FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/eatgv.c
Date: 2025-07-11 09:13:03
Exec Total Coverage
Lines: 153 181 84.5%
Functions: 5 5 100.0%
Branches: 83 112 74.1%
Line Branch Exec Source
1 /*
2 * Electronic Arts TGV Video Decoder
3 * Copyright (c) 2007-2008 Peter Ross
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 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 "libavutil/mem.h"
32
33 #define BITSTREAM_READER_LE
34 #include "avcodec.h"
35 #include "get_bits.h"
36 #include "codec_internal.h"
37 #include "decode.h"
38
39 #define EA_PREAMBLE_SIZE 8
40 #define kVGT_TAG MKTAG('k', 'V', 'G', 'T')
41
42 typedef struct TgvContext {
43 AVCodecContext *avctx;
44 AVFrame *last_frame;
45 uint8_t *frame_buffer;
46 int width,height;
47 uint32_t palette[AVPALETTE_COUNT];
48
49 int (*mv_codebook)[2];
50 uint8_t (*block_codebook)[16];
51 int num_mvs; ///< current length of mv_codebook
52 int num_blocks_packed; ///< current length of block_codebook
53 } TgvContext;
54
55 6 static av_cold int tgv_decode_init(AVCodecContext *avctx)
56 {
57 6 TgvContext *s = avctx->priv_data;
58 6 s->avctx = avctx;
59 6 avctx->framerate = (AVRational){ 15, 1 };
60 6 avctx->pix_fmt = AV_PIX_FMT_PAL8;
61
62 6 s->last_frame = av_frame_alloc();
63
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 6 if (!s->last_frame)
64 ✗ return AVERROR(ENOMEM);
65
66 6 return 0;
67 }
68
69 /**
70 * Unpack buffer
71 * @return 0 on success, -1 on critical buffer underflow
72 */
73 11 static int unpack(const uint8_t *src, const uint8_t *src_end,
74 uint8_t *dst, int width, int height)
75 {
76 11 uint8_t *dst_end = dst + width*height;
77 int size, size1, size2, offset, run;
78 11 uint8_t *dst_start = dst;
79
80
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 11 if (src[0] & 0x01)
81 ✗ src += 5;
82 else
83 11 src += 2;
84
85
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 11 if (src_end - src < 3)
86 ✗ return AVERROR_INVALIDDATA;
87 11 size = AV_RB24(src);
88 11 src += 3;
89
90
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 102029 while (size > 0 && src < src_end) {
91
92 /* determine size1 and size2 */
93 102018 size1 = (src[0] & 3);
94
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 102018 if (src[0] & 0x80) { // 1
95
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 49446 if (src[0] & 0x40 ) { // 11
96
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 15234 if (src[0] & 0x20) { // 111
97
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 10712 if (src[0] < 0xFC) // !(111111)
98 10704 size1 = (((src[0] & 31) + 1) << 2);
99 10712 src++;
100 10712 size2 = 0;
101 } else { // 110
102 4522 offset = ((src[0] & 0x10) << 12) + AV_RB16(&src[1]) + 1;
103 4522 size2 = ((src[0] & 0xC) << 6) + src[3] + 5;
104 4522 src += 4;
105 }
106 } else { // 10
107 34212 size1 = ((src[1] & 0xC0) >> 6);
108 34212 offset = (AV_RB16(&src[1]) & 0x3FFF) + 1;
109 34212 size2 = (src[0] & 0x3F) + 4;
110 34212 src += 3;
111 }
112 } else { // 0
113 52572 offset = ((src[0] & 0x60) << 3) + src[1] + 1;
114 52572 size2 = ((src[0] & 0x1C) >> 2) + 3;
115 52572 src += 2;
116 }
117
118
119 /* fetch strip from src */
120
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 102018 if (size1 > src_end - src)
121 ✗ break;
122
123
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 102018 if (size1 > 0) {
124 35301 size -= size1;
125 35301 run = FFMIN(size1, dst_end - dst);
126 35301 memcpy(dst, src, run);
127 35301 dst += run;
128 35301 src += run;
129 }
130
131
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 102018 if (size2 > 0) {
132
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 91306 if (dst - dst_start < offset)
133 ✗ return 0;
134 91306 size -= size2;
135 91306 run = FFMIN(size2, dst_end - dst);
136 91306 av_memcpy_backptr(dst, offset, run);
137 91306 dst += run;
138 }
139 }
140
141 11 return 0;
142 }
143
144 /**
145 * Decode inter-frame
146 * @return 0 on success, -1 on critical buffer underflow
147 */
148 79 static int tgv_decode_inter(TgvContext *s, AVFrame *frame,
149 const uint8_t *buf, const uint8_t *buf_end)
150 {
151 int num_mvs;
152 int num_blocks_raw;
153 int num_blocks_packed;
154 int vector_bits;
155 int i,j,x,y;
156 GetBitContext gb;
157 int mvbits;
158 const uint8_t *blocks_raw;
159
160
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 79 if(buf_end - buf < 12)
161 ✗ return AVERROR_INVALIDDATA;
162
163 79 num_mvs = AV_RL16(&buf[0]);
164 79 num_blocks_raw = AV_RL16(&buf[2]);
165 79 num_blocks_packed = AV_RL16(&buf[4]);
166 79 vector_bits = AV_RL16(&buf[6]);
167 79 buf += 12;
168
169
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 79 if (vector_bits > MIN_CACHE_BITS || !vector_bits) {
170 ✗ av_log(s->avctx, AV_LOG_ERROR,
171 "Invalid value for motion vector bits: %d\n", vector_bits);
172 ✗ return AVERROR_INVALIDDATA;
173 }
174
175 /* allocate codebook buffers as necessary */
176
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 79 if (num_mvs > s->num_mvs) {
177 8 int err = av_reallocp_array(&s->mv_codebook, num_mvs, sizeof(*s->mv_codebook));
178
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 8 if (err < 0) {
179 ✗ s->num_mvs = 0;
180 ✗ return err;
181 }
182 8 s->num_mvs = num_mvs;
183 }
184
185
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 79 if (num_blocks_packed > s->num_blocks_packed) {
186 int err;
187
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 7 if ((err = av_reallocp(&s->block_codebook, num_blocks_packed * 16)) < 0) {
188 ✗ s->num_blocks_packed = 0;
189 ✗ return err;
190 }
191 7 s->num_blocks_packed = num_blocks_packed;
192 }
193
194 /* read motion vectors */
195 79 mvbits = (num_mvs * 2 * 10 + 31) & ~31;
196
197
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 79 if (buf_end - buf < (mvbits>>3) + 16*num_blocks_raw + 8*num_blocks_packed)
198 ✗ return AVERROR_INVALIDDATA;
199
200 79 init_get_bits(&gb, buf, mvbits);
201
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 13453 for (i = 0; i < num_mvs; i++) {
202 13374 s->mv_codebook[i][0] = get_sbits(&gb, 10);
203 13374 s->mv_codebook[i][1] = get_sbits(&gb, 10);
204 }
205 79 buf += mvbits >> 3;
206
207 /* note ptr to uncompressed blocks */
208 79 blocks_raw = buf;
209 79 buf += num_blocks_raw * 16;
210
211 /* read compressed blocks */
212 79 init_get_bits(&gb, buf, (buf_end - buf) << 3);
213
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 31502 for (i = 0; i < num_blocks_packed; i++) {
214 int tmp[4];
215
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 157115 for (j = 0; j < 4; j++)
216 125692 tmp[j] = get_bits(&gb, 8);
217
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 534191 for (j = 0; j < 16; j++)
218 502768 s->block_codebook[i][15-j] = tmp[get_bits(&gb, 2)];
219 }
220
221 79 if (get_bits_left(&gb) < vector_bits *
222
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 79 (s->avctx->height / 4) * (s->avctx->width / 4))
223 1 return AVERROR_INVALIDDATA;
224
225 /* read vectors and build frame */
226
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 4418 for (y = 0; y < s->avctx->height / 4; y++)
227
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 351540 for (x = 0; x < s->avctx->width / 4; x++) {
228 347200 unsigned int vector = get_bits(&gb, vector_bits);
229 const uint8_t *src;
230 ptrdiff_t src_stride;
231
232
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 347200 if (vector < num_mvs) {
233 293708 int mx = x * 4 + s->mv_codebook[vector][0];
234 293708 int my = y * 4 + s->mv_codebook[vector][1];
235
236
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 293708 if (mx < 0 || mx + 4 > s->avctx->width ||
237
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 293708 my < 0 || my + 4 > s->avctx->height) {
238 ✗ av_log(s->avctx, AV_LOG_ERROR, "MV %d %d out of picture\n", mx, my);
239 ✗ continue;
240 }
241
242 293708 src = s->last_frame->data[0] + mx + my * s->last_frame->linesize[0];
243 293708 src_stride = s->last_frame->linesize[0];
244 } else {
245 53492 int offset = vector - num_mvs;
246
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 53492 if (offset < num_blocks_raw)
247 5411 src = blocks_raw + 16*offset;
248
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 48081 else if (offset - num_blocks_raw < num_blocks_packed)
249 48081 src = s->block_codebook[offset - num_blocks_raw];
250 else
251 ✗ continue;
252 53492 src_stride = 4;
253 }
254
255
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256
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257 5555200 frame->data[0][(y * 4 + j) * frame->linesize[0] + (x * 4 + i)] =
258 5555200 src[j * src_stride + i];
259 }
260
261 78 return 0;
262 }
263
264 90 static int tgv_decode_frame(AVCodecContext *avctx, AVFrame *frame,
265 int *got_frame, AVPacket *avpkt)
266 {
267 90 const uint8_t *buf = avpkt->data;
268 90 int buf_size = avpkt->size;
269 90 TgvContext *s = avctx->priv_data;
270 90 const uint8_t *buf_end = buf + buf_size;
271 int chunk_type, ret;
272
273
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 90 if (buf_end - buf < EA_PREAMBLE_SIZE)
274 ✗ return AVERROR_INVALIDDATA;
275
276 90 chunk_type = AV_RL32(&buf[0]);
277 90 buf += EA_PREAMBLE_SIZE;
278
279
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 90 if (chunk_type == kVGT_TAG) {
280 int pal_count, i;
281
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 11 if(buf_end - buf < 12) {
282 ✗ av_log(avctx, AV_LOG_WARNING, "truncated header\n");
283 ✗ return AVERROR_INVALIDDATA;
284 }
285
286 11 s->width = AV_RL16(&buf[0]);
287 11 s->height = AV_RL16(&buf[2]);
288
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 11 if (s->avctx->width != s->width || s->avctx->height != s->height) {
289 4 av_freep(&s->frame_buffer);
290 4 av_frame_unref(s->last_frame);
291
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 4 if ((ret = ff_set_dimensions(s->avctx, s->width, s->height)) < 0)
292 ✗ return ret;
293 }
294
295 11 pal_count = AV_RL16(&buf[6]);
296 11 buf += 12;
297
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 2827 for(i = 0; i < pal_count && i < AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
298 2816 s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
299 2816 buf += 3;
300 }
301
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 11 if (buf_end - buf < 5) {
302 ✗ return AVERROR_INVALIDDATA;
303 }
304 }
305
306
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 90 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
307 ✗ return ret;
308
309 90 memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
310
311
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 90 if (chunk_type == kVGT_TAG) {
312 int y;
313 11 frame->flags |= AV_FRAME_FLAG_KEY;
314 11 frame->pict_type = AV_PICTURE_TYPE_I;
315
316
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 11 if (!s->frame_buffer &&
317
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 6 !(s->frame_buffer = av_mallocz(s->width * s->height)))
318 ✗ return AVERROR(ENOMEM);
319
320
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 11 if (unpack(buf, buf_end, s->frame_buffer, s->avctx->width, s->avctx->height) < 0) {
321 ✗ av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n");
322 ✗ return AVERROR_INVALIDDATA;
323 }
324
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 2411 for (y = 0; y < s->height; y++)
325 2400 memcpy(frame->data[0] + y * frame->linesize[0],
326 2400 s->frame_buffer + y * s->width,
327 2400 s->width);
328 } else {
329
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 79 if (!s->last_frame->data[0]) {
330 ✗ av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n");
331 ✗ return buf_size;
332 }
333 79 frame->flags &= ~AV_FRAME_FLAG_KEY;
334 79 frame->pict_type = AV_PICTURE_TYPE_P;
335
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 79 if (tgv_decode_inter(s, frame, buf, buf_end) < 0) {
336 1 av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n");
337 1 return AVERROR_INVALIDDATA;
338 }
339 }
340
341
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 89 if ((ret = av_frame_replace(s->last_frame, frame)) < 0)
342 ✗ return ret;
343
344 89 *got_frame = 1;
345
346 89 return buf_size;
347 }
348
349 6 static av_cold int tgv_decode_end(AVCodecContext *avctx)
350 {
351 6 TgvContext *s = avctx->priv_data;
352 6 av_frame_free(&s->last_frame);
353 6 av_freep(&s->frame_buffer);
354 6 av_freep(&s->mv_codebook);
355 6 av_freep(&s->block_codebook);
356 6 return 0;
357 }
358
359 const FFCodec ff_eatgv_decoder = {
360 .p.name = "eatgv",
361 CODEC_LONG_NAME("Electronic Arts TGV video"),
362 .p.type = AVMEDIA_TYPE_VIDEO,
363 .p.id = AV_CODEC_ID_TGV,
364 .priv_data_size = sizeof(TgvContext),
365 .init = tgv_decode_init,
366 .close = tgv_decode_end,
367 FF_CODEC_DECODE_CB(tgv_decode_frame),
368 .p.capabilities = AV_CODEC_CAP_DR1,
369 };
370