FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/eamad.c
Date: 2025-07-15 08:12:33
Exec Total Coverage
Lines: 147 174 84.5%
Functions: 10 10 100.0%
Branches: 66 88 75.0%
Line Branch Exec Source
1 /*
2 * Electronic Arts Madcow Video Decoder
3 * Copyright (c) 2007-2009 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 Madcow Video Decoder
25 * @author Peter Ross <pross@xvid.org>
26 *
27 * @see technical details at
28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD
29 */
30
31 #include "libavutil/mem.h"
32 #include "libavutil/mem_internal.h"
33
34 #include "avcodec.h"
35 #include "blockdsp.h"
36 #include "bytestream.h"
37 #include "bswapdsp.h"
38 #include "codec_internal.h"
39 #include "decode.h"
40 #include "get_bits.h"
41 #include "aandcttab.h"
42 #include "eaidct.h"
43 #include "mpeg12data.h"
44 #include "mpeg12vlc.h"
45
46 #define EA_PREAMBLE_SIZE 8
47 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD I-frame */
48 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD P-frame */
49 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
50
51 typedef struct MadContext {
52 AVCodecContext *avctx;
53 BlockDSPContext bdsp;
54 BswapDSPContext bbdsp;
55 AVFrame *last_frame;
56 GetBitContext gb;
57 void *bitstream_buf;
58 unsigned int bitstream_buf_size;
59 DECLARE_ALIGNED(32, int16_t, block)[64];
60 uint16_t quant_matrix[64];
61 } MadContext;
62
63 4 static av_cold int decode_init(AVCodecContext *avctx)
64 {
65 4 MadContext *s = avctx->priv_data;
66 4 s->avctx = avctx;
67 4 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
68 4 ff_blockdsp_init(&s->bdsp);
69 4 ff_bswapdsp_init(&s->bbdsp);
70 4 ff_mpeg12_init_vlcs();
71
72 4 s->last_frame = av_frame_alloc();
73
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 4 if (!s->last_frame)
74 ✗ return AVERROR(ENOMEM);
75
76 4 return 0;
77 }
78
79 665174 static inline void comp(unsigned char *dst, ptrdiff_t dst_stride,
80 unsigned char *src, ptrdiff_t src_stride, int add)
81 {
82 int j, i;
83
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 5986566 for (j=0; j<8; j++)
84
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 47892528 for (i=0; i<8; i++)
85 42571136 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
86 665174 }
87
88 665174 static inline void comp_block(MadContext *t, AVFrame *frame,
89 int mb_x, int mb_y,
90 int j, int mv_x, int mv_y, int add)
91 {
92
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 665174 if (j < 4) {
93 437978 unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
94
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 437978 if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7)
95 ✗ return;
96 437978 comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
97 437978 frame->linesize[0],
98 437978 t->last_frame->data[0] + offset,
99 437978 t->last_frame->linesize[0], add);
100
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 227196 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
101 227196 int index = j - 3;
102 227196 unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2);
103
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 227196 if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7)
104 ✗ return;
105 227196 comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
106 227196 frame->linesize[index],
107 227196 t->last_frame->data[index] + offset,
108 227196 t->last_frame->linesize[index], add);
109 }
110 }
111
112 158158 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
113 int mb_x, int mb_y, int j)
114 {
115
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 158158 if (j < 4) {
116 110910 ff_ea_idct_put_c(
117 110910 frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
118 110910 frame->linesize[0], block);
119
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 47248 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
120 47248 int index = j - 3;
121 47248 ff_ea_idct_put_c(
122 47248 frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
123 47248 frame->linesize[index], block);
124 }
125 158158 }
126
127 158158 static inline int decode_block_intra(MadContext *s, int16_t * block)
128 {
129 int level, i, j, run;
130 158158 const uint8_t *scantable = ff_zigzag_direct;
131 158158 int16_t *quant_matrix = s->quant_matrix;
132
133 158158 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
134
135 /* The RL decoder is derived from mpeg1_decode_block_intra;
136 Escaped level and run values a decoded differently */
137 158158 i = 0;
138 {
139 158158 OPEN_READER(re, &s->gb);
140 /* now quantify & encode AC coefficients */
141 for (;;) {
142 2066278 UPDATE_CACHE(re, &s->gb);
143
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 1112218 GET_RL_VLC(level, run, re, &s->gb, ff_mpeg1_rl_vlc, TEX_VLC_BITS, 2, 0);
144
145
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 1112218 if (level == 127) {
146 158158 break;
147
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 954060 } else if (level != 0) {
148 913987 i += run;
149
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 913987 if (i > 63)
150 ✗ return -1;
151 913987 j = scantable[i];
152 913987 level = (level*quant_matrix[j]) >> 4;
153 913987 level = (level-1)|1;
154 913987 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
155 913987 LAST_SKIP_BITS(re, &s->gb, 1);
156 } else {
157 /* escape */
158 40073 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
159
160 40073 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
161
162 40073 i += run;
163
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 40073 if (i > 63)
164 ✗ return -1;
165 40073 j = scantable[i];
166
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 40073 if (level < 0) {
167 20920 level = -level;
168 20920 level = (level*quant_matrix[j]) >> 4;
169 20920 level = (level-1)|1;
170 20920 level = -level;
171 } else {
172 19153 level = (level*quant_matrix[j]) >> 4;
173 19153 level = (level-1)|1;
174 }
175 }
176
177 954060 block[j] = level;
178 }
179 158158 CLOSE_READER(re, &s->gb);
180 }
181 158158 return 0;
182 }
183
184 897656 static int decode_motion(GetBitContext *gb)
185 {
186 897656 int value = 0;
187
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 897656 if (get_bits1(gb)) {
188
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 300433 if (get_bits1(gb))
189 163614 value = -17;
190 300433 value += get_bits(gb, 4) + 1;
191 }
192 897656 return value;
193 }
194
195 137222 static int decode_mb(MadContext *s, AVFrame *frame, int inter, int mb_x, int mb_y)
196 {
197 137222 int mv_map = 0;
198 137222 int av_uninit(mv_x), av_uninit(mv_y);
199 int j;
200
201
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 137222 if (inter) {
202 119970 int v = decode210(&s->gb);
203
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 119970 if (v < 2) {
204
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 116241 mv_map = v ? get_bits(&s->gb, 6) : 63;
205 116241 mv_x = decode_motion(&s->gb);
206 116241 mv_y = decode_motion(&s->gb);
207 }
208 }
209
210
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 960554 for (j=0; j<6; j++) {
211
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 823332 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
212 665174 int add = 2*decode_motion(&s->gb);
213
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 665174 if (s->last_frame->data[0])
214 665174 comp_block(s, frame, mb_x, mb_y, j, mv_x, mv_y, add);
215 } else {
216 158158 s->bdsp.clear_block(s->block);
217
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 158158 if (decode_block_intra(s, s->block) < 0) {
218 ✗ av_log(s->avctx, AV_LOG_ERROR,
219 "ac-tex damaged at %d %d\n", mb_x, mb_y);
220 ✗ return -1;
221 }
222 158158 idct_put(s, frame, s->block, mb_x, mb_y, j);
223 }
224 }
225 137222 return 0;
226 }
227
228 99 static void calc_quant_matrix(MadContext *s, int qscale)
229 {
230 int i;
231
232 99 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
233
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 6336 for (i=1; i<64; i++)
234 6237 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
235 99 }
236
237 99 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
238 int *got_frame, AVPacket *avpkt)
239 {
240 99 const uint8_t *buf = avpkt->data;
241 99 int buf_size = avpkt->size;
242 99 MadContext *s = avctx->priv_data;
243 GetByteContext gb;
244 int width, height;
245 int chunk_type;
246 int inter, ret;
247
248 99 bytestream2_init(&gb, buf, buf_size);
249
250 99 chunk_type = bytestream2_get_le32(&gb);
251
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 99 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
252 99 bytestream2_skip(&gb, 10);
253
254 99 av_reduce(&avctx->framerate.den, &avctx->framerate.num,
255 99 bytestream2_get_le16(&gb), 1000, 1<<30);
256
257 99 width = bytestream2_get_le16(&gb);
258 99 height = bytestream2_get_le16(&gb);
259 99 bytestream2_skip(&gb, 1);
260 99 calc_quant_matrix(s, bytestream2_get_byte(&gb));
261 99 bytestream2_skip(&gb, 2);
262
263
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 99 if (bytestream2_get_bytes_left(&gb) < 2) {
264 ✗ av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
265 ✗ return AVERROR_INVALIDDATA;
266 }
267
268
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 99 if (width < 16 || height < 16) {
269 ✗ av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
270 ✗ return AVERROR_INVALIDDATA;
271 }
272
273
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 99 if (avctx->width != width || avctx->height != height) {
274 3 av_frame_unref(s->last_frame);
275
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 3 if((width * (int64_t)height)/2048*7 > bytestream2_get_bytes_left(&gb))
276 ✗ return AVERROR_INVALIDDATA;
277
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 3 if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
278 ✗ return ret;
279 }
280
281
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 99 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
282 ✗ return ret;
283
284
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 99 if (inter && !s->last_frame->data[0]) {
285 ✗ av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
286 ✗ ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
287 ✗ if (ret < 0)
288 ✗ return ret;
289 ✗ memset(s->last_frame->data[0], 0, s->last_frame->height *
290 ✗ s->last_frame->linesize[0]);
291 ✗ memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
292 ✗ s->last_frame->linesize[1]);
293 ✗ memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
294 ✗ s->last_frame->linesize[2]);
295 }
296
297 99 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
298 99 bytestream2_get_bytes_left(&gb));
299
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 99 if (!s->bitstream_buf)
300 ✗ return AVERROR(ENOMEM);
301 99 s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
302 99 bytestream2_get_bytes_left(&gb) / 2);
303 99 memset((uint8_t*)s->bitstream_buf + bytestream2_get_bytes_left(&gb), 0, AV_INPUT_BUFFER_PADDING_SIZE);
304 99 init_get_bits(&s->gb, s->bitstream_buf, 8*(bytestream2_get_bytes_left(&gb)));
305
306
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 3153 for (int mb_y = 0; mb_y < (avctx->height + 15) / 16; mb_y++)
307
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308
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 137222 if (decode_mb(s, frame, inter, mb_x, mb_y) < 0)
309 ✗ return AVERROR_INVALIDDATA;
310
311 99 *got_frame = 1;
312
313
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 99 if (chunk_type != MADe_TAG) {
314
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 51 if ((ret = av_frame_replace(s->last_frame, frame)) < 0)
315 ✗ return ret;
316 }
317
318 99 return buf_size;
319 }
320
321 4 static av_cold int decode_end(AVCodecContext *avctx)
322 {
323 4 MadContext *t = avctx->priv_data;
324 4 av_frame_free(&t->last_frame);
325 4 av_freep(&t->bitstream_buf);
326 4 return 0;
327 }
328
329 const FFCodec ff_eamad_decoder = {
330 .p.name = "eamad",
331 CODEC_LONG_NAME("Electronic Arts Madcow Video"),
332 .p.type = AVMEDIA_TYPE_VIDEO,
333 .p.id = AV_CODEC_ID_MAD,
334 .priv_data_size = sizeof(MadContext),
335 .init = decode_init,
336 .close = decode_end,
337 FF_CODEC_DECODE_CB(decode_frame),
338 .p.capabilities = AV_CODEC_CAP_DR1,
339 };
340