xref: /third_party/ffmpeg/libavcodec/vb.c (revision cabdff1a) 
1/*
2 * Beam Software VB decoder
3 * Copyright (c) 2007 Konstantin Shishkov
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 Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * VB Video decoder
25 */
26
27#include <stdio.h>
28#include <stdlib.h>
29
30#include "avcodec.h"
31#include "bytestream.h"
32#include "codec_internal.h"
33#include "internal.h"
34
35enum VBFlags {
36    VB_HAS_GMC     = 0x01,
37    VB_HAS_AUDIO   = 0x04,
38    VB_HAS_VIDEO   = 0x08,
39    VB_HAS_PALETTE = 0x10,
40    VB_HAS_LENGTH  = 0x20
41};
42
43typedef struct VBDecContext {
44    AVCodecContext *avctx;
45
46    uint8_t *frame, *prev_frame;
47    uint32_t pal[AVPALETTE_COUNT];
48    GetByteContext stream;
49} VBDecContext;
50
51static const uint16_t vb_patterns[64] = {
52    0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
53    0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
54    0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
55    0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
56    0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
57    0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
58    0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
59    0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
60};
61
62static void vb_decode_palette(VBDecContext *c, int data_size)
63{
64    int start, size, i;
65
66    start = bytestream2_get_byte(&c->stream);
67    size  = (bytestream2_get_byte(&c->stream) - 1) & 0xFF;
68    if (start + size > 255) {
69        av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
70        return;
71    }
72    if (size*3+2 > data_size) {
73        av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
74        return;
75    }
76    for (i = start; i <= start + size; i++)
77        c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&c->stream);
78}
79
80static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
81{
82    return buf >= start && buf < end;
83}
84
85static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
86{
87    return buf >= start && (buf + 4) <= end;
88}
89
90static int vb_decode_framedata(VBDecContext *c, int offset)
91{
92    GetByteContext g;
93    uint8_t *prev, *cur;
94    int blk, blocks, t, blk2;
95    int blocktypes = 0;
96    int x, y, a, b;
97    int pattype, pattern;
98    const int width = c->avctx->width;
99    uint8_t *pstart = c->prev_frame;
100    uint8_t *pend   = c->prev_frame + width*c->avctx->height;
101
102    g = c->stream;
103
104    prev = c->prev_frame + offset;
105    cur  = c->frame;
106
107    blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
108    blk2   = 0;
109    for (blk = 0; blk < blocks; blk++) {
110        if (!(blk & 3)) {
111            if (bytestream2_get_bytes_left(&g) < 1) {
112                av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
113                return AVERROR_INVALIDDATA;
114            }
115            blocktypes = bytestream2_get_byte(&g);
116        }
117        switch (blocktypes & 0xC0) {
118        case 0x00: //skip
119            for (y = 0; y < 4; y++)
120                if (check_line(prev + y*width, pstart, pend))
121                    memcpy(cur + y*width, prev + y*width, 4);
122                else
123                    memset(cur + y*width, 0, 4);
124            break;
125        case 0x40:
126            t = bytestream2_get_byte(&g);
127            if (!t) { //raw block
128                if (bytestream2_get_bytes_left(&g) < 16) {
129                    av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
130                    return AVERROR_INVALIDDATA;
131                }
132                for (y = 0; y < 4; y++)
133                    bytestream2_get_buffer(&g, cur + y * width, 4);
134            } else { // motion compensation
135                x = ((t & 0xF)^8) - 8;
136                y = ((t >> 4) ^8) - 8;
137                t = x + y*width;
138                for (y = 0; y < 4; y++)
139                    if (check_line(prev + t + y*width, pstart, pend))
140                        memcpy(cur + y*width, prev + t + y*width, 4);
141                    else
142                        memset(cur + y*width, 0, 4);
143            }
144            break;
145        case 0x80: // fill
146            t = bytestream2_get_byte(&g);
147            for (y = 0; y < 4; y++)
148                memset(cur + y*width, t, 4);
149            break;
150        case 0xC0: // pattern fill
151            t       = bytestream2_get_byte(&g);
152            pattype = t >> 6;
153            pattern = vb_patterns[t & 0x3F];
154            switch (pattype) {
155            case 0:
156                a = bytestream2_get_byte(&g);
157                b = bytestream2_get_byte(&g);
158                for (y = 0; y < 4; y++)
159                    for (x = 0; x < 4; x++, pattern >>= 1)
160                        cur[x + y*width] = (pattern & 1) ? b : a;
161                break;
162            case 1:
163                pattern = ~pattern;
164            case 2:
165                a = bytestream2_get_byte(&g);
166                for (y = 0; y < 4; y++)
167                    for (x = 0; x < 4; x++, pattern >>= 1)
168                        if (pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
169                            cur[x + y*width] = prev[x + y*width];
170                        else
171                            cur[x + y*width] = a;
172                break;
173            case 3:
174                av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n", blk);
175                return AVERROR_INVALIDDATA;
176            }
177            break;
178        }
179        blocktypes <<= 2;
180        cur  += 4;
181        prev += 4;
182        blk2++;
183        if (blk2 == (width >> 2)) {
184            blk2  = 0;
185            cur  += width * 3;
186            prev += width * 3;
187        }
188    }
189    return 0;
190}
191
192static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
193                        int *got_frame, AVPacket *avpkt)
194{
195    VBDecContext * const c = avctx->priv_data;
196    uint8_t *outptr, *srcptr;
197    int i, j, ret;
198    int flags;
199    uint32_t size;
200    int offset = 0;
201
202    if (avpkt->size < 2)
203        return AVERROR_INVALIDDATA;
204
205    bytestream2_init(&c->stream, avpkt->data, avpkt->size);
206
207    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
208        return ret;
209
210    flags = bytestream2_get_le16(&c->stream);
211
212    if (flags & VB_HAS_GMC) {
213        i = (int16_t)bytestream2_get_le16(&c->stream);
214        j = (int16_t)bytestream2_get_le16(&c->stream);
215        if (FFABS(j) > avctx->height) {
216            av_log(avctx, AV_LOG_ERROR, "GMV out of range\n");
217            return AVERROR_INVALIDDATA;
218        }
219        offset = i + j * avctx->width;
220    }
221    if (flags & VB_HAS_VIDEO) {
222        size = bytestream2_get_le32(&c->stream);
223        if(size > bytestream2_get_bytes_left(&c->stream)+4 || size<4){
224            av_log(avctx, AV_LOG_ERROR, "Frame size invalid\n");
225            return -1;
226        }
227        vb_decode_framedata(c, offset);
228        bytestream2_skip(&c->stream, size - 4);
229    }
230    if (flags & VB_HAS_PALETTE) {
231        size = bytestream2_get_le32(&c->stream);
232        vb_decode_palette(c, size);
233    }
234
235    memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
236    frame->palette_has_changed = flags & VB_HAS_PALETTE;
237
238    outptr = frame->data[0];
239    srcptr = c->frame;
240
241    for (i = 0; i < avctx->height; i++) {
242        memcpy(outptr, srcptr, avctx->width);
243        srcptr += avctx->width;
244        outptr += frame->linesize[0];
245    }
246
247    FFSWAP(uint8_t*, c->frame, c->prev_frame);
248
249    *got_frame = 1;
250
251    /* always report that the buffer was completely consumed */
252    return avpkt->size;
253}
254
255static av_cold int decode_init(AVCodecContext *avctx)
256{
257    VBDecContext * const c = avctx->priv_data;
258
259    c->avctx       = avctx;
260    avctx->pix_fmt = AV_PIX_FMT_PAL8;
261
262    c->frame      = av_mallocz(avctx->width * avctx->height);
263    c->prev_frame = av_mallocz(avctx->width * avctx->height);
264
265    if (!c->frame || !c->prev_frame)
266        return AVERROR(ENOMEM);
267
268    return 0;
269}
270
271static av_cold int decode_end(AVCodecContext *avctx)
272{
273    VBDecContext *c = avctx->priv_data;
274
275    av_freep(&c->frame);
276    av_freep(&c->prev_frame);
277
278    return 0;
279}
280
281const FFCodec ff_vb_decoder = {
282    .p.name         = "vb",
283    .p.long_name    = NULL_IF_CONFIG_SMALL("Beam Software VB"),
284    .p.type         = AVMEDIA_TYPE_VIDEO,
285    .p.id           = AV_CODEC_ID_VB,
286    .priv_data_size = sizeof(VBDecContext),
287    .init           = decode_init,
288    .close          = decode_end,
289    FF_CODEC_DECODE_CB(decode_frame),
290    .p.capabilities = AV_CODEC_CAP_DR1,
291    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
292};
293