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_internal.h"
31 
32 #include "avcodec.h"
33 #include "blockdsp.h"
34 #include "bswapdsp.h"
35 #include "codec_internal.h"
36 #include "idctdsp.h"
37 #include "mpeg12data.h"
38 #include "mpeg12dec.h"
39 #include "thread.h"
40 
41 typedef struct MDECContext {
47  uint8_t permutated_scantable[64];
48  int version;
49  int qscale;
50  int last_dc[3];
51  int mb_width;
52  int mb_height;
53  int mb_x, mb_y;
54  DECLARE_ALIGNED(32, int16_t, block)[6][64];
55  DECLARE_ALIGNED(16, uint16_t, quant_matrix)[64];
56  uint8_t *bitstream_buffer;
57  unsigned int bitstream_buffer_size;
59 } MDECContext;
60 
61 //very similar to MPEG-1
62 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
63 {
64  int level, diff, i, j, run;
65  int component;
66  const uint8_t *const scantable = a->permutated_scantable;
67  const uint16_t *quant_matrix = a->quant_matrix;
68  const int qscale = a->qscale;
69 
70  /* DC coefficient */
71  if (a->version == 2) {
72  block[0] = 2 * get_sbits(&a->gb, 10) + 1024;
73  } else {
74  component = (n <= 3 ? 0 : n - 4 + 1);
75  diff = decode_dc(&a->gb, component);
76  a->last_dc[component] += diff;
77  block[0] = a->last_dc[component] * (1 << 3);
78  }
79 
80  i = 0;
81  {
82  OPEN_READER(re, &a->gb);
83  /* now quantify & encode AC coefficients */
84  for (;;) {
85  UPDATE_CACHE(re, &a->gb);
87 
88  if (level == 127) {
89  break;
90  } else if (level != 0) {
91  i += run;
92  if (i > 63) {
93  av_log(a->avctx, AV_LOG_ERROR,
94  "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
95  return AVERROR_INVALIDDATA;
96  }
97  j = scantable[i];
98  level = (level * qscale * quant_matrix[j]) >> 3;
99  level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
100  LAST_SKIP_BITS(re, &a->gb, 1);
101  } else {
102  /* escape */
103  run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
104  UPDATE_CACHE(re, &a->gb);
105  level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
106  i += run;
107  if (i > 63) {
108  av_log(a->avctx, AV_LOG_ERROR,
109  "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
110  return AVERROR_INVALIDDATA;
111  }
112  j = scantable[i];
113  if (level < 0) {
114  level = -level;
115  level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;
116  level = (level - 1) | 1;
117  level = -level;
118  } else {
119  level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;
120  level = (level - 1) | 1;
121  }
122  }
123 
124  block[j] = level;
125  }
126  CLOSE_READER(re, &a->gb);
127  }
128  a->block_last_index[n] = i;
129  return 0;
130 }
131 
132 static inline int decode_mb(MDECContext *a, int16_t block[6][64])
133 {
134  int i, ret;
135  static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };
136 
137  a->bdsp.clear_blocks(block[0]);
138 
139  for (i = 0; i < 6; i++) {
140  if ((ret = mdec_decode_block_intra(a, block[block_index[i]],
141  block_index[i])) < 0)
142  return ret;
143  if (get_bits_left(&a->gb) < 0)
144  return AVERROR_INVALIDDATA;
145  }
146  return 0;
147 }
148 
149 static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
150 {
151  int16_t (*block)[64] = a->block;
152  int linesize = frame->linesize[0];
153 
154  uint8_t *dest_y = frame->data[0] + (mb_y * 16* linesize ) + mb_x * 16;
155  uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
156  uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
157 
158  a->idsp.idct_put(dest_y, linesize, block[0]);
159  a->idsp.idct_put(dest_y + 8, linesize, block[1]);
160  a->idsp.idct_put(dest_y + 8 * linesize, linesize, block[2]);
161  a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);
162 
163  if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {
164  a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);
165  a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);
166  }
167 }
168 
170  int *got_frame, AVPacket *avpkt)
171 {
172  MDECContext * const a = avctx->priv_data;
173  const uint8_t *buf = avpkt->data;
174  int buf_size = avpkt->size;
175  int ret;
176 
177  if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0)
178  return ret;
179  frame->pict_type = AV_PICTURE_TYPE_I;
180  frame->key_frame = 1;
181 
182  av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);
183  if (!a->bitstream_buffer)
184  return AVERROR(ENOMEM);
185  a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);
186  if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
187  return ret;
188 
189  /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
190  skip_bits(&a->gb, 32);
191 
192  a->qscale = get_bits(&a->gb, 16);
193  a->version = get_bits(&a->gb, 16);
194 
195  a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
196 
197  for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
198  for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
199  if ((ret = decode_mb(a, a->block)) < 0)
200  return ret;
201 
202  idct_put(a, frame, a->mb_x, a->mb_y);
203  }
204  }
205 
206  *got_frame = 1;
207 
208  return (get_bits_count(&a->gb) + 31) / 32 * 4;
209 }
210 
212 {
213  MDECContext * const a = avctx->priv_data;
214  int i;
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);
222  ff_bswapdsp_init(&a->bbdsp);
223  ff_idctdsp_init(&a->idsp, avctx);
225  ff_permute_scantable(a->permutated_scantable, ff_zigzag_direct,
226  a->idsp.idct_permutation);
227 
228  avctx->pix_fmt = AV_PIX_FMT_YUVJ420P;
229  avctx->color_range = AVCOL_RANGE_JPEG;
230 
231  /* init q matrix */
232  for (i = 0; i < 64; i++) {
233  int j = a->idsp.idct_permutation[i];
234 
235  a->quant_matrix[j] = ff_mpeg1_default_intra_matrix[i];
236  }
237 
238  return 0;
239 }
240 
242 {
243  MDECContext * const a = avctx->priv_data;
244 
245  av_freep(&a->bitstream_buffer);
246  a->bitstream_buffer_size = 0;
247 
248  return 0;
249 }
250 
252  .p.name = "mdec",
253  CODEC_LONG_NAME("Sony PlayStation MDEC (Motion DECoder)"),
254  .p.type = AVMEDIA_TYPE_VIDEO,
255  .p.id = AV_CODEC_ID_MDEC,
256  .priv_data_size = sizeof(MDECContext),
257  .init = decode_init,
258  .close = decode_end,
260  .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
261 };
bswapdsp.h
level
uint8_t level
Definition: svq3.c:204
blockdsp.h
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:839
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:50
MDECContext::avctx
AVCodecContext * avctx
Definition: mdec.c:42
mdec_decode_block_intra
static int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
Definition: mdec.c:62
MDECContext::permutated_scantable
uint8_t permutated_scantable[64]
Definition: mdec.c:47
get_bits_count
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:219
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVCOL_RANGE_JPEG
@ AVCOL_RANGE_JPEG
Full range content.
Definition: pixfmt.h:661
AVPacket::data
uint8_t * data
Definition: packet.h:374
FFCodec
Definition: codec_internal.h:119
UPDATE_CACHE
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:178
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:467
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:379
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:123
GetBitContext
Definition: get_bits.h:61
ff_thread_get_buffer
the pkt_dts and pkt_pts fields in AVFrame will work as usual Restrictions on codec whose streams don t reset across will not work because their bitstreams cannot be decoded in parallel *The contents of buffers must not be read before as well as code calling up to before the decode process starts Call have so the codec calls ff_thread_report set FF_CODEC_CAP_ALLOCATE_PROGRESS in AVCodec caps_internal and use ff_thread_get_buffer() to allocate frames. The frames must then be freed with ff_thread_release_buffer(). Otherwise decode directly into the user-supplied frames. Call ff_thread_report_progress() after some part of the current picture has decoded. A good place to put this is where draw_horiz_band() is called - add this if it isn 't called anywhere
AVCodecContext::coded_height
int coded_height
Definition: avcodec.h:586
MDECContext::quant_matrix
uint16_t quant_matrix[64]
Definition: mdec.c:55
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:132
av_cold
#define av_cold
Definition: attributes.h:90
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: mdec.c:211
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:667
MDECContext::mb_x
int mb_x
Definition: mdec.c:53
CLOSE_READER
#define CLOSE_READER(name, gb)
Definition: get_bits.h:149
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:298
ff_blockdsp_init
av_cold void ff_blockdsp_init(BlockDSPContext *c)
Definition: blockdsp.c:58
SHOW_SBITS
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:212
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:363
MDECContext::bitstream_buffer_size
unsigned int bitstream_buffer_size
Definition: mdec.c:57
MDECContext::mb_height
int mb_height
Definition: mdec.c:52
get_sbits
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:359
SKIP_BITS
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:193
MDECContext::idsp
IDCTDSPContext idsp
Definition: mdec.c:45
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: mdec.c:241
AV_CODEC_CAP_FRAME_THREADS
#define AV_CODEC_CAP_FRAME_THREADS
Codec supports frame-level multithreading.
Definition: codec.h:113
ff_bswapdsp_init
av_cold void ff_bswapdsp_init(BswapDSPContext *c)
Definition: bswapdsp.c:49
run
uint8_t run
Definition: svq3.c:203
AVCodecContext::color_range
enum AVColorRange color_range
MPEG vs JPEG YUV range.
Definition: avcodec.h:982
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:78
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
LAST_SKIP_BITS
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:199
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:54
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:43
AV_CODEC_FLAG_GRAY
#define AV_CODEC_FLAG_GRAY
Only decode/encode grayscale.
Definition: avcodec.h:259
AVPacket::size
int size
Definition: packet.h:375
codec_internal.h
MDECContext::gb
GetBitContext gb
Definition: mdec.c:46
idct_put
static void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)
Definition: mdec.c:149
ff_mpeg1_default_intra_matrix
const uint16_t ff_mpeg1_default_intra_matrix[256]
Definition: mpeg12data.c:31
OPEN_READER
#define OPEN_READER(name, gb)
Definition: get_bits.h:138
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:48
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)
Definition: mdec.c:169
DECLARE_ALIGNED
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:116
ff_mdec_decoder
const FFCodec ff_mdec_decoder
Definition: mdec.c:251
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
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:49
MDECContext::mb_width
int mb_width
Definition: mdec.c:51
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
MDECContext
Definition: mdec.c:41
MDECContext::qscale
int qscale
Definition: mdec.c:49
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
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:728
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:146
IDCTDSPContext
Definition: idctdsp.h:44
mpeg12data.h
AVCodecContext
main external API structure.
Definition: avcodec.h:398
SHOW_UBITS
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:211
mpeg12dec.h
MDECContext::bbdsp
BswapDSPContext bbdsp
Definition: mdec.c:44
MDECContext::block_last_index
int block_last_index[6]
Definition: mdec.c:58
AVCodecContext::coded_width
int coded_width
Bitstream width / height, may be different from width/height e.g.
Definition: avcodec.h:586
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
diff
static av_always_inline int diff(const uint32_t a, const uint32_t b)
Definition: vf_palettegen.c:139
MDECContext::bitstream_buffer
uint8_t * bitstream_buffer
Definition: mdec.c:56
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
AVPacket
This structure stores compressed data.
Definition: packet.h:351
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:53
decode_dc
static int decode_dc(GetBitContext *gb, int component)
Definition: mpeg12dec.h:28
re
float re
Definition: fft.c:79