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 #define BITSTREAM_READER_LE
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "get_bits.h"
33 #include "internal.h"
34 #include "mathops.h"
35 #include "tscc2data.h"
36 
37 typedef struct TSCC2Context {
42  int quant[2];
43  int q[2][3];
45 
47  int block[16];
48 } TSCC2Context;
49 
51 {
52  int i;
53 
54  ff_free_vlc(&c->dc_vlc);
55  for (i = 0; i < NUM_VLC_SETS; i++) {
56  ff_free_vlc(c->nc_vlc + i);
57  ff_free_vlc(c->ac_vlc + i);
58  }
59 }
60 
62 {
63  int i, ret;
64 
66  tscc2_dc_vlc_bits, 1, 1,
67  tscc2_dc_vlc_codes, 2, 2,
69  if (ret)
70  return ret;
71 
72  for (i = 0; i < NUM_VLC_SETS; i++) {
73  ret = ff_init_vlc_sparse(c->nc_vlc + i, 9, 16,
74  tscc2_nc_vlc_bits[i], 1, 1,
75  tscc2_nc_vlc_codes[i], 2, 2,
77  if (ret) {
78  free_vlcs(c);
79  return ret;
80  }
81  ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i],
82  tscc2_ac_vlc_bits[i], 1, 1,
83  tscc2_ac_vlc_codes[i], 2, 2,
84  tscc2_ac_vlc_syms[i], 2, 2, INIT_VLC_LE);
85  if (ret) {
86  free_vlcs(c);
87  return ret;
88  }
89  }
90 
91  return 0;
92 }
93 
94 #define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8)
95 #define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
96  OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \
97  OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \
98  OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \
99  OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \
100 
101 #define COL_OP(a, b) a = (b)
102 #define ROW_OP(a, b) a = ((b) + 0x20) >> 6
103 
104 static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
105 {
106  int i;
107  int tblk[4 * 4];
108  int t0, t1, t2, t3;
109 
110  for (i = 0; i < 4; i++) {
111  t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
112  t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
113  t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
114  t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
115  DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
116  tblk[2 * 4 + i], tblk[3 * 4 + i],
117  t0, t1, t2, t3, COL_OP);
118  }
119  for (i = 0; i < 4; i++) {
120  DCT1D(dst[0], dst[1], dst[2], dst[3],
121  tblk[i * 4 + 0], tblk[i * 4 + 1],
122  tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
123  dst += stride;
124  }
125 }
126 
127 static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
128  uint8_t *dst, int stride, int plane)
129 {
130  GetBitContext *gb = &c->gb;
131  int prev_dc, dc, nc, ac, bpos, val;
132  int i, j, k, l;
133 
134  if (get_bits1(gb)) {
135  if (get_bits1(gb)) {
136  val = get_bits(gb, 8);
137  for (i = 0; i < 8; i++, dst += stride)
138  memset(dst, val, 16);
139  } else {
140  if (get_bits_left(gb) < 16 * 8 * 8)
141  return AVERROR_INVALIDDATA;
142  for (i = 0; i < 8; i++) {
143  for (j = 0; j < 16; j++)
144  dst[j] = get_bits(gb, 8);
145  dst += stride;
146  }
147  }
148  return 0;
149  }
150 
151  prev_dc = 0;
152  for (j = 0; j < 2; j++) {
153  for (k = 0; k < 4; k++) {
154  if (!(j | k)) {
155  dc = get_bits(gb, 8);
156  } else {
157  dc = get_vlc2(gb, c->dc_vlc.table, 9, 2);
158  if (dc == -1)
159  return AVERROR_INVALIDDATA;
160  if (dc == 0x100)
161  dc = get_bits(gb, 8);
162  }
163  dc = (dc + prev_dc) & 0xFF;
164  prev_dc = dc;
165  c->block[0] = dc;
166 
167  nc = get_vlc2(gb, c->nc_vlc[vlc_set].table, 9, 1);
168  if (nc == -1)
169  return AVERROR_INVALIDDATA;
170 
171  bpos = 1;
172  memset(c->block + 1, 0, 15 * sizeof(*c->block));
173  for (l = 0; l < nc; l++) {
174  ac = get_vlc2(gb, c->ac_vlc[vlc_set].table, 9, 2);
175  if (ac == -1)
176  return AVERROR_INVALIDDATA;
177  if (ac == 0x1000)
178  ac = get_bits(gb, 12);
179  bpos += ac & 0xF;
180  if (bpos >= 16)
181  return AVERROR_INVALIDDATA;
182  val = sign_extend(ac >> 4, 8);
183  c->block[ff_zigzag_scan[bpos++]] = val;
184  }
185  tscc2_idct4_put(c->block, q, dst + k * 4, stride);
186  }
187  dst += 4 * stride;
188  }
189  return 0;
190 }
191 
192 static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
193  const uint8_t *buf, int buf_size)
194 {
195  int i, mb_x, q, ret;
196  int off;
197 
198  if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
199  return ret;
200 
201  for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
202  q = c->slice_quants[mb_x + c->mb_width * mb_y];
203 
204  if (q == 0 || q == 3) // skip block
205  continue;
206  for (i = 0; i < 3; i++) {
207  off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
208  ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
209  c->pic->data[i] + off, c->pic->linesize[i], i);
210  if (ret)
211  return ret;
212  }
213  }
214 
215  return 0;
216 }
217 
219  int *got_frame, AVPacket *avpkt)
220 {
221  const uint8_t *buf = avpkt->data;
222  int buf_size = avpkt->size;
223  TSCC2Context *c = avctx->priv_data;
225  uint32_t frame_type, size;
226  int i, val, len, pos = 0;
227  int num_mb = c->mb_width * c->mb_height;
228  int ret;
229 
230  bytestream2_init(&gb, buf, buf_size);
231  frame_type = bytestream2_get_byte(&gb);
232  if (frame_type > 1) {
233  av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n",
234  frame_type);
235  return AVERROR_INVALIDDATA;
236  }
237 
238  if (frame_type == 0) {
239  // Skip duplicate frames
240  return buf_size;
241  }
242 
243  if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
244  return ret;
245  }
246 
247  if (bytestream2_get_bytes_left(&gb) < 4) {
248  av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
249  return AVERROR_INVALIDDATA;
250  }
251 
252  c->quant[0] = bytestream2_get_byte(&gb);
253  c->quant[1] = bytestream2_get_byte(&gb);
254  if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
255  c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
256  av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
257  c->quant[0], c->quant[1]);
258  return AVERROR_INVALIDDATA;
259  }
260 
261  for (i = 0; i < 3; i++) {
262  c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
263  c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
264  }
265 
266  bytestream2_skip(&gb, 1);
267 
268  size = bytestream2_get_le32(&gb);
269  if (size > bytestream2_get_bytes_left(&gb)) {
270  av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
271  return AVERROR_INVALIDDATA;
272  }
273 
274  for (i = 0; i < size; i++) {
275  val = bytestream2_get_byte(&gb);
276  len = val & 0x3F;
277  val >>= 6;
278  if (pos + len > num_mb) {
279  av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
280  return AVERROR_INVALIDDATA;
281  }
282  memset(c->slice_quants + pos, val, len);
283  pos += len;
284  }
285  if (pos < num_mb) {
286  av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
287  pos, num_mb);
288  return AVERROR_INVALIDDATA;
289  }
290 
291  for (i = 0; i < c->mb_height; i++) {
292  size = bytestream2_peek_byte(&gb);
293  if (size & 1) {
294  size = bytestream2_get_byte(&gb) - 1;
295  } else {
296  size = bytestream2_get_le32(&gb) >> 1;
297  }
298  if (!size) {
299  int skip_row = 1, j, off = i * c->mb_width;
300  for (j = 0; j < c->mb_width; j++) {
301  if (c->slice_quants[off + j] == 1 ||
302  c->slice_quants[off + j] == 2) {
303  skip_row = 0;
304  break;
305  }
306  }
307  if (!skip_row) {
308  av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
309  return AVERROR_INVALIDDATA;
310  }
311  }
312  if (bytestream2_get_bytes_left(&gb) < size) {
313  av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
314  size, bytestream2_get_bytes_left(&gb));
315  return AVERROR_INVALIDDATA;
316  }
317  ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
318  if (ret) {
319  av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
320  return ret;
321  }
322  bytestream2_skip(&gb, size);
323  }
324 
325  *got_frame = 1;
326  if ((ret = av_frame_ref(data, c->pic)) < 0)
327  return ret;
328 
329  /* always report that the buffer was completely consumed */
330  return buf_size;
331 }
332 
334 {
335  TSCC2Context * const c = avctx->priv_data;
336 
337  av_frame_free(&c->pic);
338  av_freep(&c->slice_quants);
339  free_vlcs(c);
340 
341  return 0;
342 }
343 
345 {
346  TSCC2Context * const c = avctx->priv_data;
347  int ret;
348 
349  c->avctx = avctx;
350 
351  avctx->pix_fmt = AV_PIX_FMT_YUV444P;
352 
353  if ((ret = init_vlcs(c)) < 0) {
354  av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
355  return ret;
356  }
357 
358  c->mb_width = FFALIGN(avctx->width, 16) >> 4;
359  c->mb_height = FFALIGN(avctx->height, 8) >> 3;
361  if (!c->slice_quants) {
362  av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
363  free_vlcs(c);
364  return AVERROR(ENOMEM);
365  }
366 
367  c->pic = av_frame_alloc();
368  if (!c->pic) {
369  tscc2_decode_end(avctx);
370  return AVERROR(ENOMEM);
371  }
372 
373  return 0;
374 }
375 
377  .name = "tscc2",
378  .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
379  .type = AVMEDIA_TYPE_VIDEO,
380  .id = AV_CODEC_ID_TSCC2,
381  .priv_data_size = sizeof(TSCC2Context),
383  .close = tscc2_decode_end,
385  .capabilities = AV_CODEC_CAP_DR1,
386 };
int plane
Definition: avisynth_c.h:384
const char const char void * val
Definition: avisynth_c.h:863
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
Definition: tscc2.c:104
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:71
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
static const uint16_t tscc2_dc_vlc_syms[DC_VLC_COUNT]
Definition: tscc2data.h:39
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int ff_init_vlc_sparse(VLC *vlc_arg, int nb_bits, int nb_codes, const void *bits, int bits_wrap, int bits_size, const void *codes, int codes_wrap, int codes_size, const void *symbols, int symbols_wrap, int symbols_size, int flags)
Definition: bitstream.c:273
AVFrame * pic
Definition: tscc2.c:39
int size
Definition: avcodec.h:1481
#define NUM_VLC_SETS
Definition: tscc2data.h:27
int block[16]
Definition: tscc2.c:47
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1778
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
static const int tscc2_ac_vlc_sizes[NUM_VLC_SETS]
Definition: tscc2data.h:902
AVCodec.
Definition: avcodec.h:3484
AVCodecContext * avctx
Definition: tscc2.c:38
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
VLC nc_vlc[NUM_VLC_SETS]
Definition: tscc2.c:46
#define COL_OP(a, b)
Definition: tscc2.c:101
static av_cold void free_vlcs(TSCC2Context *c)
Definition: tscc2.c:50
int q[2][3]
Definition: tscc2.c:43
uint8_t
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
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
static int tscc2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: tscc2.c:218
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:443
#define t0
Definition: regdef.h:28
uint8_t * data
Definition: avcodec.h:1480
bitstream reader API header.
ptrdiff_t size
Definition: opengl_enc.c:100
static const uint8_t tscc2_dc_vlc_bits[DC_VLC_COUNT]
Definition: tscc2data.h:57
#define FFALIGN(x, a)
Definition: macros.h:48
#define av_log(a,...)
static const uint16_t *const tscc2_ac_vlc_syms[NUM_VLC_SETS]
Definition: tscc2data.h:906
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
VLC dc_vlc
Definition: tscc2.c:46
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:164
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
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:2010
const uint8_t ff_zigzag_scan[16+1]
Definition: mathtables.c:109
#define t1
Definition: regdef.h:29
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
const char * name
Name of the codec implementation.
Definition: avcodec.h:3491
static const uint16_t *const tscc2_ac_vlc_codes[NUM_VLC_SETS]
Definition: tscc2data.h:913
#define t3
Definition: regdef.h:31
Definition: vlc.h:26
static av_cold int tscc2_decode_end(AVCodecContext *avctx)
Definition: tscc2.c:333
static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set, uint8_t *dst, int stride, int plane)
Definition: tscc2.c:127
int width
picture width / height.
Definition: avcodec.h:1741
#define DC_VLC_COUNT
Definition: tscc2data.h:37
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:797
static const uint16_t tscc2_nc_vlc_codes[NUM_VLC_SETS][16]
Definition: tscc2data.h:71
#define ROW_OP(a, b)
Definition: tscc2.c:102
#define INIT_VLC_LE
Definition: vlc.h:54
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:188
Libavcodec external API header.
uint8_t * slice_quants
Definition: tscc2.c:41
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
static const uint16_t tscc2_quants[NUM_VLC_SETS][3]
Definition: tscc2data.h:29
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
main external API structure.
Definition: avcodec.h:1568
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
VLC ac_vlc[NUM_VLC_SETS]
Definition: tscc2.c:46
void * buf
Definition: avisynth_c.h:766
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31))))#define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac){}void ff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map){AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);return NULL;}return ac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;}int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){int use_generic=1;int len=in->nb_samples;int p;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
static av_cold int tscc2_decode_init(AVCodecContext *avctx)
Definition: tscc2.c:344
static const uint16_t tscc2_dc_vlc_codes[DC_VLC_COUNT]
Definition: tscc2data.h:48
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:130
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP)
Definition: tscc2.c:95
int mb_height
Definition: tscc2.c:40
static av_cold int init_vlcs(TSCC2Context *c)
Definition: tscc2.c:61
GLint GLenum GLboolean GLsizei stride
Definition: opengl_enc.c:104
int quant[2]
Definition: tscc2.c:42
static const uint8_t *const tscc2_ac_vlc_bits[NUM_VLC_SETS]
Definition: tscc2data.h:921
common internal api header.
static int tscc2_decode_slice(TSCC2Context *c, int mb_y, const uint8_t *buf, int buf_size)
Definition: tscc2.c:192
void * priv_data
Definition: avcodec.h:1595
static const uint8_t tscc2_nc_vlc_bits[NUM_VLC_SETS][16]
Definition: tscc2data.h:100
#define DEQUANT(val, q)
Definition: tscc2.c:94
static const uint8_t tscc2_nc_vlc_syms[16]
Definition: tscc2data.h:66
int len
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
int mb_width
Definition: tscc2.c:40
#define av_freep(p)
#define stride
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
GetBitContext gb
Definition: tscc2.c:44
This structure stores compressed data.
Definition: avcodec.h:1457
void ff_free_vlc(VLC *vlc)
Definition: bitstream.c:359
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:984
#define t2
Definition: regdef.h:30
AVCodec ff_tscc2_decoder
Definition: tscc2.c:376