GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/png_parser.c Lines: 48 53 90.6 %
Date: 2020-09-21 17:35:45 Branches: 28 34 82.4 %

Line Branch Exec Source
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/*
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 * PNG parser
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 * Copyright (c) 2009 Peter Holik
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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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
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * PNG parser
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 */
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#include "parser.h"
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#include "png.h"
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typedef struct PNGParseContext {
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    ParseContext pc;
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    uint32_t chunk_pos;           ///< position inside current chunk
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    uint32_t chunk_length;        ///< length of the current chunk
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    uint32_t remaining_size;      ///< remaining size of the current chunk
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} PNGParseContext;
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578
static int png_parse(AVCodecParserContext *s, AVCodecContext *avctx,
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                     const uint8_t **poutbuf, int *poutbuf_size,
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                     const uint8_t *buf, int buf_size)
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{
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578
    PNGParseContext *ppc = s->priv_data;
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578
    int next = END_NOT_FOUND;
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578
    int i = 0;
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45
578
    s->pict_type = AV_PICTURE_TYPE_NONE;
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578
    *poutbuf_size = 0;
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578
    *poutbuf = NULL;
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578
    if (!ppc->pc.frame_start_found) {
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287
        uint64_t state64 = ppc->pc.state64;
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2058
        for (; i < buf_size; i++) {
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2024
            state64 = (state64 << 8) | buf[i];
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2024
            if (state64 == PNGSIG || state64 == MNGSIG) {
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253
                i++;
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253
                ppc->pc.frame_start_found = 1;
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253
                break;
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            }
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        }
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287
        ppc->pc.state64 = state64;
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291
    } else if (ppc->remaining_size) {
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291
        i = FFMIN(ppc->remaining_size, buf_size);
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291
        ppc->remaining_size -= i;
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291
        if (ppc->remaining_size)
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150
            goto flush;
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141
        if (ppc->chunk_pos == -1) {
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            next = i;
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            goto flush;
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        }
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    }
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80290
    for (; ppc->pc.frame_start_found && i < buf_size; i++) {
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80256
        ppc->pc.state = (ppc->pc.state << 8) | buf[i];
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80256
        if (ppc->chunk_pos == 3) {
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10032
            ppc->chunk_length = ppc->pc.state;
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10032
            if (ppc->chunk_length > 0x7fffffff) {
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                ppc->chunk_pos = ppc->pc.frame_start_found = 0;
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                goto flush;
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            }
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10032
            ppc->chunk_length += 4;
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70224
        } else if (ppc->chunk_pos == 7) {
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10032
            if (ppc->chunk_length >= buf_size - i)
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142
                ppc->remaining_size = ppc->chunk_length - buf_size + i + 1;
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10032
            if (ppc->pc.state == MKBETAG('I', 'E', 'N', 'D')) {
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252
                if (ppc->remaining_size)
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                    ppc->chunk_pos = -1;
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                else
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252
                    next = ppc->chunk_length + i + 1;
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252
                break;
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            } else {
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9780
                ppc->chunk_pos = 0;
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9780
                if (ppc->remaining_size)
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142
                    break;
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                else
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9638
                    i += ppc->chunk_length;
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9638
                continue;
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            }
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        }
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70224
        ppc->chunk_pos++;
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    }
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102
34
flush:
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578
    if (ff_combine_frame(&ppc->pc, next, &buf, &buf_size) < 0)
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291
        return buf_size;
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106
287
    ppc->chunk_pos = ppc->pc.frame_start_found = 0;
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108
287
    *poutbuf      = buf;
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287
    *poutbuf_size = buf_size;
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287
    return next;
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}
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113
AVCodecParser ff_png_parser = {
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    .codec_ids      = { AV_CODEC_ID_PNG },
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    .priv_data_size = sizeof(PNGParseContext),
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    .parser_parse   = png_parse,
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    .parser_close   = ff_parse_close,
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};