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 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     GetByteContext gb;
00047 } TgqContext;
00048 
00049 static av_cold int tgq_decode_init(AVCodecContext *avctx){
00050     TgqContext *s = avctx->priv_data;
00051     s->avctx = avctx;
00052     if(avctx->idct_algo==FF_IDCT_AUTO)
00053         avctx->idct_algo=FF_IDCT_EA;
00054     dsputil_init(&s->dsp, avctx);
00055     ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
00056     avctx->time_base = (AVRational){1, 15};
00057     avctx->pix_fmt = PIX_FMT_YUV420P;
00058     return 0;
00059 }
00060 
00061 static void tgq_decode_block(TgqContext *s, DCTELEM block[64], GetBitContext *gb){
00062     uint8_t *perm = s->scantable.permutated;
00063     int i,j,value;
00064     block[0] = get_sbits(gb,8) * s->qtable[0];
00065     for(i=1; i<64; ) {
00066         switch(show_bits(gb,3)) {
00067         case 4:
00068             block[perm[i++]] = 0;
00069         case 0:
00070             block[perm[i++]] = 0;
00071             skip_bits(gb,3);
00072             break;
00073         case 5:
00074         case 1:
00075             skip_bits(gb,2);
00076             value = get_bits(gb,6);
00077             for(j=0; j<value; j++)
00078                 block[perm[i++]] = 0;
00079             break;
00080         case 6:
00081             skip_bits(gb,3);
00082             block[perm[i]] = -s->qtable[perm[i]];
00083             i++;
00084             break;
00085         case 2:
00086             skip_bits(gb,3);
00087             block[perm[i]] = s->qtable[perm[i]];
00088             i++;
00089             break;
00090         case 7: // 111b
00091         case 3: // 011b
00092             skip_bits(gb,2);
00093             if (show_bits(gb,6)==0x3F) {
00094                 skip_bits(gb, 6);
00095                 block[perm[i]] = get_sbits(gb,8)*s->qtable[perm[i]];
00096             }else{
00097                 block[perm[i]] = get_sbits(gb,6)*s->qtable[perm[i]];
00098             }
00099             i++;
00100             break;
00101         }
00102     }
00103     block[0] += 128<<4;
00104 }
00105 
00106 static void tgq_idct_put_mb(TgqContext *s, DCTELEM (*block)[64], int mb_x, int mb_y){
00107     int linesize= s->frame.linesize[0];
00108     uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
00109     uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
00110     uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
00111 
00112     s->dsp.idct_put(dest_y                 , linesize, block[0]);
00113     s->dsp.idct_put(dest_y              + 8, linesize, block[1]);
00114     s->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
00115     s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
00116     if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
00117          s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
00118          s->dsp.idct_put(dest_cr, s->frame.linesize[2], block[5]);
00119     }
00120 }
00121 
00122 static inline void tgq_dconly(TgqContext *s, unsigned char *dst, int dst_stride, int dc){
00123     int level = av_clip_uint8((dc*s->qtable[0] + 2056)>>4);
00124     int j;
00125     for(j=0;j<8;j++)
00126         memset(dst+j*dst_stride, level, 8);
00127 }
00128 
00129 static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
00130 {
00131     int linesize= s->frame.linesize[0];
00132     uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
00133     uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
00134     uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
00135     tgq_dconly(s,dest_y                 , linesize, dc[0]);
00136     tgq_dconly(s,dest_y              + 8, linesize, dc[1]);
00137     tgq_dconly(s,dest_y + 8*linesize    , linesize, dc[2]);
00138     tgq_dconly(s,dest_y + 8*linesize + 8, linesize, dc[3]);
00139     if(!(s->avctx->flags&CODEC_FLAG_GRAY)) {
00140         tgq_dconly(s,dest_cb, s->frame.linesize[1], dc[4]);
00141         tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
00142     }
00143 }
00144 
00145 static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x){
00146     int mode;
00147     int i;
00148     int8_t dc[6];
00149 
00150     mode = bytestream2_get_byte(&s->gb);
00151     if (mode>12) {
00152         GetBitContext gb;
00153         init_get_bits(&gb, s->gb.buffer, FFMIN(s->gb.buffer_end - s->gb.buffer, mode) * 8);
00154         for(i=0; i<6; i++)
00155             tgq_decode_block(s, s->block[i], &gb);
00156         tgq_idct_put_mb(s, s->block, mb_x, mb_y);
00157         bytestream2_skip(&s->gb, mode);
00158     }else{
00159         if (mode==3) {
00160             memset(dc, bytestream2_get_byte(&s->gb), 4);
00161             dc[4] = bytestream2_get_byte(&s->gb);
00162             dc[5] = bytestream2_get_byte(&s->gb);
00163         }else if (mode==6) {
00164             bytestream2_get_buffer(&s->gb, dc, 6);
00165         }else if (mode==12) {
00166             for (i = 0; i < 6; i++) {
00167                 dc[i] = bytestream2_get_byte(&s->gb);
00168                 bytestream2_skip(&s->gb, 1);
00169             }
00170         }else{
00171             av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
00172         }
00173         tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
00174     }
00175 }
00176 
00177 static void tgq_calculate_qtable(TgqContext *s, int quant){
00178     int i,j;
00179     const int a = (14*(100-quant))/100 + 1;
00180     const int b = (11*(100-quant))/100 + 4;
00181     for(j=0;j<8;j++)
00182     for(i=0;i<8;i++)
00183         if (s->avctx->idct_algo==FF_IDCT_EA)
00184             s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
00185         else
00186             s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
00187 }
00188 
00189 static int tgq_decode_frame(AVCodecContext *avctx,
00190                             void *data, int *data_size,
00191                             AVPacket *avpkt){
00192     const uint8_t *buf = avpkt->data;
00193     int buf_size = avpkt->size;
00194     TgqContext *s = avctx->priv_data;
00195     int x,y;
00196     int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
00197 
00198     if (buf_size < 16) {
00199         av_log(avctx, AV_LOG_WARNING, "truncated header\n");
00200         return -1;
00201     }
00202     bytestream2_init(&s->gb, buf + 8, buf_size - 8);
00203     if (big_endian) {
00204         s->width  = bytestream2_get_be16u(&s->gb);
00205         s->height = bytestream2_get_be16u(&s->gb);
00206     } else {
00207         s->width  = bytestream2_get_le16u(&s->gb);
00208         s->height = bytestream2_get_le16u(&s->gb);
00209     }
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, bytestream2_get_byteu(&s->gb));
00217     bytestream2_skip(&s->gb, 3);
00218 
00219     if (!s->frame.data[0]) {
00220         s->frame.key_frame = 1;
00221         s->frame.pict_type = AV_PICTURE_TYPE_I;
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 < FFALIGN(avctx->height, 16) >> 4; y++)
00230         for (x = 0; x < FFALIGN(avctx->width, 16) >> 4; x++)
00231             tgq_decode_mb(s, y, x);
00232 
00233     *data_size = sizeof(AVFrame);
00234     *(AVFrame*)data = s->frame;
00235 
00236     return avpkt->size;
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 ff_eatgq_decoder = {
00247     .name           = "eatgq",
00248     .type           = AVMEDIA_TYPE_VIDEO,
00249     .id             = CODEC_ID_TGQ,
00250     .priv_data_size = sizeof(TgqContext),
00251     .init           = tgq_decode_init,
00252     .close          = tgq_decode_end,
00253     .decode         = tgq_decode_frame,
00254     .capabilities   = CODEC_CAP_DR1,
00255     .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
00256 };