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path: root/libavcodec/eamad.c (plain)
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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 "avcodec.h"
32#include "blockdsp.h"
33#include "bytestream.h"
34#include "bswapdsp.h"
35#include "get_bits.h"
36#include "aandcttab.h"
37#include "eaidct.h"
38#include "idctdsp.h"
39#include "internal.h"
40#include "mpeg12data.h"
41#include "mpeg12vlc.h"
42
43#define EA_PREAMBLE_SIZE 8
44#define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD I-frame */
45#define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD P-frame */
46#define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
47
48typedef struct MadContext {
49 AVCodecContext *avctx;
50 BlockDSPContext bdsp;
51 BswapDSPContext bbdsp;
52 IDCTDSPContext idsp;
53 AVFrame *last_frame;
54 GetBitContext gb;
55 void *bitstream_buf;
56 unsigned int bitstream_buf_size;
57 DECLARE_ALIGNED(16, int16_t, block)[64];
58 ScanTable scantable;
59 uint16_t quant_matrix[64];
60 int mb_x;
61 int mb_y;
62} MadContext;
63
64static av_cold int decode_init(AVCodecContext *avctx)
65{
66 MadContext *s = avctx->priv_data;
67 s->avctx = avctx;
68 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
69 ff_blockdsp_init(&s->bdsp, avctx);
70 ff_bswapdsp_init(&s->bbdsp);
71 ff_idctdsp_init(&s->idsp, avctx);
72 ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
73 ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
74 ff_mpeg12_init_vlcs();
75
76 s->last_frame = av_frame_alloc();
77 if (!s->last_frame)
78 return AVERROR(ENOMEM);
79
80 return 0;
81}
82
83static inline void comp(unsigned char *dst, ptrdiff_t dst_stride,
84 unsigned char *src, ptrdiff_t src_stride, int add)
85{
86 int j, i;
87 for (j=0; j<8; j++)
88 for (i=0; i<8; i++)
89 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
90}
91
92static inline void comp_block(MadContext *t, AVFrame *frame,
93 int mb_x, int mb_y,
94 int j, int mv_x, int mv_y, int add)
95{
96 if (j < 4) {
97 unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
98 if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7)
99 return;
100 comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
101 frame->linesize[0],
102 t->last_frame->data[0] + offset,
103 t->last_frame->linesize[0], add);
104 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
105 int index = j - 3;
106 unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2);
107 if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7)
108 return;
109 comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
110 frame->linesize[index],
111 t->last_frame->data[index] + offset,
112 t->last_frame->linesize[index], add);
113 }
114}
115
116static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
117 int mb_x, int mb_y, int j)
118{
119 if (j < 4) {
120 ff_ea_idct_put_c(
121 frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
122 frame->linesize[0], block);
123 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
124 int index = j - 3;
125 ff_ea_idct_put_c(
126 frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
127 frame->linesize[index], block);
128 }
129}
130
131static inline int decode_block_intra(MadContext *s, int16_t * block)
132{
133 int level, i, j, run;
134 RLTable *rl = &ff_rl_mpeg1;
135 const uint8_t *scantable = s->scantable.permutated;
136 int16_t *quant_matrix = s->quant_matrix;
137
138 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
139
140 /* The RL decoder is derived from mpeg1_decode_block_intra;
141 Escaped level and run values a decoded differently */
142 i = 0;
143 {
144 OPEN_READER(re, &s->gb);
145 /* now quantify & encode AC coefficients */
146 for (;;) {
147 UPDATE_CACHE(re, &s->gb);
148 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
149
150 if (level == 127) {
151 break;
152 } else if (level != 0) {
153 i += run;
154 if (i > 63) {
155 av_log(s->avctx, AV_LOG_ERROR,
156 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
157 return -1;
158 }
159 j = scantable[i];
160 level = (level*quant_matrix[j]) >> 4;
161 level = (level-1)|1;
162 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
163 LAST_SKIP_BITS(re, &s->gb, 1);
164 } else {
165 /* escape */
166 UPDATE_CACHE(re, &s->gb);
167 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
168
169 UPDATE_CACHE(re, &s->gb);
170 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
171
172 i += run;
173 if (i > 63) {
174 av_log(s->avctx, AV_LOG_ERROR,
175 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
176 return -1;
177 }
178 j = scantable[i];
179 if (level < 0) {
180 level = -level;
181 level = (level*quant_matrix[j]) >> 4;
182 level = (level-1)|1;
183 level = -level;
184 } else {
185 level = (level*quant_matrix[j]) >> 4;
186 level = (level-1)|1;
187 }
188 }
189
190 block[j] = level;
191 }
192 CLOSE_READER(re, &s->gb);
193 }
194 return 0;
195}
196
197static int decode_motion(GetBitContext *gb)
198{
199 int value = 0;
200 if (get_bits1(gb)) {
201 if (get_bits1(gb))
202 value = -17;
203 value += get_bits(gb, 4) + 1;
204 }
205 return value;
206}
207
208static int decode_mb(MadContext *s, AVFrame *frame, int inter)
209{
210 int mv_map = 0;
211 int av_uninit(mv_x), av_uninit(mv_y);
212 int j;
213
214 if (inter) {
215 int v = decode210(&s->gb);
216 if (v < 2) {
217 mv_map = v ? get_bits(&s->gb, 6) : 63;
218 mv_x = decode_motion(&s->gb);
219 mv_y = decode_motion(&s->gb);
220 }
221 }
222
223 for (j=0; j<6; j++) {
224 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
225 int add = 2*decode_motion(&s->gb);
226 if (s->last_frame->data[0])
227 comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
228 } else {
229 s->bdsp.clear_block(s->block);
230 if(decode_block_intra(s, s->block) < 0)
231 return -1;
232 idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
233 }
234 }
235 return 0;
236}
237
238static void calc_quant_matrix(MadContext *s, int qscale)
239{
240 int i;
241
242 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
243 for (i=1; i<64; i++)
244 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
245}
246
247static int decode_frame(AVCodecContext *avctx,
248 void *data, int *got_frame,
249 AVPacket *avpkt)
250{
251 const uint8_t *buf = avpkt->data;
252 int buf_size = avpkt->size;
253 MadContext *s = avctx->priv_data;
254 AVFrame *frame = data;
255 GetByteContext gb;
256 int width, height;
257 int chunk_type;
258 int inter, ret;
259
260 bytestream2_init(&gb, buf, buf_size);
261
262 chunk_type = bytestream2_get_le32(&gb);
263 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
264 bytestream2_skip(&gb, 10);
265
266 av_reduce(&avctx->framerate.den, &avctx->framerate.num,
267 bytestream2_get_le16(&gb), 1000, 1<<30);
268
269 width = bytestream2_get_le16(&gb);
270 height = bytestream2_get_le16(&gb);
271 bytestream2_skip(&gb, 1);
272 calc_quant_matrix(s, bytestream2_get_byte(&gb));
273 bytestream2_skip(&gb, 2);
274
275 if (bytestream2_get_bytes_left(&gb) < 2) {
276 av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
277 return AVERROR_INVALIDDATA;
278 }
279
280 if (width < 16 || height < 16) {
281 av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
282 return AVERROR_INVALIDDATA;
283 }
284
285 if (avctx->width != width || avctx->height != height) {
286 av_frame_unref(s->last_frame);
287 if((width * height)/2048*7 > bytestream2_get_bytes_left(&gb))
288 return AVERROR_INVALIDDATA;
289 if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
290 return ret;
291 }
292
293 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
294 return ret;
295
296 if (inter && !s->last_frame->data[0]) {
297 av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
298 ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
299 if (ret < 0)
300 return ret;
301 memset(s->last_frame->data[0], 0, s->last_frame->height *
302 s->last_frame->linesize[0]);
303 memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
304 s->last_frame->linesize[1]);
305 memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
306 s->last_frame->linesize[2]);
307 }
308
309 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
310 bytestream2_get_bytes_left(&gb));
311 if (!s->bitstream_buf)
312 return AVERROR(ENOMEM);
313 s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
314 bytestream2_get_bytes_left(&gb) / 2);
315 memset((uint8_t*)s->bitstream_buf + bytestream2_get_bytes_left(&gb), 0, AV_INPUT_BUFFER_PADDING_SIZE);
316 init_get_bits(&s->gb, s->bitstream_buf, 8*(bytestream2_get_bytes_left(&gb)));
317
318 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
319 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
320 if(decode_mb(s, frame, inter) < 0)
321 return AVERROR_INVALIDDATA;
322
323 *got_frame = 1;
324
325 if (chunk_type != MADe_TAG) {
326 av_frame_unref(s->last_frame);
327 if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
328 return ret;
329 }
330
331 return buf_size;
332}
333
334static av_cold int decode_end(AVCodecContext *avctx)
335{
336 MadContext *t = avctx->priv_data;
337 av_frame_free(&t->last_frame);
338 av_freep(&t->bitstream_buf);
339 return 0;
340}
341
342AVCodec ff_eamad_decoder = {
343 .name = "eamad",
344 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
345 .type = AVMEDIA_TYPE_VIDEO,
346 .id = AV_CODEC_ID_MAD,
347 .priv_data_size = sizeof(MadContext),
348 .init = decode_init,
349 .close = decode_end,
350 .decode = decode_frame,
351 .capabilities = AV_CODEC_CAP_DR1,
352};
353
generated by cgit at 2024-05-17 04:12:25 (GMT)