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/thread.h"
30 
31 #define BITSTREAM_READER_LE
32 #include "avcodec.h"
33 #include "bytestream.h"
34 #include "get_bits.h"
35 #include "internal.h"
36 #include "mathops.h"
37 #include "tscc2data.h"
38 
39 #define TSCC2_VLC_BITS 9
40 
41 typedef struct TSCC2Context {
45  uint8_t *slice_quants;
46  int quant[2];
47  int q[2][3];
49 
50  int block[16];
51 } TSCC2Context;
52 
54 
55 static av_cold void tscc2_init_vlc(VLC *vlc, int *offset, int nb_codes,
56  const uint8_t *lens, const void *syms,
57  int sym_length)
58 {
59  static VLC_TYPE vlc_buf[15442][2];
60 
61  vlc->table = &vlc_buf[*offset];
64  lens, 1, syms, sym_length, sym_length, 0,
66  *offset += vlc->table_size;
67 }
68 
69 static av_cold void tscc2_init_vlcs(void)
70 {
71  const uint16_t *ac_vlc_syms = tscc2_ac_vlc_syms;
72  const uint8_t *ac_vlc_lens = tscc2_ac_vlc_lens;
73  int i, offset = 0;
74 
77 
78  for (i = 0; i < NUM_VLC_SETS; i++) {
79  tscc2_init_vlc(&nc_vlc[i], &offset, 16,
81 
83  ac_vlc_lens, ac_vlc_syms, 2);
84  ac_vlc_lens += tscc2_ac_vlc_sizes[i];
85  ac_vlc_syms += tscc2_ac_vlc_sizes[i];
86  }
87 }
88 
89 #define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8)
90 #define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
91  OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \
92  OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \
93  OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \
94  OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \
95 
96 #define COL_OP(a, b) a = (b)
97 #define ROW_OP(a, b) a = ((b) + 0x20) >> 6
98 
99 static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
100 {
101  int i;
102  int tblk[4 * 4];
103  int t0, t1, t2, t3;
104 
105  for (i = 0; i < 4; i++) {
106  t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
107  t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
108  t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
109  t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
110  DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
111  tblk[2 * 4 + i], tblk[3 * 4 + i],
112  t0, t1, t2, t3, COL_OP);
113  }
114  for (i = 0; i < 4; i++) {
115  DCT1D(dst[0], dst[1], dst[2], dst[3],
116  tblk[i * 4 + 0], tblk[i * 4 + 1],
117  tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
118  dst += stride;
119  }
120 }
121 
122 static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
123  uint8_t *dst, int stride, int plane)
124 {
125  GetBitContext *gb = &c->gb;
126  int prev_dc, dc, nc, ac, bpos, val;
127  int i, j, k, l;
128 
129  if (get_bits1(gb)) {
130  if (get_bits1(gb)) {
131  val = get_bits(gb, 8);
132  for (i = 0; i < 8; i++, dst += stride)
133  memset(dst, val, 16);
134  } else {
135  if (get_bits_left(gb) < 16 * 8 * 8)
136  return AVERROR_INVALIDDATA;
137  for (i = 0; i < 8; i++) {
138  for (j = 0; j < 16; j++)
139  dst[j] = get_bits(gb, 8);
140  dst += stride;
141  }
142  }
143  return 0;
144  }
145 
146  prev_dc = 0;
147  for (j = 0; j < 2; j++) {
148  for (k = 0; k < 4; k++) {
149  if (!(j | k)) {
150  dc = get_bits(gb, 8);
151  } else {
153  if (dc == 0x100)
154  dc = get_bits(gb, 8);
155  }
156  dc = (dc + prev_dc) & 0xFF;
157  prev_dc = dc;
158  c->block[0] = dc;
159 
160  nc = get_vlc2(gb, nc_vlc[vlc_set].table, TSCC2_VLC_BITS, 1);
161 
162  bpos = 1;
163  memset(c->block + 1, 0, 15 * sizeof(*c->block));
164  for (l = 0; l < nc; l++) {
165  ac = get_vlc2(gb, ac_vlc[vlc_set].table, TSCC2_VLC_BITS, 2);
166  if (ac == 0x1000)
167  ac = get_bits(gb, 12);
168  bpos += ac & 0xF;
169  if (bpos >= 16)
170  return AVERROR_INVALIDDATA;
171  val = sign_extend(ac >> 4, 8);
172  c->block[ff_zigzag_scan[bpos++]] = val;
173  }
174  tscc2_idct4_put(c->block, q, dst + k * 4, stride);
175  }
176  dst += 4 * stride;
177  }
178  return 0;
179 }
180 
181 static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
182  const uint8_t *buf, int buf_size)
183 {
184  int i, mb_x, q, ret;
185  int off;
186 
187  if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
188  return ret;
189 
190  for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
191  q = c->slice_quants[mb_x + c->mb_width * mb_y];
192 
193  if (q == 0 || q == 3) // skip block
194  continue;
195  for (i = 0; i < 3; i++) {
196  off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
197  ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
198  c->pic->data[i] + off, c->pic->linesize[i], i);
199  if (ret)
200  return ret;
201  }
202  }
203 
204  return 0;
205 }
206 
207 static int tscc2_decode_frame(AVCodecContext *avctx, void *data,
208  int *got_frame, AVPacket *avpkt)
209 {
210  const uint8_t *buf = avpkt->data;
211  int buf_size = avpkt->size;
212  TSCC2Context *c = avctx->priv_data;
213  GetByteContext gb;
214  uint32_t frame_type, size;
215  int i, val, len, pos = 0;
216  int num_mb = c->mb_width * c->mb_height;
217  int ret;
218 
219  bytestream2_init(&gb, buf, buf_size);
220  frame_type = bytestream2_get_byte(&gb);
221  if (frame_type > 1) {
222  av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n",
223  frame_type);
224  return AVERROR_INVALIDDATA;
225  }
226 
227  if (frame_type == 0) {
228  // Skip duplicate frames
229  return buf_size;
230  }
231 
232  if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
233  return ret;
234  }
235 
236  if (bytestream2_get_bytes_left(&gb) < 4) {
237  av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
238  return AVERROR_INVALIDDATA;
239  }
240 
241  c->quant[0] = bytestream2_get_byte(&gb);
242  c->quant[1] = bytestream2_get_byte(&gb);
243  if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
244  c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
245  av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
246  c->quant[0], c->quant[1]);
247  return AVERROR_INVALIDDATA;
248  }
249 
250  for (i = 0; i < 3; i++) {
251  c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
252  c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
253  }
254 
255  bytestream2_skip(&gb, 1);
256 
257  size = bytestream2_get_le32(&gb);
258  if (size > bytestream2_get_bytes_left(&gb)) {
259  av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
260  return AVERROR_INVALIDDATA;
261  }
262 
263  for (i = 0; i < size; i++) {
264  val = bytestream2_get_byte(&gb);
265  len = val & 0x3F;
266  val >>= 6;
267  if (pos + len > num_mb) {
268  av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
269  return AVERROR_INVALIDDATA;
270  }
271  memset(c->slice_quants + pos, val, len);
272  pos += len;
273  }
274  if (pos < num_mb) {
275  av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
276  pos, num_mb);
277  return AVERROR_INVALIDDATA;
278  }
279 
280  for (i = 0; i < c->mb_height; i++) {
281  size = bytestream2_peek_byte(&gb);
282  if (size & 1) {
283  size = bytestream2_get_byte(&gb) - 1;
284  } else {
285  size = bytestream2_get_le32(&gb) >> 1;
286  }
287  if (!size) {
288  int skip_row = 1, j, off = i * c->mb_width;
289  for (j = 0; j < c->mb_width; j++) {
290  if (c->slice_quants[off + j] == 1 ||
291  c->slice_quants[off + j] == 2) {
292  skip_row = 0;
293  break;
294  }
295  }
296  if (!skip_row) {
297  av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
298  return AVERROR_INVALIDDATA;
299  }
300  }
301  if (bytestream2_get_bytes_left(&gb) < size) {
302  av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
304  return AVERROR_INVALIDDATA;
305  }
306  ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
307  if (ret) {
308  av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
309  return ret;
310  }
311  bytestream2_skip(&gb, size);
312  }
313 
314  *got_frame = 1;
315  if ((ret = av_frame_ref(data, c->pic)) < 0)
316  return ret;
317 
318  /* always report that the buffer was completely consumed */
319  return buf_size;
320 }
321 
323 {
324  TSCC2Context * const c = avctx->priv_data;
325 
326  av_frame_free(&c->pic);
327  av_freep(&c->slice_quants);
328 
329  return 0;
330 }
331 
333 {
334  TSCC2Context * const c = avctx->priv_data;
335  static AVOnce init_static_once = AV_ONCE_INIT;
336 
337  c->avctx = avctx;
338 
339  avctx->pix_fmt = AV_PIX_FMT_YUV444P;
340 
341  c->mb_width = FFALIGN(avctx->width, 16) >> 4;
342  c->mb_height = FFALIGN(avctx->height, 8) >> 3;
343  c->slice_quants = av_malloc(c->mb_width * c->mb_height);
344  if (!c->slice_quants) {
345  av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
346  return AVERROR(ENOMEM);
347  }
348 
349  c->pic = av_frame_alloc();
350  if (!c->pic)
351  return AVERROR(ENOMEM);
352 
353  ff_thread_once(&init_static_once, tscc2_init_vlcs);
354 
355  return 0;
356 }
357 
359  .name = "tscc2",
360  .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
361  .type = AVMEDIA_TYPE_VIDEO,
362  .id = AV_CODEC_ID_TSCC2,
363  .priv_data_size = sizeof(TSCC2Context),
365  .close = tscc2_decode_end,
367  .capabilities = AV_CODEC_CAP_DR1,
369 };
AVCodec
AVCodec.
Definition: codec.h:197
dc_vlc
static VLC dc_vlc
Definition: tscc2.c:53
stride
int stride
Definition: mace.c:144
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
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
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
INIT_VLC_OUTPUT_LE
#define INIT_VLC_OUTPUT_LE
Definition: vlc.h:93
GetByteContext
Definition: bytestream.h:33
thread.h
tscc2_decode_init
static av_cold int tscc2_decode_init(AVCodecContext *avctx)
Definition: tscc2.c:332
TSCC2Context::quant
int quant[2]
Definition: tscc2.c:46
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:112
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
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#define t0
Definition: regdef.h:28
table
static const uint16_t table[]
Definition: prosumer.c:206
data
const char data[16]
Definition: mxf.c:143
COL_OP
#define COL_OP(a, b)
Definition: tscc2.c:96
ROW_OP
#define ROW_OP(a, b)
Definition: tscc2.c:97
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static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE(*table)[2], int bits, int max_depth)
Parse a vlc code.
Definition: get_bits.h:798
t1
#define t1
Definition: regdef.h:29
TSCC2_VLC_BITS
#define TSCC2_VLC_BITS
Definition: tscc2.c:39
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:31
bytestream2_skip
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
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static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:380
VLC_TYPE
#define VLC_TYPE
Definition: vlc.h:24
GetBitContext
Definition: get_bits.h:62
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:75
tscc2_nc_vlc_syms
static const uint8_t tscc2_nc_vlc_syms[NUM_VLC_SETS][16]
Definition: tscc2data.h:53
ff_init_vlc_from_lengths
int ff_init_vlc_from_lengths(VLC *vlc_arg, 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: bitstream.c:381
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:99
ff_thread_once
static int ff_thread_once(char *control, void(*routine)(void))
Definition: thread.h:175
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
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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:678
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static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
TSCC2Context::q
int q[2][3]
Definition: tscc2.c:47
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:55
tscc2_nc_vlc_lens
static const uint8_t tscc2_nc_vlc_lens[NUM_VLC_SETS][16]
Definition: tscc2data.h:82
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:122
nc_vlc
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Definition: tscc2.c:53
TSCC2Context::gb
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Definition: tscc2.c:48
AV_ONCE_INIT
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Definition: thread.h:173
NULL
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Definition: coverity.c:32
tscc2_dc_vlc_lens
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Definition: tscc2data.h:47
TSCC2Context
Definition: tscc2.c:41
NUM_VLC_SETS
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Definition: tscc2data.h:27
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Definition: get_bits.h:499
mathops.h
TSCC2Context::mb_height
int mb_height
Definition: tscc2.c:44
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static const uint16_t tscc2_dc_vlc_syms[DC_VLC_COUNT]
Definition: tscc2data.h:39
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#define AVOnce
Definition: thread.h:172
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
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Definition: bytestream.h:192
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Definition: vlc.h:29
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Definition: mathtables.c:109
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Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
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int size
Definition: packet.h:374
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
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:116
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:327
TSCC2Context::pic
AVFrame * pic
Definition: tscc2.c:43
size
int size
Definition: twinvq_data.h:10344
TSCC2Context::block
int block[16]
Definition: tscc2.c:50
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:214
DCT1D
#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP)
Definition: tscc2.c:90
i
int i
Definition: input.c:406
TSCC2Context::avctx
AVCodecContext * avctx
Definition: tscc2.c:42
frame_type
frame_type
Definition: jpeg2000_parser.c:31
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: internal.h:50
t3
#define t3
Definition: regdef.h:31
tscc2_decode_frame
static int tscc2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: tscc2.c:207
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:204
len
int len
Definition: vorbis_enc_data.h:426
AVCodecContext::height
int height
Definition: avcodec.h:552
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:589
DEQUANT
#define DEQUANT(val, q)
Definition: tscc2.c:89
avcodec.h
TSCC2Context::mb_width
int mb_width
Definition: tscc2.c:44
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:1755
ret
ret
Definition: filter_design.txt:187
INIT_VLC_STATIC_OVERLONG
#define INIT_VLC_STATIC_OVERLONG
Definition: vlc.h:96
pos
unsigned int pos
Definition: spdifenc.c:412
vlc_buf
static VLC_TYPE vlc_buf[16716][2]
Definition: clearvideo.c:86
AVCodecContext
main external API structure.
Definition: avcodec.h:379
t2
#define t2
Definition: regdef.h:30
VLC
Definition: vlc.h:26
sign_extend
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:130
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:71
VLC::table_size
int table_size
Definition: vlc.h:29
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:78
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:406
AVPacket
This structure stores compressed data.
Definition: packet.h:350
tscc2_init_vlcs
static av_cold void tscc2_init_vlcs(void)
Definition: tscc2.c:69
tscc2_decode_end
static av_cold int tscc2_decode_end(AVCodecContext *avctx)
Definition: tscc2.c:322
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
DC_VLC_COUNT
#define DC_VLC_COUNT
Definition: tscc2data.h:37
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:552
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:53
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
tscc2_idct4_put
static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
Definition: tscc2.c:99
tscc2_decode_slice
static int tscc2_decode_slice(TSCC2Context *c, int mb_y, const uint8_t *buf, int buf_size)
Definition: tscc2.c:181
ff_tscc2_decoder
const AVCodec ff_tscc2_decoder
Definition: tscc2.c:358
TSCC2Context::slice_quants
uint8_t * slice_quants
Definition: tscc2.c:45
VLC::table
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
tscc2_ac_vlc_syms
static const uint16_t tscc2_ac_vlc_syms[]
Definition: tscc2data.h:98