FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/tscc2.c
Date: 2022-11-26 13:19:19
Exec Total Coverage
Lines: 147 174 84.5%
Branches: 72 94 76.6%

Line Branch Exec Source
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 "decode.h"
36 #include "get_bits.h"
37 #include "mathops.h"
38 #include "tscc2data.h"
39
40 #define TSCC2_VLC_BITS 9
41
42 typedef struct TSCC2Context {
43 AVCodecContext *avctx;
44 AVFrame *pic;
45 int mb_width, mb_height;
46 uint8_t *slice_quants;
47 int quant[2];
48 int q[2][3];
49 GetBitContext gb;
50
51 int block[16];
52 } TSCC2Context;
53
54 static VLC dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS];
55
56 54 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 54 vlc->table = &vlc_buf[*offset];
63 54 vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *offset;
64 54 ff_init_vlc_from_lengths(vlc, TSCC2_VLC_BITS, nb_codes,
65 lens, 1, syms, sym_length, sym_length, 0,
66 INIT_VLC_STATIC_OVERLONG | INIT_VLC_OUTPUT_LE, NULL);
67 54 *offset += vlc->table_size;
68 54 }
69
70 2 static av_cold void tscc2_init_vlcs(void)
71 {
72 2 const uint16_t *ac_vlc_syms = tscc2_ac_vlc_syms;
73 2 const uint8_t *ac_vlc_lens = tscc2_ac_vlc_lens;
74 2 int i, offset = 0;
75
76 2 tscc2_init_vlc(&dc_vlc, &offset, DC_VLC_COUNT,
77 tscc2_dc_vlc_lens, tscc2_dc_vlc_syms, 2);
78
79
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28 for (i = 0; i < NUM_VLC_SETS; i++) {
80 26 tscc2_init_vlc(&nc_vlc[i], &offset, 16,
81 26 tscc2_nc_vlc_lens[i], tscc2_nc_vlc_syms[i], 1);
82
83 26 tscc2_init_vlc(&ac_vlc[i], &offset, tscc2_ac_vlc_sizes[i],
84 ac_vlc_lens, ac_vlc_syms, 2);
85 26 ac_vlc_lens += tscc2_ac_vlc_sizes[i];
86 26 ac_vlc_syms += tscc2_ac_vlc_sizes[i];
87 }
88 2 }
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 441488 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
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2207440 for (i = 0; i < 4; i++) {
107 1765952 t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
108 1765952 t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
109 1765952 t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
110 1765952 t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
111 1765952 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
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2207440 for (i = 0; i < 4; i++) {
116 1765952 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 1765952 dst += stride;
120 }
121 441488 }
122
123 66141 static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
124 uint8_t *dst, int stride, int plane)
125 {
126 66141 GetBitContext *gb = &c->gb;
127 int prev_dc, dc, nc, ac, bpos, val;
128 int i, j, k, l;
129
130
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66141 if (get_bits1(gb)) {
131
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10955 if (get_bits1(gb)) {
132 10954 val = get_bits(gb, 8);
133
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98586 for (i = 0; i < 8; i++, dst += stride)
134 87632 memset(dst, val, 16);
135 } else {
136
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1 if (get_bits_left(gb) < 16 * 8 * 8)
137 return AVERROR_INVALIDDATA;
138
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9 for (i = 0; i < 8; i++) {
139
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136 for (j = 0; j < 16; j++)
140 128 dst[j] = get_bits(gb, 8);
141 8 dst += stride;
142 }
143 }
144 10955 return 0;
145 }
146
147 55186 prev_dc = 0;
148
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165558 for (j = 0; j < 2; j++) {
149
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551860 for (k = 0; k < 4; k++) {
150
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441488 if (!(j | k)) {
151 55186 dc = get_bits(gb, 8);
152 } else {
153 386302 dc = get_vlc2(gb, dc_vlc.table, TSCC2_VLC_BITS, 2);
154
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386302 if (dc == 0x100)
155 22622 dc = get_bits(gb, 8);
156 }
157 441488 dc = (dc + prev_dc) & 0xFF;
158 441488 prev_dc = dc;
159 441488 c->block[0] = dc;
160
161 441488 nc = get_vlc2(gb, nc_vlc[vlc_set].table, TSCC2_VLC_BITS, 1);
162
163 441488 bpos = 1;
164 441488 memset(c->block + 1, 0, 15 * sizeof(*c->block));
165
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2082935 for (l = 0; l < nc; l++) {
166 1641447 ac = get_vlc2(gb, ac_vlc[vlc_set].table, TSCC2_VLC_BITS, 2);
167
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1641447 if (ac == 0x1000)
168 48321 ac = get_bits(gb, 12);
169 1641447 bpos += ac & 0xF;
170
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1641447 if (bpos >= 16)
171 return AVERROR_INVALIDDATA;
172 1641447 val = sign_extend(ac >> 4, 8);
173 1641447 c->block[ff_zigzag_scan[bpos++]] = val;
174 }
175 441488 tscc2_idct4_put(c->block, q, dst + k * 4, stride);
176 }
177 110372 dst += 4 * stride;
178 }
179 55186 return 0;
180 }
181
182 1084 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
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1084 if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
189 return ret;
190
191
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34860 for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
192 33776 q = c->slice_quants[mb_x + c->mb_width * mb_y];
193
194
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33776 if (q == 0 || q == 3) // skip block
195 11729 continue;
196
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88188 for (i = 0; i < 3; i++) {
197 66141 off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
198 66141 ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
199 66141 c->pic->data[i] + off, c->pic->linesize[i], i);
200
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66141 if (ret)
201 return ret;
202 }
203 }
204
205 1084 return 0;
206 }
207
208 48 static int tscc2_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
209 int *got_frame, AVPacket *avpkt)
210 {
211 48 const uint8_t *buf = avpkt->data;
212 48 int buf_size = avpkt->size;
213 48 TSCC2Context *c = avctx->priv_data;
214 GetByteContext gb;
215 uint32_t frame_type, size;
216 48 int i, val, len, pos = 0;
217 48 int num_mb = c->mb_width * c->mb_height;
218 int ret;
219
220 48 bytestream2_init(&gb, buf, buf_size);
221 48 frame_type = bytestream2_get_byte(&gb);
222
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48 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
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48 if (frame_type == 0) {
229 // Skip duplicate frames
230 17 return buf_size;
231 }
232
233
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31 if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
234 return ret;
235 }
236
237
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31 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 31 c->quant[0] = bytestream2_get_byte(&gb);
243 31 c->quant[1] = bytestream2_get_byte(&gb);
244
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31 if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
245
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31 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
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124 for (i = 0; i < 3; i++) {
252 93 c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
253 93 c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
254 }
255
256 31 bytestream2_skip(&gb, 1);
257
258 31 size = bytestream2_get_le32(&gb);
259
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31 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
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3319 for (i = 0; i < size; i++) {
265 3288 val = bytestream2_get_byte(&gb);
266 3288 len = val & 0x3F;
267 3288 val >>= 6;
268
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3288 if (pos + len > num_mb) {
269 av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
270 return AVERROR_INVALIDDATA;
271 }
272 3288 memset(c->slice_quants + pos, val, len);
273 3288 pos += len;
274 }
275
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31 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
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1115 for (i = 0; i < c->mb_height; i++) {
282 1085 size = bytestream2_peek_byte(&gb);
283
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1085 if (size & 1) {
284 103 size = bytestream2_get_byte(&gb) - 1;
285 } else {
286 982 size = bytestream2_get_le32(&gb) >> 1;
287 }
288
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1085 if (!size) {
289 103 int skip_row = 1, j, off = i * c->mb_width;
290
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5871 for (j = 0; j < c->mb_width; j++) {
291
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5768 if (c->slice_quants[off + j] == 1 ||
292
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5768 c->slice_quants[off + j] == 2) {
293 skip_row = 0;
294 break;
295 }
296 }
297
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103 if (!skip_row) {
298 av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
299 return AVERROR_INVALIDDATA;
300 }
301 }
302
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1085 if (bytestream2_get_bytes_left(&gb) < size) {
303 1 av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
304 size, bytestream2_get_bytes_left(&gb));
305 1 return AVERROR_INVALIDDATA;
306 }
307 1084 ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
308
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1084 if (ret) {
309 av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
310 return ret;
311 }
312 1084 bytestream2_skip(&gb, size);
313 }
314
315 30 *got_frame = 1;
316
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30 if ((ret = av_frame_ref(rframe, c->pic)) < 0)
317 return ret;
318
319 /* always report that the buffer was completely consumed */
320 30 return buf_size;
321 }
322
323 4 static av_cold int tscc2_decode_end(AVCodecContext *avctx)
324 {
325 4 TSCC2Context * const c = avctx->priv_data;
326
327 4 av_frame_free(&c->pic);
328 4 av_freep(&c->slice_quants);
329
330 4 return 0;
331 }
332
333 4 static av_cold int tscc2_decode_init(AVCodecContext *avctx)
334 {
335 4 TSCC2Context * const c = avctx->priv_data;
336 static AVOnce init_static_once = AV_ONCE_INIT;
337
338 4 c->avctx = avctx;
339
340 4 avctx->pix_fmt = AV_PIX_FMT_YUV444P;
341
342 4 c->mb_width = FFALIGN(avctx->width, 16) >> 4;
343 4 c->mb_height = FFALIGN(avctx->height, 8) >> 3;
344 4 c->slice_quants = av_malloc(c->mb_width * c->mb_height);
345
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4 if (!c->slice_quants) {
346 av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
347 return AVERROR(ENOMEM);
348 }
349
350 4 c->pic = av_frame_alloc();
351
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4 if (!c->pic)
352 return AVERROR(ENOMEM);
353
354 4 ff_thread_once(&init_static_once, tscc2_init_vlcs);
355
356 4 return 0;
357 }
358
359 const FFCodec ff_tscc2_decoder = {
360 .p.name = "tscc2",
361 CODEC_LONG_NAME("TechSmith Screen Codec 2"),
362 .p.type = AVMEDIA_TYPE_VIDEO,
363 .p.id = AV_CODEC_ID_TSCC2,
364 .priv_data_size = sizeof(TSCC2Context),
365 .init = tscc2_decode_init,
366 .close = tscc2_decode_end,
367 FF_CODEC_DECODE_CB(tscc2_decode_frame),
368 .p.capabilities = AV_CODEC_CAP_DR1,
369 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
370 };
371