aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/yop.c
blob: 38014edef600f71447411630a2617c9ee03e6d14 (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
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
/*
 * Psygnosis YOP decoder
 *
 * Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
 * derived from the code by
 * Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@gmail.com>
 *
 * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <string.h>

#include "libavutil/imgutils.h"
#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"

#include "avcodec.h"
#include "internal.h"

typedef struct YopDecContext {
    AVCodecContext *avctx;
    AVFrame *frame;

    int num_pal_colors;
    int first_color[2];
    int frame_data_length;

    uint8_t *low_nibble;
    uint8_t *srcptr;
    uint8_t *src_end;
    uint8_t *dstptr;
    uint8_t *dstbuf;
} YopDecContext;

// These tables are taken directly from:
// http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP

/**
 * Lookup table for painting macroblocks. Bytes 0-2 of each entry contain
 * the macroblock positions to be painted (taken as (0, B0, B1, B2)).
 * Byte 3 contains the number of bytes consumed on the input,
 * equal to max(bytes 0-2) + 1.
 */
static const uint8_t paint_lut[15][4] =
    {{1, 2, 3, 4}, {1, 2, 0, 3},
     {1, 2, 1, 3}, {1, 2, 2, 3},
     {1, 0, 2, 3}, {1, 0, 0, 2},
     {1, 0, 1, 2}, {1, 1, 2, 3},
     {0, 1, 2, 3}, {0, 1, 0, 2},
     {1, 1, 0, 2}, {0, 1, 1, 2},
     {0, 0, 1, 2}, {0, 0, 0, 1},
     {1, 1, 1, 2},
    };

/**
 * Lookup table for copying macroblocks. Each entry contains the respective
 * x and y pixel offset for the copy source.
 */
static const int8_t motion_vector[16][2] =
    {{-4, -4}, {-2, -4},
     { 0, -4}, { 2, -4},
     {-4, -2}, {-4,  0},
     {-3, -3}, {-1, -3},
     { 1, -3}, { 3, -3},
     {-3, -1}, {-2, -2},
     { 0, -2}, { 2, -2},
     { 4, -2}, {-2,  0},
    };

static av_cold int yop_decode_close(AVCodecContext *avctx)
{
    YopDecContext *s = avctx->priv_data;

    av_frame_free(&s->frame);

    return 0;
}

static av_cold int yop_decode_init(AVCodecContext *avctx)
{
    YopDecContext *s = avctx->priv_data;
    s->avctx = avctx;

    if (avctx->width & 1 || avctx->height & 1 ||
        av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
        av_log(avctx, AV_LOG_ERROR, "YOP has invalid dimensions\n");
        return AVERROR_INVALIDDATA;
    }

    if (avctx->extradata_size < 3) {
        av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata.\n");
        return AVERROR_INVALIDDATA;
    }

    avctx->pix_fmt = AV_PIX_FMT_PAL8;

    s->num_pal_colors = avctx->extradata[0];
    s->first_color[0] = avctx->extradata[1];
    s->first_color[1] = avctx->extradata[2];

    if (s->num_pal_colors + s->first_color[0] > 256 ||
        s->num_pal_colors + s->first_color[1] > 256) {
        av_log(avctx, AV_LOG_ERROR,
               "Palette parameters invalid, header probably corrupt\n");
        return AVERROR_INVALIDDATA;
    }

    s->frame = av_frame_alloc();
    if (!s->frame)
        return AVERROR(ENOMEM);

    return 0;
}

/**
 * Paint a macroblock using the pattern in paint_lut.
 * @param s codec context
 * @param tag the tag that was in the nibble
 */
static int yop_paint_block(YopDecContext *s, int linesize, int tag)
{
    if (s->src_end - s->srcptr < paint_lut[tag][3]) {
        av_log(s->avctx, AV_LOG_ERROR, "Packet too small.\n");
        return AVERROR_INVALIDDATA;
    }

    s->dstptr[0]            = s->srcptr[0];
    s->dstptr[1]            = s->srcptr[paint_lut[tag][0]];
    s->dstptr[linesize]     = s->srcptr[paint_lut[tag][1]];
    s->dstptr[linesize + 1] = s->srcptr[paint_lut[tag][2]];

    // The number of src bytes consumed is in the last part of the lut entry.
    s->srcptr += paint_lut[tag][3];
    return 0;
}

/**
 * Copy a previously painted macroblock to the current_block.
 * @param copy_tag the tag that was in the nibble
 */
static int yop_copy_previous_block(YopDecContext *s, int linesize, int copy_tag)
{
    uint8_t *bufptr;

    // Calculate position for the copy source
    bufptr = s->dstptr + motion_vector[copy_tag][0] +
             linesize * motion_vector[copy_tag][1];
    if (bufptr < s->dstbuf) {
        av_log(s->avctx, AV_LOG_ERROR, "File probably corrupt\n");
        return AVERROR_INVALIDDATA;
    }

    s->dstptr[0]            = bufptr[0];
    s->dstptr[1]            = bufptr[1];
    s->dstptr[linesize]     = bufptr[linesize];
    s->dstptr[linesize + 1] = bufptr[linesize + 1];

    return 0;
}

/**
 * Return the next nibble in sequence, consuming a new byte on the input
 * only if necessary.
 */
static uint8_t yop_get_next_nibble(YopDecContext *s)
{
    int ret;

    if (s->low_nibble) {
        ret           = *s->low_nibble & 0xf;
        s->low_nibble = NULL;
    }else {
        s->low_nibble = s->srcptr++;
        ret           = *s->low_nibble >> 4;
    }
    return ret;
}

static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                            AVPacket *avpkt)
{
    YopDecContext *s = avctx->priv_data;
    AVFrame *frame = s->frame;
    int tag, firstcolor, is_odd_frame;
    int ret, i, x, y;
    uint32_t *palette;

    if (avpkt->size < 4 + 3 * s->num_pal_colors) {
        av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
        return AVERROR_INVALIDDATA;
    }

    if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
        return ret;

    if (!avctx->frame_number)
        memset(frame->data[1], 0, AVPALETTE_SIZE);

    s->dstbuf     = frame->data[0];
    s->dstptr     = frame->data[0];
    s->srcptr     = avpkt->data + 4;
    s->src_end    = avpkt->data + avpkt->size;
    s->low_nibble = NULL;

    is_odd_frame = avpkt->data[0];
    if(is_odd_frame>1){
        av_log(avctx, AV_LOG_ERROR, "frame is too odd %d\n", is_odd_frame);
        return AVERROR_INVALIDDATA;
    }
    firstcolor   = s->first_color[is_odd_frame];
    palette      = (uint32_t *)frame->data[1];

    for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3) {
        palette[i + firstcolor] = (s->srcptr[0] << 18) |
                                  (s->srcptr[1] << 10) |
                                  (s->srcptr[2] << 2);
        palette[i + firstcolor] |= 0xFFU << 24 |
                                   (palette[i + firstcolor] >> 6) & 0x30303;
    }

    frame->palette_has_changed = 1;

    for (y = 0; y < avctx->height; y += 2) {
        for (x = 0; x < avctx->width; x += 2) {
            if (s->srcptr - avpkt->data >= avpkt->size) {
                av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
                return AVERROR_INVALIDDATA;
            }

            tag = yop_get_next_nibble(s);

            if (tag != 0xf) {
                ret = yop_paint_block(s, frame->linesize[0], tag);
                if (ret < 0)
                    return ret;
            } else {
                tag = yop_get_next_nibble(s);
                ret = yop_copy_previous_block(s, frame->linesize[0], tag);
                if (ret < 0)
                    return ret;
            }
            s->dstptr += 2;
        }
        s->dstptr += 2*frame->linesize[0] - x;
    }

    if ((ret = av_frame_ref(data, s->frame)) < 0)
        return ret;

    *got_frame = 1;
    return avpkt->size;
}

const AVCodec ff_yop_decoder = {
    .name           = "yop",
    .long_name      = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_YOP,
    .priv_data_size = sizeof(YopDecContext),
    .init           = yop_decode_init,
    .close          = yop_decode_close,
    .decode         = yop_decode_frame,
    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
};