aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/eatgq.c
blob: 05f03e7b057c7b130e4a2a80f96559ee89007b50 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
/*
 * Electronic Arts TGQ Video Decoder
 * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

/**
 * @file libavcodec/eatgq.c
 * Electronic Arts TGQ Video Decoder
 * @author Peter Ross <pross@xvid.org>
 *
 * Technical details here:
 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGQ
 */

#include "avcodec.h"
#define ALT_BITSTREAM_READER_LE
#include "bitstream.h"
#include "bytestream.h"
#include "dsputil.h"
#include "aandcttab.h"

typedef struct TgqContext {
    AVCodecContext *avctx;
    DSPContext dsp;
    AVFrame frame;
    int width,height;
    ScanTable scantable;
    int qtable[64];
} TgqContext;

static av_cold int tgq_decode_init(AVCodecContext *avctx){
    TgqContext *s = avctx->priv_data;
    s->avctx = avctx;
    if(avctx->idct_algo==FF_IDCT_AUTO)
        avctx->idct_algo=FF_IDCT_EA;
    dsputil_init(&s->dsp, avctx);
    ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
    avctx->time_base = (AVRational){1, 15};
    avctx->pix_fmt = PIX_FMT_YUV420P;
    return 0;
}

static void tgq_decode_block(TgqContext *s, DCTELEM block[64], GetBitContext *gb){
    uint8_t *perm = s->scantable.permutated;
    int i,j,value;
    block[0] = get_sbits(gb,8) * s->qtable[0];
    for(i=1; i<64; ) {
        switch(show_bits(gb,3)) {
        case 4:
            block[perm[i++]] = 0;
        case 0:
            block[perm[i++]] = 0;
            skip_bits(gb,3);
            break;
        case 5:
        case 1:
            skip_bits(gb,2);
            value = get_bits(gb,6);
            for(j=0; j<value; j++)
                block[perm[i++]] = 0;
            break;
        case 6:
            skip_bits(gb,3);
            block[perm[i]] = -s->qtable[perm[i]];
            i++;
            break;
        case 2:
            skip_bits(gb,3);
            block[perm[i]] = s->qtable[perm[i]];
            i++;
            break;
        case 7: // 111b
        case 3: // 011b
            skip_bits(gb,2);
            if (show_bits(gb,6)==0x3F) {
                skip_bits(gb, 6);
                block[perm[i]] = get_sbits(gb,8)*s->qtable[perm[i]];
            }else{
                block[perm[i]] = get_sbits(gb,6)*s->qtable[perm[i]];
            }
            i++;
            break;
        }
    }
    block[0] += 128<<4;
}

static void tgq_idct_put_mb(TgqContext *s, DCTELEM (*block)[64], int mb_x, int mb_y){
    int linesize= s->frame.linesize[0];
    uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
    uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
    uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;

    s->dsp.idct_put(dest_y                 , linesize, block[0]);
    s->dsp.idct_put(dest_y              + 8, linesize, block[1]);
    s->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
    s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
    if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
         s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
         s->dsp.idct_put(dest_cr, s->frame.linesize[2], block[5]);
    }
}

static inline void tgq_dconly(TgqContext *s, unsigned char *dst, int dst_stride, int dc){
    int level = av_clip_uint8((dc*s->qtable[0] + 2056)>>4);
    int j;
    for(j=0;j<8;j++)
        memset(dst+j*dst_stride, level, 8);
}

static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
{
    int linesize= s->frame.linesize[0];
    uint8_t *dest_y  = s->frame.data[0] + (mb_y * 16* linesize            ) + mb_x * 16;
    uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
    uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
    tgq_dconly(s,dest_y                 , linesize, dc[0]);
    tgq_dconly(s,dest_y              + 8, linesize, dc[1]);
    tgq_dconly(s,dest_y + 8*linesize    , linesize, dc[2]);
    tgq_dconly(s,dest_y + 8*linesize + 8, linesize, dc[3]);
    if(!(s->avctx->flags&CODEC_FLAG_GRAY)) {
        tgq_dconly(s,dest_cb, s->frame.linesize[1], dc[4]);
        tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
    }
}

static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x, const int8_t **bs, const int8_t *buf_end){
    int mode;
    int i;
    int8_t dc[6];
    DCTELEM block[6][64];

    mode = bytestream_get_byte((const uint8_t**)bs);
    if (mode>buf_end-*bs) {
        av_log(s->avctx, AV_LOG_ERROR, "truncated macroblock\n");
        return;
    }

    if (mode>12) {
        GetBitContext gb;
        init_get_bits(&gb, *bs, mode*8);
        for(i=0; i<6; i++)
            tgq_decode_block(s, block[i], &gb);
        tgq_idct_put_mb(s, block, mb_x, mb_y);
    }else{
        if (mode==3) {
            memset(dc, (*bs)[0], 4);
            dc[4] = (*bs)[1];
            dc[5] = (*bs)[2];
        }else if (mode==6) {
            memcpy(dc, *bs, 6);
        }else if (mode==12) {
            for(i=0; i<6; i++)
                dc[i] = (*bs)[i*2];
        }else{
            av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
        }
        tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
    }
    *bs += mode;
}

static void tgq_calculate_qtable(TgqContext *s, int quant){
    int i,j;
    const int a = (14*(100-quant))/100 + 1;
    const int b = (11*(100-quant))/100 + 4;
    for(j=0;j<8;j++)
    for(i=0;i<8;i++)
        if (s->avctx->idct_algo==FF_IDCT_EA)
            s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
        else
            s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
}

static int tgq_decode_frame(AVCodecContext *avctx,
                            void *data, int *data_size,
                            AVPacket *avpkt){
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    const uint8_t *buf_start = buf;
    const uint8_t *buf_end = buf + buf_size;
    TgqContext *s = avctx->priv_data;
    int x,y;

    int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
    buf += 8;

    if(8>buf_end-buf) {
        av_log(avctx, AV_LOG_WARNING, "truncated header\n");
        return -1;
    }
    s->width  = big_endian ? AV_RB16(&buf[0]) : AV_RL16(&buf[0]);
    s->height = big_endian ? AV_RB16(&buf[2]) : AV_RL16(&buf[2]);

    if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
        avcodec_set_dimensions(s->avctx, s->width, s->height);
        if (s->frame.data[0])
            avctx->release_buffer(avctx, &s->frame);
    }
    tgq_calculate_qtable(s, buf[4]);
    buf += 8;

    if (!s->frame.data[0]) {
        s->frame.key_frame = 1;
        s->frame.pict_type = FF_I_TYPE;
        s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
        if (avctx->get_buffer(avctx, &s->frame)) {
            av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
            return -1;
        }
    }

    for (y=0; y<(avctx->height+15)/16; y++)
    for (x=0; x<(avctx->width+15)/16; x++)
        tgq_decode_mb(s, y, x, (const int8_t**)&buf, (const int8_t*)buf_end);

    *data_size = sizeof(AVFrame);
    *(AVFrame*)data = s->frame;

    return buf-buf_start;
}

static av_cold int tgq_decode_end(AVCodecContext *avctx){
    TgqContext *s = avctx->priv_data;
    if (s->frame.data[0])
        s->avctx->release_buffer(avctx, &s->frame);
    return 0;
}

AVCodec eatgq_decoder = {
    "eatgq",
    CODEC_TYPE_VIDEO,
    CODEC_ID_TGQ,
    sizeof(TgqContext),
    tgq_decode_init,
    NULL,
    tgq_decode_end,
    tgq_decode_frame,
    CODEC_CAP_DR1,
    .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
};