FFmpeg
mdec.c
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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 "libavutil/mem.h"
31 #include "libavutil/mem_internal.h"
32 
33 #include "avcodec.h"
34 #include "blockdsp.h"
35 #include "bswapdsp.h"
36 #include "codec_internal.h"
37 #include "idctdsp.h"
38 #include "mpeg12data.h"
39 #include "mpeg12dec.h"
40 #include "thread.h"
41 
42 typedef struct MDECContext {
48  uint8_t permutated_scantable[64];
49  int version;
50  int qscale;
51  int last_dc[3];
52  int mb_width;
53  int mb_height;
54  int mb_x, mb_y;
55  DECLARE_ALIGNED(32, int16_t, block)[6][64];
56  DECLARE_ALIGNED(16, uint16_t, quant_matrix)[64];
57  uint8_t *bitstream_buffer;
58  unsigned int bitstream_buffer_size;
60 } MDECContext;
61 
62 //very similar to MPEG-1
63 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
64 {
65  int level, diff, i, j, run;
66  int component;
67  const uint8_t *const scantable = a->permutated_scantable;
68  const uint16_t *quant_matrix = a->quant_matrix;
69  const int qscale = a->qscale;
70 
71  /* DC coefficient */
72  if (a->version <= 2) {
73  block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
74  } else {
75  component = (n <= 3 ? 0 : n - 4 + 1);
76  diff = decode_dc(&a->gb, component);
77  a->last_dc[component] += diff;
78  block[0] = a->last_dc[component] * (1 << 3);
79  }
80 
81  i = 0;
82  {
83  OPEN_READER(re, &a->gb);
84  /* now quantify & encode AC coefficients */
85  for (;;) {
86  UPDATE_CACHE(re, &a->gb);
87  GET_RL_VLC(level, run, re, &a->gb, ff_mpeg1_rl_vlc, TEX_VLC_BITS, 2, 0);
88 
89  if (level == 127) {
90  break;
91  } else if (level != 0) {
92  i += run;
93  if (i > 63) {
94  av_log(a->avctx, AV_LOG_ERROR,
95  "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
96  return AVERROR_INVALIDDATA;
97  }
98  j = scantable[i];
99  level = (level * qscale * quant_matrix[j]) >> 3;
100  level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
101  LAST_SKIP_BITS(re, &a->gb, 1);
102  } else {
103  /* escape */
104  run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
105  UPDATE_CACHE(re, &a->gb);
106  level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
107  i += run;
108  if (i > 63) {
109  av_log(a->avctx, AV_LOG_ERROR,
110  "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
111  return AVERROR_INVALIDDATA;
112  }
113  j = scantable[i];
114  if (level < 0) {
115  level = -level;
116  level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;
117  level = (level - 1) | 1;
118  level = -level;
119  } else {
120  level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;
121  level = (level - 1) | 1;
122  }
123  }
124 
125  block[j] = level;
126  }
127  CLOSE_READER(re, &a->gb);
128  }
129  a->block_last_index[n] = i;
130  return 0;
131 }
132 
133 static inline int decode_mb(MDECContext *a, int16_t block[6][64])
134 {
135  int i, ret;
136  static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };
137 
138  a->bdsp.clear_blocks(block[0]);
139 
140  for (i = 0; i < 6; i++) {
141  if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
142  block_index[i])) < 0)
143  return ret;
144  if (get_bits_left(&a->gb) < 0)
145  return AVERROR_INVALIDDATA;
146  }
147  return 0;
148 }
149 
150 static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
151 {
152  int16_t (*block)[64] = a->block;
153  int linesize = frame->linesize[0];
154 
155  uint8_t *dest_y = frame->data[0] + (mb_y * 16* linesize ) + mb_x * 16;
156  uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
157  uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
158 
159  a->idsp.idct_put(dest_y, linesize, block[0]);
160  a->idsp.idct_put(dest_y + 8, linesize, block[1]);
161  a->idsp.idct_put(dest_y + 8 * linesize, linesize, block[2]);
162  a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);
163 
164  if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {
165  a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
166  a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);
167  }
168 }
169 
171  int *got_frame, AVPacket *avpkt)
172 {
173  MDECContext * const a = avctx->priv_data;
174  const uint8_t *buf = avpkt->data;
175  int buf_size = avpkt->size;
176  int ret;
177 
178  if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0)
179  return ret;
180 
181  av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);
182  if (!a->bitstream_buffer)
183  return AVERROR(ENOMEM);
184  a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);
185  if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
186  return ret;
187 
188  /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
189  skip_bits(&a->gb, 32);
190 
191  a->qscale = get_bits(&a->gb, 16);
192  a->version = get_bits(&a->gb, 16);
193 
194  a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
195 
196  for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
197  for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
198  if ((ret = decode_mb(a, a->block)) < 0)
199  return ret;
200 
201  idct_put(a, frame, a->mb_x, a->mb_y);
202  }
203  }
204 
205  *got_frame = 1;
206 
207  return (get_bits_count(&a->gb) + 31) / 32 * 4;
208 }
209 
211 {
212  MDECContext * const a = avctx->priv_data;
213  int i;
214 
215  a->mb_width = (avctx->coded_width + 15) / 16;
216  a->mb_height = (avctx->coded_height + 15) / 16;
217 
218  a->avctx = avctx;
219 
220  ff_blockdsp_init(&a->bdsp);
221  ff_bswapdsp_init(&a->bbdsp);
222  ff_idctdsp_init(&a->idsp, avctx);
224  ff_permute_scantable(a->permutated_scantable, ff_zigzag_direct,
225  a->idsp.idct_permutation);
226 
227  avctx->pix_fmt = AV_PIX_FMT_YUVJ420P;
228  avctx->color_range = AVCOL_RANGE_JPEG;
229 
230  /* init q matrix */
231  for (i = 0; i < 64; i++) {
232  int j = a->idsp.idct_permutation[i];
233 
234  a->quant_matrix[j] = ff_mpeg1_default_intra_matrix[i];
235  }
236 
237  return 0;
238 }
239 
241 {
242  MDECContext * const a = avctx->priv_data;
243 
244  av_freep(&a->bitstream_buffer);
245  a->bitstream_buffer_size = 0;
246 
247  return 0;
248 }
249 
251  .p.name = "mdec",
252  CODEC_LONG_NAME("Sony PlayStation MDEC (Motion DECoder)"),
253  .p.type = AVMEDIA_TYPE_VIDEO,
254  .p.id = AV_CODEC_ID_MDEC,
255  .priv_data_size = sizeof(MDECContext),
256  .init = decode_init,
257  .close = decode_end,
259  .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
260 };
bswapdsp.h
level
uint8_t level
Definition: svq3.c:205
blockdsp.h
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:695
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
mem_internal.h
MDECContext::last_dc
int last_dc[3]
Definition: mdec.c:51
MDECContext::avctx
AVCodecContext * avctx
Definition: mdec.c:43
mdec_decode_block_intra
static int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
Definition: mdec.c:63
MDECContext::permutated_scantable
uint8_t permutated_scantable[64]
Definition: mdec.c:48
get_bits_count
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:266
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:374
AVCOL_RANGE_JPEG
@ AVCOL_RANGE_JPEG
Full range content.
Definition: pixfmt.h:686
AVPacket::data
uint8_t * data
Definition: packet.h:524
FFCodec
Definition: codec_internal.h:126
UPDATE_CACHE
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:225
BlockDSPContext
Definition: blockdsp.h:32
thread.h
ff_idctdsp_init
av_cold void ff_idctdsp_init(IDCTDSPContext *c, AVCodecContext *avctx)
Definition: idctdsp.c:228
skip_bits
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:381
ff_permute_scantable
av_cold void ff_permute_scantable(uint8_t dst[64], const uint8_t src[64], const uint8_t permutation[64])
Definition: idctdsp.c:30
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:335
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:130
GetBitContext
Definition: get_bits.h:108
AVCodecContext::coded_height
int coded_height
Definition: avcodec.h:633
MDECContext::quant_matrix
uint16_t quant_matrix[64]
Definition: mdec.c:56
AV_CODEC_ID_MDEC
@ AV_CODEC_ID_MDEC
Definition: codec_id.h:89
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
decode_mb
static int decode_mb(MDECContext *a, int16_t block[6][64])
Definition: mdec.c:133
av_cold
#define av_cold
Definition: attributes.h:90
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: mdec.c:210
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:545
MDECContext::mb_x
int mb_x
Definition: mdec.c:54
CLOSE_READER
#define CLOSE_READER(name, gb)
Definition: get_bits.h:188
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:286
ff_blockdsp_init
av_cold void ff_blockdsp_init(BlockDSPContext *c)
Definition: blockdsp.c:58
ff_thread_get_buffer
int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *f, int flags)
Wrapper around get_buffer() for frame-multithreaded codecs.
Definition: pthread_frame.c:986
SHOW_SBITS
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:260
MDECContext::bitstream_buffer_size
unsigned int bitstream_buffer_size
Definition: mdec.c:58
MDECContext::mb_height
int mb_height
Definition: mdec.c:53
get_sbits
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:320
SKIP_BITS
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:241
MDECContext::idsp
IDCTDSPContext idsp
Definition: mdec.c:46
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:271
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: mdec.c:240
AV_CODEC_CAP_FRAME_THREADS
#define AV_CODEC_CAP_FRAME_THREADS
Codec supports frame-level multithreading.
Definition: codec.h:110
ff_bswapdsp_init
av_cold void ff_bswapdsp_init(BswapDSPContext *c)
Definition: bswapdsp.c:49
run
uint8_t run
Definition: svq3.c:204
AVCodecContext::color_range
enum AVColorRange color_range
MPEG vs JPEG YUV range.
Definition: avcodec.h:695
AV_PIX_FMT_YUVJ420P
@ AV_PIX_FMT_YUVJ420P
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
Definition: pixfmt.h:85
LAST_SKIP_BITS
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:247
ff_mpeg1_rl_vlc
RL_VLC_ELEM ff_mpeg1_rl_vlc[680]
Definition: mpeg12.c:128
MDECContext::block
int16_t block[6][64]
Definition: mdec.c:55
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:366
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
MDECContext::bdsp
BlockDSPContext bdsp
Definition: mdec.c:44
AV_CODEC_FLAG_GRAY
#define AV_CODEC_FLAG_GRAY
Only decode/encode grayscale.
Definition: avcodec.h:322
AVPacket::size
int size
Definition: packet.h:525
codec_internal.h
DECLARE_ALIGNED
#define DECLARE_ALIGNED(n, t, v)
Definition: mem_internal.h:109
MDECContext::gb
GetBitContext gb
Definition: mdec.c:47
idct_put
static void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
Definition: mdec.c:150
ff_mpeg1_default_intra_matrix
const uint16_t ff_mpeg1_default_intra_matrix[256]
Definition: mpeg12data.c:31
diff
static av_always_inline int diff(const struct color_info *a, const struct color_info *b, const int trans_thresh)
Definition: vf_paletteuse.c:165
OPEN_READER
#define OPEN_READER(name, gb)
Definition: get_bits.h:177
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
MDECContext::version
int version
Definition: mdec.c:49
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)
Definition: mdec.c:170
ff_mdec_decoder
const FFCodec ff_mdec_decoder
Definition: mdec.c:250
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
ff_mpeg12_init_vlcs
av_cold void ff_mpeg12_init_vlcs(void)
Definition: mpeg12.c:164
av_fast_padded_malloc
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:52
MDECContext::mb_width
int mb_width
Definition: mdec.c:52
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
MDECContext
Definition: mdec.c:42
MDECContext::qscale
int qscale
Definition: mdec.c:50
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:657
idctdsp.h
avcodec.h
GET_RL_VLC
#define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)
Definition: get_bits.h:606
ff_zigzag_direct
const uint8_t ff_zigzag_direct[64]
Definition: mathtables.c:98
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
TEX_VLC_BITS
#define TEX_VLC_BITS
Definition: dvdec.c:147
IDCTDSPContext
Definition: idctdsp.h:43
mpeg12data.h
AVCodecContext
main external API structure.
Definition: avcodec.h:445
SHOW_UBITS
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:259
mpeg12dec.h
MDECContext::bbdsp
BswapDSPContext bbdsp
Definition: mdec.c:45
MDECContext::block_last_index
int block_last_index[6]
Definition: mdec.c:59
AVCodecContext::coded_width
int coded_width
Bitstream width / height, may be different from width/height e.g.
Definition: avcodec.h:633
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
MDECContext::bitstream_buffer
uint8_t * bitstream_buffer
Definition: mdec.c:57
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:472
AVPacket
This structure stores compressed data.
Definition: packet.h:501
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
BswapDSPContext
Definition: bswapdsp.h:24
MDECContext::mb_y
int mb_y
Definition: mdec.c:54
decode_dc
static int decode_dc(GetBitContext *gb, int component)
Definition: mpeg12dec.h:28