static int txd_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                            AVPacket *avpkt) {
    GetByteContext gb;
    AVFrame * const p = data;
    unsigned int version, w, h, d3d_format, depth, stride, flags;
    unsigned int y, v;
    uint8_t *ptr;
    uint32_t *pal;
    int ret;

    bytestream2_init(&gb, avpkt->data, avpkt->size);
    version         = bytestream2_get_le32(&gb);
    bytestream2_skip(&gb, 72);
    d3d_format      = bytestream2_get_le32(&gb);
    w               = bytestream2_get_le16(&gb);
    h               = bytestream2_get_le16(&gb);
    depth           = bytestream2_get_byte(&gb);
    bytestream2_skip(&gb, 2);
    flags           = bytestream2_get_byte(&gb);

    if (version < 8 || version > 9) {
        av_log(avctx, AV_LOG_ERROR, "texture data version %i is unsupported\n",
                                                                    version);
        return AVERROR_PATCHWELCOME;
    }

    if (depth == 8) {
        avctx->pix_fmt = AV_PIX_FMT_PAL8;
    } else if (depth == 16 || depth == 32) {
        avctx->pix_fmt = AV_PIX_FMT_RGB32;
    } else {
        av_log(avctx, AV_LOG_ERROR, "depth of %i is unsupported\n", depth);
        return AVERROR_PATCHWELCOME;
    }

    if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
        return ret;

    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
        return ret;

    p->pict_type = AV_PICTURE_TYPE_I;

    ptr    = p->data[0];
    stride = p->linesize[0];

    if (depth == 8) {
        pal = (uint32_t *) p->data[1];
        for (y = 0; y < 256; y++) {
            v = bytestream2_get_be32(&gb);
            pal[y] = (v >> 8) + (v << 24);
        }
        if (bytestream2_get_bytes_left(&gb) < w * h)
            return AVERROR_INVALIDDATA;
        bytestream2_skip(&gb, 4);
        for (y=0; y<h; y++) {
            bytestream2_get_buffer(&gb, ptr, w);
            ptr += stride;
        }
    } else if (depth == 16) {
        bytestream2_skip(&gb, 4);
        switch (d3d_format) {
        case 0:
            if (!(flags & 1))
                goto unsupported;
        case FF_S3TC_DXT1:
            if (bytestream2_get_bytes_left(&gb) < (w/4) * (h/4) * 8)
                return AVERROR_INVALIDDATA;
            ff_decode_dxt1(&gb, ptr, w, h, stride);
            break;
        case FF_S3TC_DXT3:
            if (bytestream2_get_bytes_left(&gb) < (w/4) * (h/4) * 16)
                return AVERROR_INVALIDDATA;
            ff_decode_dxt3(&gb, ptr, w, h, stride);
            break;
        default:
            goto unsupported;
        }
    } else if (depth == 32) {
        switch (d3d_format) {
        case 0x15:
        case 0x16:
            if (bytestream2_get_bytes_left(&gb) < h * w * 4)
                return AVERROR_INVALIDDATA;
            for (y=0; y<h; y++) {
                bytestream2_get_buffer(&gb, ptr, w * 4);
                ptr += stride;
            }
            break;
        default:
            goto unsupported;
        }
    }

    *got_frame = 1;

    return avpkt->size;

unsupported:
    av_log(avctx, AV_LOG_ERROR, "unsupported d3d format (%08x)\n", d3d_format);
    return AVERROR_PATCHWELCOME;
}