170eeb10d54cae8b4d01039df070159b71bdcb0a
[libav.git] / libavcodec / eatgv.c
1 /*
2 * Electronic Arts TGV Video Decoder
3 * Copyright (c) 2007-2008 Peter Ross
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 TGV Video Decoder
25 * by Peter Ross (pross@xvid.org)
26 *
27 * Technical details here:
28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGV
29 */
30
31 #include "avcodec.h"
32 #define BITSTREAM_READER_LE
33 #include "get_bits.h"
34 #include "libavutil/imgutils.h"
35 #include "libavutil/mem.h"
36
37 #define EA_PREAMBLE_SIZE 8
38 #define kVGT_TAG MKTAG('k', 'V', 'G', 'T')
39
40 typedef struct TgvContext {
41 AVCodecContext *avctx;
42 AVFrame frame;
43 AVFrame last_frame;
44 int width,height;
45 unsigned int palette[AVPALETTE_COUNT];
46
47 int (*mv_codebook)[2];
48 unsigned char (*block_codebook)[16];
49 int num_mvs; ///< current length of mv_codebook
50 int num_blocks_packed; ///< current length of block_codebook
51 } TgvContext;
52
53 static av_cold int tgv_decode_init(AVCodecContext *avctx){
54 TgvContext *s = avctx->priv_data;
55 s->avctx = avctx;
56 avctx->time_base = (AVRational){1, 15};
57 avctx->pix_fmt = AV_PIX_FMT_PAL8;
58 return 0;
59 }
60
61 /**
62 * Unpack buffer
63 * @return 0 on success, -1 on critical buffer underflow
64 */
65 static int unpack(const uint8_t *src, const uint8_t *src_end, unsigned char *dst, int width, int height) {
66 unsigned char *dst_end = dst + width*height;
67 int size, size1, size2, offset, run;
68 unsigned char *dst_start = dst;
69
70 if (src[0] & 0x01)
71 src += 5;
72 else
73 src += 2;
74
75 if (src+3>src_end)
76 return -1;
77 size = AV_RB24(src);
78 src += 3;
79
80 while(size>0 && src<src_end) {
81
82 /* determine size1 and size2 */
83 size1 = (src[0] & 3);
84 if ( src[0] & 0x80 ) { // 1
85 if (src[0] & 0x40 ) { // 11
86 if ( src[0] & 0x20 ) { // 111
87 if ( src[0] < 0xFC ) // !(111111)
88 size1 = (((src[0] & 31) + 1) << 2);
89 src++;
90 size2 = 0;
91 } else { // 110
92 offset = ((src[0] & 0x10) << 12) + AV_RB16(&src[1]) + 1;
93 size2 = ((src[0] & 0xC) << 6) + src[3] + 5;
94 src += 4;
95 }
96 } else { // 10
97 size1 = ( ( src[1] & 0xC0) >> 6 );
98 offset = (AV_RB16(&src[1]) & 0x3FFF) + 1;
99 size2 = (src[0] & 0x3F) + 4;
100 src += 3;
101 }
102 } else { // 0
103 offset = ((src[0] & 0x60) << 3) + src[1] + 1;
104 size2 = ((src[0] & 0x1C) >> 2) + 3;
105 src += 2;
106 }
107
108
109 /* fetch strip from src */
110 if (size1>src_end-src)
111 break;
112
113 if (size1>0) {
114 size -= size1;
115 run = FFMIN(size1, dst_end-dst);
116 memcpy(dst, src, run);
117 dst += run;
118 src += run;
119 }
120
121 if (size2>0) {
122 if (dst-dst_start<offset)
123 return 0;
124 size -= size2;
125 run = FFMIN(size2, dst_end-dst);
126 av_memcpy_backptr(dst, offset, run);
127 dst += run;
128 }
129 }
130
131 return 0;
132 }
133
134 /**
135 * Decode inter-frame
136 * @return 0 on success, -1 on critical buffer underflow
137 */
138 static int tgv_decode_inter(TgvContext * s, const uint8_t *buf, const uint8_t *buf_end){
139 int num_mvs;
140 int num_blocks_raw;
141 int num_blocks_packed;
142 int vector_bits;
143 int i,j,x,y;
144 GetBitContext gb;
145 int mvbits;
146 const unsigned char *blocks_raw;
147
148 if(buf+12>buf_end)
149 return -1;
150
151 num_mvs = AV_RL16(&buf[0]);
152 num_blocks_raw = AV_RL16(&buf[2]);
153 num_blocks_packed = AV_RL16(&buf[4]);
154 vector_bits = AV_RL16(&buf[6]);
155 buf += 12;
156
157 if (vector_bits > MIN_CACHE_BITS || !vector_bits) {
158 av_log(s->avctx, AV_LOG_ERROR,
159 "Invalid value for motion vector bits: %d\n", vector_bits);
160 return AVERROR_INVALIDDATA;
161 }
162
163 /* allocate codebook buffers as necessary */
164 if (num_mvs > s->num_mvs) {
165 s->mv_codebook = av_realloc(s->mv_codebook, num_mvs*2*sizeof(int));
166 s->num_mvs = num_mvs;
167 }
168
169 if (num_blocks_packed > s->num_blocks_packed) {
170 s->block_codebook = av_realloc(s->block_codebook, num_blocks_packed*16*sizeof(unsigned char));
171 s->num_blocks_packed = num_blocks_packed;
172 }
173
174 /* read motion vectors */
175 mvbits = (num_mvs*2*10+31) & ~31;
176
177 if (buf+(mvbits>>3)+16*num_blocks_raw+8*num_blocks_packed>buf_end)
178 return -1;
179
180 init_get_bits(&gb, buf, mvbits);
181 for (i=0; i<num_mvs; i++) {
182 s->mv_codebook[i][0] = get_sbits(&gb, 10);
183 s->mv_codebook[i][1] = get_sbits(&gb, 10);
184 }
185 buf += mvbits>>3;
186
187 /* note ptr to uncompressed blocks */
188 blocks_raw = buf;
189 buf += num_blocks_raw*16;
190
191 /* read compressed blocks */
192 init_get_bits(&gb, buf, (buf_end-buf)<<3);
193 for (i=0; i<num_blocks_packed; i++) {
194 int tmp[4];
195 for(j=0; j<4; j++)
196 tmp[j] = get_bits(&gb, 8);
197 for(j=0; j<16; j++)
198 s->block_codebook[i][15-j] = tmp[get_bits(&gb, 2)];
199 }
200
201 if (get_bits_left(&gb) < vector_bits *
202 (s->avctx->height/4) * (s->avctx->width/4))
203 return -1;
204
205 /* read vectors and build frame */
206 for(y=0; y<s->avctx->height/4; y++)
207 for(x=0; x<s->avctx->width/4; x++) {
208 unsigned int vector = get_bits(&gb, vector_bits);
209 const unsigned char *src;
210 int src_stride;
211
212 if (vector < num_mvs) {
213 int mx = x * 4 + s->mv_codebook[vector][0];
214 int my = y * 4 + s->mv_codebook[vector][1];
215
216 if ( mx < 0 || mx + 4 > s->avctx->width
217 || my < 0 || my + 4 > s->avctx->height)
218 continue;
219
220 src = s->last_frame.data[0] + mx + my * s->last_frame.linesize[0];
221 src_stride = s->last_frame.linesize[0];
222 }else{
223 int offset = vector - num_mvs;
224 if (offset<num_blocks_raw)
225 src = blocks_raw + 16*offset;
226 else if (offset-num_blocks_raw<num_blocks_packed)
227 src = s->block_codebook[offset-num_blocks_raw];
228 else
229 continue;
230 src_stride = 4;
231 }
232
233 for(j=0; j<4; j++)
234 for(i=0; i<4; i++)
235 s->frame.data[0][ (y*4+j)*s->frame.linesize[0] + (x*4+i) ] =
236 src[j*src_stride + i];
237 }
238
239 return 0;
240 }
241
242 /** release AVFrame buffers if allocated */
243 static void cond_release_buffer(AVFrame *pic)
244 {
245 if (pic->data[0]) {
246 av_freep(&pic->data[0]);
247 av_free(pic->data[1]);
248 }
249 }
250
251 static int tgv_decode_frame(AVCodecContext *avctx,
252 void *data, int *data_size,
253 AVPacket *avpkt)
254 {
255 const uint8_t *buf = avpkt->data;
256 int buf_size = avpkt->size;
257 TgvContext *s = avctx->priv_data;
258 const uint8_t *buf_end = buf + buf_size;
259 int chunk_type;
260
261 chunk_type = AV_RL32(&buf[0]);
262 buf += EA_PREAMBLE_SIZE;
263
264 if (chunk_type==kVGT_TAG) {
265 int pal_count, i;
266 if(buf+12>buf_end) {
267 av_log(avctx, AV_LOG_WARNING, "truncated header\n");
268 return -1;
269 }
270
271 s->width = AV_RL16(&buf[0]);
272 s->height = AV_RL16(&buf[2]);
273 if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
274 avcodec_set_dimensions(s->avctx, s->width, s->height);
275 cond_release_buffer(&s->frame);
276 cond_release_buffer(&s->last_frame);
277 }
278
279 pal_count = AV_RL16(&buf[6]);
280 buf += 12;
281 for(i=0; i<pal_count && i<AVPALETTE_COUNT && buf+2<buf_end; i++) {
282 s->palette[i] = AV_RB24(buf);
283 buf += 3;
284 }
285 }
286
287 if (av_image_check_size(s->width, s->height, 0, avctx))
288 return -1;
289
290 /* shuffle */
291 FFSWAP(AVFrame, s->frame, s->last_frame);
292 if (!s->frame.data[0]) {
293 s->frame.reference = 1;
294 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
295 s->frame.linesize[0] = s->width;
296
297 s->frame.data[0] = av_malloc(s->width * s->height);
298 if (!s->frame.data[0])
299 return AVERROR(ENOMEM);
300 s->frame.data[1] = av_malloc(AVPALETTE_SIZE);
301 if (!s->frame.data[1]) {
302 av_freep(&s->frame.data[0]);
303 return AVERROR(ENOMEM);
304 }
305 }
306 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
307
308 if(chunk_type==kVGT_TAG) {
309 s->frame.key_frame = 1;
310 s->frame.pict_type = AV_PICTURE_TYPE_I;
311 if (unpack(buf, buf_end, s->frame.data[0], s->avctx->width, s->avctx->height)<0) {
312 av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n");
313 return -1;
314 }
315 }else{
316 if (!s->last_frame.data[0]) {
317 av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n");
318 return buf_size;
319 }
320 s->frame.key_frame = 0;
321 s->frame.pict_type = AV_PICTURE_TYPE_P;
322 if (tgv_decode_inter(s, buf, buf_end)<0) {
323 av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n");
324 return -1;
325 }
326 }
327
328 *data_size = sizeof(AVFrame);
329 *(AVFrame*)data = s->frame;
330
331 return buf_size;
332 }
333
334 static av_cold int tgv_decode_end(AVCodecContext *avctx)
335 {
336 TgvContext *s = avctx->priv_data;
337 cond_release_buffer(&s->frame);
338 cond_release_buffer(&s->last_frame);
339 av_free(s->mv_codebook);
340 av_free(s->block_codebook);
341 return 0;
342 }
343
344 AVCodec ff_eatgv_decoder = {
345 .name = "eatgv",
346 .type = AVMEDIA_TYPE_VIDEO,
347 .id = AV_CODEC_ID_TGV,
348 .priv_data_size = sizeof(TgvContext),
349 .init = tgv_decode_init,
350 .close = tgv_decode_end,
351 .decode = tgv_decode_frame,
352 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGV video"),
353 };