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 "idctdsp.h"
36 #include "mpeg12.h"
37 #include "thread.h"
38 
39 typedef struct MDECContext {
47  int version;
48  int qscale;
49  int last_dc[3];
50  int mb_width;
51  int mb_height;
52  int mb_x, mb_y;
53  DECLARE_ALIGNED(32, int16_t, block)[6][64];
54  DECLARE_ALIGNED(16, uint16_t, quant_matrix)[64];
55  uint8_t *bitstream_buffer;
56  unsigned int bitstream_buffer_size;
58 } MDECContext;
59 
60 //very similar to MPEG-1
61 static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
62 {
63  int level, diff, i, j, run;
64  int component;
65  RLTable *rl = &ff_rl_mpeg1;
66  uint8_t * const scantable = a->scantable.permutated;
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);
86  GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
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 
169 static int decode_frame(AVCodecContext *avctx,
170  void *data, int *got_frame,
171  AVPacket *avpkt)
172 {
173  MDECContext * const a = avctx->priv_data;
174  const uint8_t *buf = avpkt->data;
175  int buf_size = avpkt->size;
176  ThreadFrame frame = { .f = data };
177  int ret;
178 
179  if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
180  return ret;
181  frame.f->pict_type = AV_PICTURE_TYPE_I;
182  frame.f->key_frame = 1;
183 
184  av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);
185  if (!a->bitstream_buffer)
186  return AVERROR(ENOMEM);
187  a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);
188  if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)
189  return ret;
190 
191  /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
192  skip_bits(&a->gb, 32);
193 
194  a->qscale = get_bits(&a->gb, 16);
195  a->version = get_bits(&a->gb, 16);
196 
197  a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;
198 
199  for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {
200  for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {
201  if ((ret = decode_mb(a, a->block)) < 0)
202  return ret;
203 
204  idct_put(a, frame.f, a->mb_x, a->mb_y);
205  }
206  }
207 
208  *got_frame = 1;
209 
210  return (get_bits_count(&a->gb) + 31) / 32 * 4;
211 }
212 
214 {
215  MDECContext * const a = avctx->priv_data;
216  int i;
217 
218  a->mb_width = (avctx->coded_width + 15) / 16;
219  a->mb_height = (avctx->coded_height + 15) / 16;
220 
221  a->avctx = avctx;
222 
223  ff_blockdsp_init(&a->bdsp, avctx);
224  ff_bswapdsp_init(&a->bbdsp);
225  ff_idctdsp_init(&a->idsp, avctx);
227  ff_init_scantable(a->idsp.idct_permutation, &a->scantable,
229 
230  avctx->pix_fmt = AV_PIX_FMT_YUVJ420P;
231  avctx->color_range = AVCOL_RANGE_JPEG;
232 
233  /* init q matrix */
234  for (i = 0; i < 64; i++) {
235  int j = a->idsp.idct_permutation[i];
236 
237  a->quant_matrix[j] = ff_mpeg1_default_intra_matrix[i];
238  }
239 
240  return 0;
241 }
242 
244 {
245  MDECContext * const a = avctx->priv_data;
246 
247  av_freep(&a->bitstream_buffer);
248  a->bitstream_buffer_size = 0;
249 
250  return 0;
251 }
252 
254  .name = "mdec",
255  .long_name = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
256  .type = AVMEDIA_TYPE_VIDEO,
257  .id = AV_CODEC_ID_MDEC,
258  .priv_data_size = sizeof(MDECContext),
259  .init = decode_init,
260  .close = decode_end,
261  .decode = decode_frame,
263  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
264 };
AVCodec
AVCodec.
Definition: codec.h:202
bswapdsp.h
FF_CODEC_CAP_INIT_THREADSAFE
#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:42
ff_init_scantable
av_cold void ff_init_scantable(uint8_t *permutation, ScanTable *st, const uint8_t *src_scantable)
Definition: idctdsp.c:29
level
uint8_t level
Definition: svq3.c:204
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
blockdsp.h
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:850
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:49
MDECContext::avctx
AVCodecContext * avctx
Definition: mdec.c:40
mdec_decode_block_intra
static int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)
Definition: mdec.c:61
get_bits_count
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:220
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
AVCOL_RANGE_JPEG
@ AVCOL_RANGE_JPEG
Full range content.
Definition: pixfmt.h:576
AVPacket::data
uint8_t * data
Definition: packet.h:373
data
const char data[16]
Definition: mxf.c:143
UPDATE_CACHE
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:179
BlockDSPContext
Definition: blockdsp.h:34
thread.h
skip_bits
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:468
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:380
RLTable
RLTable.
Definition: rl.h:39
GetBitContext
Definition: get_bits.h:62
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:571
MDECContext::quant_matrix
uint16_t quant_matrix[64]
Definition: mdec.c:54
mpeg12.h
AV_CODEC_ID_MDEC
@ AV_CODEC_ID_MDEC
Definition: codec_id.h:87
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
ff_mdec_decoder
const AVCodec ff_mdec_decoder
Definition: mdec.c:253
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: mdec.c:213
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:678
MDECContext::mb_x
int mb_x
Definition: mdec.c:52
MDECContext::frame
ThreadFrame frame
Definition: mdec.c:44
ff_rl_mpeg1
RLTable ff_rl_mpeg1
Definition: mpeg12data.c:166
CLOSE_READER
#define CLOSE_READER(name, gb)
Definition: get_bits.h:150
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
SHOW_SBITS
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:213
MDECContext::bitstream_buffer_size
unsigned int bitstream_buffer_size
Definition: mdec.c:56
MDECContext::mb_height
int mb_height
Definition: mdec.c:51
get_sbits
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:360
SKIP_BITS
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:194
MDECContext::idsp
IDCTDSPContext idsp
Definition: mdec.c:43
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: mdec.c:243
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:967
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:200
MDECContext::block
int16_t block[6][64]
Definition: mdec.c:53
decode_frame
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: mdec.c:169
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:41
AV_CODEC_FLAG_GRAY
#define AV_CODEC_FLAG_GRAY
Only decode/encode grayscale.
Definition: avcodec.h:243
AVPacket::size
int size
Definition: packet.h:374
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
MDECContext::gb
GetBitContext gb
Definition: mdec.c:45
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:30
MDECContext::scantable
ScanTable scantable
Definition: mdec.c:46
OPEN_READER
#define OPEN_READER(name, gb)
Definition: get_bits.h:139
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:47
DECLARE_ALIGNED
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:116
i
int i
Definition: input.c:406
ff_mpeg12_init_vlcs
av_cold void ff_mpeg12_init_vlcs(void)
Definition: mpeg12.c:165
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:50
MDECContext::mb_width
int mb_width
Definition: mdec.c:50
ff_idctdsp_init
av_cold void ff_idctdsp_init(IDCTDSPContext *c, AVCodecContext *avctx)
Definition: idctdsp.c:238
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:209
MDECContext
Definition: mdec.c:39
MDECContext::qscale
int qscale
Definition: mdec.c:48
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:593
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:739
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:132
IDCTDSPContext
Definition: idctdsp.h:53
AVCodecContext
main external API structure.
Definition: avcodec.h:383
ThreadFrame
Definition: thread.h:34
decode_dc
static int decode_dc(GetBitContext *gb, int component)
Definition: mpeg12.h:50
SHOW_UBITS
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:212
MDECContext::bbdsp
BswapDSPContext bbdsp
Definition: mdec.c:42
MDECContext::block_last_index
int block_last_index[6]
Definition: mdec.c:57
AVCodecContext::coded_width
int coded_width
Bitstream width / height, may be different from width/height e.g.
Definition: avcodec.h:571
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
ScanTable
Scantable.
Definition: idctdsp.h:31
diff
static av_always_inline int diff(const uint32_t a, const uint32_t b)
Definition: vf_palettegen.c:136
MDECContext::bitstream_buffer
uint8_t * bitstream_buffer
Definition: mdec.c:55
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:410
AVPacket
This structure stores compressed data.
Definition: packet.h:350
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
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:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
BswapDSPContext
Definition: bswapdsp.h:24
ff_blockdsp_init
av_cold void ff_blockdsp_init(BlockDSPContext *c, AVCodecContext *avctx)
Definition: blockdsp.c:59
MDECContext::mb_y
int mb_y
Definition: mdec.c:52
RLTable::rl_vlc
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48
re
float re
Definition: fft.c:78