libavcodec/eatgq.c

   1 /*
   2  * Electronic Arts TGQ Video Decoder
   3  * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20  */
  21
  22 /**
  23  * @file libavcodec/eatgq.c
  24  * Electronic Arts TGQ Video Decoder
  25  * @author Peter Ross <pross@xvid.org>
  26  *
  27  * Technical details here:
  28  * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGQ
  29  */
  30
  31 #include "avcodec.h"
  32 #define ALT_BITSTREAM_READER_LE
  33 #include "get_bits.h"
  34 #include "bytestream.h"
  35 #include "dsputil.h"
  36 #include "aandcttab.h"
  37
  38 typedef struct TgqContext {
  39     AVCodecContext *avctx;
  40     DSPContext dsp;
  41     AVFrame frame;
  42     int width,height;
  43     ScanTable scantable;
  44     int qtable[64];
  45     DECLARE_ALIGNED_16(DCTELEM, block[6][64]);
  46 } TgqContext;
  47
  48 static av_cold int tgq_decode_init(AVCodecContext *avctx){
  49     TgqContext *s = avctx->priv_data;
  50     s->avctx = avctx;
  51     if(avctx->idct_algo==FF_IDCT_AUTO)
  52         avctx->idct_algo=FF_IDCT_EA;
  53     dsputil_init(&s->dsp, avctx);
  54     ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
  55     avctx->time_base = (AVRational){1, 15};
  56     avctx->pix_fmt = PIX_FMT_YUV420P;
  57     return 0;
  58 }
  59
  60 static void tgq_decode_block(TgqContext *s, DCTELEM block[64], GetBitContext *gb){
  61     uint8_t *perm = s->scantable.permutated;
  62     int i,j,value;
  63     block[0] = get_sbits(gb,8) * s->qtable[0];
  64     for(i=1; i<64; ) {
  65         switch(show_bits(gb,3)) {
  66         case 4:
  67             block[perm[i++]] = 0;
  68         case 0:
  69             block[perm[i++]] = 0;
  70             skip_bits(gb,3);
  71             break;
  72         case 5:
  73         case 1:
  74             skip_bits(gb,2);
  75             value = get_bits(gb,6);
  76             for(j=0; j<value; j++)
  77                 block[perm[i++]] = 0;
  78             break;
  79         case 6:
  80             skip_bits(gb,3);
  81             block[perm[i]] = -s->qtable[perm[i]];
  82             i++;
  83             break;
  84         case 2:
  85             skip_bits(gb,3);
  86             block[perm[i]] = s->qtable[perm[i]];
  87             i++;
  88             break;
  89         case 7: // 111b
  90         case 3: // 011b
  91             skip_bits(gb,2);
  92             if (show_bits(gb,6)==0x3F) {
  93                 skip_bits(gb, 6);
  94                 block[perm[i]] = get_sbits(gb,8)*s->qtable[perm[i]];
  95             }else{
  96                 block[perm[i]] = get_sbits(gb,6)*s->qtable[perm[i]];
  97             }
  98             i++;
  99             break;
 100         }
 101     }
 102     block[0] += 128<<4;
 103 }
 104
 105 static void tgq_idct_put_mb(TgqContext *s, DCTELEM (*block)[64], int mb_x, int mb_y){
 106     int linesize= s->frame.linesize[0];
 107     uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
 108     uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
 109     uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
 110
 111     s->dsp.idct_put(dest_y                 , linesize, block[0]);
 112     s->dsp.idct_put(dest_y              + 8, linesize, block[1]);
 113     s->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
 114     s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
 115     if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
 116          s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
 117          s->dsp.idct_put(dest_cr, s->frame.linesize[2], block[5]);
 118     }
 119 }
 120
 121 static inline void tgq_dconly(TgqContext *s, unsigned char *dst, int dst_stride, int dc){
 122     int level = av_clip_uint8((dc*s->qtable[0] + 2056)>>4);
 123     int j;
 124     for(j=0;j<8;j++)
 125         memset(dst+j*dst_stride, level, 8);
 126 }
 127
 128 static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
 129 {
 130     int linesize= s->frame.linesize[0];
 131     uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
 132     uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
 133     uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
 134     tgq_dconly(s,dest_y                 , linesize, dc[0]);
 135     tgq_dconly(s,dest_y              + 8, linesize, dc[1]);
 136     tgq_dconly(s,dest_y + 8*linesize    , linesize, dc[2]);
 137     tgq_dconly(s,dest_y + 8*linesize + 8, linesize, dc[3]);
 138     if(!(s->avctx->flags&CODEC_FLAG_GRAY)) {
 139         tgq_dconly(s,dest_cb, s->frame.linesize[1], dc[4]);
 140         tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
 141     }
 142 }
 143
 144 static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x, const uint8_t **bs, const uint8_t *buf_end){
 145     int mode;
 146     int i;
 147     int8_t dc[6];
 148
 149     mode = bytestream_get_byte(bs);
 150     if (mode>buf_end-*bs) {
 151         av_log(s->avctx, AV_LOG_ERROR, "truncated macroblock\n");
 152         return;
 153     }
 154
 155     if (mode>12) {
 156         GetBitContext gb;
 157         init_get_bits(&gb, *bs, mode*8);
 158         for(i=0; i<6; i++)
 159             tgq_decode_block(s, s->block[i], &gb);
 160         tgq_idct_put_mb(s, s->block, mb_x, mb_y);
 161     }else{
 162         if (mode==3) {
 163             memset(dc, (*bs)[0], 4);
 164             dc[4] = (*bs)[1];
 165             dc[5] = (*bs)[2];
 166         }else if (mode==6) {
 167             memcpy(dc, *bs, 6);
 168         }else if (mode==12) {
 169             for(i=0; i<6; i++)
 170                 dc[i] = (*bs)[i*2];
 171         }else{
 172             av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
 173         }
 174         tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
 175     }
 176     *bs += mode;
 177 }
 178
 179 static void tgq_calculate_qtable(TgqContext *s, int quant){
 180     int i,j;
 181     const int a = (14*(100-quant))/100 + 1;
 182     const int b = (11*(100-quant))/100 + 4;
 183     for(j=0;j<8;j++)
 184     for(i=0;i<8;i++)
 185         if (s->avctx->idct_algo==FF_IDCT_EA)
 186             s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
 187         else
 188             s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
 189 }
 190
 191 static int tgq_decode_frame(AVCodecContext *avctx,
 192                             void *data, int *data_size,
 193                             AVPacket *avpkt){
 194     const uint8_t *buf = avpkt->data;
 195     int buf_size = avpkt->size;
 196     const uint8_t *buf_start = buf;
 197     const uint8_t *buf_end = buf + buf_size;
 198     TgqContext *s = avctx->priv_data;
 199     int x,y;
 200
 201     int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
 202     buf += 8;
 203
 204     if(8>buf_end-buf) {
 205         av_log(avctx, AV_LOG_WARNING, "truncated header\n");
 206         return -1;
 207     }
 208     s->width  = big_endian ? AV_RB16(&buf[0]) : AV_RL16(&buf[0]);
 209     s->height = big_endian ? AV_RB16(&buf[2]) : AV_RL16(&buf[2]);
 210
 211     if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
 212         avcodec_set_dimensions(s->avctx, s->width, s->height);
 213         if (s->frame.data[0])
 214             avctx->release_buffer(avctx, &s->frame);
 215     }
 216     tgq_calculate_qtable(s, buf[4]);
 217     buf += 8;
 218
 219     if (!s->frame.data[0]) {
 220         s->frame.key_frame = 1;
 221         s->frame.pict_type = FF_I_TYPE;
 222         s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
 223         if (avctx->get_buffer(avctx, &s->frame)) {
 224             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 225             return -1;
 226         }
 227     }
 228
 229     for (y=0; y<(avctx->height+15)/16; y++)
 230     for (x=0; x<(avctx->width+15)/16; x++)
 231         tgq_decode_mb(s, y, x, &buf, buf_end);
 232
 233     *data_size = sizeof(AVFrame);
 234     *(AVFrame*)data = s->frame;
 235
 236     return buf-buf_start;
 237 }
 238
 239 static av_cold int tgq_decode_end(AVCodecContext *avctx){
 240     TgqContext *s = avctx->priv_data;
 241     if (s->frame.data[0])
 242         s->avctx->release_buffer(avctx, &s->frame);
 243     return 0;
 244 }
 245
 246 AVCodec eatgq_decoder = {
 247     "eatgq",
 248     CODEC_TYPE_VIDEO,
 249     CODEC_ID_TGQ,
 250     sizeof(TgqContext),
 251     tgq_decode_init,
 252     NULL,
 253     tgq_decode_end,
 254     tgq_decode_frame,
 255     CODEC_CAP_DR1,
 256     .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
 257 };