FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
mdec.c
Go to the documentation of this file.
1 /*
2  * Sony PlayStation MDEC (Motion DECoder)
3  * Copyright (c) 2003 Michael Niedermayer
4  *
5  * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 /**
25  * @file
26  * Sony PlayStation MDEC (Motion DECoder)
27  * This is very similar to intra-only MPEG-1.
28  */
29 
30 #include "avcodec.h"
31 #include "blockdsp.h"
32 #include "bswapdsp.h"
33 #include "idctdsp.h"
34 #include "mpeg12.h"
35 #include "thread.h"
36 
37 typedef struct MDECContext {
45  int version;
46  int qscale;
47  int last_dc[3];
48  int mb_width;
49  int mb_height;
50  int mb_x, mb_y;
51  DECLARE_ALIGNED(16, int16_t, block)[6][64];
53  unsigned int bitstream_buffer_size;
55 } MDECContext;
56 
57 //very similar to MPEG-1
58 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
59 {
60  int level, diff, i, j, run;
61  int component;
62  RLTable *rl = &ff_rl_mpeg1;
63  uint8_t * const scantable = a->scantable.permutated;
64  const uint16_t *quant_matrix = ff_mpeg1_default_intra_matrix;
65  const int qscale = a->qscale;
66 
67  /* DC coefficient */
68  if (a->version == 2) {
69  block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
70  } else {
71  component = (n <= 3 ? 0 : n - 4 + 1);
72  diff = decode_dc(&a->gb, component);
73  if (diff >= 0xffff)
74  return AVERROR_INVALIDDATA;
75  a->last_dc[component] += diff;
76  block[0] = a->last_dc[component] << 3;
77  }
78 
79  i = 0;
80  {
81  OPEN_READER(re, &a->gb);
82  /* now quantify & encode AC coefficients */
83  for (;;) {
84  UPDATE_CACHE(re, &a->gb);
85  GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
86 
87  if (level == 127) {
88  break;
89  } else if (level != 0) {
90  i += run;
91  if (i > 63) {
93  "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
94  return AVERROR_INVALIDDATA;
95  }
96  j = scantable[i];
97  level = (level * qscale * quant_matrix[j]) >> 3;
98  level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
99  LAST_SKIP_BITS(re, &a->gb, 1);
100  } else {
101  /* escape */
102  run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
103  UPDATE_CACHE(re, &a->gb);
104  level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
105  i += run;
106  if (i > 63) {
108  "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
109  return AVERROR_INVALIDDATA;
110  }
111  j = scantable[i];
112  if (level < 0) {
113  level = -level;
114  level = (level * qscale * quant_matrix[j]) >> 3;
115  level = (level - 1) | 1;
116  level = -level;
117  } else {
118  level = (level * qscale * quant_matrix[j]) >> 3;
119  level = (level - 1) | 1;
120  }
121  }
122 
123  block[j] = level;
124  }
125  CLOSE_READER(re, &a->gb);
126  }
127  a->block_last_index[n] = i;
128  return 0;
129 }
130 
131 static inline int decode_mb(MDECContext *a, int16_t block[6][64])
132 {
133  int i, ret;
134  static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };
135 
136  a->bdsp.clear_blocks(block[0]);
137 
138  for (i = 0; i < 6; i++) {
139  if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
140  block_index[i])) < 0)
141  return ret;
142  if (get_bits_left(&a->gb) < 0)
143  return AVERROR_INVALIDDATA;
144  }
145  return 0;
146 }
147 
148 static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
149 {
150  int16_t (*block)[64] = a->block;
151  int linesize = frame->linesize[0];
152 
153  uint8_t *dest_y = frame->data[0] + (mb_y * 16* linesize ) + mb_x * 16;
154  uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
155  uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
156 
157  a->idsp.idct_put(dest_y, linesize, block[0]);
158  a->idsp.idct_put(dest_y + 8, linesize, block[1]);
159  a->idsp.idct_put(dest_y + 8 * linesize, linesize, block[2]);
160  a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);
161 
162  if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {
163  a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
164  a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);
165  }
166 }
167 
168 static int decode_frame(AVCodecContext *avctx,
169  void *data, int *got_frame,
170  AVPacket *avpkt)
171 {
172  MDECContext * const a = avctx->priv_data;
173  const uint8_t *buf = avpkt->data;
174  int buf_size = avpkt->size;
175  ThreadFrame frame = { .f = data };
176  int ret;
177 
178  if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
179  return ret;
180  frame.f->pict_type = AV_PICTURE_TYPE_I;
181  frame.f->key_frame = 1;
182 
184  if (!a->bitstream_buffer)
185  return AVERROR(ENOMEM);
186  a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);
187  if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
188  return ret;
189 
190  /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
191  skip_bits(&a->gb, 32);
192 
193  a->qscale = get_bits(&a->gb, 16);
194  a->version = get_bits(&a->gb, 16);
195 
196  a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
197 
198  for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
199  for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
200  if ((ret = decode_mb(a, a->block)) < 0)
201  return ret;
202 
203  idct_put(a, frame.f, a->mb_x, a->mb_y);
204  }
205  }
206 
207  *got_frame = 1;
208 
209  return (get_bits_count(&a->gb) + 31) / 32 * 4;
210 }
211 
213 {
214  MDECContext * const a = avctx->priv_data;
215 
216  a->mb_width = (avctx->coded_width + 15) / 16;
217  a->mb_height = (avctx->coded_height + 15) / 16;
218 
219  a->avctx = avctx;
220 
221  ff_blockdsp_init(&a->bdsp, avctx);
222  ff_bswapdsp_init(&a->bbdsp);
223  ff_idctdsp_init(&a->idsp, avctx);
227 
228  if (avctx->idct_algo == FF_IDCT_AUTO)
229  avctx->idct_algo = FF_IDCT_SIMPLE;
230  avctx->pix_fmt = AV_PIX_FMT_YUVJ420P;
231  avctx->color_range = AVCOL_RANGE_JPEG;
232 
233  return 0;
234 }
235 
236 #if HAVE_THREADS
237 static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
238 {
239  MDECContext * const a = avctx->priv_data;
240 
241  a->avctx = avctx;
242 
243  return 0;
244 }
245 #endif
246 
248 {
249  MDECContext * const a = avctx->priv_data;
250 
252  a->bitstream_buffer_size = 0;
253 
254  return 0;
255 }
256 
258  .name = "mdec",
259  .long_name = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
260  .type = AVMEDIA_TYPE_VIDEO,
261  .id = AV_CODEC_ID_MDEC,
262  .priv_data_size = sizeof(MDECContext),
263  .init = decode_init,
264  .close = decode_end,
265  .decode = decode_frame,
267  .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy)
268 };
static int decode_mb(MDECContext *a, int16_t block[6][64])
Definition: mdec.c:131
AVCodecContext * avctx
Definition: mdec.c:38
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:184
#define GET_RL_VLC
Definition: get_bits.h:669
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
int coded_width
Bitstream width / height, may be different from width/height e.g.
Definition: avcodec.h:1850
float re
Definition: fft.c:73
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:247
static int init_thread_copy(AVCodecContext *avctx)
Definition: tta.c:390
av_cold void ff_mpeg12_init_vlcs(void)
Definition: mpeg12.c:145
AVFrame * f
Definition: thread.h:36
#define FF_IDCT_SIMPLE
Definition: avcodec.h:3009
void(* bswap16_buf)(uint16_t *dst, const uint16_t *src, int len)
Definition: bswapdsp.h:26
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
ThreadFrame frame
Definition: mdec.c:42
int mb_x
Definition: mdec.c:50
enum AVColorRange color_range
MPEG vs JPEG YUV range.
Definition: avcodec.h:2384
Scantable.
Definition: idctdsp.h:29
int size
Definition: avcodec.h:1580
void(* clear_blocks)(int16_t *blocks)
Definition: blockdsp.h:36
GetBitContext gb
Definition: mdec.c:43
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:53
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1876
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:120
uint8_t permutated[64]
Definition: idctdsp.h:31
uint8_t run
Definition: svq3.c:192
AVCodec.
Definition: avcodec.h:3541
RLTable.
Definition: rl.h:39
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:232
static int16_t block[64]
Definition: dct.c:113
uint8_t
#define av_cold
Definition: attributes.h:82
Multithreading support functions.
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: mdec.c:168
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1579
int mb_width
Definition: mdec.c:48
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:199
int block_last_index[6]
Definition: mdec.c:54
#define AV_CODEC_FLAG_GRAY
Only decode/encode grayscale.
Definition: avcodec.h:857
#define av_log(a,...)
#define FF_IDCT_AUTO
Definition: avcodec.h:3007
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:568
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:160
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int qscale
Definition: mdec.c:46
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1743
BswapDSPContext bbdsp
Definition: mdec.c:40
const char * name
Name of the codec implementation.
Definition: avcodec.h:3548
int16_t block[6][64]
Definition: mdec.c:51
#define CLOSE_READER(name, gb)
Definition: get_bits.h:131
static int decode_dc(GetBitContext *gb, int component)
Definition: mpeg12.h:32
#define AV_CODEC_CAP_FRAME_THREADS
Codec supports frame-level multithreading.
Definition: avcodec.h:1018
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:175
#define ONLY_IF_THREADS_ENABLED(x)
Define a function with only the non-default version specified.
Definition: internal.h:215
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:258
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
Definition: pixfmt.h:74
int idct_algo
IDCT algorithm, see FF_IDCT_* below.
Definition: avcodec.h:3006
RLTable ff_rl_mpeg1
Definition: mpeg12data.c:166
int mb_height
Definition: mdec.c:49
unsigned int bitstream_buffer_size
Definition: mdec.c:53
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:181
int n
Definition: avisynth_c.h:547
uint8_t * bitstream_buffer
Definition: mdec.c:52
uint8_t idct_permutation[64]
IDCT input permutation.
Definition: idctdsp.h:94
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:193
the normal 2^n-1 "JPEG" YUV ranges
Definition: pixfmt.h:457
void(* idct_put)(uint8_t *dest, int line_size, int16_t *block)
block -> idct -> clip to unsigned 8 bit -> dest.
Definition: idctdsp.h:70
Libavcodec external API header.
av_cold void ff_blockdsp_init(BlockDSPContext *c, AVCodecContext *avctx)
Definition: blockdsp.c:58
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:215
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:437
IDCTDSPContext idsp
Definition: mdec.c:41
int ff_thread_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
Wrapper around get_buffer() for frame-multithreaded codecs.
ScanTable scantable
Definition: mdec.c:44
main external API structure.
Definition: avcodec.h:1648
#define OPEN_READER(name, gb)
Definition: get_bits.h:120
static av_cold int decode_end(AVCodecContext *avctx)
Definition: mdec.c:247
void * buf
Definition: avisynth_c.h:553
int coded_height
Definition: avcodec.h:1850
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:292
static int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
Definition: mdec.c:58
const uint16_t ff_mpeg1_default_intra_matrix[256]
Definition: mpeg12data.c:30
const uint8_t ff_zigzag_direct[64]
Definition: mathtables.c:98
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:198
uint8_t level
Definition: svq3.c:193
BlockDSPContext bdsp
Definition: mdec.c:39
static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
Definition: ccaption_dec.c:722
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:194
#define TEX_VLC_BITS
Definition: dv.h:93
int mb_y
Definition: mdec.c:50
av_cold void ff_bswapdsp_init(BswapDSPContext *c)
Definition: bswapdsp.c:49
void * priv_data
Definition: avcodec.h:1690
static av_always_inline int diff(const uint32_t a, const uint32_t b)
av_cold void ff_init_scantable(uint8_t *permutation, ScanTable *st, const uint8_t *src_scantable)
Definition: idctdsp.c:29
av_cold void ff_idctdsp_init(IDCTDSPContext *c, AVCodecContext *avctx)
Definition: idctdsp.c:241
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:253
AVCodec ff_mdec_decoder
Definition: mdec.c:257
static void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
Definition: mdec.c:148
#define av_freep(p)
static av_cold int decode_init(AVCodecContext *avctx)
Definition: mdec.c:212
This structure stores compressed data.
Definition: avcodec.h:1556
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:955
int last_dc[3]
Definition: mdec.c:47
int version
Definition: mdec.c:45