FFmpeg
tscc2.c
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1 /*
2  * TechSmith Screen Codec 2 (aka Dora) decoder
3  * Copyright (c) 2012 Konstantin Shishkov
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 Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * TechSmith Screen Codec 2 decoder
25  */
26 
27 #include <inttypes.h>
28 
29 #include "libavutil/mem.h"
30 #include "libavutil/thread.h"
31 
32 #define BITSTREAM_READER_LE
33 #include "avcodec.h"
34 #include "bytestream.h"
35 #include "codec_internal.h"
36 #include "decode.h"
37 #include "get_bits.h"
38 #include "mathops.h"
39 #include "tscc2data.h"
40 
41 #define TSCC2_VLC_BITS 9
42 
43 typedef struct TSCC2Context {
47  uint8_t *slice_quants;
48  int quant[2];
49  int q[2][3];
51 
52  int block[16];
53 } TSCC2Context;
54 
56 
57 static av_cold void tscc2_init_vlc(VLC *vlc, int *offset, int nb_codes,
58  const uint8_t *lens, const void *syms,
59  int sym_length)
60 {
61  static VLCElem vlc_buf[15442];
62 
63  vlc->table = &vlc_buf[*offset];
64  vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *offset;
66  lens, 1, syms, sym_length, sym_length, 0,
68  *offset += vlc->table_size;
69 }
70 
71 static av_cold void tscc2_init_vlcs(void)
72 {
73  const uint16_t *ac_vlc_syms = tscc2_ac_vlc_syms;
74  const uint8_t *ac_vlc_lens = tscc2_ac_vlc_lens;
75  int i, offset = 0;
76 
79 
80  for (i = 0; i < NUM_VLC_SETS; i++) {
81  tscc2_init_vlc(&nc_vlc[i], &offset, 16,
83 
85  ac_vlc_lens, ac_vlc_syms, 2);
86  ac_vlc_lens += tscc2_ac_vlc_sizes[i];
87  ac_vlc_syms += tscc2_ac_vlc_sizes[i];
88  }
89 }
90 
91 #define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8)
92 #define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
93  OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \
94  OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \
95  OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \
96  OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \
97 
98 #define COL_OP(a, b) a = (b)
99 #define ROW_OP(a, b) a = ((b) + 0x20) >> 6
100 
101 static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
102 {
103  int i;
104  int tblk[4 * 4];
105  int t0, t1, t2, t3;
106 
107  for (i = 0; i < 4; i++) {
108  t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
109  t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
110  t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
111  t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
112  DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
113  tblk[2 * 4 + i], tblk[3 * 4 + i],
114  t0, t1, t2, t3, COL_OP);
115  }
116  for (i = 0; i < 4; i++) {
117  DCT1D(dst[0], dst[1], dst[2], dst[3],
118  tblk[i * 4 + 0], tblk[i * 4 + 1],
119  tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
120  dst += stride;
121  }
122 }
123 
124 static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
125  uint8_t *dst, int stride, int plane)
126 {
127  GetBitContext *gb = &c->gb;
128  int prev_dc, dc, nc, ac, bpos, val;
129  int i, j, k, l;
130 
131  if (get_bits1(gb)) {
132  if (get_bits1(gb)) {
133  val = get_bits(gb, 8);
134  for (i = 0; i < 8; i++, dst += stride)
135  memset(dst, val, 16);
136  } else {
137  if (get_bits_left(gb) < 16 * 8 * 8)
138  return AVERROR_INVALIDDATA;
139  for (i = 0; i < 8; i++) {
140  for (j = 0; j < 16; j++)
141  dst[j] = get_bits(gb, 8);
142  dst += stride;
143  }
144  }
145  return 0;
146  }
147 
148  prev_dc = 0;
149  for (j = 0; j < 2; j++) {
150  for (k = 0; k < 4; k++) {
151  if (!(j | k)) {
152  dc = get_bits(gb, 8);
153  } else {
155  if (dc == 0x100)
156  dc = get_bits(gb, 8);
157  }
158  dc = (dc + prev_dc) & 0xFF;
159  prev_dc = dc;
160  c->block[0] = dc;
161 
162  nc = get_vlc2(gb, nc_vlc[vlc_set].table, TSCC2_VLC_BITS, 1);
163 
164  bpos = 1;
165  memset(c->block + 1, 0, 15 * sizeof(*c->block));
166  for (l = 0; l < nc; l++) {
167  ac = get_vlc2(gb, ac_vlc[vlc_set].table, TSCC2_VLC_BITS, 2);
168  if (ac == 0x1000)
169  ac = get_bits(gb, 12);
170  bpos += ac & 0xF;
171  if (bpos >= 16)
172  return AVERROR_INVALIDDATA;
173  val = sign_extend(ac >> 4, 8);
174  c->block[ff_zigzag_scan[bpos++]] = val;
175  }
176  tscc2_idct4_put(c->block, q, dst + k * 4, stride);
177  }
178  dst += 4 * stride;
179  }
180  return 0;
181 }
182 
183 static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
184  const uint8_t *buf, int buf_size)
185 {
186  int i, mb_x, q, ret;
187  int off;
188 
189  if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
190  return ret;
191 
192  for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
193  q = c->slice_quants[mb_x + c->mb_width * mb_y];
194 
195  if (q == 0 || q == 3) // skip block
196  continue;
197  for (i = 0; i < 3; i++) {
198  off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
199  ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
200  c->pic->data[i] + off, c->pic->linesize[i], i);
201  if (ret)
202  return ret;
203  }
204  }
205 
206  return 0;
207 }
208 
209 static int tscc2_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
210  int *got_frame, AVPacket *avpkt)
211 {
212  const uint8_t *buf = avpkt->data;
213  int buf_size = avpkt->size;
214  TSCC2Context *c = avctx->priv_data;
215  GetByteContext gb;
216  uint32_t frame_type, size;
217  int i, val, len, pos = 0;
218  int num_mb = c->mb_width * c->mb_height;
219  int ret;
220 
221  bytestream2_init(&gb, buf, buf_size);
222  frame_type = bytestream2_get_byte(&gb);
223  if (frame_type > 1) {
224  av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n",
225  frame_type);
226  return AVERROR_INVALIDDATA;
227  }
228 
229  if (frame_type == 0) {
230  // Skip duplicate frames
231  return buf_size;
232  }
233 
234  if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
235  return ret;
236  }
237 
238  if (bytestream2_get_bytes_left(&gb) < 4) {
239  av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
240  return AVERROR_INVALIDDATA;
241  }
242 
243  c->quant[0] = bytestream2_get_byte(&gb);
244  c->quant[1] = bytestream2_get_byte(&gb);
245  if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
246  c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
247  av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
248  c->quant[0], c->quant[1]);
249  return AVERROR_INVALIDDATA;
250  }
251 
252  for (i = 0; i < 3; i++) {
253  c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
254  c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
255  }
256 
257  bytestream2_skip(&gb, 1);
258 
259  size = bytestream2_get_le32(&gb);
260  if (size > bytestream2_get_bytes_left(&gb)) {
261  av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
262  return AVERROR_INVALIDDATA;
263  }
264 
265  for (i = 0; i < size; i++) {
266  val = bytestream2_get_byte(&gb);
267  len = val & 0x3F;
268  val >>= 6;
269  if (pos + len > num_mb) {
270  av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
271  return AVERROR_INVALIDDATA;
272  }
273  memset(c->slice_quants + pos, val, len);
274  pos += len;
275  }
276  if (pos < num_mb) {
277  av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
278  pos, num_mb);
279  return AVERROR_INVALIDDATA;
280  }
281 
282  for (i = 0; i < c->mb_height; i++) {
283  size = bytestream2_peek_byte(&gb);
284  if (size & 1) {
285  size = bytestream2_get_byte(&gb) - 1;
286  } else {
287  size = bytestream2_get_le32(&gb) >> 1;
288  }
289  if (!size) {
290  int skip_row = 1, j, off = i * c->mb_width;
291  for (j = 0; j < c->mb_width; j++) {
292  if (c->slice_quants[off + j] == 1 ||
293  c->slice_quants[off + j] == 2) {
294  skip_row = 0;
295  break;
296  }
297  }
298  if (!skip_row) {
299  av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
300  return AVERROR_INVALIDDATA;
301  }
302  }
303  if (bytestream2_get_bytes_left(&gb) < size) {
304  av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
306  return AVERROR_INVALIDDATA;
307  }
308  ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
309  if (ret) {
310  av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
311  return ret;
312  }
313  bytestream2_skip(&gb, size);
314  }
315 
316  *got_frame = 1;
317  if ((ret = av_frame_ref(rframe, c->pic)) < 0)
318  return ret;
319 
320  /* always report that the buffer was completely consumed */
321  return buf_size;
322 }
323 
325 {
326  TSCC2Context * const c = avctx->priv_data;
327 
328  av_frame_free(&c->pic);
329  av_freep(&c->slice_quants);
330 
331  return 0;
332 }
333 
335 {
336  TSCC2Context * const c = avctx->priv_data;
337  static AVOnce init_static_once = AV_ONCE_INIT;
338 
339  c->avctx = avctx;
340 
341  avctx->pix_fmt = AV_PIX_FMT_YUV444P;
342 
343  c->mb_width = FFALIGN(avctx->width, 16) >> 4;
344  c->mb_height = FFALIGN(avctx->height, 8) >> 3;
345  c->slice_quants = av_malloc(c->mb_width * c->mb_height);
346  if (!c->slice_quants) {
347  av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
348  return AVERROR(ENOMEM);
349  }
350 
351  c->pic = av_frame_alloc();
352  if (!c->pic)
353  return AVERROR(ENOMEM);
354 
355  ff_thread_once(&init_static_once, tscc2_init_vlcs);
356 
357  return 0;
358 }
359 
361  .p.name = "tscc2",
362  CODEC_LONG_NAME("TechSmith Screen Codec 2"),
363  .p.type = AVMEDIA_TYPE_VIDEO,
364  .p.id = AV_CODEC_ID_TSCC2,
365  .priv_data_size = sizeof(TSCC2Context),
367  .close = tscc2_decode_end,
369  .p.capabilities = AV_CODEC_CAP_DR1,
370  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
371 };
dc_vlc
static VLC dc_vlc
Definition: tscc2.c:55
ff_vlc_init_from_lengths
int ff_vlc_init_from_lengths(VLC *vlc, int nb_bits, int nb_codes, const int8_t *lens, int lens_wrap, const void *symbols, int symbols_wrap, int symbols_size, int offset, int flags, void *logctx)
Build VLC decoding tables suitable for use with get_vlc2()
Definition: vlc.c:306
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: codec_internal.h:42
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
GetByteContext
Definition: bytestream.h:33
thread.h
tscc2_decode_init
static av_cold int tscc2_decode_init(AVCodecContext *avctx)
Definition: tscc2.c:334
TSCC2Context::quant
int quant[2]
Definition: tscc2.c:48
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:160
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:374
AVPacket::data
uint8_t * data
Definition: packet.h:524
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#define t0
Definition: regdef.h:28
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static const uint16_t table[]
Definition: prosumer.c:203
COL_OP
#define COL_OP(a, b)
Definition: tscc2.c:98
FFCodec
Definition: codec_internal.h:126
ROW_OP
#define ROW_OP(a, b)
Definition: tscc2.c:99
t1
#define t1
Definition: regdef.h:29
TSCC2_VLC_BITS
#define TSCC2_VLC_BITS
Definition: tscc2.c:41
tscc2_quants
static const uint16_t tscc2_quants[NUM_VLC_SETS][3]
Definition: tscc2data.h:29
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
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static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
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
tscc2_ac_vlc_lens
static const uint8_t tscc2_ac_vlc_lens[]
Definition: tscc2data.h:312
val
static double val(void *priv, double ch)
Definition: aeval.c:78
tscc2_nc_vlc_syms
static const uint8_t tscc2_nc_vlc_syms[NUM_VLC_SETS][16]
Definition: tscc2data.h:53
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:148
ff_thread_once
static int ff_thread_once(char *control, void(*routine)(void))
Definition: thread.h:205
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
FF_ARRAY_ELEMS
#define FF_ARRAY_ELEMS(a)
Definition: sinewin_tablegen.c:29
av_cold
#define av_cold
Definition: attributes.h:90
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:545
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:286
TSCC2Context::q
int q[2][3]
Definition: tscc2.c:49
tscc2_init_vlc
static av_cold void tscc2_init_vlc(VLC *vlc, int *offset, int nb_codes, const uint8_t *lens, const void *syms, int sym_length)
Definition: tscc2.c:57
tscc2_nc_vlc_lens
static const uint8_t tscc2_nc_vlc_lens[NUM_VLC_SETS][16]
Definition: tscc2data.h:82
decode.h
get_bits.h
tscc2_decode_mb
static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set, uint8_t *dst, int stride, int plane)
Definition: tscc2.c:124
nc_vlc
static VLC nc_vlc[NUM_VLC_SETS]
Definition: tscc2.c:55
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:271
TSCC2Context::gb
GetBitContext gb
Definition: tscc2.c:50
AV_ONCE_INIT
#define AV_ONCE_INIT
Definition: thread.h:203
NULL
#define NULL
Definition: coverity.c:32
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static const uint8_t tscc2_dc_vlc_lens[DC_VLC_COUNT]
Definition: tscc2data.h:47
TSCC2Context
Definition: tscc2.c:43
NUM_VLC_SETS
#define NUM_VLC_SETS
Definition: tscc2data.h:27
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:388
mathops.h
TSCC2Context::mb_height
int mb_height
Definition: tscc2.c:46
get_vlc2
static av_always_inline int get_vlc2(GetBitContext *s, const VLCElem *table, int bits, int max_depth)
Parse a vlc code.
Definition: get_bits.h:652
tscc2_dc_vlc_syms
static const uint16_t tscc2_dc_vlc_syms[DC_VLC_COUNT]
Definition: tscc2data.h:39
AVOnce
#define AVOnce
Definition: thread.h:202
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
bytestream2_tell
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:192
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int table_allocated
Definition: vlc.h:39
init
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Definition: dts2pts.c:366
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const uint8_t ff_zigzag_scan[16+1]
Definition: mathtables.c:109
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
AVPacket::size
int size
Definition: packet.h:525
dc
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled top and top right vectors is used as motion vector prediction the used motion vector is the sum of the predictor and(mvx_diff, mvy_diff) *mv_scale Intra DC Prediction block[y][x] dc[1]
Definition: snow.txt:400
av_frame_ref
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:384
codec_internal.h
TSCC2Context::pic
AVFrame * pic
Definition: tscc2.c:45
size
int size
Definition: twinvq_data.h:10344
VLCElem
Definition: vlc.h:32
TSCC2Context::block
int block[16]
Definition: tscc2.c:52
offset
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Definition: writing_filters.txt:86
tscc2data.h
AV_CODEC_ID_TSCC2
@ AV_CODEC_ID_TSCC2
Definition: codec_id.h:216
DCT1D
#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP)
Definition: tscc2.c:92
TSCC2Context::avctx
AVCodecContext * avctx
Definition: tscc2.c:44
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
frame_type
frame_type
Definition: jpeg2000_parser.c:31
t3
#define t3
Definition: regdef.h:31
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
len
int len
Definition: vorbis_enc_data.h:426
AVCodecContext::height
int height
Definition: avcodec.h:618
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:657
DEQUANT
#define DEQUANT(val, q)
Definition: tscc2.c:91
avcodec.h
stride
#define stride
Definition: h264pred_template.c:537
TSCC2Context::mb_width
int mb_width
Definition: tscc2.c:46
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1684
ret
ret
Definition: filter_design.txt:187
pos
unsigned int pos
Definition: spdifenc.c:414
AVCodecContext
main external API structure.
Definition: avcodec.h:445
VLC_INIT_STATIC_OVERLONG
#define VLC_INIT_STATIC_OVERLONG
Definition: vlc.h:183
t2
#define t2
Definition: regdef.h:30
VLC
Definition: vlc.h:36
sign_extend
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:133
VLC::table
VLCElem * table
Definition: vlc.h:38
AV_PIX_FMT_YUV444P
@ AV_PIX_FMT_YUV444P
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:78
VLC::table_size
int table_size
Definition: vlc.h:39
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
VLC_INIT_OUTPUT_LE
#define VLC_INIT_OUTPUT_LE
Definition: vlc.h:188
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:78
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:472
AVPacket
This structure stores compressed data.
Definition: packet.h:501
tscc2_init_vlcs
static av_cold void tscc2_init_vlcs(void)
Definition: tscc2.c:71
tscc2_decode_end
static av_cold int tscc2_decode_end(AVCodecContext *avctx)
Definition: tscc2.c:324
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
DC_VLC_COUNT
#define DC_VLC_COUNT
Definition: tscc2data.h:37
tscc2_decode_frame
static int tscc2_decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: tscc2.c:209
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:618
tscc2_ac_vlc_sizes
static const int tscc2_ac_vlc_sizes[NUM_VLC_SETS]
Definition: tscc2data.h:431
bytestream.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
ac_vlc
static VLC ac_vlc[NUM_VLC_SETS]
Definition: tscc2.c:55
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
ff_tscc2_decoder
const FFCodec ff_tscc2_decoder
Definition: tscc2.c:360
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
tscc2_idct4_put
static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
Definition: tscc2.c:101
tscc2_decode_slice
static int tscc2_decode_slice(TSCC2Context *c, int mb_y, const uint8_t *buf, int buf_size)
Definition: tscc2.c:183
TSCC2Context::slice_quants
uint8_t * slice_quants
Definition: tscc2.c:47
tscc2_ac_vlc_syms
static const uint16_t tscc2_ac_vlc_syms[]
Definition: tscc2data.h:98