GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/cpia.c Lines: 0 94 0.0 %
Date: 2019-11-18 18:00:01 Branches: 0 72 0.0 %

Line Branch Exec Source
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/*
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 * CPiA video decoder.
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 * Copyright (c) 2010 Hans de Goede <hdegoede@redhat.com>
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 *
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 * This decoder is based on the LGPL code available at
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 * https://v4l4j.googlecode.com/svn/v4l4j/trunk/libvideo/libv4lconvert/cpia1.c
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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 "get_bits.h"
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#include "internal.h"
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#define FRAME_HEADER_SIZE 64
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#define MAGIC_0         0x19    /**< First header byte */
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#define MAGIC_1         0x68    /**< Second header byte */
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#define SUBSAMPLE_420      0
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#define SUBSAMPLE_422      1
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#define YUVORDER_YUYV      0
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#define YUVORDER_UYVY      1
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#define NOT_COMPRESSED     0
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#define COMPRESSED         1
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#define NO_DECIMATION      0
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#define DECIMATION_ENAB    1
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#define EOL             0xfd    /**< End Of Line marker */
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#define EOI             0xff    /**< End Of Image marker */
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typedef struct {
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    AVFrame *frame;
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} CpiaContext;
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static int cpia_decode_frame(AVCodecContext *avctx,
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                             void *data, int *got_frame, AVPacket* avpkt)
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{
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    CpiaContext* const cpia = avctx->priv_data;
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    int i,j,ret;
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    uint8_t* const header = avpkt->data;
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    uint8_t* src;
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    int src_size;
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    uint16_t linelength;
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    uint8_t skip;
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    AVFrame *frame = cpia->frame;
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    uint8_t *y, *u, *v, *y_end, *u_end, *v_end;
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    // Check header
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    if ( avpkt->size < FRAME_HEADER_SIZE + avctx->height * 3
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      || header[0] != MAGIC_0 || header[1] != MAGIC_1
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      || (header[17] != SUBSAMPLE_420 && header[17] != SUBSAMPLE_422)
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      || (header[18] != YUVORDER_YUYV && header[18] != YUVORDER_UYVY)
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      || (header[28] != NOT_COMPRESSED && header[28] != COMPRESSED)
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      || (header[29] != NO_DECIMATION && header[29] != DECIMATION_ENAB)
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    ) {
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        av_log(avctx, AV_LOG_ERROR, "Invalid header!\n");
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        return AVERROR_INVALIDDATA;
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    }
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    // currently unsupported properties
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    if (header[17] == SUBSAMPLE_422) {
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        avpriv_report_missing_feature(avctx, "4:2:2 subsampling");
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        return AVERROR_PATCHWELCOME;
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    }
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    if (header[18] == YUVORDER_UYVY) {
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        avpriv_report_missing_feature(avctx, "YUV byte order UYVY");
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        return AVERROR_PATCHWELCOME;
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    }
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    if (header[29] == DECIMATION_ENAB) {
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        avpriv_report_missing_feature(avctx, "Decimation");
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        return AVERROR_PATCHWELCOME;
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    }
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    src = header + FRAME_HEADER_SIZE;
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    src_size = avpkt->size - FRAME_HEADER_SIZE;
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    if (header[28] == NOT_COMPRESSED) {
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        frame->pict_type = AV_PICTURE_TYPE_I;
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        frame->key_frame = 1;
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    } else {
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        frame->pict_type = AV_PICTURE_TYPE_P;
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        frame->key_frame = 0;
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    }
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    // Get buffer filled with previous frame
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    if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
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        return ret;
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    for ( i = 0;
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          i < frame->height;
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          i++, src += linelength, src_size -= linelength
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    ) {
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        // Read line length, two byte little endian
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        linelength = AV_RL16(src);
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        src += 2;
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        if (src_size < linelength) {
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            frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;
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            av_log(avctx, AV_LOG_WARNING, "Frame ended unexpectedly!\n");
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            break;
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        }
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        if (src[linelength - 1] != EOL) {
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            frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;
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            av_log(avctx, AV_LOG_WARNING, "Wrong line length %d or line not terminated properly (found 0x%02x)!\n", linelength, src[linelength - 1]);
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            break;
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        }
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        /* Update the data pointers. Y data is on every line.
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         * U and V data on every second line
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         */
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        y = &frame->data[0][i * frame->linesize[0]];
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        u = &frame->data[1][(i >> 1) * frame->linesize[1]];
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        v = &frame->data[2][(i >> 1) * frame->linesize[2]];
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        y_end = y + frame->linesize[0] - 1;
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        u_end = u + frame->linesize[1] - 1;
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        v_end = v + frame->linesize[2] - 1;
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        if ((i & 1) && header[17] == SUBSAMPLE_420) {
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            /* We are on an odd line and 420 subsample is used.
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             * On this line only Y values are specified, one per pixel.
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             */
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            for (j = 0; j < linelength - 1; j++) {
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                if (y > y_end) {
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                    frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;
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                    av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n");
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                    break;
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                }
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                if ((src[j] & 1) && header[28] == COMPRESSED) {
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                    /* It seems that odd lines are always uncompressed, but
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                     * we do it according to specification anyways.
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                     */
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                    skip = src[j] >> 1;
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                    y += skip;
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                } else {
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                    *(y++) = src[j];
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                }
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            }
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        } else if (header[17] == SUBSAMPLE_420) {
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            /* We are on an even line and 420 subsample is used.
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             * On this line each pair of pixels is described by four bytes.
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             */
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            for (j = 0; j < linelength - 4; ) {
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                if (y + 1 > y_end || u > u_end || v > v_end) {
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                    frame->decode_error_flags = FF_DECODE_ERROR_INVALID_BITSTREAM;
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                    av_log(avctx, AV_LOG_WARNING, "Decoded data exceeded linesize!\n");
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                    break;
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                }
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                if ((src[j] & 1) && header[28] == COMPRESSED) {
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                    // Skip amount of pixels and move forward one byte
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                    skip = src[j] >> 1;
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                    y += skip;
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                    u += skip >> 1;
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                    v += skip >> 1;
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                    j++;
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                } else {
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                    // Set image data as specified and move forward 4 bytes
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                    *(y++) = src[j];
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                    *(u++) = src[j+1];
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                    *(y++) = src[j+2];
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                    *(v++) = src[j+3];
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                    j += 4;
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                }
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            }
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        }
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    }
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    *got_frame = 1;
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    if ((ret = av_frame_ref(data, cpia->frame)) < 0)
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        return ret;
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    return avpkt->size;
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}
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static av_cold int cpia_decode_init(AVCodecContext *avctx)
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{
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    CpiaContext *s = avctx->priv_data;
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    // output pixel format
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    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
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    /* The default timebase set by the v4l2 demuxer leads to probing which is buggy.
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     * Set some reasonable time_base to skip this.
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     */
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    if (avctx->time_base.num == 1 && avctx->time_base.den == 1000000) {
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        avctx->time_base.num = 1;
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        avctx->time_base.den = 60;
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    }
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    s->frame = av_frame_alloc();
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    if (!s->frame)
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        return AVERROR(ENOMEM);
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    return 0;
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}
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static av_cold int cpia_decode_end(AVCodecContext *avctx)
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{
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    CpiaContext *s = avctx->priv_data;
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    av_frame_free(&s->frame);
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    return 0;
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}
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AVCodec ff_cpia_decoder = {
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    .name           = "cpia",
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    .long_name      = NULL_IF_CONFIG_SMALL("CPiA video format"),
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    .type           = AVMEDIA_TYPE_VIDEO,
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    .id             = AV_CODEC_ID_CPIA,
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    .priv_data_size = sizeof(CpiaContext),
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    .init           = cpia_decode_init,
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    .close          = cpia_decode_end,
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    .decode         = cpia_decode_frame,
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    .capabilities   = AV_CODEC_CAP_DR1,
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};