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libavcodec/eatgq.c

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00001 /*
00002  * Electronic Arts TGQ Video Decoder
00003  * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00020  */
00021 
00031 #include "avcodec.h"
00032 #define ALT_BITSTREAM_READER_LE
00033 #include "get_bits.h"
00034 #include "bytestream.h"
00035 #include "dsputil.h"
00036 #include "aandcttab.h"
00037 
00038 typedef struct TgqContext {
00039     AVCodecContext *avctx;
00040     DSPContext dsp;
00041     AVFrame frame;
00042     int width,height;
00043     ScanTable scantable;
00044     int qtable[64];
00045     DECLARE_ALIGNED(16, DCTELEM, block)[6][64];
00046 } TgqContext;
00047 
00048 static av_cold int tgq_decode_init(AVCodecContext *avctx){
00049     TgqContext *s = avctx->priv_data;
00050     s->avctx = avctx;
00051     if(avctx->idct_algo==FF_IDCT_AUTO)
00052         avctx->idct_algo=FF_IDCT_EA;
00053     dsputil_init(&s->dsp, avctx);
00054     ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
00055     avctx->time_base = (AVRational){1, 15};
00056     avctx->pix_fmt = PIX_FMT_YUV420P;
00057     return 0;
00058 }
00059 
00060 static void tgq_decode_block(TgqContext *s, DCTELEM block[64], GetBitContext *gb){
00061     uint8_t *perm = s->scantable.permutated;
00062     int i,j,value;
00063     block[0] = get_sbits(gb,8) * s->qtable[0];
00064     for(i=1; i<64; ) {
00065         switch(show_bits(gb,3)) {
00066         case 4:
00067             block[perm[i++]] = 0;
00068         case 0:
00069             block[perm[i++]] = 0;
00070             skip_bits(gb,3);
00071             break;
00072         case 5:
00073         case 1:
00074             skip_bits(gb,2);
00075             value = get_bits(gb,6);
00076             for(j=0; j<value; j++)
00077                 block[perm[i++]] = 0;
00078             break;
00079         case 6:
00080             skip_bits(gb,3);
00081             block[perm[i]] = -s->qtable[perm[i]];
00082             i++;
00083             break;
00084         case 2:
00085             skip_bits(gb,3);
00086             block[perm[i]] = s->qtable[perm[i]];
00087             i++;
00088             break;
00089         case 7: // 111b
00090         case 3: // 011b
00091             skip_bits(gb,2);
00092             if (show_bits(gb,6)==0x3F) {
00093                 skip_bits(gb, 6);
00094                 block[perm[i]] = get_sbits(gb,8)*s->qtable[perm[i]];
00095             }else{
00096                 block[perm[i]] = get_sbits(gb,6)*s->qtable[perm[i]];
00097             }
00098             i++;
00099             break;
00100         }
00101     }
00102     block[0] += 128<<4;
00103 }
00104 
00105 static void tgq_idct_put_mb(TgqContext *s, DCTELEM (*block)[64], int mb_x, int mb_y){
00106     int linesize= s->frame.linesize[0];
00107     uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
00108     uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
00109     uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
00110 
00111     s->dsp.idct_put(dest_y                 , linesize, block[0]);
00112     s->dsp.idct_put(dest_y              + 8, linesize, block[1]);
00113     s->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
00114     s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
00115     if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
00116          s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
00117          s->dsp.idct_put(dest_cr, s->frame.linesize[2], block[5]);
00118     }
00119 }
00120 
00121 static inline void tgq_dconly(TgqContext *s, unsigned char *dst, int dst_stride, int dc){
00122     int level = av_clip_uint8((dc*s->qtable[0] + 2056)>>4);
00123     int j;
00124     for(j=0;j<8;j++)
00125         memset(dst+j*dst_stride, level, 8);
00126 }
00127 
00128 static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
00129 {
00130     int linesize= s->frame.linesize[0];
00131     uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
00132     uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
00133     uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
00134     tgq_dconly(s,dest_y                 , linesize, dc[0]);
00135     tgq_dconly(s,dest_y              + 8, linesize, dc[1]);
00136     tgq_dconly(s,dest_y + 8*linesize    , linesize, dc[2]);
00137     tgq_dconly(s,dest_y + 8*linesize + 8, linesize, dc[3]);
00138     if(!(s->avctx->flags&CODEC_FLAG_GRAY)) {
00139         tgq_dconly(s,dest_cb, s->frame.linesize[1], dc[4]);
00140         tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
00141     }
00142 }
00143 
00144 static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x, const uint8_t **bs, const uint8_t *buf_end){
00145     int mode;
00146     int i;
00147     int8_t dc[6];
00148 
00149     mode = bytestream_get_byte(bs);
00150     if (mode>buf_end-*bs) {
00151         av_log(s->avctx, AV_LOG_ERROR, "truncated macroblock\n");
00152         return;
00153     }
00154 
00155     if (mode>12) {
00156         GetBitContext gb;
00157         init_get_bits(&gb, *bs, mode*8);
00158         for(i=0; i<6; i++)
00159             tgq_decode_block(s, s->block[i], &gb);
00160         tgq_idct_put_mb(s, s->block, mb_x, mb_y);
00161     }else{
00162         if (mode==3) {
00163             memset(dc, (*bs)[0], 4);
00164             dc[4] = (*bs)[1];
00165             dc[5] = (*bs)[2];
00166         }else if (mode==6) {
00167             memcpy(dc, *bs, 6);
00168         }else if (mode==12) {
00169             for(i=0; i<6; i++)
00170                 dc[i] = (*bs)[i*2];
00171         }else{
00172             av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
00173         }
00174         tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
00175     }
00176     *bs += mode;
00177 }
00178 
00179 static void tgq_calculate_qtable(TgqContext *s, int quant){
00180     int i,j;
00181     const int a = (14*(100-quant))/100 + 1;
00182     const int b = (11*(100-quant))/100 + 4;
00183     for(j=0;j<8;j++)
00184     for(i=0;i<8;i++)
00185         if (s->avctx->idct_algo==FF_IDCT_EA)
00186             s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
00187         else
00188             s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
00189 }
00190 
00191 static int tgq_decode_frame(AVCodecContext *avctx,
00192                             void *data, int *data_size,
00193                             AVPacket *avpkt){
00194     const uint8_t *buf = avpkt->data;
00195     int buf_size = avpkt->size;
00196     const uint8_t *buf_start = buf;
00197     const uint8_t *buf_end = buf + buf_size;
00198     TgqContext *s = avctx->priv_data;
00199     int x,y;
00200 
00201     int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
00202     buf += 8;
00203 
00204     if(8>buf_end-buf) {
00205         av_log(avctx, AV_LOG_WARNING, "truncated header\n");
00206         return -1;
00207     }
00208     s->width  = big_endian ? AV_RB16(&buf[0]) : AV_RL16(&buf[0]);
00209     s->height = big_endian ? AV_RB16(&buf[2]) : AV_RL16(&buf[2]);
00210 
00211     if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
00212         avcodec_set_dimensions(s->avctx, s->width, s->height);
00213         if (s->frame.data[0])
00214             avctx->release_buffer(avctx, &s->frame);
00215     }
00216     tgq_calculate_qtable(s, buf[4]);
00217     buf += 8;
00218 
00219     if (!s->frame.data[0]) {
00220         s->frame.key_frame = 1;
00221         s->frame.pict_type = FF_I_TYPE;
00222         s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
00223         if (avctx->get_buffer(avctx, &s->frame)) {
00224             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00225             return -1;
00226         }
00227     }
00228 
00229     for (y=0; y<(avctx->height+15)/16; y++)
00230     for (x=0; x<(avctx->width+15)/16; x++)
00231         tgq_decode_mb(s, y, x, &buf, buf_end);
00232 
00233     *data_size = sizeof(AVFrame);
00234     *(AVFrame*)data = s->frame;
00235 
00236     return buf-buf_start;
00237 }
00238 
00239 static av_cold int tgq_decode_end(AVCodecContext *avctx){
00240     TgqContext *s = avctx->priv_data;
00241     if (s->frame.data[0])
00242         s->avctx->release_buffer(avctx, &s->frame);
00243     return 0;
00244 }
00245 
00246 AVCodec eatgq_decoder = {
00247     "eatgq",
00248     AVMEDIA_TYPE_VIDEO,
00249     CODEC_ID_TGQ,
00250     sizeof(TgqContext),
00251     tgq_decode_init,
00252     NULL,
00253     tgq_decode_end,
00254     tgq_decode_frame,
00255     CODEC_CAP_DR1,
00256     .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
00257 };

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