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
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
38typedef 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
48static 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
60static 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
105static 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
121static 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
128static 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
144static 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
179static 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
191static 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
239static 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
246AVCodec eatgq_decoder = {
247    "eatgq",
248    AVMEDIA_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};
258