1/*
2 * Electronic Arts TGQ Video Decoder
3 * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 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    GetByteContext gb;
47} TgqContext;
48
49static av_cold int tgq_decode_init(AVCodecContext *avctx){
50    TgqContext *s = avctx->priv_data;
51    s->avctx = avctx;
52    if(avctx->idct_algo==FF_IDCT_AUTO)
53        avctx->idct_algo=FF_IDCT_EA;
54    dsputil_init(&s->dsp, avctx);
55    ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
56    avctx->time_base = (AVRational){1, 15};
57    avctx->pix_fmt = PIX_FMT_YUV420P;
58    return 0;
59}
60
61static void tgq_decode_block(TgqContext *s, DCTELEM block[64], GetBitContext *gb){
62    uint8_t *perm = s->scantable.permutated;
63    int i,j,value;
64    block[0] = get_sbits(gb,8) * s->qtable[0];
65    for(i=1; i<64; ) {
66        switch(show_bits(gb,3)) {
67        case 4:
68            block[perm[i++]] = 0;
69        case 0:
70            block[perm[i++]] = 0;
71            skip_bits(gb,3);
72            break;
73        case 5:
74        case 1:
75            skip_bits(gb,2);
76            value = get_bits(gb,6);
77            for(j=0; j<value; j++)
78                block[perm[i++]] = 0;
79            break;
80        case 6:
81            skip_bits(gb,3);
82            block[perm[i]] = -s->qtable[perm[i]];
83            i++;
84            break;
85        case 2:
86            skip_bits(gb,3);
87            block[perm[i]] = s->qtable[perm[i]];
88            i++;
89            break;
90        case 7: // 111b
91        case 3: // 011b
92            skip_bits(gb,2);
93            if (show_bits(gb,6)==0x3F) {
94                skip_bits(gb, 6);
95                block[perm[i]] = get_sbits(gb,8)*s->qtable[perm[i]];
96            }else{
97                block[perm[i]] = get_sbits(gb,6)*s->qtable[perm[i]];
98            }
99            i++;
100            break;
101        }
102    }
103    block[0] += 128<<4;
104}
105
106static void tgq_idct_put_mb(TgqContext *s, DCTELEM (*block)[64], int mb_x, int mb_y){
107    int linesize= s->frame.linesize[0];
108    uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
109    uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
110    uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
111
112    s->dsp.idct_put(dest_y                 , linesize, block[0]);
113    s->dsp.idct_put(dest_y              + 8, linesize, block[1]);
114    s->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
115    s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
116    if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
117         s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
118         s->dsp.idct_put(dest_cr, s->frame.linesize[2], block[5]);
119    }
120}
121
122static inline void tgq_dconly(TgqContext *s, unsigned char *dst, int dst_stride, int dc){
123    int level = av_clip_uint8((dc*s->qtable[0] + 2056)>>4);
124    int j;
125    for(j=0;j<8;j++)
126        memset(dst+j*dst_stride, level, 8);
127}
128
129static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
130{
131    int linesize= s->frame.linesize[0];
132    uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
133    uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
134    uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
135    tgq_dconly(s,dest_y                 , linesize, dc[0]);
136    tgq_dconly(s,dest_y              + 8, linesize, dc[1]);
137    tgq_dconly(s,dest_y + 8*linesize    , linesize, dc[2]);
138    tgq_dconly(s,dest_y + 8*linesize + 8, linesize, dc[3]);
139    if(!(s->avctx->flags&CODEC_FLAG_GRAY)) {
140        tgq_dconly(s,dest_cb, s->frame.linesize[1], dc[4]);
141        tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
142    }
143}
144
145static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x){
146    int mode;
147    int i;
148    int8_t dc[6];
149
150    mode = bytestream2_get_byte(&s->gb);
151    if (mode>12) {
152        GetBitContext gb;
153        init_get_bits(&gb, s->gb.buffer, FFMIN(s->gb.buffer_end - s->gb.buffer, mode) * 8);
154        for(i=0; i<6; i++)
155            tgq_decode_block(s, s->block[i], &gb);
156        tgq_idct_put_mb(s, s->block, mb_x, mb_y);
157        bytestream2_skip(&s->gb, mode);
158    }else{
159        if (mode==3) {
160            memset(dc, bytestream2_get_byte(&s->gb), 4);
161            dc[4] = bytestream2_get_byte(&s->gb);
162            dc[5] = bytestream2_get_byte(&s->gb);
163        }else if (mode==6) {
164            bytestream2_get_buffer(&s->gb, dc, 6);
165        }else if (mode==12) {
166            for (i = 0; i < 6; i++) {
167                dc[i] = bytestream2_get_byte(&s->gb);
168                bytestream2_skip(&s->gb, 1);
169            }
170        }else{
171            av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
172        }
173        tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
174    }
175}
176
177static void tgq_calculate_qtable(TgqContext *s, int quant){
178    int i,j;
179    const int a = (14*(100-quant))/100 + 1;
180    const int b = (11*(100-quant))/100 + 4;
181    for(j=0;j<8;j++)
182    for(i=0;i<8;i++)
183        if (s->avctx->idct_algo==FF_IDCT_EA)
184            s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
185        else
186            s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
187}
188
189static int tgq_decode_frame(AVCodecContext *avctx,
190                            void *data, int *data_size,
191                            AVPacket *avpkt){
192    const uint8_t *buf = avpkt->data;
193    int buf_size = avpkt->size;
194    TgqContext *s = avctx->priv_data;
195    int x,y;
196    int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
197
198    if (buf_size < 16) {
199        av_log(avctx, AV_LOG_WARNING, "truncated header\n");
200        return -1;
201    }
202    bytestream2_init(&s->gb, buf + 8, buf_size - 8);
203    if (big_endian) {
204        s->width  = bytestream2_get_be16u(&s->gb);
205        s->height = bytestream2_get_be16u(&s->gb);
206    } else {
207        s->width  = bytestream2_get_le16u(&s->gb);
208        s->height = bytestream2_get_le16u(&s->gb);
209    }
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, bytestream2_get_byteu(&s->gb));
217    bytestream2_skip(&s->gb, 3);
218
219    if (!s->frame.data[0]) {
220        s->frame.key_frame = 1;
221        s->frame.pict_type = AV_PICTURE_TYPE_I;
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 < FFALIGN(avctx->height, 16) >> 4; y++)
230        for (x = 0; x < FFALIGN(avctx->width, 16) >> 4; x++)
231            tgq_decode_mb(s, y, x);
232
233    *data_size = sizeof(AVFrame);
234    *(AVFrame*)data = s->frame;
235
236    return avpkt->size;
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 ff_eatgq_decoder = {
247    .name           = "eatgq",
248    .type           = AVMEDIA_TYPE_VIDEO,
249    .id             = CODEC_ID_TGQ,
250    .priv_data_size = sizeof(TgqContext),
251    .init           = tgq_decode_init,
252    .close          = tgq_decode_end,
253    .decode         = tgq_decode_frame,
254    .capabilities   = CODEC_CAP_DR1,
255    .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
256};
257