FFmpeg  4.4
eamad.c
Go to the documentation of this file.
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_internal.h"
32 
33 #include "avcodec.h"
34 #include "blockdsp.h"
35 #include "bytestream.h"
36 #include "bswapdsp.h"
37 #include "get_bits.h"
38 #include "aandcttab.h"
39 #include "eaidct.h"
40 #include "idctdsp.h"
41 #include "internal.h"
42 #include "mpeg12data.h"
43 #include "mpeg12vlc.h"
44 
45 #define EA_PREAMBLE_SIZE 8
46 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD I-frame */
47 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD P-frame */
48 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
49 
50 typedef struct MadContext {
58  unsigned int bitstream_buf_size;
59  DECLARE_ALIGNED(32, int16_t, block)[64];
61  uint16_t quant_matrix[64];
62  int mb_x;
63  int mb_y;
64 } MadContext;
65 
67 {
68  MadContext *s = avctx->priv_data;
69  s->avctx = avctx;
70  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
71  ff_blockdsp_init(&s->bdsp, avctx);
72  ff_bswapdsp_init(&s->bbdsp);
73  ff_idctdsp_init(&s->idsp, avctx);
74  ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
75  ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
77 
78  s->last_frame = av_frame_alloc();
79  if (!s->last_frame)
80  return AVERROR(ENOMEM);
81 
82  return 0;
83 }
84 
85 static inline void comp(unsigned char *dst, ptrdiff_t dst_stride,
86  unsigned char *src, ptrdiff_t src_stride, int add)
87 {
88  int j, i;
89  for (j=0; j<8; j++)
90  for (i=0; i<8; i++)
91  dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
92 }
93 
94 static inline void comp_block(MadContext *t, AVFrame *frame,
95  int mb_x, int mb_y,
96  int j, int mv_x, int mv_y, int add)
97 {
98  if (j < 4) {
99  unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
100  if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7)
101  return;
102  comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
103  frame->linesize[0],
104  t->last_frame->data[0] + offset,
105  t->last_frame->linesize[0], add);
106  } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
107  int index = j - 3;
108  unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2);
109  if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7)
110  return;
111  comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
112  frame->linesize[index],
113  t->last_frame->data[index] + offset,
114  t->last_frame->linesize[index], add);
115  }
116 }
117 
118 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
119  int mb_x, int mb_y, int j)
120 {
121  if (j < 4) {
123  frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
124  frame->linesize[0], block);
125  } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
126  int index = j - 3;
128  frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
130  }
131 }
132 
133 static inline int decode_block_intra(MadContext *s, int16_t * block)
134 {
135  int level, i, j, run;
136  RLTable *rl = &ff_rl_mpeg1;
137  const uint8_t *scantable = s->scantable.permutated;
138  int16_t *quant_matrix = s->quant_matrix;
139 
140  block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
141 
142  /* The RL decoder is derived from mpeg1_decode_block_intra;
143  Escaped level and run values a decoded differently */
144  i = 0;
145  {
146  OPEN_READER(re, &s->gb);
147  /* now quantify & encode AC coefficients */
148  for (;;) {
149  UPDATE_CACHE(re, &s->gb);
150  GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
151 
152  if (level == 127) {
153  break;
154  } else if (level != 0) {
155  i += run;
156  if (i > 63) {
157  av_log(s->avctx, AV_LOG_ERROR,
158  "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
159  return -1;
160  }
161  j = scantable[i];
162  level = (level*quant_matrix[j]) >> 4;
163  level = (level-1)|1;
164  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
165  LAST_SKIP_BITS(re, &s->gb, 1);
166  } else {
167  /* escape */
168  UPDATE_CACHE(re, &s->gb);
169  level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
170 
171  UPDATE_CACHE(re, &s->gb);
172  run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
173 
174  i += run;
175  if (i > 63) {
176  av_log(s->avctx, AV_LOG_ERROR,
177  "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
178  return -1;
179  }
180  j = scantable[i];
181  if (level < 0) {
182  level = -level;
183  level = (level*quant_matrix[j]) >> 4;
184  level = (level-1)|1;
185  level = -level;
186  } else {
187  level = (level*quant_matrix[j]) >> 4;
188  level = (level-1)|1;
189  }
190  }
191 
192  block[j] = level;
193  }
194  CLOSE_READER(re, &s->gb);
195  }
196  return 0;
197 }
198 
200 {
201  int value = 0;
202  if (get_bits1(gb)) {
203  if (get_bits1(gb))
204  value = -17;
205  value += get_bits(gb, 4) + 1;
206  }
207  return value;
208 }
209 
210 static int decode_mb(MadContext *s, AVFrame *frame, int inter)
211 {
212  int mv_map = 0;
213  int av_uninit(mv_x), av_uninit(mv_y);
214  int j;
215 
216  if (inter) {
217  int v = decode210(&s->gb);
218  if (v < 2) {
219  mv_map = v ? get_bits(&s->gb, 6) : 63;
220  mv_x = decode_motion(&s->gb);
221  mv_y = decode_motion(&s->gb);
222  }
223  }
224 
225  for (j=0; j<6; j++) {
226  if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
227  int add = 2*decode_motion(&s->gb);
228  if (s->last_frame->data[0])
229  comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
230  } else {
231  s->bdsp.clear_block(s->block);
232  if(decode_block_intra(s, s->block) < 0)
233  return -1;
234  idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
235  }
236  }
237  return 0;
238 }
239 
240 static void calc_quant_matrix(MadContext *s, int qscale)
241 {
242  int i;
243 
244  s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
245  for (i=1; i<64; i++)
246  s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
247 }
248 
249 static int decode_frame(AVCodecContext *avctx,
250  void *data, int *got_frame,
251  AVPacket *avpkt)
252 {
253  const uint8_t *buf = avpkt->data;
254  int buf_size = avpkt->size;
255  MadContext *s = avctx->priv_data;
256  AVFrame *frame = data;
257  GetByteContext gb;
258  int width, height;
259  int chunk_type;
260  int inter, ret;
261 
262  bytestream2_init(&gb, buf, buf_size);
263 
264  chunk_type = bytestream2_get_le32(&gb);
265  inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
266  bytestream2_skip(&gb, 10);
267 
268  av_reduce(&avctx->framerate.den, &avctx->framerate.num,
269  bytestream2_get_le16(&gb), 1000, 1<<30);
270 
271  width = bytestream2_get_le16(&gb);
272  height = bytestream2_get_le16(&gb);
273  bytestream2_skip(&gb, 1);
274  calc_quant_matrix(s, bytestream2_get_byte(&gb));
275  bytestream2_skip(&gb, 2);
276 
277  if (bytestream2_get_bytes_left(&gb) < 2) {
278  av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
279  return AVERROR_INVALIDDATA;
280  }
281 
282  if (width < 16 || height < 16) {
283  av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
284  return AVERROR_INVALIDDATA;
285  }
286 
287  if (avctx->width != width || avctx->height != height) {
288  av_frame_unref(s->last_frame);
289  if((width * (int64_t)height)/2048*7 > bytestream2_get_bytes_left(&gb))
290  return AVERROR_INVALIDDATA;
291  if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
292  return ret;
293  }
294 
295  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
296  return ret;
297 
298  if (inter && !s->last_frame->data[0]) {
299  av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
300  ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
301  if (ret < 0)
302  return ret;
303  memset(s->last_frame->data[0], 0, s->last_frame->height *
304  s->last_frame->linesize[0]);
305  memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
306  s->last_frame->linesize[1]);
307  memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
308  s->last_frame->linesize[2]);
309  }
310 
311  av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
313  if (!s->bitstream_buf)
314  return AVERROR(ENOMEM);
315  s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
316  bytestream2_get_bytes_left(&gb) / 2);
317  memset((uint8_t*)s->bitstream_buf + bytestream2_get_bytes_left(&gb), 0, AV_INPUT_BUFFER_PADDING_SIZE);
318  init_get_bits(&s->gb, s->bitstream_buf, 8*(bytestream2_get_bytes_left(&gb)));
319 
320  for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
321  for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
322  if(decode_mb(s, frame, inter) < 0)
323  return AVERROR_INVALIDDATA;
324 
325  *got_frame = 1;
326 
327  if (chunk_type != MADe_TAG) {
328  av_frame_unref(s->last_frame);
329  if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
330  return ret;
331  }
332 
333  return buf_size;
334 }
335 
337 {
338  MadContext *t = avctx->priv_data;
340  av_freep(&t->bitstream_buf);
341  return 0;
342 }
343 
345  .name = "eamad",
346  .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
347  .type = AVMEDIA_TYPE_VIDEO,
348  .id = AV_CODEC_ID_MAD,
349  .priv_data_size = sizeof(MadContext),
350  .init = decode_init,
351  .close = decode_end,
352  .decode = decode_frame,
353  .capabilities = AV_CODEC_CAP_DR1,
354  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
355 };
const uint16_t ff_inv_aanscales[64]
Definition: aandcttab.c:38
AAN (Arai, Agui and Nakajima) (I)DCT tables.
#define av_uninit(x)
Definition: attributes.h:154
#define av_cold
Definition: attributes.h:88
uint8_t
Libavcodec external API header.
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:192
#define s(width, name)
Definition: cbs_vp9.c:257
#define av_clip_uint8
Definition: common.h:128
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1893
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
static AVFrame * frame
static float add(float src0, float src1)
void ff_ea_idct_put_c(uint8_t *dest, ptrdiff_t linesize, int16_t *block)
Definition: eaidct.c:80
static void idct_put(MadContext *t, AVFrame *frame, int16_t *block, int mb_x, int mb_y, int j)
Definition: eamad.c:118
#define MADm_TAG
Definition: eamad.c:47
static void comp(unsigned char *dst, ptrdiff_t dst_stride, unsigned char *src, ptrdiff_t src_stride, int add)
Definition: eamad.c:85
static int decode_motion(GetBitContext *gb)
Definition: eamad.c:199
static void calc_quant_matrix(MadContext *s, int qscale)
Definition: eamad.c:240
static int decode_block_intra(MadContext *s, int16_t *block)
Definition: eamad.c:133
static int decode_mb(MadContext *s, AVFrame *frame, int inter)
Definition: eamad.c:210
static av_cold int decode_init(AVCodecContext *avctx)
Definition: eamad.c:66
static av_cold int decode_end(AVCodecContext *avctx)
Definition: eamad.c:336
AVCodec ff_eamad_decoder
Definition: eamad.c:344
static void comp_block(MadContext *t, AVFrame *frame, int mb_x, int mb_y, int j, int mv_x, int mv_y, int add)
Definition: eamad.c:94
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: eamad.c:249
#define MADe_TAG
Definition: eamad.c:48
double value
Definition: eval.c:98
float re
Definition: fft.c:82
bitstream reader API header.
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:359
#define CLOSE_READER(name, gb)
Definition: get_bits.h:149
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:211
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:212
static int decode210(GetBitContext *gb)
Definition: get_bits.h:841
#define OPEN_READER(name, gb)
Definition: get_bits.h:138
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:193
#define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)
Definition: get_bits.h:738
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:178
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:199
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:659
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
#define AV_GET_BUFFER_FLAG_REF
The decoder will keep a reference to the frame and may reuse it later.
Definition: avcodec.h:514
#define AV_CODEC_FLAG_GRAY
Only decode/encode grayscale.
Definition: avcodec.h:308
@ AV_CODEC_ID_MAD
Definition: codec_id.h:178
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding.
Definition: avcodec.h:215
void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size)
Same behaviour av_fast_malloc but the buffer has additional AV_INPUT_BUFFER_PADDING_SIZE at the end w...
Definition: utils.c:50
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR(e)
Definition: error.h:43
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:553
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:443
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:190
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
#define DECLARE_ALIGNED(n, t, v)
Declare a variable that is aligned in memory.
Definition: mem.h:117
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
int index
Definition: gxfenc.c:89
av_cold void ff_idctdsp_init(IDCTDSPContext *c, AVCodecContext *avctx)
Definition: idctdsp.c:238
av_cold void ff_init_scantable(uint8_t *permutation, ScanTable *st, const uint8_t *src_scantable)
Definition: idctdsp.c:29
av_cold void ff_init_scantable_permutation(uint8_t *idct_permutation, enum idct_permutation_type perm_type)
Definition: idctdsp.c:50
@ FF_IDCT_PERM_NONE
Definition: idctdsp.h:38
int i
Definition: input.c:407
av_cold void ff_blockdsp_init(BlockDSPContext *c, AVCodecContext *avctx)
Definition: blockdsp.c:60
av_cold void ff_bswapdsp_init(BswapDSPContext *c)
Definition: bswapdsp.c:49
#define TEX_VLC_BITS
Definition: dv.h:99
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:41
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:84
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
const uint8_t ff_zigzag_direct[64]
Definition: mathtables.c:98
av_cold void ff_mpeg12_init_vlcs(void)
Definition: mpeg12.c:165
const uint16_t ff_mpeg1_default_intra_matrix[256]
Definition: mpeg12data.c:30
RLTable ff_rl_mpeg1
Definition: mpeg12data.c:166
MPEG-1/2 tables.
MPEG-1/2 VLC.
const char data[16]
Definition: mxf.c:142
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
main external API structure.
Definition: avcodec.h:536
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:746
int width
picture width / height.
Definition: avcodec.h:709
AVRational framerate
Definition: avcodec.h:2071
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:616
void * priv_data
Definition: avcodec.h:563
AVCodec.
Definition: codec.h:197
const char * name
Name of the codec implementation.
Definition: codec.h:204
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:332
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:349
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
int num
Numerator.
Definition: rational.h:59
int den
Denominator.
Definition: rational.h:60
void * bitstream_buf
Definition: eamad.c:57
AVFrame * last_frame
Definition: eamad.c:55
BlockDSPContext bdsp
Definition: eamad.c:52
int mb_x
Definition: eamad.c:62
AVCodecContext * avctx
Definition: eamad.c:51
BswapDSPContext bbdsp
Definition: eamad.c:53
int mb_y
Definition: eamad.c:63
uint16_t quant_matrix[64]
Definition: eamad.c:61
ScanTable scantable
Definition: eamad.c:60
GetBitContext gb
Definition: eamad.c:56
IDCTDSPContext idsp
Definition: eamad.c:54
int16_t block[64]
Definition: eamad.c:59
unsigned int bitstream_buf_size
Definition: eamad.c:58
RLTable.
Definition: rl.h:39
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48
Scantable.
Definition: idctdsp.h:31
uint8_t run
Definition: svq3.c:205
uint8_t level
Definition: svq3.c:206
#define av_freep(p)
#define av_log(a,...)
#define src
Definition: vp8dsp.c:255
static int16_t block[64]
Definition: dct.c:116
#define height
#define width
static const uint8_t offset[127][2]
Definition: vf_spp.c:107