Function decode_header

libavcodec/exr.c:1602–2112

}

static int decode_header(EXRContext *s, AVFrame *frame)
{
    AVDictionary *metadata = NULL;
    GetByteContext *gb = &s->gb;
    int magic_number, version, flags;
    int layer_match = 0;
    int ret;
    int dup_channels = 0;

    s->current_channel_offset = 0;
    s->xmin               = ~0;
    s->xmax               = ~0;
    s->ymin               = ~0;
    s->ymax               = ~0;
    s->xdelta             = ~0;
    s->ydelta             = ~0;
    s->channel_offsets[0] = -1;
    s->channel_offsets[1] = -1;
    s->channel_offsets[2] = -1;
    s->channel_offsets[3] = -1;
    s->pixel_type         = EXR_UNKNOWN;
    s->compression        = EXR_UNKN;
    s->nb_channels        = 0;
    s->w                  = 0;
    s->h                  = 0;
    s->tile_attr.xSize    = -1;
    s->tile_attr.ySize    = -1;
    s->is_tile            = 0;
    s->is_multipart       = 0;
    s->is_luma            = 0;
    s->has_channel        = 0;
    s->current_part       = 0;

    if (bytestream2_get_bytes_left(gb) < 10) {
        av_log(s->avctx, AV_LOG_ERROR, "Header too short to parse.\n");
        return AVERROR_INVALIDDATA;
    }

    magic_number = bytestream2_get_le32(gb);
    if (magic_number != 20000630) {
        /* As per documentation of OpenEXR, it is supposed to be
         * int 20000630 little-endian */
        av_log(s->avctx, AV_LOG_ERROR, "Wrong magic number %d.\n", magic_number);
        return AVERROR_INVALIDDATA;
    }

    version = bytestream2_get_byte(gb);
    if (version != 2) {
        avpriv_report_missing_feature(s->avctx, "Version %d", version);
        return AVERROR_PATCHWELCOME;
    }

    flags = bytestream2_get_le24(gb);

    if (flags & 0x02)
        s->is_tile = 1;
    if (flags & 0x10)
        s->is_multipart = 1;