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  return ret;
79  ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i],
80  tscc2_ac_vlc_bits[i], 1, 1,
81  tscc2_ac_vlc_codes[i], 2, 2,
82  tscc2_ac_vlc_syms[i], 2, 2, INIT_VLC_LE);
83  if (ret)
84  return ret;
85  }
86 
87  return 0;
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 {
153  dc = get_vlc2(gb, c->dc_vlc.table, 9, 2);
154  if (dc == -1)
155  return AVERROR_INVALIDDATA;
156  if (dc == 0x100)
157  dc = get_bits(gb, 8);
158  }
159  dc = (dc + prev_dc) & 0xFF;
160  prev_dc = dc;
161  c->block[0] = dc;
162 
163  nc = get_vlc2(gb, c->nc_vlc[vlc_set].table, 9, 1);
164  if (nc == -1)
165  return AVERROR_INVALIDDATA;
166 
167  bpos = 1;
168  memset(c->block + 1, 0, 15 * sizeof(*c->block));
169  for (l = 0; l < nc; l++) {
170  ac = get_vlc2(gb, c->ac_vlc[vlc_set].table, 9, 2);
171  if (ac == -1)
172  return AVERROR_INVALIDDATA;
173  if (ac == 0x1000)
174  ac = get_bits(gb, 12);
175  bpos += ac & 0xF;
176  if (bpos >= 16)
177  return AVERROR_INVALIDDATA;
178  val = sign_extend(ac >> 4, 8);
179  c->block[ff_zigzag_scan[bpos++]] = val;
180  }
181  tscc2_idct4_put(c->block, q, dst + k * 4, stride);
182  }
183  dst += 4 * stride;
184  }
185  return 0;
186 }
187 
188 static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
189  const uint8_t *buf, int buf_size)
190 {
191  int i, mb_x, q, ret;
192  int off;
193 
194  if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
195  return ret;
196 
197  for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
198  q = c->slice_quants[mb_x + c->mb_width * mb_y];
199 
200  if (q == 0 || q == 3) // skip block
201  continue;
202  for (i = 0; i < 3; i++) {
203  off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
204  ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
205  c->pic->data[i] + off, c->pic->linesize[i], i);
206  if (ret)
207  return ret;
208  }
209  }
210 
211  return 0;
212 }
213 
215  int *got_frame, AVPacket *avpkt)
216 {
217  const uint8_t *buf = avpkt->data;
218  int buf_size = avpkt->size;
219  TSCC2Context *c = avctx->priv_data;
221  uint32_t frame_type, size;
222  int i, val, len, pos = 0;
223  int num_mb = c->mb_width * c->mb_height;
224  int ret;
225 
226  bytestream2_init(&gb, buf, buf_size);
227  frame_type = bytestream2_get_byte(&gb);
228  if (frame_type > 1) {
229  av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n",
230  frame_type);
231  return AVERROR_INVALIDDATA;
232  }
233 
234  if (frame_type == 0) {
235  // Skip duplicate frames
236  return buf_size;
237  }
238 
239  if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
240  return ret;
241  }
242 
243  if (bytestream2_get_bytes_left(&gb) < 4) {
244  av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
245  return AVERROR_INVALIDDATA;
246  }
247 
248  c->quant[0] = bytestream2_get_byte(&gb);
249  c->quant[1] = bytestream2_get_byte(&gb);
250  if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
251  c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
252  av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
253  c->quant[0], c->quant[1]);
254  return AVERROR_INVALIDDATA;
255  }
256 
257  for (i = 0; i < 3; i++) {
258  c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
259  c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
260  }
261 
262  bytestream2_skip(&gb, 1);
263 
264  size = bytestream2_get_le32(&gb);
265  if (size > bytestream2_get_bytes_left(&gb)) {
266  av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
267  return AVERROR_INVALIDDATA;
268  }
269 
270  for (i = 0; i < size; i++) {
271  val = bytestream2_get_byte(&gb);
272  len = val & 0x3F;
273  val >>= 6;
274  if (pos + len > num_mb) {
275  av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
276  return AVERROR_INVALIDDATA;
277  }
278  memset(c->slice_quants + pos, val, len);
279  pos += len;
280  }
281  if (pos < num_mb) {
282  av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
283  pos, num_mb);
284  return AVERROR_INVALIDDATA;
285  }
286 
287  for (i = 0; i < c->mb_height; i++) {
288  size = bytestream2_peek_byte(&gb);
289  if (size & 1) {
290  size = bytestream2_get_byte(&gb) - 1;
291  } else {
292  size = bytestream2_get_le32(&gb) >> 1;
293  }
294  if (!size) {
295  int skip_row = 1, j, off = i * c->mb_width;
296  for (j = 0; j < c->mb_width; j++) {
297  if (c->slice_quants[off + j] == 1 ||
298  c->slice_quants[off + j] == 2) {
299  skip_row = 0;
300  break;
301  }
302  }
303  if (!skip_row) {
304  av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
305  return AVERROR_INVALIDDATA;
306  }
307  }
308  if (bytestream2_get_bytes_left(&gb) < size) {
309  av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
310  size, bytestream2_get_bytes_left(&gb));
311  return AVERROR_INVALIDDATA;
312  }
313  ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
314  if (ret) {
315  av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
316  return ret;
317  }
318  bytestream2_skip(&gb, size);
319  }
320 
321  *got_frame = 1;
322  if ((ret = av_frame_ref(data, c->pic)) < 0)
323  return ret;
324 
325  /* always report that the buffer was completely consumed */
326  return buf_size;
327 }
328 
330 {
331  TSCC2Context * const c = avctx->priv_data;
332 
333  av_frame_free(&c->pic);
334  av_freep(&c->slice_quants);
335  free_vlcs(c);
336 
337  return 0;
338 }
339 
341 {
342  TSCC2Context * const c = avctx->priv_data;
343  int ret;
344 
345  c->avctx = avctx;
346 
347  avctx->pix_fmt = AV_PIX_FMT_YUV444P;
348 
349  if ((ret = init_vlcs(c)) < 0) {
350  av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
351  return ret;
352  }
353 
354  c->mb_width = FFALIGN(avctx->width, 16) >> 4;
355  c->mb_height = FFALIGN(avctx->height, 8) >> 3;
357  if (!c->slice_quants) {
358  av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
359  return AVERROR(ENOMEM);
360  }
361 
362  c->pic = av_frame_alloc();
363  if (!c->pic)
364  return AVERROR(ENOMEM);
365 
366  return 0;
367 }
368 
370  .name = "tscc2",
371  .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
372  .type = AVMEDIA_TYPE_VIDEO,
373  .id = AV_CODEC_ID_TSCC2,
374  .priv_data_size = sizeof(TSCC2Context),
376  .close = tscc2_decode_end,
378  .capabilities = AV_CODEC_CAP_DR1,
379  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
380 };
#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:48
#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:100
This structure describes decoded (raw) audio or video data.
Definition: frame.h:308
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:270
AVFrame * pic
Definition: tscc2.c:39
int size
Definition: packet.h:364
#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:736
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
static const int tscc2_ac_vlc_sizes[NUM_VLC_SETS]
Definition: tscc2data.h:902
AVCodec.
Definition: codec.h:190
AVCodecContext * avctx
Definition: tscc2.c:38
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
frame_type
VLC nc_vlc[NUM_VLC_SETS]
Definition: tscc2.c:46
#define COL_OP(a, b)
Definition: tscc2.c:97
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:88
#define av_malloc(s)
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:190
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:214
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:456
#define t0
Definition: regdef.h:28
uint8_t * data
Definition: packet.h:363
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 av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
VLC dc_vlc
Definition: tscc2.c:46
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
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:1986
const uint8_t ff_zigzag_scan[16+1]
Definition: mathtables.c:109
unsigned int pos
Definition: spdifenc.c:410
#define t1
Definition: regdef.h:29
const char * name
Name of the codec implementation.
Definition: codec.h:197
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:329
static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set, uint8_t *dst, int stride, int plane)
Definition: tscc2.c:123
int width
picture width / height.
Definition: avcodec.h:699
#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:98
#define INIT_VLC_LE
Definition: vlc.h:59
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:192
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:339
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:526
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
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:340
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:322
#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP)
Definition: tscc2.c:91
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:188
void * priv_data
Definition: avcodec.h:553
static const uint8_t tscc2_nc_vlc_bits[NUM_VLC_SETS][16]
Definition: tscc2data.h:100
#define DEQUANT(val, q)
Definition: tscc2.c:90
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
static double val(void *priv, double ch)
Definition: aeval.c:76
This structure stores compressed data.
Definition: packet.h:340
void ff_free_vlc(VLC *vlc)
Definition: bitstream.c:358
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:50
#define t2
Definition: regdef.h:30
int i
Definition: input.c:407
AVCodec ff_tscc2_decoder
Definition: tscc2.c:369