Function decode_frame

libavcodec/tiff.c:455–567

}

static int decode_frame(AVCodecContext *avctx,
                        void *data, int *data_size,
                        AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    TiffContext * const s = avctx->priv_data;
    AVFrame *picture = data;
    AVFrame * const p= (AVFrame*)&s->picture;
    const uint8_t *orig_buf = buf, *end_buf = buf + buf_size;
    int id, le, off;
    int i, j, entries;
    int stride, soff, ssize;
    uint8_t *dst;

    //parse image header
    id = AV_RL16(buf); buf += 2;
    if(id == 0x4949) le = 1;
    else if(id == 0x4D4D) le = 0;
    else{
        av_log(avctx, AV_LOG_ERROR, "TIFF header not found\n");
        return -1;
    }
    s->le = le;
    s->invert = 0;
    s->compr = TIFF_RAW;
    s->fill_order = 0;
    // As TIFF 6.0 specification puts it "An arbitrary but carefully chosen number
    // that further identifies the file as a TIFF file"
    if(tget_short(&buf, le) != 42){
        av_log(avctx, AV_LOG_ERROR, "The answer to life, universe and everything is not correct!\n");
        return -1;
    }
    /* parse image file directory */
    off = tget_long(&buf, le);
    if(orig_buf + off + 14 >= end_buf){
        av_log(avctx, AV_LOG_ERROR, "IFD offset is greater than image size\n");
        return -1;
    }
    buf = orig_buf + off;
    entries = tget_short(&buf, le);
    for(i = 0; i < entries; i++){
        if(tiff_decode_tag(s, orig_buf, buf, end_buf) < 0)
            return -1;
        buf += 12;
    }
    if(!s->stripdata && !s->stripoff){
        av_log(avctx, AV_LOG_ERROR, "Image data is missing\n");
        return -1;
    }
    /* now we have the data and may start decoding */
    if(!p->data[0]){
        s->bpp = 1;
        avctx->pix_fmt = PIX_FMT_MONOBLACK;
        if(s->width != s->avctx->width || s->height != s->avctx->height){
            if(avcodec_check_dimensions(s->avctx, s->width, s->height))
                return -1;
            avcodec_set_dimensions(s->avctx, s->width, s->height);