GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/c93.c Lines: 107 127 84.3 %
Date: 2020-09-21 17:35:45 Branches: 58 80 72.5 %

Line Branch Exec Source
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/*
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 * Interplay C93 video decoder
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 * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
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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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#include "avcodec.h"
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#include "bytestream.h"
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#include "internal.h"
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typedef struct C93DecoderContext {
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    AVFrame *pictures[2];
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    int currentpic;
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} C93DecoderContext;
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typedef enum {
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    C93_8X8_FROM_PREV  = 0x02,
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    C93_4X4_FROM_PREV  = 0x06,
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    C93_4X4_FROM_CURR  = 0x07,
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    C93_8X8_2COLOR     = 0x08,
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    C93_4X4_2COLOR     = 0x0A,
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    C93_4X4_4COLOR_GRP = 0x0B,
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    C93_4X4_4COLOR     = 0x0D,
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    C93_NOOP           = 0x0E,
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    C93_8X8_INTRA      = 0x0F,
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} C93BlockType;
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#define WIDTH   320
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#define HEIGHT  192
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#define C93_HAS_PALETTE 0x01
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#define C93_FIRST_FRAME 0x02
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2
static av_cold int decode_end(AVCodecContext *avctx)
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{
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2
    C93DecoderContext * const c93 = avctx->priv_data;
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53
2
    av_frame_free(&c93->pictures[0]);
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2
    av_frame_free(&c93->pictures[1]);
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56
2
    return 0;
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}
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2
static av_cold int decode_init(AVCodecContext *avctx)
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{
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2
    C93DecoderContext *s = avctx->priv_data;
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2
    avctx->pix_fmt = AV_PIX_FMT_PAL8;
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2
    s->pictures[0] = av_frame_alloc();
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2
    s->pictures[1] = av_frame_alloc();
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2
    if (!s->pictures[0] || !s->pictures[1])
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        return AVERROR(ENOMEM);
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2
    return 0;
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}
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98205
static inline int copy_block(AVCodecContext *avctx, uint8_t *to,
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        uint8_t *from, int offset, int height, int stride)
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{
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    int i;
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98205
    int width = height;
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98205
    int from_x = offset % WIDTH;
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98205
    int from_y = offset / WIDTH;
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98205
    int overflow = from_x + width - WIDTH;
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81
98205
    if (!from) {
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        /* silently ignoring predictive blocks in first frame */
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        return 0;
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    }
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86
98205
    if (from_y + height > HEIGHT) {
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        av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
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               offset);
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        return AVERROR_INVALIDDATA;
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    }
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92
98205
    if (overflow > 0) {
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        width -= overflow;
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        for (i = 0; i < height; i++) {
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            memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow);
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        }
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    }
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573461
    for (i = 0; i < height; i++) {
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475256
        memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width);
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    }
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98205
    return 0;
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}
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2576
static inline void draw_n_color(uint8_t *out, int stride, int width,
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         int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
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{
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    int x, y;
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11584
    for (y = 0; y < height; y++) {
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9008
        if (grps)
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480
            cols[0] = grps[3 * (y >> 1)];
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46768
        for (x = 0; x < width; x++) {
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37760
            if (grps)
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1920
                cols[1]= grps[(x >> 1) + 1];
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37760
            out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
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37760
            col >>= bpp;
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        }
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    }
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2576
}
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static int decode_frame(AVCodecContext *avctx, void *data,
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                        int *got_frame, AVPacket *avpkt)
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{
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45
    const uint8_t *buf = avpkt->data;
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    int buf_size = avpkt->size;
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    C93DecoderContext * const c93 = avctx->priv_data;
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    AVFrame * const newpic = c93->pictures[c93->currentpic];
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45
    AVFrame * const oldpic = c93->pictures[c93->currentpic^1];
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    GetByteContext gb;
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    uint8_t *out;
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45
    int stride, ret, i, x, y, b, bt = 0;
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134
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    if ((ret = ff_set_dimensions(avctx, WIDTH, HEIGHT)) < 0)
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        return ret;
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137
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    c93->currentpic ^= 1;
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139
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    if ((ret = ff_reget_buffer(avctx, newpic, 0)) < 0)
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        return ret;
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    stride = newpic->linesize[0];
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144
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    bytestream2_init(&gb, buf, buf_size);
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    b = bytestream2_get_byte(&gb);
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45
    if (b & C93_FIRST_FRAME) {
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1
        newpic->pict_type = AV_PICTURE_TYPE_I;
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1
        newpic->key_frame = 1;
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    } else {
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44
        newpic->pict_type = AV_PICTURE_TYPE_P;
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44
        newpic->key_frame = 0;
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    }
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1125
    for (y = 0; y < HEIGHT; y += 8) {
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1080
        out = newpic->data[0] + y * stride;
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44280
        for (x = 0; x < WIDTH; x += 8) {
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43200
            uint8_t *copy_from = oldpic->data[0];
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            unsigned int offset, j;
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            uint8_t cols[4], grps[4];
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            C93BlockType block_type;
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162
43200
            if (!bt)
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21600
                bt = bytestream2_get_byte(&gb);
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43200
            block_type= bt & 0x0F;
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43200
            switch (block_type) {
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20609
            case C93_8X8_FROM_PREV:
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20609
                offset = bytestream2_get_le16(&gb);
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20609
                if ((ret = copy_block(avctx, out, copy_from, offset, 8, stride)) < 0)
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                    return ret;
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20609
                break;
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621
            case C93_4X4_FROM_CURR:
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621
                copy_from = newpic->data[0];
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19399
            case C93_4X4_FROM_PREV:
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58197
                for (j = 0; j < 8; j += 4) {
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116394
                    for (i = 0; i < 8; i += 4) {
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77596
                        int offset = bytestream2_get_le16(&gb);
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77596
                        int from_x = offset % WIDTH;
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77596
                        int from_y = offset / WIDTH;
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77596
                        if (block_type == C93_4X4_FROM_CURR && from_y == y+j &&
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                            (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) {
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                            avpriv_request_sample(avctx, "block overlap %d %d %d %d", from_x, x+i, from_y, y+j);
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                            return AVERROR_INVALIDDATA;
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                        }
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77596
                        if ((ret = copy_block(avctx, &out[j*stride+i],
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                                              copy_from, offset, 4, stride)) < 0)
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                            return ret;
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                    }
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                }
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19399
                break;
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193
54
            case C93_8X8_2COLOR:
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54
                bytestream2_get_buffer(&gb, cols, 2);
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486
                for (i = 0; i < 8; i++) {
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432
                    draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
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                                     NULL, bytestream2_get_byte(&gb));
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                }
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200
54
                break;
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202
536
            case C93_4X4_2COLOR:
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            case C93_4X4_4COLOR:
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            case C93_4X4_4COLOR_GRP:
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1608
                for (j = 0; j < 8; j += 4) {
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3216
                    for (i = 0; i < 8; i += 4) {
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2144
                        if (block_type == C93_4X4_2COLOR) {
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108
                            bytestream2_get_buffer(&gb, cols, 2);
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108
                            draw_n_color(out + i + j*stride, stride, 4, 4,
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                                    1, cols, NULL, bytestream2_get_le16(&gb));
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2036
                        } else if (block_type == C93_4X4_4COLOR) {
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1916
                            bytestream2_get_buffer(&gb, cols, 4);
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1916
                            draw_n_color(out + i + j*stride, stride, 4, 4,
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                                    2, cols, NULL, bytestream2_get_le32(&gb));
215
                        } else {
216
120
                            bytestream2_get_buffer(&gb, grps, 4);
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120
                            draw_n_color(out + i + j*stride, stride, 4, 4,
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                                    1, cols, grps, bytestream2_get_le16(&gb));
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                        }
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                    }
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                }
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536
                break;
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224
            case C93_NOOP:
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                break;
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227
2602
            case C93_8X8_INTRA:
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23418
                for (j = 0; j < 8; j++)
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20816
                    bytestream2_get_buffer(&gb, out + j*stride, 8);
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2602
                break;
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232
            default:
233
                av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
234
                       block_type, x, y);
235
                return AVERROR_INVALIDDATA;
236
            }
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43200
            bt >>= 4;
238
43200
            out += 8;
239
        }
240
    }
241
242
45
    if (b & C93_HAS_PALETTE) {
243
1
        uint32_t *palette = (uint32_t *) newpic->data[1];
244
257
        for (i = 0; i < 256; i++) {
245
256
            palette[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
246
        }
247
1
        newpic->palette_has_changed = 1;
248
    } else {
249
44
        if (oldpic->data[1])
250
44
            memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
251
    }
252
253
45
    if ((ret = av_frame_ref(data, newpic)) < 0)
254
        return ret;
255
45
    *got_frame = 1;
256
257
45
    return buf_size;
258
}
259
260
AVCodec ff_c93_decoder = {
261
    .name           = "c93",
262
    .long_name      = NULL_IF_CONFIG_SMALL("Interplay C93"),
263
    .type           = AVMEDIA_TYPE_VIDEO,
264
    .id             = AV_CODEC_ID_C93,
265
    .priv_data_size = sizeof(C93DecoderContext),
266
    .init           = decode_init,
267
    .close          = decode_end,
268
    .decode         = decode_frame,
269
    .capabilities   = AV_CODEC_CAP_DR1,
270
    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
271
};