FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/tscc2.c	Lines:	147	174	84.5 %
Date:	2021-04-18 21:26:34	Branches:	72	94	76.6 %


/*
 * TechSmith Screen Codec 2 (aka Dora) decoder
 * Copyright (c) 2012 Konstantin Shishkov
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * TechSmith Screen Codec 2 decoder
 */

#include <inttypes.h>

#include "libavutil/thread.h"

#define BITSTREAM_READER_LE
#include "avcodec.h"
#include "bytestream.h"
#include "get_bits.h"
#include "internal.h"
#include "mathops.h"
#include "tscc2data.h"

#define TSCC2_VLC_BITS 9

typedef struct TSCC2Context {
    AVCodecContext *avctx;
    AVFrame       *pic;
    int            mb_width, mb_height;
    uint8_t        *slice_quants;
    int            quant[2];
    int            q[2][3];
    GetBitContext  gb;

    int            block[16];
} TSCC2Context;

static VLC dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS];

static av_cold void tscc2_init_vlc(VLC *vlc, int *offset, int nb_codes,
                                   const uint8_t *lens, const void *syms,
                                   int sym_length)
{
    static VLC_TYPE vlc_buf[15442][2];

    vlc->table           = &vlc_buf[*offset];
    vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *offset;
    ff_init_vlc_from_lengths(vlc, TSCC2_VLC_BITS, nb_codes,
                             lens, 1, syms, sym_length, sym_length, 0,
                             INIT_VLC_STATIC_OVERLONG | INIT_VLC_OUTPUT_LE, NULL);
    *offset += vlc->table_size;
}

static av_cold void tscc2_init_vlcs(void)
{
    const uint16_t *ac_vlc_syms = tscc2_ac_vlc_syms;
    const uint8_t  *ac_vlc_lens = tscc2_ac_vlc_lens;
    int i, offset = 0;

    tscc2_init_vlc(&dc_vlc, &offset, DC_VLC_COUNT,
                   tscc2_dc_vlc_lens, tscc2_dc_vlc_syms, 2);

    for (i = 0; i < NUM_VLC_SETS; i++) {
        tscc2_init_vlc(&nc_vlc[i], &offset, 16,
                       tscc2_nc_vlc_lens[i], tscc2_nc_vlc_syms[i], 1);

        tscc2_init_vlc(&ac_vlc[i], &offset, tscc2_ac_vlc_sizes[i],
                       ac_vlc_lens, ac_vlc_syms, 2);
        ac_vlc_lens += tscc2_ac_vlc_sizes[i];
        ac_vlc_syms += tscc2_ac_vlc_sizes[i];
    }
}

#define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8)
#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
    OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3));  \
    OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1));  \
    OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1));  \
    OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3));  \

#define COL_OP(a, b)  a = (b)
#define ROW_OP(a, b)  a = ((b) + 0x20) >> 6

static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
{
    int i;
    int tblk[4 * 4];
    int t0, t1, t2, t3;

    for (i = 0; i < 4; i++) {
        t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
        t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
        t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
        t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
        DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
              tblk[2 * 4 + i], tblk[3 * 4 + i],
              t0, t1, t2, t3, COL_OP);
    }
    for (i = 0; i < 4; i++) {
        DCT1D(dst[0], dst[1], dst[2], dst[3],
              tblk[i * 4 + 0], tblk[i * 4 + 1],
              tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
        dst += stride;
    }
}

static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
                           uint8_t *dst, int stride, int plane)
{
    GetBitContext *gb = &c->gb;
    int prev_dc, dc, nc, ac, bpos, val;
    int i, j, k, l;

    if (get_bits1(gb)) {
        if (get_bits1(gb)) {
            val = get_bits(gb, 8);
            for (i = 0; i < 8; i++, dst += stride)
                memset(dst, val, 16);
        } else {
            if (get_bits_left(gb) < 16 * 8 * 8)
                return AVERROR_INVALIDDATA;
            for (i = 0; i < 8; i++) {
                for (j = 0; j < 16; j++)
                    dst[j] = get_bits(gb, 8);
                dst += stride;
            }
        }
        return 0;
    }

    prev_dc = 0;
    for (j = 0; j < 2; j++) {
        for (k = 0; k < 4; k++) {
            if (!(j | k)) {
                dc = get_bits(gb, 8);
            } else {
                dc = get_vlc2(gb, dc_vlc.table, TSCC2_VLC_BITS, 2);
                if (dc == 0x100)
                    dc = get_bits(gb, 8);
            }
            dc          = (dc + prev_dc) & 0xFF;
            prev_dc     = dc;
            c->block[0] = dc;

            nc = get_vlc2(gb, nc_vlc[vlc_set].table, TSCC2_VLC_BITS, 1);

            bpos = 1;
            memset(c->block + 1, 0, 15 * sizeof(*c->block));
            for (l = 0; l < nc; l++) {
                ac = get_vlc2(gb, ac_vlc[vlc_set].table, TSCC2_VLC_BITS, 2);
                if (ac == 0x1000)
                    ac = get_bits(gb, 12);
                bpos += ac & 0xF;
                if (bpos >= 16)
                    return AVERROR_INVALIDDATA;
                val = sign_extend(ac >> 4, 8);
                c->block[ff_zigzag_scan[bpos++]] = val;
            }
            tscc2_idct4_put(c->block, q, dst + k * 4, stride);
        }
        dst += 4 * stride;
    }
    return 0;
}

static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
                              const uint8_t *buf, int buf_size)
{
    int i, mb_x, q, ret;
    int off;

    if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
        return ret;

    for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
        q = c->slice_quants[mb_x + c->mb_width * mb_y];

        if (q == 0 || q == 3) // skip block
            continue;
        for (i = 0; i < 3; i++) {
            off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
            ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
                                  c->pic->data[i] + off, c->pic->linesize[i], i);
            if (ret)
                return ret;
        }
    }

    return 0;
}

static int tscc2_decode_frame(AVCodecContext *avctx, void *data,
                              int *got_frame, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    TSCC2Context *c = avctx->priv_data;
    GetByteContext gb;
    uint32_t frame_type, size;
    int i, val, len, pos = 0;
    int num_mb = c->mb_width * c->mb_height;
    int ret;

    bytestream2_init(&gb, buf, buf_size);
    frame_type = bytestream2_get_byte(&gb);
    if (frame_type > 1) {
        av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n",
               frame_type);
        return AVERROR_INVALIDDATA;
    }

    if (frame_type == 0) {
        // Skip duplicate frames
        return buf_size;
    }

    if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
        return ret;
    }

    if (bytestream2_get_bytes_left(&gb) < 4) {
        av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
        return AVERROR_INVALIDDATA;
    }

    c->quant[0] = bytestream2_get_byte(&gb);
    c->quant[1] = bytestream2_get_byte(&gb);
    if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
        c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
        av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
               c->quant[0], c->quant[1]);
        return AVERROR_INVALIDDATA;
    }

    for (i = 0; i < 3; i++) {
        c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
        c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
    }

    bytestream2_skip(&gb, 1);

    size = bytestream2_get_le32(&gb);
    if (size > bytestream2_get_bytes_left(&gb)) {
        av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
        return AVERROR_INVALIDDATA;
    }

    for (i = 0; i < size; i++) {
        val   = bytestream2_get_byte(&gb);
        len   = val & 0x3F;
        val >>= 6;
        if (pos + len > num_mb) {
            av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
            return AVERROR_INVALIDDATA;
        }
        memset(c->slice_quants + pos, val, len);
        pos += len;
    }
    if (pos < num_mb) {
        av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
               pos, num_mb);
        return AVERROR_INVALIDDATA;
    }

    for (i = 0; i < c->mb_height; i++) {
        size = bytestream2_peek_byte(&gb);
        if (size & 1) {
            size = bytestream2_get_byte(&gb) - 1;
        } else {
            size = bytestream2_get_le32(&gb) >> 1;
        }
        if (!size) {
            int skip_row = 1, j, off = i * c->mb_width;
            for (j = 0; j < c->mb_width; j++) {
                if (c->slice_quants[off + j] == 1 ||
                    c->slice_quants[off + j] == 2) {
                    skip_row = 0;
                    break;
                }
            }
            if (!skip_row) {
                av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
                return AVERROR_INVALIDDATA;
            }
        }
        if (bytestream2_get_bytes_left(&gb) < size) {
            av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
                   size, bytestream2_get_bytes_left(&gb));
            return AVERROR_INVALIDDATA;
        }
        ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
        if (ret) {
            av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
            return ret;
        }
        bytestream2_skip(&gb, size);
    }

    *got_frame      = 1;
    if ((ret = av_frame_ref(data, c->pic)) < 0)
        return ret;

    /* always report that the buffer was completely consumed */
    return buf_size;
}

static av_cold int tscc2_decode_end(AVCodecContext *avctx)
{
    TSCC2Context * const c = avctx->priv_data;

    av_frame_free(&c->pic);
    av_freep(&c->slice_quants);

    return 0;
}

static av_cold int tscc2_decode_init(AVCodecContext *avctx)
{
    TSCC2Context * const c = avctx->priv_data;
    static AVOnce init_static_once = AV_ONCE_INIT;

    c->avctx = avctx;

    avctx->pix_fmt = AV_PIX_FMT_YUV444P;

    c->mb_width     = FFALIGN(avctx->width,  16) >> 4;
    c->mb_height    = FFALIGN(avctx->height,  8) >> 3;
    c->slice_quants = av_malloc(c->mb_width * c->mb_height);
    if (!c->slice_quants) {
        av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
        return AVERROR(ENOMEM);
    }

    c->pic = av_frame_alloc();
    if (!c->pic)
        return AVERROR(ENOMEM);

    ff_thread_once(&init_static_once, tscc2_init_vlcs);

    return 0;
}

AVCodec ff_tscc2_decoder = {
    .name           = "tscc2",
    .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_TSCC2,
    .priv_data_size = sizeof(TSCC2Context),
    .init           = tscc2_decode_init,
    .close          = tscc2_decode_end,
    .decode         = tscc2_decode_frame,
    .capabilities   = AV_CODEC_CAP_DR1,
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
};


Generated by: GCOVR (Version 4.2)

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 "get_bits.h"
35			#include "internal.h"
36			#include "mathops.h"
37			#include "tscc2data.h"
38
39			#define TSCC2_VLC_BITS 9
40
41			typedef struct TSCC2Context {
42			AVCodecContext *avctx;
43			AVFrame *pic;
44			int mb_width, mb_height;
45			uint8_t *slice_quants;
46			int quant[2];
47			int q[2][3];
48			GetBitContext gb;
49
50			int block[16];
51			} TSCC2Context;
52
53			static VLC dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS];
54
55		54	static av_cold void tscc2_init_vlc(VLC vlc, int offset, int nb_codes,
56			const uint8_t lens, const void syms,
57			int sym_length)
58			{
59			static VLC_TYPE vlc_buf[15442][2];
60
61		54	vlc->table = &vlc_buf[*offset];
62		54	vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *offset;
63		54	ff_init_vlc_from_lengths(vlc, TSCC2_VLC_BITS, nb_codes,
64			lens, 1, syms, sym_length, sym_length, 0,
65			INIT_VLC_STATIC_OVERLONG \| INIT_VLC_OUTPUT_LE, NULL);
66		54	*offset += vlc->table_size;
67		54	}
68
69		2	static av_cold void tscc2_init_vlcs(void)
70			{
71		2	const uint16_t *ac_vlc_syms = tscc2_ac_vlc_syms;
72		2	const uint8_t *ac_vlc_lens = tscc2_ac_vlc_lens;
73		2	int i, offset = 0;
74
75		2	tscc2_init_vlc(&dc_vlc, &offset, DC_VLC_COUNT,
76			tscc2_dc_vlc_lens, tscc2_dc_vlc_syms, 2);
77
78	✓✓	28	for (i = 0; i < NUM_VLC_SETS; i++) {
79		26	tscc2_init_vlc(&nc_vlc[i], &offset, 16,
80		26	tscc2_nc_vlc_lens[i], tscc2_nc_vlc_syms[i], 1);
81
82		26	tscc2_init_vlc(&ac_vlc[i], &offset, tscc2_ac_vlc_sizes[i],
83			ac_vlc_lens, ac_vlc_syms, 2);
84		26	ac_vlc_lens += tscc2_ac_vlc_sizes[i];
85		26	ac_vlc_syms += tscc2_ac_vlc_sizes[i];
86			}
87		2	}
88
89			#define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8)
90			#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
91			OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \
92			OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \
93			OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \
94			OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \
95
96			#define COL_OP(a, b) a = (b)
97			#define ROW_OP(a, b) a = ((b) + 0x20) >> 6
98
99		441488	static void tscc2_idct4_put(int in, int q[3], uint8_t dst, int stride)
100			{
101			int i;
102			int tblk[4 * 4];
103			int t0, t1, t2, t3;
104
105	✓✓	2207440	for (i = 0; i < 4; i++) {
106		1765952	t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
107		1765952	t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
108		1765952	t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
109		1765952	t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
110		1765952	DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
111			tblk[2 * 4 + i], tblk[3 * 4 + i],
112			t0, t1, t2, t3, COL_OP);
113			}
114	✓✓	2207440	for (i = 0; i < 4; i++) {
115		1765952	DCT1D(dst[0], dst[1], dst[2], dst[3],
116			tblk[i * 4 + 0], tblk[i * 4 + 1],
117			tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
118		1765952	dst += stride;
119			}
120		441488	}
121
122		66141	static int tscc2_decode_mb(TSCC2Context c, int q, int vlc_set,
123			uint8_t *dst, int stride, int plane)
124			{
125		66141	GetBitContext *gb = &c->gb;
126			int prev_dc, dc, nc, ac, bpos, val;
127			int i, j, k, l;
128
129	✓✓	66141	if (get_bits1(gb)) {
130	✓✓	10955	if (get_bits1(gb)) {
131		10954	val = get_bits(gb, 8);
132	✓✓	98586	for (i = 0; i < 8; i++, dst += stride)
133		87632	memset(dst, val, 16);
134			} else {
135	✗✓	1	if (get_bits_left(gb) < 16 * 8 * 8)
136			return AVERROR_INVALIDDATA;
137	✓✓	9	for (i = 0; i < 8; i++) {
138	✓✓	136	for (j = 0; j < 16; j++)
139		128	dst[j] = get_bits(gb, 8);
140		8	dst += stride;
141			}
142			}
143		10955	return 0;
144			}
145
146		55186	prev_dc = 0;
147	✓✓	165558	for (j = 0; j < 2; j++) {
148	✓✓	551860	for (k = 0; k < 4; k++) {
149	✓✓	441488	if (!(j \| k)) {
150		55186	dc = get_bits(gb, 8);
151			} else {
152		386302	dc = get_vlc2(gb, dc_vlc.table, TSCC2_VLC_BITS, 2);
153	✓✓	386302	if (dc == 0x100)
154		22622	dc = get_bits(gb, 8);
155			}
156		441488	dc = (dc + prev_dc) & 0xFF;
157		441488	prev_dc = dc;
158		441488	c->block[0] = dc;
159
160		441488	nc = get_vlc2(gb, nc_vlc[vlc_set].table, TSCC2_VLC_BITS, 1);
161
162		441488	bpos = 1;
163		441488	memset(c->block + 1, 0, 15 * sizeof(*c->block));
164	✓✓	2082935	for (l = 0; l < nc; l++) {
165		1641447	ac = get_vlc2(gb, ac_vlc[vlc_set].table, TSCC2_VLC_BITS, 2);
166	✓✓	1641447	if (ac == 0x1000)
167		48321	ac = get_bits(gb, 12);
168		1641447	bpos += ac & 0xF;
169	✗✓	1641447	if (bpos >= 16)
170			return AVERROR_INVALIDDATA;
171		1641447	val = sign_extend(ac >> 4, 8);
172		1641447	c->block[ff_zigzag_scan[bpos++]] = val;
173			}
174		441488	tscc2_idct4_put(c->block, q, dst + k * 4, stride);
175			}
176		110372	dst += 4 * stride;
177			}
178		55186	return 0;
179			}
180
181		1084	static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
182			const uint8_t *buf, int buf_size)
183			{
184			int i, mb_x, q, ret;
185			int off;
186
187	✗✓	1084	if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0)
188			return ret;
189
190	✓✓	34860	for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
191		33776	q = c->slice_quants[mb_x + c->mb_width * mb_y];
192
193	✓✓✗✓	33776	if (q == 0 \|\| q == 3) // skip block
194		11729	continue;
195	✓✓	88188	for (i = 0; i < 3; i++) {
196		66141	off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
197		66141	ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
198		66141	c->pic->data[i] + off, c->pic->linesize[i], i);
199	✗✓	66141	if (ret)
200			return ret;
201			}
202			}
203
204		1084	return 0;
205			}
206
207		48	static int tscc2_decode_frame(AVCodecContext avctx, void data,
208			int got_frame, AVPacket avpkt)
209			{
210		48	const uint8_t *buf = avpkt->data;
211		48	int buf_size = avpkt->size;
212		48	TSCC2Context *c = avctx->priv_data;
213			GetByteContext gb;
214			uint32_t frame_type, size;
215		48	int i, val, len, pos = 0;
216		48	int num_mb = c->mb_width * c->mb_height;
217			int ret;
218
219		48	bytestream2_init(&gb, buf, buf_size);
220		48	frame_type = bytestream2_get_byte(&gb);
221	✗✓	48	if (frame_type > 1) {
222			av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n",
223			frame_type);
224			return AVERROR_INVALIDDATA;
225			}
226
227	✓✓	48	if (frame_type == 0) {
228			// Skip duplicate frames
229		17	return buf_size;
230			}
231
232	✗✓	31	if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) {
233			return ret;
234			}
235
236	✗✓	31	if (bytestream2_get_bytes_left(&gb) < 4) {
237			av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
238			return AVERROR_INVALIDDATA;
239			}
240
241		31	c->quant[0] = bytestream2_get_byte(&gb);
242		31	c->quant[1] = bytestream2_get_byte(&gb);
243	✓✗✓✗	31	if (c->quant[0] < 2 \|\| c->quant[0] > NUM_VLC_SETS + 1 \|\|
244	✓✗✗✓	31	c->quant[1] < 2 \|\| c->quant[1] > NUM_VLC_SETS + 1) {
245			av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
246			c->quant[0], c->quant[1]);
247			return AVERROR_INVALIDDATA;
248			}
249
250	✓✓	124	for (i = 0; i < 3; i++) {
251		93	c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
252		93	c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
253			}
254
255		31	bytestream2_skip(&gb, 1);
256
257		31	size = bytestream2_get_le32(&gb);
258	✗✓	31	if (size > bytestream2_get_bytes_left(&gb)) {
259			av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
260			return AVERROR_INVALIDDATA;
261			}
262
263	✓✓	3319	for (i = 0; i < size; i++) {
264		3288	val = bytestream2_get_byte(&gb);
265		3288	len = val & 0x3F;
266		3288	val >>= 6;
267	✗✓	3288	if (pos + len > num_mb) {
268			av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
269			return AVERROR_INVALIDDATA;
270			}
271		3288	memset(c->slice_quants + pos, val, len);
272		3288	pos += len;
273			}
274	✗✓	31	if (pos < num_mb) {
275			av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
276			pos, num_mb);
277			return AVERROR_INVALIDDATA;
278			}
279
280	✓✓	1115	for (i = 0; i < c->mb_height; i++) {
281		1085	size = bytestream2_peek_byte(&gb);
282	✓✓	1085	if (size & 1) {
283		103	size = bytestream2_get_byte(&gb) - 1;
284			} else {
285		982	size = bytestream2_get_le32(&gb) >> 1;
286			}
287	✓✓	1085	if (!size) {
288		103	int skip_row = 1, j, off = i * c->mb_width;
289	✓✓	5871	for (j = 0; j < c->mb_width; j++) {
290	✓✗	5768	if (c->slice_quants[off + j] == 1 \|\|
291	✗✓	5768	c->slice_quants[off + j] == 2) {
292			skip_row = 0;
293			break;
294			}
295			}
296	✗✓	103	if (!skip_row) {
297			av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
298			return AVERROR_INVALIDDATA;
299			}
300			}
301	✓✓	1085	if (bytestream2_get_bytes_left(&gb) < size) {
302		1	av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
303			size, bytestream2_get_bytes_left(&gb));
304		1	return AVERROR_INVALIDDATA;
305			}
306		1084	ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
307	✗✓	1084	if (ret) {
308			av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
309			return ret;
310			}
311		1084	bytestream2_skip(&gb, size);
312			}
313
314		30	*got_frame = 1;
315	✗✓	30	if ((ret = av_frame_ref(data, c->pic)) < 0)
316			return ret;
317
318			/* always report that the buffer was completely consumed */
319		30	return buf_size;
320			}
321
322		4	static av_cold int tscc2_decode_end(AVCodecContext *avctx)
323			{
324		4	TSCC2Context * const c = avctx->priv_data;
325
326		4	av_frame_free(&c->pic);
327		4	av_freep(&c->slice_quants);
328
329		4	return 0;
330			}
331
332		4	static av_cold int tscc2_decode_init(AVCodecContext *avctx)
333			{
334		4	TSCC2Context * const c = avctx->priv_data;
335			static AVOnce init_static_once = AV_ONCE_INIT;
336
337		4	c->avctx = avctx;
338
339		4	avctx->pix_fmt = AV_PIX_FMT_YUV444P;
340
341		4	c->mb_width = FFALIGN(avctx->width, 16) >> 4;
342		4	c->mb_height = FFALIGN(avctx->height, 8) >> 3;
343		4	c->slice_quants = av_malloc(c->mb_width * c->mb_height);
344	✗✓	4	if (!c->slice_quants) {
345			av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
346			return AVERROR(ENOMEM);
347			}
348
349		4	c->pic = av_frame_alloc();
350	✗✓	4	if (!c->pic)
351			return AVERROR(ENOMEM);
352
353		4	ff_thread_once(&init_static_once, tscc2_init_vlcs);
354
355		4	return 0;
356			}
357
358			AVCodec ff_tscc2_decoder = {
359			.name = "tscc2",
360			.long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
361			.type = AVMEDIA_TYPE_VIDEO,
362			.id = AV_CODEC_ID_TSCC2,
363			.priv_data_size = sizeof(TSCC2Context),
364			.init = tscc2_decode_init,
365			.close = tscc2_decode_end,
366			.decode = tscc2_decode_frame,
367			.capabilities = AV_CODEC_CAP_DR1,
368			.caps_internal = FF_CODEC_CAP_INIT_CLEANUP \| FF_CODEC_CAP_INIT_THREADSAFE,
369			};