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 "codec_internal.h"
35 #include "get_bits.h"
36 #include "internal.h"
37 #include "mathops.h"
38 #include "tscc2data.h"
39 
40 #define TSCC2_VLC_BITS 9
41 
42 typedef struct TSCC2Context {
46  uint8_t *slice_quants;
47  int quant[2];
48  int q[2][3];
50 
51  int block[16];
52 } TSCC2Context;
53 
55 
56 static av_cold void tscc2_init_vlc(VLC *vlc, int *offset, int nb_codes,
57  const uint8_t *lens, const void *syms,
58  int sym_length)
59 {
60  static VLCElem vlc_buf[15442];
61 
62  vlc->table = &vlc_buf[*offset];
65  lens, 1, syms, sym_length, sym_length, 0,
67  *offset += vlc->table_size;
68 }
69 
70 static av_cold void tscc2_init_vlcs(void)
71 {
72  const uint16_t *ac_vlc_syms = tscc2_ac_vlc_syms;
73  const uint8_t *ac_vlc_lens = tscc2_ac_vlc_lens;
74  int i, offset = 0;
75 
78 
79  for (i = 0; i < NUM_VLC_SETS; i++) {
80  tscc2_init_vlc(&nc_vlc[i], &offset, 16,
82 
84  ac_vlc_lens, ac_vlc_syms, 2);
85  ac_vlc_lens += tscc2_ac_vlc_sizes[i];
86  ac_vlc_syms += tscc2_ac_vlc_sizes[i];
87  }
88 }
89 
90 #define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8)
91 #define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
92  OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \
93  OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \
94  OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \
95  OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \
96 
97 #define COL_OP(a, b) a = (b)
98 #define ROW_OP(a, b) a = ((b) + 0x20) >> 6
99 
100 static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
101 {
102  int i;
103  int tblk[4 * 4];
104  int t0, t1, t2, t3;
105 
106  for (i = 0; i < 4; i++) {
107  t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
108  t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
109  t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
110  t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
111  DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
112  tblk[2 * 4 + i], tblk[3 * 4 + i],
113  t0, t1, t2, t3, COL_OP);
114  }
115  for (i = 0; i < 4; i++) {
116  DCT1D(dst[0], dst[1], dst[2], dst[3],
117  tblk[i * 4 + 0], tblk[i * 4 + 1],
118  tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
119  dst += stride;
120  }
121 }
122 
123 static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
124  uint8_t *dst, int stride, int plane)
125 {
126  GetBitContext *gb = &c->gb;
127  int prev_dc, dc, nc, ac, bpos, val;
128  int i, j, k, l;
129 
130  if (get_bits1(gb)) {
131  if (get_bits1(gb)) {
132  val = get_bits(gb, 8);
133  for (i = 0; i < 8; i++, dst += stride)
134  memset(dst, val, 16);
135  } else {
136  if (get_bits_left(gb) < 16 * 8 * 8)
137  return AVERROR_INVALIDDATA;
138  for (i = 0; i < 8; i++) {
139  for (j = 0; j < 16; j++)
140  dst[j] = get_bits(gb, 8);
141  dst += stride;
142  }
143  }
144  return 0;
145  }
146 
147  prev_dc = 0;
148  for (j = 0; j < 2; j++) {
149  for (k = 0; k < 4; k++) {
150  if (!(j | k)) {
151  dc = get_bits(gb, 8);
152  } else {
154  if (dc == 0x100)
155  dc = get_bits(gb, 8);
156  }
157  dc = (dc + prev_dc) & 0xFF;
158  prev_dc = dc;
159  c->block[0] = dc;
160 
161  nc = get_vlc2(gb, nc_vlc[vlc_set].table, TSCC2_VLC_BITS, 1);
162 
163  bpos = 1;
164  memset(c->block + 1, 0, 15 * sizeof(*c->block));
165  for (l = 0; l < nc; l++) {
166  ac = get_vlc2(gb, ac_vlc[vlc_set].table, TSCC2_VLC_BITS, 2);
167  if (ac == 0x1000)
168  ac = get_bits(gb, 12);
169  bpos += ac & 0xF;
170  if (bpos >= 16)
171  return AVERROR_INVALIDDATA;
172  val = sign_extend(ac >> 4, 8);
173  c->block[ff_zigzag_scan[bpos++]] = val;
174  }
175  tscc2_idct4_put(c->block, q, dst + k * 4, stride);
176  }
177  dst += 4 * stride;
178  }
179  return 0;
180 }
181 
182 static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
183  const uint8_t *buf, int buf_size)
184 {
185  int i, mb_x, q, ret;
186  int off;
187 
188  if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
189  return ret;
190 
191  for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
192  q = c->slice_quants[mb_x + c->mb_width * mb_y];
193 
194  if (q == 0 || q == 3) // skip block
195  continue;
196  for (i = 0; i < 3; i++) {
197  off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
198  ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
199  c->pic->data[i] + off, c->pic->linesize[i], i);
200  if (ret)
201  return ret;
202  }
203  }
204 
205  return 0;
206 }
207 
208 static int tscc2_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
209  int *got_frame, AVPacket *avpkt)
210 {
211  const uint8_t *buf = avpkt->data;
212  int buf_size = avpkt->size;
213  TSCC2Context *c = avctx->priv_data;
214  GetByteContext gb;
215  uint32_t frame_type, size;
216  int i, val, len, pos = 0;
217  int num_mb = c->mb_width * c->mb_height;
218  int ret;
219 
220  bytestream2_init(&gb, buf, buf_size);
221  frame_type = bytestream2_get_byte(&gb);
222  if (frame_type > 1) {
223  av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n",
224  frame_type);
225  return AVERROR_INVALIDDATA;
226  }
227 
228  if (frame_type == 0) {
229  // Skip duplicate frames
230  return buf_size;
231  }
232 
233  if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
234  return ret;
235  }
236 
237  if (bytestream2_get_bytes_left(&gb) < 4) {
238  av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
239  return AVERROR_INVALIDDATA;
240  }
241 
242  c->quant[0] = bytestream2_get_byte(&gb);
243  c->quant[1] = bytestream2_get_byte(&gb);
244  if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
245  c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
246  av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
247  c->quant[0], c->quant[1]);
248  return AVERROR_INVALIDDATA;
249  }
250 
251  for (i = 0; i < 3; i++) {
252  c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
253  c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
254  }
255 
256  bytestream2_skip(&gb, 1);
257 
258  size = bytestream2_get_le32(&gb);
259  if (size > bytestream2_get_bytes_left(&gb)) {
260  av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
261  return AVERROR_INVALIDDATA;
262  }
263 
264  for (i = 0; i < size; i++) {
265  val = bytestream2_get_byte(&gb);
266  len = val & 0x3F;
267  val >>= 6;
268  if (pos + len > num_mb) {
269  av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
270  return AVERROR_INVALIDDATA;
271  }
272  memset(c->slice_quants + pos, val, len);
273  pos += len;
274  }
275  if (pos < num_mb) {
276  av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
277  pos, num_mb);
278  return AVERROR_INVALIDDATA;
279  }
280 
281  for (i = 0; i < c->mb_height; i++) {
282  size = bytestream2_peek_byte(&gb);
283  if (size & 1) {
284  size = bytestream2_get_byte(&gb) - 1;
285  } else {
286  size = bytestream2_get_le32(&gb) >> 1;
287  }
288  if (!size) {
289  int skip_row = 1, j, off = i * c->mb_width;
290  for (j = 0; j < c->mb_width; j++) {
291  if (c->slice_quants[off + j] == 1 ||
292  c->slice_quants[off + j] == 2) {
293  skip_row = 0;
294  break;
295  }
296  }
297  if (!skip_row) {
298  av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
299  return AVERROR_INVALIDDATA;
300  }
301  }
302  if (bytestream2_get_bytes_left(&gb) < size) {
303  av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
305  return AVERROR_INVALIDDATA;
306  }
307  ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
308  if (ret) {
309  av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
310  return ret;
311  }
312  bytestream2_skip(&gb, size);
313  }
314 
315  *got_frame = 1;
316  if ((ret = av_frame_ref(rframe, c->pic)) < 0)
317  return ret;
318 
319  /* always report that the buffer was completely consumed */
320  return buf_size;
321 }
322 
324 {
325  TSCC2Context * const c = avctx->priv_data;
326 
327  av_frame_free(&c->pic);
328  av_freep(&c->slice_quants);
329 
330  return 0;
331 }
332 
334 {
335  TSCC2Context * const c = avctx->priv_data;
336  static AVOnce init_static_once = AV_ONCE_INIT;
337 
338  c->avctx = avctx;
339 
340  avctx->pix_fmt = AV_PIX_FMT_YUV444P;
341 
342  c->mb_width = FFALIGN(avctx->width, 16) >> 4;
343  c->mb_height = FFALIGN(avctx->height, 8) >> 3;
344  c->slice_quants = av_malloc(c->mb_width * c->mb_height);
345  if (!c->slice_quants) {
346  av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
347  return AVERROR(ENOMEM);
348  }
349 
350  c->pic = av_frame_alloc();
351  if (!c->pic)
352  return AVERROR(ENOMEM);
353 
354  ff_thread_once(&init_static_once, tscc2_init_vlcs);
355 
356  return 0;
357 }
358 
360  .p.name = "tscc2",
361  .p.long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
362  .p.type = AVMEDIA_TYPE_VIDEO,
363  .p.id = AV_CODEC_ID_TSCC2,
364  .priv_data_size = sizeof(TSCC2Context),
366  .close = tscc2_decode_end,
368  .p.capabilities = AV_CODEC_CAP_DR1,
369  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
370 };
dc_vlc
static VLC dc_vlc
Definition: tscc2.c:54
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:41
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:839
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
INIT_VLC_OUTPUT_LE
#define INIT_VLC_OUTPUT_LE
Definition: vlc.h:98
GetByteContext
Definition: bytestream.h:33
thread.h
tscc2_decode_init
static av_cold int tscc2_decode_init(AVCodecContext *avctx)
Definition: tscc2.c:333
TSCC2Context::quant
int quant[2]
Definition: tscc2.c:47
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:116
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:374
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#define t0
Definition: regdef.h:28
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static const uint16_t table[]
Definition: prosumer.c:206
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#define COL_OP(a, b)
Definition: tscc2.c:97
FFCodec
Definition: codec_internal.h:118
ROW_OP
#define ROW_OP(a, b)
Definition: tscc2.c:98
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#define t1
Definition: regdef.h:29
TSCC2_VLC_BITS
#define TSCC2_VLC_BITS
Definition: tscc2.c:40
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static const uint16_t tscc2_quants[NUM_VLC_SETS][3]
Definition: tscc2data.h:29
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Definition: tableprint_vlc.h:30
init
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Definition: av_tx.c:47
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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:379
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:122
GetBitContext
Definition: get_bits.h:61
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:77
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:104
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static int ff_thread_once(char *control, void(*routine)(void))
Definition: thread.h:179
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
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#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:667
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:260
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int q[2][3]
Definition: tscc2.c:48
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:56
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Definition: clearvideo.c:87
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Definition: tscc2data.h:82
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static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set, uint8_t *dst, int stride, int plane)
Definition: tscc2.c:123
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Definition: tscc2.c:54
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Definition: tscc2.c:49
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Definition: thread.h:177
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Definition: coverity.c:32
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Definition: tscc2data.h:47
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Definition: tscc2.c:42
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Definition: tscc2data.h:27
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Definition: get_bits.h:498
ff_init_vlc_from_lengths
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Build VLC decoding tables suitable for use with get_vlc2()
Definition: vlc.c:328
mathops.h
TSCC2Context::mb_height
int mb_height
Definition: tscc2.c:45
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:787
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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:176
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
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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:34
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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:375
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:117
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:353
codec_internal.h
TSCC2Context::pic
AVFrame * pic
Definition: tscc2.c:44
size
int size
Definition: twinvq_data.h:10344
VLCElem
Definition: vlc.h:27
TSCC2Context::block
int block[16]
Definition: tscc2.c:51
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:91
TSCC2Context::avctx
AVCodecContext * avctx
Definition: tscc2.c:43
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
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:211
len
int len
Definition: vorbis_enc_data.h:426
AVCodecContext::height
int height
Definition: avcodec.h:571
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
DEQUANT
#define DEQUANT(val, q)
Definition: tscc2.c:90
avcodec.h
stride
#define stride
Definition: h264pred_template.c:537
TSCC2Context::mb_width
int mb_width
Definition: tscc2.c:45
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:1580
ret
ret
Definition: filter_design.txt:187
INIT_VLC_STATIC_OVERLONG
#define INIT_VLC_STATIC_OVERLONG
Definition: vlc.h:101
pos
unsigned int pos
Definition: spdifenc.c:412
AVCodecContext
main external API structure.
Definition: avcodec.h:398
t2
#define t2
Definition: regdef.h:30
VLC
Definition: vlc.h:31
sign_extend
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:132
VLC::table
VLCElem * table
Definition: vlc.h:33
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:34
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:425
AVPacket
This structure stores compressed data.
Definition: packet.h:351
tscc2_init_vlcs
static av_cold void tscc2_init_vlcs(void)
Definition: tscc2.c:70
tscc2_decode_end
static av_cold int tscc2_decode_end(AVCodecContext *avctx)
Definition: tscc2.c:323
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:208
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:571
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:54
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
ff_tscc2_decoder
const FFCodec ff_tscc2_decoder
Definition: tscc2.c:359
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:100
tscc2_decode_slice
static int tscc2_decode_slice(TSCC2Context *c, int mb_y, const uint8_t *buf, int buf_size)
Definition: tscc2.c:182
TSCC2Context::slice_quants
uint8_t * slice_quants
Definition: tscc2.c:46
tscc2_ac_vlc_syms
static const uint16_t tscc2_ac_vlc_syms[]
Definition: tscc2data.h:98