GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/tscc2.c Lines: 153 188 81.4 %
Date: 2020-10-23 17:01:47 Branches: 81 110 73.6 %

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
 *
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 * 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
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 * Lesser General Public License for more details.
16
 *
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 * You should have received a copy of the GNU Lesser General Public
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 * 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 {
38
    AVCodecContext *avctx;
39
    AVFrame       *pic;
40
    int            mb_width, mb_height;
41
    uint8_t        *slice_quants;
42
    int            quant[2];
43
    int            q[2][3];
44
    GetBitContext  gb;
45
46
    VLC            dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS];
47
    int            block[16];
48
} TSCC2Context;
49
50
4
static av_cold void free_vlcs(TSCC2Context *c)
51
{
52
    int i;
53
54
4
    ff_free_vlc(&c->dc_vlc);
55
56
    for (i = 0; i < NUM_VLC_SETS; i++) {
56
52
        ff_free_vlc(c->nc_vlc + i);
57
52
        ff_free_vlc(c->ac_vlc + i);
58
    }
59
4
}
60
61
4
static av_cold int init_vlcs(TSCC2Context *c)
62
{
63
    int i, ret;
64
65
4
    ret = ff_init_vlc_sparse(&c->dc_vlc, 9, DC_VLC_COUNT,
66
                             tscc2_dc_vlc_bits,  1, 1,
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                             tscc2_dc_vlc_codes, 2, 2,
68
                             tscc2_dc_vlc_syms,  2, 2, INIT_VLC_LE);
69
4
    if (ret)
70
        return ret;
71
72
56
    for (i = 0; i < NUM_VLC_SETS; i++) {
73
52
        ret = ff_init_vlc_sparse(c->nc_vlc + i, 9, 16,
74
52
                                 tscc2_nc_vlc_bits[i],  1, 1,
75
52
                                 tscc2_nc_vlc_codes[i], 2, 2,
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                                 tscc2_nc_vlc_syms,     1, 1, INIT_VLC_LE);
77
52
        if (ret)
78
            return ret;
79
52
        ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i],
80
52
                                 tscc2_ac_vlc_bits[i],  1, 1,
81
52
                                 tscc2_ac_vlc_codes[i], 2, 2,
82
52
                                 tscc2_ac_vlc_syms[i],  2, 2, INIT_VLC_LE);
83
52
        if (ret)
84
            return ret;
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    }
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87
4
    return 0;
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}
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#define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8)
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#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
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    OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3));  \
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    OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1));  \
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    OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1));  \
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    OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3));  \
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#define COL_OP(a, b)  a = (b)
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#define ROW_OP(a, b)  a = ((b) + 0x20) >> 6
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441488
static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
101
{
102
    int i;
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    int tblk[4 * 4];
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    int t0, t1, t2, t3;
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106
2207440
    for (i = 0; i < 4; i++) {
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1765952
        t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
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1765952
        t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
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1765952
        t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
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1765952
        t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
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1765952
        DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
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              tblk[2 * 4 + i], tblk[3 * 4 + i],
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              t0, t1, t2, t3, COL_OP);
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    }
115
2207440
    for (i = 0; i < 4; i++) {
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1765952
        DCT1D(dst[0], dst[1], dst[2], dst[3],
117
              tblk[i * 4 + 0], tblk[i * 4 + 1],
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              tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
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1765952
        dst += stride;
120
    }
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441488
}
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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;
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    int prev_dc, dc, nc, ac, bpos, val;
128
    int i, j, k, l;
129
130
66141
    if (get_bits1(gb)) {
131
10955
        if (get_bits1(gb)) {
132
10954
            val = get_bits(gb, 8);
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98586
            for (i = 0; i < 8; i++, dst += stride)
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87632
                memset(dst, val, 16);
135
        } else {
136
1
            if (get_bits_left(gb) < 16 * 8 * 8)
137
                return AVERROR_INVALIDDATA;
138
9
            for (i = 0; i < 8; i++) {
139
136
                for (j = 0; j < 16; j++)
140
128
                    dst[j] = get_bits(gb, 8);
141
8
                dst += stride;
142
            }
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        }
144
10955
        return 0;
145
    }
146
147
55186
    prev_dc = 0;
148
165558
    for (j = 0; j < 2; j++) {
149
551860
        for (k = 0; k < 4; k++) {
150
441488
            if (!(j | k)) {
151
55186
                dc = get_bits(gb, 8);
152
            } else {
153
386302
                dc = get_vlc2(gb, c->dc_vlc.table, 9, 2);
154
386302
                if (dc == -1)
155
                    return AVERROR_INVALIDDATA;
156
386302
                if (dc == 0x100)
157
22622
                    dc = get_bits(gb, 8);
158
            }
159
441488
            dc          = (dc + prev_dc) & 0xFF;
160
441488
            prev_dc     = dc;
161
441488
            c->block[0] = dc;
162
163
441488
            nc = get_vlc2(gb, c->nc_vlc[vlc_set].table, 9, 1);
164
441488
            if (nc == -1)
165
                return AVERROR_INVALIDDATA;
166
167
441488
            bpos = 1;
168
441488
            memset(c->block + 1, 0, 15 * sizeof(*c->block));
169
2082935
            for (l = 0; l < nc; l++) {
170
1641447
                ac = get_vlc2(gb, c->ac_vlc[vlc_set].table, 9, 2);
171
1641447
                if (ac == -1)
172
                    return AVERROR_INVALIDDATA;
173
1641447
                if (ac == 0x1000)
174
48321
                    ac = get_bits(gb, 12);
175
1641447
                bpos += ac & 0xF;
176
1641447
                if (bpos >= 16)
177
                    return AVERROR_INVALIDDATA;
178
1641447
                val = sign_extend(ac >> 4, 8);
179
1641447
                c->block[ff_zigzag_scan[bpos++]] = val;
180
            }
181
441488
            tscc2_idct4_put(c->block, q, dst + k * 4, stride);
182
        }
183
110372
        dst += 4 * stride;
184
    }
185
55186
    return 0;
186
}
187
188
1084
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
1084
    if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
195
        return ret;
196
197
34860
    for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
198
33776
        q = c->slice_quants[mb_x + c->mb_width * mb_y];
199
200

33776
        if (q == 0 || q == 3) // skip block
201
11729
            continue;
202
88188
        for (i = 0; i < 3; i++) {
203
66141
            off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
204
66141
            ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
205
66141
                                  c->pic->data[i] + off, c->pic->linesize[i], i);
206
66141
            if (ret)
207
                return ret;
208
        }
209
    }
210
211
1084
    return 0;
212
}
213
214
48
static int tscc2_decode_frame(AVCodecContext *avctx, void *data,
215
                              int *got_frame, AVPacket *avpkt)
216
{
217
48
    const uint8_t *buf = avpkt->data;
218
48
    int buf_size = avpkt->size;
219
48
    TSCC2Context *c = avctx->priv_data;
220
    GetByteContext gb;
221
    uint32_t frame_type, size;
222
48
    int i, val, len, pos = 0;
223
48
    int num_mb = c->mb_width * c->mb_height;
224
    int ret;
225
226
48
    bytestream2_init(&gb, buf, buf_size);
227
48
    frame_type = bytestream2_get_byte(&gb);
228
48
    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
48
    if (frame_type == 0) {
235
        // Skip duplicate frames
236
17
        return buf_size;
237
    }
238
239
31
    if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
240
        return ret;
241
    }
242
243
31
    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
31
    c->quant[0] = bytestream2_get_byte(&gb);
249
31
    c->quant[1] = bytestream2_get_byte(&gb);
250

31
    if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
251

31
        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
124
    for (i = 0; i < 3; i++) {
258
93
        c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
259
93
        c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
260
    }
261
262
31
    bytestream2_skip(&gb, 1);
263
264
31
    size = bytestream2_get_le32(&gb);
265
31
    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
3319
    for (i = 0; i < size; i++) {
271
3288
        val   = bytestream2_get_byte(&gb);
272
3288
        len   = val & 0x3F;
273
3288
        val >>= 6;
274
3288
        if (pos + len > num_mb) {
275
            av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
276
            return AVERROR_INVALIDDATA;
277
        }
278
3288
        memset(c->slice_quants + pos, val, len);
279
3288
        pos += len;
280
    }
281
31
    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
1115
    for (i = 0; i < c->mb_height; i++) {
288
1085
        size = bytestream2_peek_byte(&gb);
289
1085
        if (size & 1) {
290
103
            size = bytestream2_get_byte(&gb) - 1;
291
        } else {
292
982
            size = bytestream2_get_le32(&gb) >> 1;
293
        }
294
1085
        if (!size) {
295
103
            int skip_row = 1, j, off = i * c->mb_width;
296
5871
            for (j = 0; j < c->mb_width; j++) {
297
5768
                if (c->slice_quants[off + j] == 1 ||
298
5768
                    c->slice_quants[off + j] == 2) {
299
                    skip_row = 0;
300
                    break;
301
                }
302
            }
303
103
            if (!skip_row) {
304
                av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
305
                return AVERROR_INVALIDDATA;
306
            }
307
        }
308
1085
        if (bytestream2_get_bytes_left(&gb) < size) {
309
1
            av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
310
                   size, bytestream2_get_bytes_left(&gb));
311
1
            return AVERROR_INVALIDDATA;
312
        }
313
1084
        ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
314
1084
        if (ret) {
315
            av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
316
            return ret;
317
        }
318
1084
        bytestream2_skip(&gb, size);
319
    }
320
321
30
    *got_frame      = 1;
322
30
    if ((ret = av_frame_ref(data, c->pic)) < 0)
323
        return ret;
324
325
    /* always report that the buffer was completely consumed */
326
30
    return buf_size;
327
}
328
329
4
static av_cold int tscc2_decode_end(AVCodecContext *avctx)
330
{
331
4
    TSCC2Context * const c = avctx->priv_data;
332
333
4
    av_frame_free(&c->pic);
334
4
    av_freep(&c->slice_quants);
335
4
    free_vlcs(c);
336
337
4
    return 0;
338
}
339
340
4
static av_cold int tscc2_decode_init(AVCodecContext *avctx)
341
{
342
4
    TSCC2Context * const c = avctx->priv_data;
343
    int ret;
344
345
4
    c->avctx = avctx;
346
347
4
    avctx->pix_fmt = AV_PIX_FMT_YUV444P;
348
349
4
    if ((ret = init_vlcs(c)) < 0) {
350
        av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
351
        return ret;
352
    }
353
354
4
    c->mb_width     = FFALIGN(avctx->width,  16) >> 4;
355
4
    c->mb_height    = FFALIGN(avctx->height,  8) >> 3;
356
4
    c->slice_quants = av_malloc(c->mb_width * c->mb_height);
357
4
    if (!c->slice_quants) {
358
        av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
359
        return AVERROR(ENOMEM);
360
    }
361
362
4
    c->pic = av_frame_alloc();
363
4
    if (!c->pic)
364
        return AVERROR(ENOMEM);
365
366
4
    return 0;
367
}
368
369
AVCodec ff_tscc2_decoder = {
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),
375
    .init           = tscc2_decode_init,
376
    .close          = tscc2_decode_end,
377
    .decode         = tscc2_decode_frame,
378
    .capabilities   = AV_CODEC_CAP_DR1,
379
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
380
};