buf_start;
 }
 
 static av_cold int tgq_decode_end(AVCodecContext *avctx){
     TgqContext *s = avctx->priv_data;
     if (s->frame.data[0])
         s->avctx->release_buffer(avctx, &s->frame);
     return 0;
 }
 

 AVCodec ff_eatgq_decoder = {

     "eatgq",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_TGQ,
     sizeof(TgqContext),
     tgq_decode_init,
     NULL,
     tgq_decode_end,
     tgq_decode_frame,
     CODEC_CAP_DR1,

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

 };